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1.
Laryngorhinootologie ; 102(10): 735-741, 2023 10.
Artigo em Alemão | MEDLINE | ID: mdl-37054747

RESUMO

BACKGROUND: The cutaneous squamous cell carcinoma (CSCC) is the second most common nonmelanoma skin cancer with an increasing incidence rate. Patients presenting with high-risk lesions associated with locally advanced or metastatic CSCC face high rates of recurrence and mortality. METHODS: Selective literature review based on PubMed and consideration of current guidelines "Aktinische Keratosen und Plattenepithelkarzinom der Haut" and "Prävention von Hautkrebs". FINDINGS: Complete surgical excision with histopathological control of excision margins is the gold standard in the treatment of primary CSCC. Radiotherapy can be used as an alternative treatment of inoperable CSCCs. In 2019, the PD1-antibody cemiplimab, has been approved for the treatment of locally advanced and metastatic CSCC by the European Medicines Agency. After 3 years of follow up, Cemiplimab shows overall response rates of 46 %, the median overall survival and median response rate had not been reached yet. Additional immunotherapeutics, combinations with other agents and oncolytic viruses are all potentially worth study to try, so clinical trial data will be forthcoming over the next few years to guide optimal use of these agents. CONCLUSION: Multidisciplinary board decisions are mandatory for all patients with advanced disease who require more than surgery. Further development of existing therapeutic concepts, identification of new combination therapies and the development of new immunotherapeutics will be the key challenge over the next few years.


Assuntos
Carcinoma de Células Escamosas , Neoplasias Cutâneas , Humanos , Carcinoma de Células Escamosas/patologia , Neoplasias Cutâneas/terapia
2.
J Clin Med ; 11(23)2022 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-36498674

RESUMO

(1) Background: Pyoderma gangrenosum (PG) is often situated on the lower legs, and the differentiation from conventional leg ulcers (LU) is a challenging task due to the lack of clear clinical diagnostic criteria. Because of the different therapy concepts, misdiagnosis or delayed diagnosis bears a great risk for patients. (2) Objective: to develop a deep convolutional neural network (CNN) capable of analysing wound photographs to facilitate the PG diagnosis for health professionals. (3) Methods: A CNN was trained with 422 expert-selected pictures of PG and LU. In a man vs. machine contest, 33 pictures of PG and 36 pictures of LU were presented for diagnosis to 18 dermatologists at two maximum care hospitals and to the CNN. The results were statistically evaluated in terms of sensitivity, specificity and accuracy for the CNN and for dermatologists with different experience levels. (4) Results: The CNN achieved a sensitivity of 97% (95% confidence interval (CI) 84.2−99.9%) and outperformed dermatologists, with a sensitivity of 72.7% (CI 54.4−86.7%) significantly (p < 0.03). However, dermatologists achieved a slightly higher specificity (88.9% vs. 83.3%). (5) Conclusions: For the first time, a deep neural network was demonstrated to be capable of diagnosing PG, solely on the basis of photographs, and with a greater sensitivity compared to that of dermatologists.

3.
Eur Heart J Case Rep ; 6(11): ytac425, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36381177

RESUMO

Background: Giant coronary aneurysms are a rare finding on coronary angiography. Given its very low prevalence, little is known about optimal management of this coronary pathology. Case summary: In this case report, we review the two presentations of a patient with acute coronary syndrome during a 6-year period. With regard to the second presentation, we review the investigations that demonstrate the progression of a coronary aneurysm in the right coronary artery as well as the Heart Team evaluations that resulted in surgical treatment of the coronary aneurysm. Discussion: Following perspectives on prevalence and risk factors, we emphasize upon the available data with regard to interventional options in coronary aneurysms and describe the considerations with regard to interventional treatment in patients with giant coronary aneurysms. Finally, we discuss the available literature with regard to antithrombotic regimens in patients with coronary aneurysms.

4.
Circ Cardiovasc Interv ; 15(7): e011848, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35861798

RESUMO

BACKGROUND: Heyde syndrome is the co-occurrence of aortic stenosis and gastrointestinal bleeding secondary to angiodysplasias. Surgical aortic valve replacement effectively reduces bleeding, but the effects of transcatheter aortic valve implantation (TAVI) are largely unknown. This study aimed to describe the reduction of gastrointestinal bleeding in patients with Heyde syndrome after TAVI and to identify the factors associated with rebleeding. METHODS: We enrolled patients with Heyde syndrome from a prospective TAVI registry. Gastrointestinal bleeding episodes were assessed by the Bleeding Academic Research Consortium classification, and cumulative incidence functions were used to calculate cessation rates. Factors potentially associated with rebleeding were analyzed using logistic regression. Differences between Heyde and non-Heyde patients were assessed through a case-cohort study. RESULTS: Between December 2008 and June 2020, 1111 patients underwent TAVI. There were 70 patients with Heyde syndrome (6.3%). In the first year following TAVI, gastrointestinal bleeding ceased in 46 of 70 patients (62% [95% CI, 50%-74%]). Bleeding episodes decreased from 3.2 (95% CI, 2.5-4.2) to 1.6 ([95% CI, 1.2-2.2] P=0.001) and hemoglobin levels increased from 10.3 (95% CI, 10.0-10.8) to 11.3 (95% CI, 10.8-11.6) g/dL (P=0.007). Between 1 and 5 years after TAVI (35 [interquartile range, 21-51] months), 53 of 62 patients (83% [95% CI, 72%-92%]) no longer experienced gastrointestinal bleeding. Paravalvular leakage (≥mild) was associated with rebleeding risk (odds ratio, 3.65 [95% CI, 1.36-9.80]; P=0.010). Periprocedural bleeding was more common in Heyde than in control patients (adjusted odds ratio, 2.55 [95% CI, 1.37-4.73]; P=0.003). CONCLUSIONS: Patients with Heyde syndrome are at increased risk for periprocedural bleeding. Post-TAVI, gastrointestinal bleeding disappears in the majority of patients. Paravalvular leakage may curtail these clinical benefits.


Assuntos
Estenose da Valva Aórtica , Implante de Prótese de Valva Cardíaca , Substituição da Valva Aórtica Transcateter , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/complicações , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/cirurgia , Estudos de Coortes , Hemorragia Gastrointestinal/diagnóstico , Hemorragia Gastrointestinal/etiologia , Hemorragia Gastrointestinal/terapia , Implante de Prótese de Valva Cardíaca/efeitos adversos , Humanos , Estudos Prospectivos , Fatores de Risco , Síndrome , Substituição da Valva Aórtica Transcateter/efeitos adversos , Resultado do Tratamento
5.
J Diabetes Sci Technol ; 16(1): 70-77, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32954812

RESUMO

BACKGROUND: In this study, we evaluated the analytical performance of the second-generation factory-calibrated FreeStyle Libre Flash Glucose Monitoring (FreeStyle Libre 2) System compared to plasma venous blood glucose reference, Yellow Springs Instrument 2300 (YSI). METHODS: The study enrolled participants aged four and above with type 1 or type 2 diabetes at seven sites in the United States. Adult participants (18+ years) participated in three in-clinic sessions and pediatric participants (4-17 years) participated in up to two in-clinic sessions stratified to provide data for days 1, 2, 3, 7, 8, 9, 12, 13, or 14 of sensor wear. Participants aged 11+ underwent supervised glycemic manipulation during in-clinic sessions to achieve glucose levels across the measurement range of the System. Performance evaluation included accuracy measures such as the proportion of continuous glucose monitoring (CGM) values that were within ±20% or ±20 mg/dL of reference glucose values, and bias measures such as the mean absolute relative difference (MARD) between CGM and reference values. RESULTS: Data from the 144 adults and 129 pediatric participants were analyzed. Percent of sensor results within ±20%/20 mg/dL of YSI reference were 93.2% and 92.1%, and MARD was 9.2% and 9.7% for the adults and pediatric participants, respectively. The System performed well in the hypoglycemic range, with 94.3% of the results for the adult population and 96.1% of the data for pediatric population being within 15 mg/dL of the YSI reference. The time lag was 2.4 ± 4.6 minutes for adults and 2.1 ± 5.0 minutes for pediatrics. CONCLUSIONS: The System demonstrated improved analytical accuracy performance across the dynamic range during the 14-day sensor wear period as compared to the previous-generation device.NCT#: NCT03607448 and NCT03820050.


Assuntos
Diabetes Mellitus Tipo 1 , Diabetes Mellitus Tipo 2 , Pediatria , Adulto , Idoso , Algoritmos , Glicemia , Automonitorização da Glicemia , Criança , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Glucose , Humanos , Reprodutibilidade dos Testes
6.
Eur J Cancer ; 158: 72-84, 2021 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-34655839

RESUMO

BACKGROUND: Combination of immune checkpoint inhibitors and mitogen-activated protein kinase (MAPK) pathway inhibitors (MAPKi) has been proposed to enhance the durability of anti-tumour responses induced by MAPKi. Here, we present phase I safety results from an open-label, phase I/II study of pembrolizumab (PEM), encorafenib (ENC) and binimetinib (BIN) triplet therapy in advanced, B-Raf proto-oncogene serine/threonine kinase (BRAF)V600-mutated melanoma (IMMU-TARGET, NCT02902042). METHODS: The dose finding phase I part used a 3 + 3 design, starting with the approved doses of PEM (200 mg every three weeks), ENC (450 mg once daily [QD]) and BIN (45 mg twice daily [BID]) as dose level (DL) 0. Reduction of the ENC and BIN doses (300 mg QD and 30 mg BID at DL-1 and 200 mg QD and 30 mg BID at DL-2) was preplanned in case of ≥2 dose-limiting toxicities (DLTs). Primary objectives were to estimate the recommended phase II dose of the triplet combination, DLT and safety. As per the sponsor's decision, the study was terminated after the phase I part, as the clinical efficacy of the combination is currently being investigated in a pivotal, placebo-controlled (PEM mono), double-blinded phase III trial (STARBOARD,NCT04657991). RESULTS: Fifteen patients were enrolled. DLTs of DL0 were creatine phosphokinase (CPK) elevation plus cytokine release syndrome (n = 1) and gamma glutamyl transferase (GGT) increase (n = 1). No DLT was observed in further 3 + 3 patients at DL-1. One (isolated GGT elevations) DLT of DL0 was questionable, as the patient had further episodes of isolated GGT elevations after treatment discontinuation. Hence, further 6 patients were enrolled at DL0: here, no DLT occurred. In total, 13 of 15 patients (87%) experienced a treatment-related adverse event (TRAE) and 8 patients (53%), a grade ≥III TRAE; there were no TRAE-related deaths. Increases in aspartate aminotransferases, GGT (6/15 patients) and CPK elevations (4/15) were the most common grade III-IV TRAE. In median, patients received triplet therapy for 24 weeks (interquartile range [IQR], 12-45). Of the 14 patients evaluable for efficacy, the overall response rate was 64% (95% confidence interval [CI], 35-87). At a median follow-up of 25 months (IQR, 9-28), progression-free survival at 12 months was 41% (95% CI, 13-68). CONCLUSIONS: Triplet therapy with PEM, ENC and BIN as used in the study was feasible and safe and led to clinically meaningful disease control.

7.
BMJ Open Sport Exerc Med ; 7(3): e001159, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34567787

RESUMO

Many patients lapse into a physically inactive lifestyle within months after cardiac rehabilitation (CR) programme completion. A mobile-health (mHealth) home-based training application can be used to intensify and/or prolong the CR programme to induce long-lasting improvements of habitual physical activity levels. This study will assess the effect of an additional home-based training module during CR and post-CR on habitual physical activity levels among coronary artery disease patients. A total of 132 patients (>18 years old) will be recruited in an 18-week randomised controlled trial with four arms: (1) 6 weeks centre-based CR (ie, standard care), (2) 6 weeks combined centre-based+mHealth home-based CR, (3) 6 weeks centre-based CR followed by 12 weeks mHealth home-based CR, (4) 6 weeks combined centre-based+mHealth home-based CR followed by 12 weeks mHealth home-based CR. The intervention groups will receive a daily and personalised exercise training using a smartphone application (Virtual Training) in addition to and/or as extension of the centre-based CR programme. The participants will be assessed prior to the centre-based CR programme, after completion of the 6-week CR programme and after the 12 weeks extension. Primary outcome will be objectively measured habitual physical activity levels expressed as moderate to vigorous intensity activities (min/week). Secondary outcome parameters include sedentary behaviour, physical fitness (estimated VO2max), handgrip strength, cardiovascular risk profile, quality of life and cardiac anxiety scores. The findings of the Cardiac RehApp study will provide insight into the added value of a personalised mHealth home-based training application on physical activity levels during and after centre-based CR. Trial registration number: NL72182.091.019.

8.
Artigo em Inglês | MEDLINE | ID: mdl-32718934

RESUMO

INTRODUCTION: This pilot study evaluated the impact of a diabetes-specific nutritional shake (DSNS) used twice daily by people with type 2 diabetes (T2D) on glycemic response assessed by continuous glucose monitoring (CGM). RESEARCH DESIGN AND METHODS: Adults (n=81) with T2D managed by oral medications were studied in a randomized, open-label, three-group parallel study design. The study was conducted in two phases over 14 days: Baseline (days 1-6), during which study participants consumed their habitual self-selected diets (SSD), followed by the Intervention (days 7-14), during which participants were randomized as follows: (1) SSD group received no study product (n=32); (2) DSNS breakfast/afternoon snack (Bkfst/AS) group consumed one DSNS as a breakfast meal replacement and a second to replace their mid-afternoon snack (n=24); (3) DSNS breakfast/prebed snack (Bkfst/PBS) group consumed one DSNS as a breakfast meal replacement and added a second as a prebed snack (n=25). Glucose was assessed by CGM throughout the study. Additionally, participants were asked about snacking behaviors, cravings, and other questions related to the use of DSNS as meal replacements and snacks. RESULTS: All groups reduced their postprandial glycemic response (positive area under the curve (pAUC, mg/min*dL-1)) and adjusted peak value (mg/dL) when compared with the baseline phase. Participants consuming DSNS in place of their usual breakfast showed greater reductions in pAUC compared with the SSD group (p=0.008) for the DSNS Bkfst/AS group with a trend (p=0.069) for the DSNS Bkfst/PBS group. Adjusted peak value showed greater reductions in both DSNS groups as compared with the SSD group (p=0.002 for DSNS Bkfst/AS and p=0.010 for DSNS Bkfst/PBS). Nocturnal glucose variability was significantly decreased during the intervention phase compared with baseline phase in the DSNS Bkfst/AS group (p=0.020), with no significant differences between groups. After intervention, the DSNS Bkfst/AS group had a significantly lower percentage of participants (17%) reporting cravings for starchy meals/sides compared with before the study (33%) (p=0.046). This group also reported a significant increase in confidence in choosing foods to control their diabetes (from 58.3% to 91.7%, preintervention vs postintervention, respectively, p=0.005). CONCLUSIONS: Use of DSNS to replace breakfast and as an afternoon snack improves both glycemic control and behavioral factors related to dietary management of diabetes. TRAIL REGISTRATION NUMBER: NCT04230889.


Assuntos
Diabetes Mellitus Tipo 2 , Lanches , Adulto , Glicemia , Automonitorização da Glicemia , Desjejum , Diabetes Mellitus Tipo 2/terapia , Humanos , Projetos Piloto
10.
Phys Rev Lett ; 124(1): 016102, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31976688

RESUMO

The self-assembly of submonolayer amounts of Au on the densely stepped Si(553) surface creates an array of closely spaced "atomic wires" separated by 1.5 nm. At low temperature, charge transfer between the terraces and the row of silicon dangling bonds at the step edges leads to a charge-ordered state within the row of dangling bonds with ×3 periodicity. Interactions between the dangling bonds lead to their ordering into a fully two-dimensional (2D) array with centered registry between adjacent steps. We show that as the temperature is raised, soliton defects are created within each step edge. The concentration of solitons rises with increasing temperature and eventually destroys the 2D order by decoupling the step edges, reducing the effective dimensionality of the system to 1D. This crossover from higher to lower dimensionality is unexpected and, indeed, opposite to the behavior in other systems.

11.
Virchows Arch ; 473(2): 241-246, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29934657

RESUMO

Multiple familial trichoepitheliomas (MFT) is an autosomal dominantly inherited disease characterized by multiple skin appendage tumors. We describe a patient showing a continuous spectrum of follicular differentiated neoplasms including classical trichoepitheliomas but also infiltrative growing and finally metastasizing malignant follicular differentiated tumors. Germline mutation analysis revealed a nonsense mutation in the cylindromatosis (CYLD) gene. Gene expression analysis by real-time PCR of tumor tissue showed overexpression of glioma-associated oncogene Gli1 mRNA. Treatment with the Hedgehog pathway inhibitor vismodegib resulted in a significant regression of the highly differentiated trichoepitheliomas. Gli upregulation is indicative of an active Hedgehog signaling pathway. We hypothesize that its upregulation is indirectly caused by CYLD mutation which promotes tumor development. Vismodegib treatment could thus provide a new treatment option for patients with this debilitating disorder.


Assuntos
Anilidas/uso terapêutico , Antineoplásicos/uso terapêutico , Síndromes Neoplásicas Hereditárias/tratamento farmacológico , Piridinas/uso terapêutico , Neoplasias Cutâneas/tratamento farmacológico , Códon sem Sentido , Enzima Desubiquitinante CYLD/genética , Predisposição Genética para Doença , Hereditariedade , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Síndromes Neoplásicas Hereditárias/genética , Síndromes Neoplásicas Hereditárias/metabolismo , Síndromes Neoplásicas Hereditárias/patologia , Linhagem , Fenótipo , Transdução de Sinais/efeitos dos fármacos , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Regulação para Cima , Proteína GLI1 em Dedos de Zinco/genética , Proteína GLI1 em Dedos de Zinco/metabolismo
12.
Ann Thorac Surg ; 103(5): 1434-1440, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27793402

RESUMO

BACKGROUND: The direct aortic (DA) approach allows for transcatheter aortic valve implantation (TAVI) in patients with difficult peripheral vascular anatomy. The CoreValve ADVANCE Direct Aortic (ADVANCE DA) study was performed to assess the outcomes of DA TAVI with the CoreValve System (Medtronic, Minneapolis, MN) in routine practice. METHODS: Patients were selected for the DA approach by local cardiac surgical teams, and TAVI was performed with patients under general anesthesia. Safety events were adjudicated according to the Valve Academic Research Consortium-2 definitions by an independent clinical events committee. All imaging data, including that from multislice computed tomography and follow-up echocardiography, were analyzed by an independent core laboratory. RESULTS: From September 2012 to February 2014, 100 patients were enrolled (52.0% male, age 81.9 ± 5.9 years, The Society of Thoracic Surgeons Score 5.9 ± 3.2%) at 9 centers in Europe. Peripheral vascular disease was present in 51.0% of patients, and 38.0% had diabetes. Of the 100 patients enrolled, 92 underwent TAVI. At 30 days after TAVI, 98.1% were free of moderate or severe paravalvular leak. At 1 year, 16 patients had died (Kaplan-Meier rate 17.9%), 1 (1.1%) patient had had a stroke, classified as nondisabling, and 15 (17.0%) patients had received a permanent pacemaker. Most patients experienced improved quality of life as measured by the Kansas City Cardiomyopathy Questionnaire overall summary score (mean change from baseline to 1 year, 39.6 ± 26.3; p < 0.01). CONCLUSIONS: The DA approach provides a feasible alternative for patients with challenging anatomic features that may otherwise preclude use of the TAVI procedure.


Assuntos
Estenose da Valva Aórtica/cirurgia , Complicações Pós-Operatórias/etiologia , Substituição da Valva Aórtica Transcateter/métodos , Idoso , Idoso de 80 Anos ou mais , Estenose da Valva Aórtica/diagnóstico por imagem , Aortografia , Ecocardiografia , Feminino , Seguimentos , Humanos , Masculino , Tomografia Computadorizada Multidetectores , Estudos Prospectivos , Desenho de Prótese , Qualidade de Vida , Resultado do Tratamento
13.
Cancer Immunol Immunother ; 65(8): 951-9, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27294607

RESUMO

Growing evidence suggests that concurrent loco-regional and systemic treatment modalities may lead to synergistic anti-tumor effects in advanced melanoma. In this retrospective multicenter study, we evaluate the use of electrochemotherapy (ECT) combined with ipilimumab or PD-1 inhibition. We investigated patients with unresectable or metastatic melanoma who received the combination of ECT and immune checkpoint blockade for distant or cutaneous metastases within 4 weeks. Clinical and laboratory data were collected and analyzed with respect to safety and efficacy. A total of 33 patients from 13 centers were identified with a median follow-up time of 9 months. Twenty-eight patients received ipilimumab, while five patients were treated with a PD-1 inhibitor (pembrolizumab n = 3, nivolumab n = 2). The local overall response rate (ORR) was 66.7 %. The systemic ORR was 19.2 and 40.0 % in the ipilimumab and PD-1 cohort, respectively. The median duration of response was not reached in either group. The median time to disease progression was 2.5 months for the entire population with 2 months for ipilimumab and 5 months for PD-1 blockade. The median overall survival was not reached in patients with ipilimumab and 15 months in the PD-1 group. Severe systemic adverse events were detected in 25.0 % in the ipilimumab group. No treatment-related deaths were observed. This is the first reported evaluation of ECT and simultaneous PD-1 inhibition and the largest published dataset on ECT with concurrent ipilimumab. The local response was lower than reported for ECT only. Ipilimumab combined with ECT was feasible, tolerable and showed a high systemic response rate.


Assuntos
Pontos de Checagem do Ciclo Celular/imunologia , Eletroquimioterapia/métodos , Melanoma/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Humanos , Melanoma/patologia , Pessoa de Meia-Idade , Estudos Retrospectivos
14.
Lung Cancer ; 95: 35-8, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27040849

RESUMO

INTRODUCTION: Afatinib is a tyrosine kinase inhibitor (TKI), that has been approved for treating patients with epidermal growth factor receptor (EGFR) mutated advanced non-small-cell lung cancer (NSCLC). Stevens-Johnson syndrome (SJS) related to EGFR directed TKIs is a rare adverse event. CASE PRESENTATION: We report a case of a 79-year-old white female with EGFR-mutated, metastatic non-small-cell lung cancer treated with afatinib as first-line palliative treatment, who developed a SJS after two months of treatment. Discontinuation of the TKI and systemic glucocorticoid treatment led to improvement of symptoms and recovery. CONCLUSION: Severe adverse cutaneous drug reactions that predominantly involve the skin and mucous membranes during treatment with afatinib should alert clinicians to suspect SJS and react appropriately.


Assuntos
Receptores ErbB/genética , Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/genética , Mutação , Inibidores de Proteínas Quinases/efeitos adversos , Quinazolinas/efeitos adversos , Síndrome de Stevens-Johnson/etiologia , Corticosteroides/uso terapêutico , Afatinib , Idoso , Feminino , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/tratamento farmacológico , Pele/patologia , Síndrome de Stevens-Johnson/diagnóstico , Síndrome de Stevens-Johnson/tratamento farmacológico , Resultado do Tratamento
15.
Nano Lett ; 16(4): 2698-704, 2016 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-26974012

RESUMO

High-index surfaces of silicon with adsorbed gold can reconstruct to form highly ordered linear step arrays. These steps take the form of a narrow strip of graphitic silicon. In some cases--specifically, for Si(553)-Au and Si(557)-Au--a large fraction of the silicon atoms at the exposed edge of this strip are known to be spin-polarized and charge-ordered along the edge. The periodicity of this charge ordering is always commensurate with the structural periodicity along the step edge and hence leads to highly ordered arrays of local magnetic moments that can be regarded as "spin chains." Here, we demonstrate theoretically as well as experimentally that the closely related Si(775)-Au surface has--despite its very similar overall structure--zero spin polarization at its step edge. Using a combination of density-functional theory and scanning tunneling microscopy, we propose an electron-counting model that accounts for these differences. The model also predicts that unintentional defects and intentional dopants can create local spin moments at Si(hhk)-Au step edges. We analyze in detail one of these predictions and verify it experimentally. This finding opens the door to using techniques of surface chemistry and atom manipulation to create and control silicon spin chains.

17.
Eur J Cardiothorac Surg ; 49(4): 1174-80, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26224338

RESUMO

OBJECTIVES: The aim of this study was to investigate the mid-term haemodynamic and clinical results after aortic valve replacement (AVR) using the Sorin Freedom Solo (SFS) stentless bioprosthesis, compared with the standard Carpentier Edwards Perimount (CEP) stented bioprosthesis. METHODS: In this retrospective cohort study of prospectively collected data, 116 patients were included in the SFS group (53 males; median age 74 years, range 56-85 years), and 122 patients in the CEP group (85 males; median age 73 years, range 43-88 years) between July 2007 and January 2013. Echocardiography was performed at 6 weeks after surgery in our centre, and the most recent echocardiography (in our centre or in referring cardiology departments) was requested. Between September 2013 and April 2014, all patients were called by the same researcher to gain clinical follow-up data. RESULTS: Mid-term mortality was 16.4% in the SFS group (19 patients) and 21.3% in the CEP group (26 patients); (P = 0.3). The mean transvalvular gradient was 7.4 ± 3.1 mmHg in the SFS group, and 11.6 ± 3.2 mmHg in the CEP group at 6 weeks postoperatively (P < 0.001). When stratified by labelled valve size, mean gradients were significantly lower in the SFS group for every size (P ≤ 0.03). After 3.3 ± 1.4 years of follow-up, the mean gradient was still significantly lower in the SFS group than that in the CEP group (P < 0.001). Clinical follow-up showed relatively low complication rates. CONCLUSION: These data suggest that the Sorin Freedom Solo stentless bioprosthesis is as safe as the Carpentier Edwards bioprosthesis, and provides better short- and mid-term haemodynamic performance than the Carpentier Edwards bioprosthesis.


Assuntos
Valva Aórtica/cirurgia , Implante de Prótese de Valva Cardíaca , Próteses Valvulares Cardíacas , Função Ventricular Esquerda/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estenose da Valva Aórtica/cirurgia , Eletrocardiografia , Feminino , Próteses Valvulares Cardíacas/efeitos adversos , Próteses Valvulares Cardíacas/estatística & dados numéricos , Implante de Prótese de Valva Cardíaca/efeitos adversos , Implante de Prótese de Valva Cardíaca/mortalidade , Implante de Prótese de Valva Cardíaca/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
18.
Resuscitation ; 86: 95-9, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25449343

RESUMO

BACKGROUND: Ventricular fibrillation (VF) waveform characteristics are associated with cardiac arrest duration and defibrillation success. Recent animal studies found that VF characteristics and shock success also depend on the presence of myocardial infarction (MI). In patients, VF induction after implantable cardioverter defibrillator (ICD) implantation offers a unique setting to study early VF characteristics: we studied the relation with cardiac disease--either presence or absence of a previous MI--and with shock success. METHODS: Retrospective cohort study of ICD-patients who underwent defibrillation testing, 117 (63%) with and 69 (37%) without a previous MI. Intracardiac recordings of induced VF were analysed using Fourier analysis. RESULTS: In previous MI-patients, the fundamental frequency and organisation index of the VF signal were significantly lower as compared with patients without a previous MI: 4.9 Hz ± 0.6 vs. 5.2 Hz ± 0.6 (p = 0.005) and 56% ± 10 vs. 60% ± 9 (p = 0.001), respectively. The median frequency was not different (p = 0.25). We found no association between VF characteristics and ICD shock success. CONCLUSIONS: In analogy with observations in animals, we found that a history of a previous MI was associated with slower and less organised VF. In our cohort of ICD-patients, early VF waveform characteristics were not associated with shock outcomes. Further study is warranted to determine to what extent VF characteristics are influenced by the underlying aetiology on the one hand, and time delay on the other. These findings could improve insight into the potential value of VF analysis to guide shock delivery.


Assuntos
Desfibriladores Implantáveis , Cardioversão Elétrica , Fibrilação Ventricular/fisiopatologia , Fibrilação Ventricular/terapia , Estudos de Coortes , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/complicações , Indução de Remissão , Estudos Retrospectivos , Fibrilação Ventricular/etiologia
19.
Ann Thorac Surg ; 99(1): 26-32, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25440265

RESUMO

BACKGROUND: Cell-saving devices (CS) are frequently used in cardiac surgery to reduce transfusion requirements, but convincing evidence from randomized clinical trials is missing. Filtration of salvaged blood in combination with the CS is widely used to improve the quality of retransfused blood, but there are no data to justify this approach. METHODS: To determine the contribution of CS and filters on transfusion requirements, we performed a multicenter factorial randomized clinical trial in two academic and four nonacademic hospitals. Patients undergoing elective coronary, valve, or combined surgical procedures were included. The primary end point was the number of allogeneic blood products transfused in each group during hospital admission. RESULTS: From 738 included patients, 716 patients completed the study (CS+filter, 175; CS, 189; filter, 175; neither CS nor filter, 177). There was no significant effect of CS or filter on the total number of blood products (fraction [95% confidence interval]: CS, 0.96 [0.79, 1.18]; filter, 1.17 [0.96, 1.43]). Use of a CS significantly reduced red blood cell transfusions within 24 hours (0.75 [0.61,0.92]), but not during hospital stay (0.86 [0.71, 1.05]). Use of a CS was significantly associated with increased transfusions of fresh frozen plasma (1.39 [1.04, 1.86]), but not with platelets (1.25 [0.93, 1.68]). Use of a CS significantly reduced the percentage of patients who received any transfusion (odds ratio [95% confidence interval]: 0.67 [0.49, 0.91]), whereas filters did not (0.92 [0.68, 1.25]). CONCLUSIONS: Use of a CS, with or without a filter, does not reduce the total number of allogeneic blood products, but reduces the percentage of patients who need blood products during cardiac surgery.


Assuntos
Transfusão de Sangue/estatística & dados numéricos , Procedimentos Cirúrgicos Cardíacos , Recuperação de Sangue Operatório/instrumentação , Idoso , Feminino , Humanos , Masculino
20.
J Diabetes Sci Technol ; 8(1): 89-94, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24876543

RESUMO

BACKGROUND: Continuous glucose monitoring using subcutaneously inserted sensors currently requires blood glucose tests for sensor calibration. Alternatively, sensors precalibrated during the manufacturing process may eliminate the need for fingerstick calibrations. In this study we evaluated the feasibility of sensor factory calibration in subjects with diabetes. METHODS: A total of 33 subjects with diabetes were asked to wear 4 sensors in parallel, 2 on the arm and 2 on the abdomen. Sensors from a lot with low in vitro sensitivity coefficient of variation were used in the study. Based on frequent capillary blood glucose measurements, the average glucose sensitivity of each sensor was determined over a 5-day wear time. The in vivo sensitivities were analyzed for inter- and intrasubject variation. Mean absolute relative difference (MARD) calculation and consensus error grid analysis (EGA) were performed using a single calibration factor for all sensors, to simulate factory calibration and compared against conventional finger-stick calibration. RESULTS: The sensitivity coefficient of variation between sensors increased from 2.9% in vitro to 6.0% in vivo. No difference in sensor response between subjects (P = .069) as well as between insertion sites (arm and abdomen) was detected (P = .104). Applying one calibration factor to all sensors in the study resulted in an MARD of 13.4%, and 83.5% of the values fell in consensus EGA zone A. Multiple fingerstick calibration resulted in an MARD of 12.7% and 84.1% in zone A. CONCLUSIONS: Feasibility of factory calibration was demonstrated in subjects with diabetes using sensors based on "wired enzyme" technology, resulting in accuracy metrics similar to sensors calibrated with capillary blood glucose.

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