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Background and Objectives. Distinct pressure curve differences exist between akinetic (A-LVA) and dyskinetic (D-LVA) aneurysms. In D-LVA, left ventricular (LV) ejection pressure decreases relative to the aneurysm size, whereas A-LVA does not impact pressure curves, indicating that the decrease in stroke volume (SV) and cardiac output is proportional to the size of dyskinesia. This study aimed to assess the frequency of A-LVA and D-LVA, determine aneurysm size parameters (volume and surface area), and evaluate predictive parameters using echocardiography in A-LVA and D-LVA. Furthermore, it aimed to compare individual echocardiographic parameters, according to ejection fraction (EF) and SV, with hemodynamic events shown in experimental models of A-LVA and D-LVA and their significance in everyday clinical practice. Materials and Methods. This clinical study included patients with post-infarction left ventricular aneurysm (LVA) admitted to the cardiovascular institute ''Dedinje", Serbia. Echocardiographic volume and surface area of LV and LVA were determined (by the area-length method) along with EF (by Simpson's method). Results. A-LVA was present in 62.9% of patients, while D-LVA was present in 37.1%. Patients with D-LVA had significantly higher systolic aneurysm volume (LVAVs) (94.07 ± 74.66 vs. 51.54 ± 53.09, p = 0.009), systolic aneurysm surface area (LVAAs) (23.22 ± 11.73 vs. 16.41 ± 8.58, p = 0.018), and end-systolic left ventricular surface areas (LVESA) (50.79 ± 13.33 vs. 42.76 ± 14.11, p = 0.045) compared to patients with A-LVA. The ratio of LVA volume to LV volume was higher in the D-LVA in systole (LVAVs/LVESV). The end-diastolic volume of LV (LVEDV) and end-systolic volume of LV (LVESV) did not significantly differ between D-LVA and A-LVA. EF (21.25 ± 11.92 vs. 28.18 ± 11.91, p = 0.044) was significantly lower among patients with D-LVA. Conclusions. Differentiating between A-LVA and D-LVA using echocardiography is crucial since D-LVA causes greater hemodynamic disturbances in LV function, and thus surgical resection of the aneurysm or LV reconstruction must have a positive effect regardless of myocardial revascularization surgery.
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Ecocardiografia , Aneurisma Cardíaco , Ventrículos do Coração , Volume Sistólico , Humanos , Masculino , Feminino , Aneurisma Cardíaco/fisiopatologia , Aneurisma Cardíaco/diagnóstico por imagem , Aneurisma Cardíaco/complicações , Ecocardiografia/métodos , Pessoa de Meia-Idade , Idoso , Volume Sistólico/fisiologia , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/fisiopatologiaRESUMO
DNA degradation in biological material needs to be better understood. Bloodstains on washed clothing are disturbed by washing procedures, sometimes transferred to other fabrics, often with latent bloodstains and usually with significantly degraded DNA. The samples (cotton fabric with bloodstains) are divided into six main groups, depending on the washing method regarding water temperature (95, 60, and 30 °C) and the detergent use. After completing the washing process, samples were stored for a certain period (1 day to 6 months) and subsequently analyzed. Analyses were performed using standard protocols and commercial kits to measure the remaining DNA quantity (concentration) and DNA degradation index in the processed samples. Our results revealed that the high washing temperature (60 and 95 °C) and the application of detergent have a synergic action on DNA degradation, while at 30 °C this effect is absent. Furthermore, the effect of detergent on accelerated DNA degradation is observed about a month after the washing. This delayed effect of detergent has no explanation in current literature data. To obtain optimal results from the bloodstains, we recommended that the period from the crime event and attempted cleaning by a perpetrator to the laboratory analysis should be less than 1 month.
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We present a case of a 42-year-old man who suffered an iatrogenic injury to his left circumflex (Cx) coronary artery after mitral valve (MV) repair surgery. After the patient suffered from myocardial infarction without ST-segment elevation following minimally invasive MV surgery, we performed repeated coronary angiography and optical coherence tomography (OCT), which revealed severe coronary stenosis of the dominant Cx caused by intramural hematoma. In addition, we proceeded with percutaneous coronary intervention and stent implantation.
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The application of organic coatings is a common way of protecting metal substrates against corrosion. To dry the coating faster, catalytic infrared radiation (IR) can be applied. This paper aims to assess the differences in the physical, chemical, and corrosion properties of primer coatings dried with catalytic infrared radiation, compared to the same coatings dried under atmospheric conditions. Corrosion properties were characterized using humidity and a salt spray chamber, as well as electrochemical impedance spectroscopy (EIS), preceded by open circuit potential (OCP) measurement. Pencil hardness, cross-cut, and pull-off adhesion tests were used to compare the properties of examined primers before and after testing in the corrosion acceleration chambers. The microstructure and distribution of chemical composition were studied by scanning electron microscope (SEM) with energy-dispersive X-ray spectroscopy (EDX) together with Fourier-transform infrared spectroscopy (FTIR). Phase transitions in the coating were determined by differential scanning calorimeter (DSC). Infrared-dried primers achieved a higher curing degree. Therefore, their mechanical and corrosion properties are superior when compared to the same coatings dried under atmospheric conditions.
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BACKGROUND: Some variations of the cerebral arterial circle (CAC) are associated with an increased risk for the development of various pathological conditions. This paper aimed to determine the prevalence of hypoplastic arteries of CAC and to emphasize the limited possibility of their visualization by computed tomography angiography (CTA). MATERIALS AND METHODS: The research was performed on 400 adult cadavers by macro- and microdissection of the cerebral arteries. Each case was photographed and the diameter of the arteries was measured digitally, by analyzing photographs of the bases of the brain in the ImageJ program. RESULTS: The largest prevalence of artery diameter <1mm (<0.6mm) in CAC had the posterior communicating artery (PCoA). PCoA on the left side was hypoplastic in 44.9% (11.4%) of cases, while the same artery on the right side was hypoplastic in 44.3% (6.6%) of cases. The posterior cerebral artery was hypoplastic on the left side in 3% (0.6%) and on the right side in 4.2% (0.6%) of cases. The anterior cerebral artery had a hypoplastic caliber only on the right side in 2.4% (0.6%) of the cases, while the internal carotid arteries did not have a diameter <1mm in any case. The anterior communicating artery showed the greatest variability in morphology. Studies on CTA describe the occurrence of aplasia in a statistically significantly higher percentage, and the occurrence of hypoplastic arteries in a statistically significantly lower percentage compared to studies on cadavers. CONCLUSIONS: Due to significant differences between cadaveric and radiological studies, it is necessary to analyze their results regarding arterial hypoplasia and aplasia separately. A diameter of less than 1 mm has been suggested as a criterion for arterial hypoplasia.
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Background and Objectives: There is a lack of data about the survival of patients after the implantation of sutureless relative to stented bioprostheses in middle-income settings. The objective of this study was to compare the survival of people with isolated severe aortic stenosis after the implantation of sutureless and stented bioprostheses in a tertiary referral center in Serbia. Materials and Methods: This retrospective cohort study included all people treated for isolated severe aortic stenosis with sutureless and stented bioprostheses from 1 January 2018 to 1 July 2021 at the Institute for Cardiovascular Diseases "Dedinje". Demographic, clinical, perioperative and postoperative data were extracted from the medical records. The follow-up lasted for a median of 2 years. Results: The study sample comprised a total of 238 people with a stented (conventional) bioprosthesis and 101 people with a sutureless bioprosthesis (Perceval). Over the follow-up, 13.9% of people who received the conventional and 10.9% of people who received the Perceval valve died (p = 0.400). No difference in the overall survival was observed (p = 0.797). The multivariate Cox proportional hazard model suggested that being older, having a higher preoperative EuroScore II, having a stroke over the follow-up period and having valve-related complications were independently associated with all-cause mortality over a median of 2 years after the bioprosthesis implantation. Conclusions: This research conducted in a middle-income country supports previous findings in high-income countries regarding the survival of people with sutureless and stented valves. Survival after bioprosthesis implantation should be monitored long-term to ensure optimum postoperative outcomes.
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Estenose da Valva Aórtica , Bioprótese , Implante de Prótese de Valva Cardíaca , Próteses Valvulares Cardíacas , Humanos , Valva Aórtica/cirurgia , Implante de Prótese de Valva Cardíaca/métodos , Próteses Valvulares Cardíacas/efeitos adversos , Estudos Retrospectivos , Resultado do Tratamento , Desenho de Prótese , Estenose da Valva Aórtica/cirurgiaRESUMO
Increasing attention is given to waterborne coatings for corrosion protection due to the lower ecological impact on the environment. It has been found that by using waterborne coatings, the emission of harmful volatile organic compounds (VOCs) is reduced by more than 50 g/L. However, they require longer drying time, their anti-corrosion performance is not as good as solvent-borne coatings and they still have not been developed for all corrosion environments. Another way to reduce VOCs is by using infrared (IR) drying technology. With catalytic infrared radiation, it is possible to cure all surfaces at notably reduced costs compared to traditional systems and in total respect for the environment, thanks to significant energy savings and minimal CO2 emissions. The aim of this paper was to evaluate corrosion protective properties of waterborne coatings which were dried with traditional and accelerated drying techniques, i.e., under atmospheric conditions and by using IR technology. Two different coating systems were applied, with and without Zn in the primer. To achieve this goal, the test samples were subjected to electrochemical, corrosion, and physical tests. It was shown that infrared technology does not affect the quality of the coating and it drastically reduces the intercoating interval. A coating system with zinc in the primer showed better overall protection properties after being subjected to impedance and salt spray testing, but generally, solvent-borne coatings still have higher durability than waterborne in extreme marine conditions according to recent research. Microstructure and porosity remained intact and the atomic force microscope confirmed that the flash-off was conducted correctly since there were no pinholes and blisters detected on the coating's surface. This study can serve as a foundation for further investigations of IC-dried waterborne coatings because there are not many at the moment.
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BACKGROUND: Anterior mitral leaflet prolapse repair is a highly effective procedure, but despite excellent operative results still has an inferior long-term durability when compared to posterior leaflet repair. METHODS: We analysed mitral repair durability in 74 consecutive patients operated for anterior leaflet prolapse between 2010 and 2021. Their pre- and postoperative clinical, echocardiographic data and repair durability as well, were compared with 74 randomly assigned posterior leaflet prolapse patients who underwent valve repair during the same period. RESULTS: While groups were of similar age, patients with anterior leaflet prolapse had an inferior preoperative status in terms of functional reserve, atrial fibrillation, operative risk, ejection fraction and had more dilated left heart chambers as well. 1, 5, and 10-year freedom from repair failure was 87.1 ± 4.6%, 79.8 ± 6.5% and 50.7 ± 12.5% in the anterior, and 98.5 ± 1.5% respectively in the posterior leaflet group. Atrial fibrilation (hazard ratio [HR] 5.365; 95%; confidence interval [CI] 1.093-26.324 p = .038) and left ventricle end-systolic diameter (HR 1.160 95%; CI 1.037-1.299 p = .010) independently predicted anterior leaflet repair failure. Receiver Operating Curve analysis established left ventricle end-systolic diameter ≤42 mm as a cut-off value associated with improved anterior leaflet repair durability. Accordingly, 10-year repair durability in a subset of patients, with preserved left ventricle end-systolic diameter (≤42 mm) was 86.4 ± 7.8%. CONCLUSION: Better long-term repair durability in patients with anterior mitral leaflet prolapse and preserved sinus rhytm and left-ventricle diameters justifies early reconstructive approach.
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Insuficiência da Valva Mitral , Prolapso da Valva Mitral , Ecocardiografia , Humanos , Valva Mitral/diagnóstico por imagem , Valva Mitral/cirurgia , Insuficiência da Valva Mitral/diagnóstico por imagem , Insuficiência da Valva Mitral/cirurgia , Prolapso da Valva Mitral/diagnóstico por imagem , Prolapso da Valva Mitral/cirurgia , Prolapso , Resultado do TratamentoRESUMO
Suicide is an act of intentionally causing one's own death. Every year, approximately 800,000 people commit suicide. The average suicide rate in Serbia is around 19 per 100,000 people, which puts Serbia in the upper half on the list of European countries. The aim of this study was to define the number of suicides committed in the 2001-2015 period in the Province of Vojvodina, the male to female ratio of suicides, the most commonly used method of execution, the proportion of complex suicide, and distribution of suicides according to age groups, seasons, and days of week. This study was conducted as a descriptive retrospective study in the Center for Forensic Medicine, Toxicology and Molecular Genetics, Clinical Center of Vojvodina, by examining autopsy medical records. All suicide cases were divided according to age, gender, method of execution, season of the year, and day of the week. For statistical analysis, χ2 test included in Statistical Package for the Social Sciences (SPSS) version 23.0 was used, where the value of p<0.05 was considered statistically significant. During the 2001-2015 period, in the Province of Vojvodina, suicide was committed by 2241 people, 1812 men and 429 women. The highest number of suicides was recorded in the 45-54 age group in men and in the ≥75 age group in women. The most commonly used method was hanging in both genders. The proportion of complex suicides was 0.4%. There was no statistically significant difference in the number of suicides committed in different seasons. The highest number of suicides was committed on Friday. This research suggests that there is a need for intensive work on the prevention of suicides, especially among males aged 45-54 and females older than 75, especially in certain months and days when the suicide rate is higher.
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Suicídio , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Estações do Ano , Sérvia/epidemiologia , IugosláviaRESUMO
Abstract Pseudoaneurysm of the ascending aorta (PAA) is a hazardous and potentially fatal cardiovascular disease. This condition is caused by the rupture of at least one layer of the vessel and contained by the remaining vascular layers or the surrounding mediastinal structures. We presented the surgical treatment of a patient with sepsis and large PAA and brachiocephalic trunk, which was compressing the brachiocephalic trunk leading to syncope.
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Humanos , Falso Aneurisma/cirurgia , Falso Aneurisma/diagnóstico por imagem , Sepse/complicações , Aorta/cirurgia , Tronco Braquiocefálico/cirurgia , Tronco Braquiocefálico/diagnóstico por imagemRESUMO
Hydrogen sulfide (H2 S) represents the third and the youngest member of the gaseous transmitters family. The dominant effect of H2 S on isolated vessels is vasodilation. As the mechanism of H2 S-induced relaxation in human vessels remains unclear, the present study aimed to investigate the effects of H2 S donor, sodium hydrosulfide (NaHS), on isolated human saphenous vein (HSV) and to determine the mechanism of action. Our results showed that NaHS (1 µM-3 mM) induced a concentration-dependent relaxation of endothelium-intact HSV rings pre-contracted by phenylephrine. Pre-treatment with L-NAME, ODQ and KT5823 significantly inhibited NaHS-induced relaxation, while indomethacin induced partial inhibition. Among K+ channel blockers, the combination of apamin and TRAM-34 significantly affected the relaxation produced by NaHS, while iberiotoxin and glibenclamide only reduced maximal relaxation of HSV. NaHS partially relaxed endothelium-intact rings pre-contracted by high K+ , as well as phenylephrine-contracted rings in the presence of nifedipine. Additionally, the incubation of HSV rings with NaHS increased NO production. These results demonstrate that NaHS produces the concentration- and endothelium-dependent relaxation of isolated HSV. Vasorelaxation to NaHS probably involves activation of NO/cGMP/PKG pathway and partially prostacyclin. In addition, different K+ channels subtypes, especially SKCa and IKCa , as well as BKCa and KATP channels in high concentrations of NaHS, probably participate in the NaHS-induced vasorelaxation.
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Sulfeto de Hidrogênio/farmacologia , Vasodilatadores/farmacologia , Relação Dose-Resposta a Droga , Humanos , Sulfeto de Hidrogênio/administração & dosagem , Canais de Potássio/metabolismo , Veia Safena/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos , Vasodilatadores/administração & dosagemRESUMO
Pseudoaneurysm of the ascending aorta (PAA) is a hazardous and potentially fatal cardiovascular disease. This condition is caused by the rupture of at least one layer of the vessel and contained by the remaining vascular layers or the surrounding mediastinal structures. We presented the surgical treatment of a patient with sepsis and large PAA and brachiocephalic trunk, which was compressing the brachiocephalic trunk leading to syncope.
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Falso Aneurisma , Sepse , Falso Aneurisma/diagnóstico por imagem , Falso Aneurisma/cirurgia , Aorta/cirurgia , Tronco Braquiocefálico/diagnóstico por imagem , Tronco Braquiocefálico/cirurgia , Humanos , Sepse/complicaçõesRESUMO
DNA analysts in forensic laboratories are engaged in analysing and sampling bloodstains from bloodstained items. Detailed and precise descriptions of bloodstains on items of interest are very important for bloodstain pattern analysis (BPA). DNA and BPA reports were examined from forensic laboratories in Serbia (N = 88). About 400 reports were observed from the past three years. First, we analysed descriptions of items (clothing and shoes) in DNA reports, and special attention was paid to descriptions of bloodstains. Subsequently, we estimated the value of descriptions of bloodstained items of interest in linking specific types of bloodstains to the obtained DNA profiles. Observed descriptions of bloodstained items in DNA reports are usually limited to phrases. A major problem exists in cases where several people were injured in the same bloodshed event. Connecting specific types of bloodstains to obtained DNA profiles is essential for the reconstruction of crime events. The complete analysis should therefore include detailed descriptions of all types of observed and sampled bloodstains. In DNA laboratories that are within a larger institute, it would be more appropriate and productive if BPA and DNA experts examined bloodstained items cooperatively. Moderately sized laboratories have a limited number of employees. So, in those DNA laboratories, it would be more appropriate to educate DNA analysts in the basic principles of BPA.
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Manchas de Sangue , Impressões Digitais de DNA , DNA/análise , Documentação/métodos , Medicina Legal/métodos , Vestuário , Humanos , Fotografação , Sérvia , Sapatos , Manejo de EspécimesRESUMO
Cardioprotective abilities of procyanidins, might, at least in part, attribute to their vasodilator properties. The present study was undertaken to assess the vasorelaxant effect of procyanidin B2 on isolated human saphenous vein (HSV) and its underlying mechanisms. Procyanidin B2 relaxed phenylephrine-induced contraction of HSV rings in concentration-dependent manner. The relaxation was dependent on the presence of endothelium and was strongly affected by l-NAME, hydroxocobalamin or ODQ, the inhibitors of NO/cGMP pathway. Indomethacin significantly affected only the relaxation produced by the highest concentrations of procyanidin B2. Apamin and TRAM-34 combination, in the presence of l-NAME and indomethacin, did not additionally decreased procyanidin B2-induced relaxation. In the presence of K+ channel blockers, relaxation induced by procyanidin B2 was partially attenuated by 4-aminopyridine, significantly inhibited by glibenclamide and almost abolished by iberiotoxin. Procyanidin B2 also relaxed the contractions induced by phenylephrine or caffeine in Ca2+-free solution. Finally, nifedipine slightly, while thapsigargin strongly antagonized HSV relaxation. Our results indicate that procyanidin B2 induces endothelium-dependent relaxation of HSV, which results primarily from stimulation of NO production, as well K+ channels opening, especially BKCa, and partially KATP and KV. Regulation of the intracellular Ca2+ release and inhibition of Ca2+ influx probably contribute to procyanidin B2-induced relaxation.
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Biflavonoides/farmacologia , Cardiotônicos , Catequina/farmacologia , Endotélio Vascular/efeitos dos fármacos , Proantocianidinas/farmacologia , Veia Safena/efeitos dos fármacos , Vasodilatadores , Canais de Cálcio/metabolismo , Relação Dose-Resposta a Droga , Humanos , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , Canais de Potássio/metabolismoRESUMO
Rapid multiplex cell surface marker analysis can expedite investigations in which large number of antigens need to be analyzed. Simultaneous analysis of multiple surface antigens at the same level of sensitivity is however limited in the current golden standard analysis method, flow cytometry. In this paper we introduce a surface plasmon resonance imaging (SPRi)-based technique for 44-plex parameter analysis using a single sample, in less than 20 min. We analyzed the expression on cells from five different cancer cell lines by SPRi on a 44-plex antibody array including 4 negative controls and compared the output with flow cytometry. The combined correlation of the markers that showed expression by flow cytometry was 0.76. The results demonstrate as a proof of principle that SPRi can be applied for rapid semi-quantitative multiplex cell surface marker analysis.
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Antígenos de Neoplasias/análise , Citometria de Fluxo/métodos , Ressonância de Plasmônio de Superfície/métodos , Humanos , Células MCF-7RESUMO
BACKGROUND AND AIMS: The purpose of this prospective randomized study was to compare the early and midterm outcomes of aortic valve replacement (AVR) through upper ministernotomy with conventional AVR through median sternotomy. METHODS: One hundred patients undergoing elective AVR were randomized into two groups: the M group (upper ministernotomy group, n = 50) and the C group (conventional sternotomy group, n = 50). The operative data, major adverse outcomes, and postoperative variables were compared between the two groups of patients. A cross-sectional follow-up was performed 24.9 ± 5.8 months after surgery. RESULTS: The aortic cross-clamp time and cardiopulmonary bypass time were significantly longer in the M group. Similar incidences of major cardiac, neurologic and renal complications were recorded in both groups. Two patients (4%) in the C group developed wound infections. The length of ICU stay was similar in both groups. The patients in the M group had a shorter hospital stay compared with the patients in the C group (7.6 ± 2 days vs 9.3 ± 4.8 days; P = 0.022). Follow-up revealed that the time period needed to reach full recovery was significantly shorter in the ministernotomy group (1.7 ± 1.2 months vs 2.8 ± 1.6 months; P = 0.001). Morbidity and mortality data did not differ between the two groups. CONCLUSIONS: There was no difference in the major outcomes between the patients who underwent upper ministernotomy and those who underwent full sternotomy. The benefits of the minimally invasive approach were the shorter hospital stay and significantly faster recovery of patients after discharge from the hospital.
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Valva Aórtica/cirurgia , Implante de Prótese de Valva Cardíaca/métodos , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Esternotomia/métodos , Idoso , Ponte Cardiopulmonar , Constrição , Estudos Transversais , Feminino , Seguimentos , Humanos , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Estudos Prospectivos , Recuperação de Função Fisiológica , Fatores de Tempo , Resultado do TratamentoRESUMO
SPR cytometry entails the measurement of parameters from intact cells using the surface plasmon resonance (SPR) phenomenon. Specific real-time and label-free binding of living cells to sensor surfaces has been made possible through the availability of SPR imaging (SPRi) instruments and researchers have started to explore its potential in the last decade. Here we will discuss the mechanisms of detection and additionally describe the problems and issues of mammalian cells in SPR biosensing, both from our own experience and with information from the literature. Finally, we build on the knowledge and applications that has already materialized in this field to give a forecast of some exciting applications for SPRi cytometry.
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Técnicas Biossensoriais/métodos , Ressonância de Plasmônio de Superfície/métodosRESUMO
There is a large unmet need for reliable biomarker measurement systems for clinical application. Such systems should meet challenging requirements for large scale use, including a large dynamic detection range, multiplexing capacity, and both high specificity and sensitivity. More importantly, these requirements need to apply to complex biological samples, which require extensive quality control. In this paper, we present the development of an enhancement detection cascade for surface plasmon resonance imaging (SPRi). The cascade applies an antibody sandwich assay, followed by neutravidin and a gold nanoparticle enhancement for quantitative biomarker measurements in small volumes of complex fluids. We present a feasibility study both in simple buffers and in spiked equine synovial fluid with four cytokines, IL-1ß, IL-6, IFN-γ, and TNF-α. Our enhancement cascade leads to an antibody dependent improvement in sensitivity up to 40â¯000 times, resulting in a limit of detection as low as 50 fg/mL and a dynamic detection range of more than 7 logs. Additionally, measurements at these low concentrations are highly reliable with intra- and interassay CVs between 2% and 20%. We subsequently showed this assay is suitable for multiplex measurements with good specificity and limited cross-reactivity. Moreover, we demonstrated robust detection of IL-6 and IL-1ß in spiked undiluted equine synovial fluid with small variation compared to buffer controls. In addition, the availability of real time measurements provides extensive quality control opportunities, essential for clinical applications. Therefore, we consider this method is suitable for broad application in SPRi for multiplex biomarker detection in both research and clinical settings.
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Citocinas/análise , Nanopartículas/química , Ressonância de Plasmônio de Superfície , Líquido Sinovial/química , Animais , Biomarcadores/análise , Cavalos , HumanosRESUMO
In this study, we aimed to investigate relaxant effect of flavanol (-)-epicatechin on the isolated human saphenous vein (HSV), as a part of its cardioprotective action, and to define the mechanisms underlying this vasorelaxation. (-)-Epicatechin induced a concentration-dependent relaxation of HSV pre-contracted by phenylephrine. Among K+ channel blockers, 4-aminopyridine, margatoxin, and iberiotoxin significantly inhibited relaxation of HSV, while glibenclamide considerably reduced effects of the high concentrations of (-)-epicatechin. Additionally, (-)-epicatechin relaxed contraction induced by 80 mM K+ , whereas in the presence of nifedipine produced partial relaxation of HSV rings pre-contracted by phenylephrine. In Ca2+ -free solution, (-)-epicatechin relaxed contraction induced by phenylephrine, but had no effect on contraction induced by caffeine. A sarcoplasmic reticulum Ca2+ -ATPase inhibitor, thapsigargin, significantly reduced relaxation of HSV produced by (-)-epicatechin. These results demonstrate that (-)-epicatechin produces endothelium-independent relaxation of isolated HSV rings. Vasorelaxation to (-)-epicatechin probably involves activation of 4-aminopyridine- and margatoxin-sensitive KV channels, BKCa channels, and at least partly, KATP channels. In addition, not only the inhibition of extracellular Ca2+ influx, but regulation of the intracellular Ca2+ release, via inositol-trisphosphate receptors and reuptake into sarcoplasmic reticulum, via stimulation of Ca2+ -ATPase, as well, most likely participate in (-)-epicatechin-induced relaxation of HSV.
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Canais de Cálcio/química , Catequina/uso terapêutico , Canais de Potássio/química , Veia Safena/efeitos dos fármacos , Catequina/farmacologia , Feminino , Humanos , Masculino , Vasodilatadores/farmacologiaRESUMO
BACKGROUND: Identification, enumeration, and characterization of extracellular vesicles (EVs) are hampered by the small size of EVs, a low refractive index, and low numbers of antigens on their surface. METHODS: We investigated the potential of a 48-multiplex surface plasmon resonance imaging (SPRi) system to perform EV phenotyping. Antigen surface density of 11 antigens was measured on the human breast cancer cell lines HS578T, MCF7, and SKBR3 and their EVs by use of both SPRi and the widely used flow cytometry (FCM). RESULTS: For cells, the SPRi and FCM signals for antigen exposure correlated (RHS578T cells2 = 0.66, RMCF7 cells2 = 0.78, RSKBR3 cells2 = 0.60). With regard to EVs, SPRi detected 31 out of 33 tested antibody-EV pairs, whereas our flow cytometer detected 5 antibody-EV pairs because of high blank and isotype control signals. For HS578T-derived EVs, the SPRi and FCM signals correlated (R2HS578T EVs = 0.98). However, on MCF7- and SKBR3-derived EVs, insufficient antigens were detected by our flow cytometer. To confirm that the SPRi responses correlated with mean antigen density on EVs, the SPRi responses of EVs were correlated with antigen density on parental cells as measured by FCM (RHS578T2 = 0.77, RMCF72 = 0.49, RSKBR32 = 0.52). CONCLUSIONS: SPRi responses correlate with mean antigen density. Moreover, SPRi detects lower antigen-exposure levels than FCM because SPRi measures an ensemble of EVs binding to the sensor surface, whereas FCM detects antigens of single EV.