RESUMO
Little is known about the impact of standardized imaging surveillance on anxiety levels and well-being of patients after endovascular aortic aneurysm repair (EVAR). We hypothesize that patient anxiety levels increase just before receiving the imaging results compared with standard anxiety levels. METHODS: Prospective cohort study from November 2018 to May 2020 including post-EVAR patients visiting the outpatient clinics of 4 Dutch hospitals for imaging follow-up. The Patient-Reported Outcomes Measurement Information System (PROMIS) was used. Patients completed the PROMIS Anxiety v1.0 Short Form (SF) 4a, PROMIS-Global Health Scale v1.2, and PROMIS-Physical Function v1.2 SF8b at 2 time points: prior to the result of the imaging study (T1: pre-visit) and 6-8 months later (T2: reference measurement). Mean T-scores at T1 were compared to T2, and T2 to the general 65+ Dutch population. RESULTS: Altogether 342 invited patients were eligible, 214 completed the first questionnaire, 189 returned 2 completed questionnaires and 128 patients did not participate. Out of 214 respondents, 195 were male (91.1%) and the mean (standard deviation) age was 75.2 (7.0) years. There were no significant differences between T1 and T2 in anxiety levels (0.48; 95% confidence interval[CI] -0.42-1.38), global mental health (0.27; 95% CI -0.79-0.84), global physical health (0.10; 95% CI -0.38-1.18) and physical function (0.53; 95% CI -0.26-1.32). Compared with the 65+ Dutch population, at T2 patients experienced more anxiety (3.8; 95% CI 2.96-5.54), had worse global physical health (-3.2; 95% CI -4.38 - -2.02) and physical function (-2.4; 95% CI -4.00 - -0.80). Global mental health was similar (-1.0; 95% CI -2.21 - 0.21). CONCLUSIONS: Post-EVAR patients do not experience more anxiety just before receiving surveillance imaging results than outside this period, but do suffer from more anxiety and worse physical outcomes than the 65+ Dutch population.
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Aneurisma da Aorta Abdominal , Implante de Prótese Vascular , Procedimentos Endovasculares , Idoso , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aneurisma da Aorta Abdominal/etiologia , Aneurisma da Aorta Abdominal/cirurgia , Implante de Prótese Vascular/efeitos adversos , Procedimentos Endovasculares/efeitos adversos , Feminino , Humanos , Masculino , Medidas de Resultados Relatados pelo Paciente , Estudos Prospectivos , Qualidade de Vida , Estudos Retrospectivos , Fatores de Tempo , Resultado do TratamentoRESUMO
Here, we report the development of a novel photoactive biomolecular nanoarchitecture based on the genetically engineered extremophilic photosystem I (PSI) biophotocatalyst interfaced with a single layer graphene via pyrene-nitrilotriacetic acid self-assembled monolayer (SAM). For the oriented and stable immobilization of the PSI biophotocatalyst, an His6-tag was genetically engineered at the N-terminus of the stromal PsaD subunit of PSI, allowing for the preferential binding of this photoactive complex with its reducing side towards the graphene monolayer. This approach yielded a novel robust and ordered nanoarchitecture designed to generate an efficient direct electron transfer pathway between graphene, the metal redox center in the organic SAM and the photo-oxidized PSI biocatalyst. The nanosystem yielded an overall current output of 16.5 µA·cm-2 for the nickel- and 17.3 µA·cm-2 for the cobalt-based nanoassemblies, and was stable for at least 1 h of continuous standard illumination. The novel green nanosystem described in this work carries the high potential for future applications due to its robustness, highly ordered and simple architecture characterized by the high biophotocatalyst loading as well as simplicity of manufacturing.
Assuntos
Grafite/química , Microalgas/química , Nanoestruturas/química , Complexo de Proteína do Fotossistema I/química , Luz , Oxirredução/efeitos dos fármacos , Rodófitas/química , Transdução de Sinais/efeitos dos fármacosRESUMO
BACKGROUND: Traditionally uncomplicated acute diverticulitis was routinely treated with antibiotics, although evidence for this strategy was lacking. Recently, two randomized clinical trials (AVOD trial and DIABOLO trial) published short-term results of omitting antibiotics compared to routine antibiotic treatment. Both showed no significant differences regarding recovery from the initial episode, as well as rates of complicated or recurrent diverticulitis and sigmoid resection. However, both studies showed a trend of higher rates of sigmoid resection in the observational groups. Here, the long-term effects of omitting antibiotics in first episode uncomplicated acute diverticulitis were assessed. METHODS: A total of 528 patients with CT-proven, primary, left-sided, uncomplicated acute diverticulitis were randomized to either an observational or an antibiotic treatment strategy (DIABOLO trial). Outcome measures were complicated diverticulitis, recurrent diverticulitis and sigmoid resection at 24 months' follow up. Differences between the groups were explored and risk factors were identified using multivariable logistic regression. RESULTS: Complete case analyses showed no difference in rates of recurrent diverticulitis (15.4% in the observational group versus 14.9% in the antibiotic group; p = 0.885), complicated diverticulitis (4.8% versus 3.3%; p = 0.403) and sigmoid resection (9.0% versus. 5.0%; p = 0.085). Young patients (<50 years) and patients with a pain score at presentation of 8 or higher on a visual analogue pain scale were at risk for complicated or recurrent diverticulitis. In this multivariable analysis, treatment type (with or without antibiotics) was not an independent predictor for complicated or recurrent diverticulitis. CONCLUSION: Omitting antibiotics in the treatment of uncomplicated acute diverticulitis did not result in more complicated diverticulitis, recurrent diverticulitis or sigmoid resections at long-term follow up. As the DIABOLO trial was not powered for these secondary outcome measures, some uncertainty remains whether (small) non-significant differences could be true associations.
Assuntos
Antibacterianos/uso terapêutico , Doença Diverticular do Colo/tratamento farmacológico , Antibacterianos/administração & dosagem , Esquema de Medicação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Países Baixos , Recidiva , Conduta ExpectanteRESUMO
BACKGROUND: Antibiotics are advised in most guidelines on acute diverticulitis, despite a lack of evidence to support their routine use. This trial compared the effectiveness of a strategy with or without antibiotics for a first episode of uncomplicated acute diverticulitis. METHODS: Patients with CT-proven, primary, left-sided, uncomplicated, acute diverticulitis were included at 22 clinical sites in the Netherlands, and assigned randomly to an observational or antibiotic treatment strategy. The primary endpoint was time to recovery during 6 months of follow-up. Main secondary endpoints were readmission rate, complicated, ongoing and recurrent diverticulitis, sigmoid resection and mortality. Intention-to-treat and per-protocol analyses were done. RESULTS: A total of 528 patients were included. Median time to recovery was 14 (i.q.r. 6-35) days for the observational and 12 (7-30) days for the antibiotic treatment strategy, with a hazard ratio for recovery of 0·91 (lower limit of 1-sided 95 per cent c.i. 0·78; P = 0·151). No significant differences between the observation and antibiotic treatment groups were found for secondary endpoints: complicated diverticulitis (3·8 versus 2·6 per cent respectively; P = 0·377), ongoing diverticulitis (7·3 versus 4·1 per cent; P = 0·183), recurrent diverticulitis (3·4 versus 3·0 per cent; P = 0·494), sigmoid resection (3·8 versus 2·3 per cent; P = 0·323), readmission (17·6 versus 12·0 per cent; P = 0·148), adverse events (48·5 versus 54·5 per cent; P = 0·221) and mortality (1·1 versus 0·4 per cent; P = 0·432). Hospital stay was significantly shorter in the observation group (2 versus 3 days; P = 0·006). Per-protocol analyses were concordant with the intention-to-treat analyses. CONCLUSION: Observational treatment without antibiotics did not prolong recovery and can be considered appropriate in patients with uncomplicated diverticulitis. Registration number: NCT01111253 (http://www.clinicaltrials.gov).
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Antibacterianos/uso terapêutico , Doença Diverticular do Colo/terapia , Conduta Expectante , Doença Aguda , Combinação Amoxicilina e Clavulanato de Potássio/uso terapêutico , Colo Sigmoide/cirurgia , Doença Diverticular do Colo/diagnóstico por imagem , Doença Diverticular do Colo/epidemiologia , Feminino , Humanos , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Readmissão do Paciente/estatística & dados numéricos , Recuperação de Função Fisiológica , Tomografia Computadorizada por Raios X , Escala Visual AnalógicaRESUMO
BACKGROUND: Critical limb ischaemia (CLI) is the end stage of peripheral artery disease (PAD) and is associated with high amputation and mortality rates and poor quality of life. For CLI patients with no revascularisation options, venous arterialisation could be a last resort for limb salvage. OBJECTIVE: To review the literature on the clinical effectiveness of venous arterialisation for lower limb salvage in CLI patients with no revascularisation options. METHOD: Different databases were searched for papers published between January 1966 and January 2016. The criteria for eligible articles were studies describing outcomes of venous arterialisation, published in English, human studies, and with the full text available. Additionally, studies were excluded if they did not report limb salvage, wound healing or amputation as outcome measures. The primary outcome measure was post-operative limb salvage at 12 months. Secondary outcome measures were 30 day or in-hospital mortality, survival, patency, technical success, and wound healing. RESULTS: Fifteen articles met the inclusion criteria. The included studies described 768 patients. According to the MINORS score, methodological quality was moderate to poor. The estimated pooled limb salvage rate at one year was 75% (0.75, 95% CI 0.70-0.81). Thirty day or in-hospital mortality was reported in 12 studies and ranged from 0 to 10%. Overall survival was reported in 10 studies and ranged from 54% to 100% with a mean follow-up ranging from 5 to 60 months. Six studies reported on patency of the venous arterialisations performed, with a range of 59-71% at 12 months. CONCLUSION: In this systematic review on venous arterialisation in patients with non-reconstructable critical limb ischaemia, the pooled proportion of limb salvage at 12 months was 75%. Venous arterialisation could be a valuable treatment option in patients facing amputation of the affected limb; however, the current evidence is of low quality.
Assuntos
Isquemia/cirurgia , Salvamento de Membro , Extremidade Inferior/irrigação sanguínea , Procedimentos Cirúrgicos Vasculares/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Amputação Cirúrgica , Estado Terminal , Feminino , Humanos , Isquemia/diagnóstico por imagem , Isquemia/mortalidade , Isquemia/fisiopatologia , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Grau de Desobstrução Vascular , Procedimentos Cirúrgicos Vasculares/efeitos adversos , Procedimentos Cirúrgicos Vasculares/mortalidade , CicatrizaçãoRESUMO
OBJECTIVE: Near-infrared spectroscopy (NIRS) non-invasively determines tissue oxygen saturation (Sto2) in muscle tissue. Its application to monitor real time hemodynamic changes during percutaneous transluminal angioplasty (PTA) and Sto2 changes in feet 4 weeks after PTA was evaluated. METHODS: This study included 14 patients with critical limb ischemia (CLI, six patients Rutherford classification Stage IV, two patients Stage V, and six patients Stage VI). In patients with arterial ulcers, NIRS optodes were placed near the ulcer of the diseased foot (Optode 1), and at the same spot at the contralateral foot (Optode 2). In patients without arterial ulcers, Optode 1 was placed on the dorsum of the diseased foot, and Optode 2 was placed on the dorsum of the contralateral foot. Single Sto2 values, ankle brachial indices, and toe brachial indices were obtained at rest before the start of endovascular revascularization and 4 weeks after treatment. During the endovascular procedure, continuous Sto2 measurements were recorded throughout the intervention. Completion angiograms were used to evaluate the success of intervention. RESULTS: Patients underwent treatment of the superficial femoral artery (79%), popliteal artery (21%), and below the knee arteries (43%). In 13 of the 14 patients, completion angiograms showed successful treatment of target lesions. Ankle brachial indices and toe brachial indices significantly increased 4 weeks after treatment (both p < .01). Single Sto2 values of Optode 1 also significantly increased four weeks after treatment (p < .01). In contrast, single Sto2 values of Optode 2 did not (p = .73). During the endovascular procedure, continuous Sto2 measurements of Optode 1 and 2 did not increase (p = .80, and p = .61, respectively). CONCLUSIONS: NIRS monitoring of foot oxygenation in patients undergoing endovascular revascularization is safe and feasible. NIRS is a promising non-invasive technique to monitor hemodynamic changes in the feet of CLI patients after endovascular treatment using single Sto2 values.
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Angioplastia com Balão , Monitorização Transcutânea dos Gases Sanguíneos/métodos , Pé/irrigação sanguínea , Isquemia/terapia , Oxigênio/sangue , Doença Arterial Periférica/terapia , Espectroscopia de Luz Próxima ao Infravermelho , Idoso , Idoso de 80 Anos ou mais , Índice Tornozelo-Braço , Biomarcadores/sangue , Estado Terminal , Estudos de Viabilidade , Feminino , Hemodinâmica , Humanos , Isquemia/sangue , Isquemia/diagnóstico , Isquemia/fisiopatologia , Masculino , Pessoa de Meia-Idade , Doença Arterial Periférica/sangue , Doença Arterial Periférica/diagnóstico , Doença Arterial Periférica/fisiopatologia , Projetos Piloto , Valor Preditivo dos Testes , Fluxo Sanguíneo Regional , Reprodutibilidade dos Testes , Fatores de Tempo , Resultado do TratamentoRESUMO
More challenging abdominal aortic aneurysms with unfavorable proximal aortic neck anatomy are treated with endovascular means. As a consequence, proximal inadequate sealing may result in type IA endoleak, which in turn can lead to abdominal aortic aneurysm progression or rupture. The presence of type IA endoleak is an indication for secondary interventions. External aortic banding can be a good option to solve a type IA endoleak, but is underreported in literature; we present two cases and review literature.
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Aneurisma da Aorta Abdominal/cirurgia , Implante de Prótese Vascular/efeitos adversos , Endoleak/cirurgia , Procedimentos Endovasculares/efeitos adversos , Idoso de 80 Anos ou mais , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aortografia , Endoleak/diagnóstico por imagem , Endoleak/etiologia , Feminino , Humanos , Ligadura , Reoperação , Resultado do TratamentoRESUMO
We present a patient with a recurrent precaval left renal artery, stemming from a right-sided common trunk renal artery. The patient was a 44-year male who presented with a post-traumatic grade IV renal injury. After 3 months without renal function improvement and repeated urinary tract infection, a laparoscopic nephrectomy of the affected right kidney was performed, without upfront identification of the vascular variation, resulting in ischemia of the remaining left kidney. An anastomosis of the common renal trunk and the distal left renal artery was created in between the abdominal aorta and the inferior vena cava. This case describes the importance of upfront detection of renal vascular variations using the appropriate imaging techniques.
Assuntos
Artéria Renal/anormalidades , Injúria Renal Aguda/diagnóstico por imagem , Adulto , Variação Anatômica , Humanos , Masculino , Artéria Renal/diagnóstico por imagemRESUMO
AIM: The wide use of computed tomography (CT) for diverticulitis has initiated new classifications, but their reliability has not been studied. The aim of the study was to assess the inter-observer agreement of radiologists on the classifications of diverticulitis. METHOD: A set of 100 CT examinations of patients with an episode of diverticulitis was used to assess inter-observer agreement. Cases were derived from two prospective trials and a retrospective cohort to comprise an evenly distributed case mix of patients. The reference standard was the modified Hinchey classification based on all available information. Three blinded radiologists independently read all CT examinations. We calculated the proportion of agreement and kappa values for the Hinchey and Ambrosetti classifications. For the Dharmarajan classification only inter-observer agreement was calculated. RESULTS: The agreement with the reference standard was substantial for both the modified Hinchey and the Ambrosetti classifications (P = 0.68 and P = 0.76). Overall inter-observer agreement for the modified Hinchey classification was substantial (median kappa 0.72), for the Ambrosetti classification almost perfect (median kappa 0.83) and for the Dharmarajan classification substantial (median kappa 0.76). CONCLUSION: The Ambrosetti classification is more reproducible than the modified Hinchey and Dharmarajan classifications. The Ambrosetti and modified Hinchey classifications have a substantial agreement with the reference standard and therefore produce a reliable classification. The Dhamarajan is applicable only in complicated diverticulitis and is an important complementary classification to the other more general classifications of diverticulitis.
Assuntos
Doença Diverticular do Colo/classificação , Doença Diverticular do Colo/diagnóstico por imagem , Tomografia Computadorizada por Raios X/estatística & dados numéricos , Adulto , Diagnóstico Diferencial , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Estudos Prospectivos , Reprodutibilidade dos Testes , Fatores de TempoRESUMO
Presented are three cases of volleyball players with ischaemia of the hand due to arterial emboli originating from an injured posterior circumflex humeral artery (PCHA). An operative treatment with ligation of the PCHA was performed in all patients because of the proximity of the occlusion to the axillary artery. After a rehabilitation programme, all patients could return to their previous level of competition. During overhead motion, the PCHA is prone to injury in its position overlying the humeral head and its course through the quadrilateral space. Recognition of the vascular origin of these symptoms in athletes is important to prevent serious ischaemic complications. Signs of ischaemia might be subtle and may be misdiagnosed as musculoskeletal injuries. Therefore, the examining physician must have a high index of suspicion and awareness about these injuries is important.
Assuntos
Embolia/etiologia , Mãos/irrigação sanguínea , Úmero/irrigação sanguínea , Isquemia/etiologia , Lesões do Sistema Vascular/etiologia , Voleibol/lesões , Adulto , Artérias/lesões , Artérias/cirurgia , Embolia/diagnóstico por imagem , Embolia/cirurgia , Humanos , Isquemia/diagnóstico por imagem , Isquemia/cirurgia , Ligadura , Masculino , Valor Preditivo dos Testes , Radiografia , Resultado do Tratamento , Procedimentos Cirúrgicos Vasculares , Lesões do Sistema Vascular/diagnóstico por imagem , Lesões do Sistema Vascular/cirurgia , Adulto JovemRESUMO
BACKGROUND: Acute appendicitis is still a difficult diagnosis. Scoring systems are designed to aid in the clinical assessment of patients with acute appendicitis. The Alvarado score is the most well known and best performing in validation studies. The purpose of the present study was to externally validate a recently developed appendicitis inflammatory response (AIR) score and compare it to the Alvarado score. METHODS: The present study selected consecutive patients who presented with suspicion of acute appendicitis between 2006 and 2009. Variables necessary to evaluate the scoring systems were registered. The diagnostic performance of the two scores was compared. RESULTS: The present study included 941 consecutive patients with suspicion of acute appendicitis. There were 410 male patients (44%) and 531 female patients (56%). The area under the receiver operating characteristic curve of the AIR score was 0.96 and significantly better than the area under the curve of 0.82 of the Alvarado score (p < 0.05). The AIR score also outperformed the Alvarado score when analyzing the more difficult patients, including women, children, and the elderly. CONCLUSIONS: This study externally validates the AIR Score for patients with acute appendicitis. The scoring system has a high discriminating power and outperforms the Alvarado score.
Assuntos
Apendicite/diagnóstico , Índice de Gravidade de Doença , Apendicite/cirurgia , Humanos , Inflamação , Tomografia Computadorizada por Raios X , UltrassonografiaRESUMO
Introduction: Current treatment strategies for primary upper extremity deep venous thrombosis (pUEDVT) range from conservative treatment with anticoagulation therapy to invasive treatment with thoracic outlet decompression surgery (TOD), frequently combined with catheter directed thrombolysis, percutaneous transluminal angioplasty, or stenting. Due to a lack of large prospective series with uniform data collection or a randomized trial, the optimal treatment strategy is still under debate. We conducted a multicenter observational study to assess the efficacy and safety of both the conservative and invasive treatment strategies for patients with pUEDVT. Methods: We retrospectively collected data from patients treated in five vascular referral and teaching hospitals in the Netherlands between 2008 and 2019. Patients were divided into a conservative (Group 1), an invasive treatment group (Group 2) and a cross-over group (Group 3) of patients who received surgical treatment after initial conservative therapy. Follow-up consisted of outpatient clinic visits and an electronic survey. Primary outcome was symptom free survival defined as absence of any symptom of the affected arm reported at last follow-up regardless of severity, or extent of functional disability. Secondary outcomes were incidence of bleeding complications, recurrent venous thromboembolism, surgical complications, and reinterventions. Results: A total of 115 patients were included (group 1 (N = 45), group 2 (N = 53) or group 3 (N = 27). The symptom free survival was 35.6%, 54.7% and 48.1% after a median follow-up of 36, 26 and 22 months in groups 1, 2 and 3 respectively. Incidence of bleeding complications was 8.6%, 3.8% and 18.5% and recurrent thrombosis occurred in 15.6%, 13.2% and 14.8% in groups 1-3 respectively. Conclusion: In this multicenter retrospective observational cohort analysis the conservative and direct invasive treatments for pUEDVT were deemed safe with low percentages of bleeding complications. Symptom free survival was highest in the direct surgical treatment group but still modest in all subgroups. Perioperative complications were infrequent with no related long term morbidity. Of relevance, pUEDVT patients with confirmed VTOS and recurrent symptoms after conservative treatment may still benefit from TOD surgery. However, symptom free survival of this delayed TOD seems lower than direct surgical treatment and bleeding complications seem to occur more frequently.
RESUMO
BACKGROUND: The value of antibiotics in the treatment of acute uncomplicated left-sided diverticulitis is not well established. The aim of this review was to assess whether or not antibiotics contribute to the (uneventful) recovery from acute uncomplicated left-sided diverticulitis, and which types of antibiotic and route of administration are most effective. METHODS: Medline, the Cochrane Library and Embase databases were searched. Randomized controlled trials (RCTs), prospective or retrospective cohort studies addressing conservative treatment of mild uncomplicated left-sided diverticulitis and use of antibiotics were included. RESULTS: No randomized or prospective studies were found on the topic of effect on outcome. One retrospective cohort study was retrieved that compared a group treated with antibiotics with observation alone. This study showed no difference in success rate between groups. Only one RCT of moderate quality compared intravenous and oral administration of antibiotics, and found no differences. One other RCT of very poor quality compared two different kinds of intravenous antibiotic and also found no difference. A small retrospective cohort study comparing antibiotics with and without anaerobe coverage showed no difference in group outcomes. CONCLUSION: Evidence on the use of antibiotics in mild or uncomplicated diverticulitis is sparse and of low quality. There is no evidence mandating the routine use of antibiotics in uncomplicated diverticulitis, although several guidelines recommend this. Copyright © 2011 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.
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Antibacterianos/administração & dosagem , Doença Diverticular do Colo/tratamento farmacológico , Administração Oral , Humanos , Infusões Intravenosas , Guias de Prática Clínica como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do TratamentoRESUMO
Construction of green nanodevices characterised by excellent long-term performance remains high priority in biotechnology and medicine. Tight electronic coupling of proteins to electrodes is essential for efficient direct electron transfer (DET) across the bio-organic interface. Rational modulation of this coupling depends on in-depth understanding of the intricate properties of interfacial DET. Here, we dissect the molecular mechanism of DET in a hybrid nanodevice in which a model electroactive protein, cytochrome c 553 (cyt c 553), naturally interacting with photosystem I, was interfaced with single layer graphene (SLG) via the conductive self-assembled monolayer (SAM) formed by pyrene-nitrilotriacetic acid (pyr-NTA) molecules chelated to transition metal redox centers. We demonstrate that efficient DET occurs between graphene and cyt c 553 whose kinetics and directionality depends on the metal incorporated into the bio-organic interface: Co enhances the cathodic current from SLG to haem, whereas Ni exerts the opposite effect. QM/MM simulations yield the mechanistic model of interfacial DET based on either tunnelling or hopping of electrons between graphene, pyr-NTA-M2+ SAM and cyt c 553 depending on the metal in SAM. Considerably different electronic configurations were identified for the interfacial metal redox centers: a closed-shell system for Ni and a radical system for the Co with altered occupancy of HOMO/LUMO levels. The feasibility of fine-tuning the electronic properties of the bio-molecular SAM upon incorporation of various metal centers paves the way for the rational design of the optimal molecular interface between abiotic and biotic components of the viable green hybrid devices, e.g. solar cells, optoelectronic nanosystems and solar-to-fuel assemblies.
RESUMO
The highly efficient bioelectrodes based on single layer graphene (SLG) functionalized with pyrene self-assembled monolayer and novel cytochromec553(cytc553)peptide linker variants were rationally designed to optimize the direct electron transfer (DET) between SLG and the heme group of cyt. Through a combination of photoelectrochemical and quantum mechanical (QM/MM) approaches we show that the specific amino acid sequence of a short peptide genetically inserted between the cytc553holoprotein and thesurface anchoring C-terminal His6-tag plays a crucial role in ensuring the optimal orientation and distance of the heme group with respect to the SLG surface. Consequently, efficient DET occurring between graphene and cyt c553 leads to a 20-fold enhancement of the cathodic photocurrent output compared to the previously reported devices of a similar type. The QM/MM modeling implies that a perpendicular or parallel orientation of the heme group with respect to the SLG surface is detrimental to DET, whereas the tilted orientation favors the cathodic photocurrent generation. Our work confirms the possibility of fine-tuning the electronic communication within complex bio-organic nanoarchitectures and interfaces due to optimization of the tilt angle of the heme group, its distance from the SLG surface and optimal HOMO/LUMO levels of the interacting redox centers.
Assuntos
Grupo dos Citocromos c/química , Grupo dos Citocromos c/genética , Grafite/química , Heme , Mutação , Sequência de Aminoácidos , Eletrodos , Transporte de ElétronsRESUMO
The objective of this study was to investigate the effects of nutrient supplementation on anaerobic biomass. While many studies emphasized the importance of supplementing trace metals such as iron, cobalt, and nickel for maximum methanogenic activity, there is no evidence whether such supplements, even at relatively low concentration, could perturb anaerobic biomass. Effects of supplementing nutrients, including yeast extract, on anaerobic biomass from two full-scale mesophilic digesters, operating under different conditions, at the North East Water Pollution Control Plant in Philadelphia, Pennsylvania, USA, were assessed using biochemical methane potential tests. The results show that acetoclastic methanogens from a recently cleaned digester was not stimulated by nutrient supplementation at relatively low concentrations and a slight perturbation was observed when supplementation was at a relatively high concentration. Furthermore, greater degree of susceptibility to the trace metal supplementation was observed for biomass from another digester that had not been cleaned for over 10 years, thus it had reduced active volume due to grit accumulation. For instance, supplementation of 200 mg/L of iron as FeCl(2)·4H(2)O to the biomass from the reduced-active-volume digester caused 17% reduction in CH(4) production, as compared to a control which did not receive any supplements, while the same concentration had no effect on the biomass from full-active-volume digester. Results strongly suggest that acetoclastic methanogens stressed due to reduced hydraulic/solids retention time may be susceptible to trace metal addition. Therefore, trace metal supplementation for anaerobic digesters should be considered on a case by case basis.
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Bactérias Anaeróbias/efeitos dos fármacos , Bactérias Anaeróbias/metabolismo , Reatores Biológicos , Metais/farmacologia , Acetatos , Anaerobiose , Biomassa , Metais/química , Metano/metabolismo , Poluentes da ÁguaRESUMO
INTRODUCTION: Despite improvements in endograft design, operator skills, and patient selection, late endovascular abdominal aortic aneurysm repair (EVAR) associated complications and need for reinterventions remains the Achilles heel. These complications erode the early benefit over open aneurysm repair during long-term follow-up. The recently introduced endovascular aneurysm sealing (EVAS) is an innovative technology with the intention to lower these EVAR related complications. Areas covered: In this review the EVAS technique, indications, and possible applications, will be discussed, as well as a critical appraisal of clinical outcomes. Expertcommentary: EVAS is a promising technique for treating abdominal aortic aneurysms, and early efficacy data are encouraging in very suitable straight forward anatomy. The Nellix device is still in development. Longterm results are awaited.
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Aneurisma da Aorta Abdominal/cirurgia , Procedimentos Endovasculares/instrumentação , Complicações Pós-Operatórias , Procedimentos Endovasculares/efeitos adversos , Procedimentos Endovasculares/métodos , Humanos , Seleção de Pacientes , Resultado do TratamentoRESUMO
Renal angiomyolipoma (AML) is a benign renal tumour and is nowadays considered a relatively common lesion. When an AML increases in size or becomes symptomatic, embolisation via the renal artery should then be considered, because rupture is an important complication and interventional therapies are required to stop bleeding. We present a 21 year old woman who was seen at the emergency department following a low velocity trauma. After a period of 9 weeks, clinical examination and radiological examination revealed a haemorrhage from a renal AML, which was treated by selective embolisation. A discussion of the relevant literature is also presented.
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Angiomiolipoma/complicações , Embolização Terapêutica , Hemorragia/etiologia , Neoplasias Renais/complicações , Acidentes de Trânsito , Adulto , Angiomiolipoma/diagnóstico por imagem , Feminino , Hemorragia/diagnóstico por imagem , Hemorragia/terapia , Humanos , Neoplasias Renais/diagnóstico por imagem , Espaço Retroperitoneal , Tomografia Computadorizada por Raios X , Resultado do TratamentoRESUMO
OBJECTIVE: To examine the effectiveness of a cross-linked hyaluronan solution (auto-cross-linked polysaccharide [ACP] gel) for the prevention of postsurgical adhesions. DESIGN: A randomized blinded study using a rat model of laparotomy. SETTING: Surgical Research Laboratory in a university medical school. ANIMAL(S): Sixty-seven sexually mature rats. INTERVENTION(S): Standardized surgical trauma was induced in the rat uterine horn to induce adhesion formation. After trauma, group-1 animals (n = 23) received no treatment, group 2 (n = 21) received noncross-linked hyaluronic acid (HA), and group 3 (n = 23) received cross-linked HA applied on the lesion. MAIN OUTCOME MEASURE(S): Six weeks after laparotomy, repeat laparotomy was performed and the adhesions were scored according to Blauer's scoring system. RESULT(S): Overall, 84% of the untreated animals and 65% of the animals treated with noncross-linked HA presented with severe adhesions. The mean (+/-SEM) increase in the adhesion score was 2.46+/-0.23 in the untreated group, 2.23+/-0.29 in the group receiving noncross-linked HA, and 1.27+/-0.12 in the ACP gel group. CONCLUSION(S): ACP gel holds promise as a novel resorbable biomaterial for the reduction of postoperative adhesions after laparotomy.
Assuntos
Ácido Hialurônico/uso terapêutico , Laparotomia/efeitos adversos , Complicações Pós-Operatórias/prevenção & controle , Aderências Teciduais/prevenção & controle , Animais , Reagentes de Ligações Cruzadas , Feminino , Distribuição Aleatória , RatosRESUMO
OBJECTIVE: To evaluate whether the GnRH antagonist ganirelix exerts an effect on cyclic adenosine monophosphate (cAMP) production of human granulosa-lutein (GL) cells in vitro. DESIGN: In vitro cell culture study. SETTING: Research laboratory of a university hospital. PATIENT(S): Mural GL and cumulus cells were obtained from 15 patients on whom controlled ovarian hyperstimulation was being performed for intracytoplasmic sperm injection treatment. INTERVENTION(S): Mural GL and cumulus cells were cultured for 48 hours with and without 1 nM ganirelix or triptorelin. For the last 6 hours, the cells were either exposed to 1-5 IU hCG or left unstimulated. MAIN OUTCOME MEASURE(S): At the end of the culturing period, the intracellular and extracellular cAMP accumulations were measured by an (125)I-scintillation proximity assay. RESULT(S): hCG induced dose-dependent increases in total cAMP accumulation. Stimulation with 1 IU/mL hCG resulted in 9-fold and 13-fold increases, and 5 IU/mL hCG resulted in 19-fold and 14-fold increases in total cAMP release from cumulus and mural GL cells, respectively. On the other hand, treatments with 1 nM GnRH antagonist ganirelix and 1 nM GnRH agonist triptorelin did not exert any significant changes on the basal and hCG-stimulated cAMP accumulation of mural GL cells and cumulus cells as compared with controls. CONCLUSION(S): Ganirelix does not influence basal and hCG-stimulated cAMP accumulation of human GL cells in vitro. cAMP is apparently not involved in the mechanism of action of GnRH analogs in human ovary.