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1.
NeuroImmune Pharm Ther ; 3(1): 7-15, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38532784

RESUMO

Objectives: Cerebrovascular complications are prevalent in COVID-19 infection and post-COVID conditions; therefore, interactions of SARS-CoV-2 with cerebral microvascular cells became an emerging concern. Methods: We examined the inflammatory responses of human brain microvascular endothelial cells (HBMEC), the main structural element of the blood-brain barrier (BBB), following exposure to the S1 subunit of the spike protein of different SARS-CoV-2 variants. Specifically, we used the S1 subunit derived from the D614 variant of SARS-CoV-2, which started widely circulating in March of 2020, and from the Delta variant, which started widely circulating in early 2021. We then further examined the impact of the HBMEC secretome, produced in response to the S1 exposure, on microglial proinflammatory responses. Results: Treatment with S1 derived from the D614 variant and from the Delta variant resulted in differential alterations of the IL-6 signaling pathway. Moreover, the HBMEC secretome obtained after exposure to the S1 subunit of the D614 variant activated STAT3 in microglial cells, indicating that proinflammatory signals from endothelial cells can propagate to other cells of the neurovascular unit. Overall, these results indicate the potential for different SARS-CoV-2 variants to induce unique cellular signatures and warrant individualized treatment strategies. The findings from this study also bring further awareness to proinflammatory responses involving brain microvasculature in COVID-19 and demonstrate how the surrounding microglia react to each unique variant derived response.

2.
Appl Spectrosc ; 78(5): 456-476, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38439705

RESUMO

Here, Raman spectroscopy is used to develop a univariate partial least squares (PLS) calibration capable of quantifying geochemistry in synthetic and natural silicate glass samples. The calibration yields eight oxide-specific models that allow predictions of silicon dioxide (SiO2), sodium oxide (Na2O), potassium oxide (K2O), calcium oxide (CaO), titanium dioxide (TiO2), aluminum oxide (Al2O3), ferrous oxide (FeOT), and magnesium oxide (MgO) (wt%) in glasses spanning a wide range of compositions, while also providing correlation-coefficient matrices that highlight the importance of specific Raman channels in the regression of a particular oxide. The PLS suite is trained on 48 of the 69 total glasses, and tested against 21 validation samples (i.e., held out of training). Trends in root mean square error of calibration (RMSEC), root mean square error of cross-validation (RMSECV), and root mean square error of prediction (RMSEP) model accuracy metrics are investigated to uncover the efficacy of utilizing multivariate analysis for such Raman data and are contextualized against recently produced strategies. The technique yields an average root mean of calibration (∼2.4 wt%), cross-validation (∼ 2.9 wt%), prediction (∼ 2.6 wt%), and normalized variance (∼ 28%). Raman band positional shifts are also mapped against underlying chemical variations; with major influences arising primarily as a function of overall oxidation state and silica concentration: via ferric cation (Fe3+)/ferrous cation (Fe2+) ratios and SiO2 (wt%). The algorithm is further validated preliminarily against a separate external set of 11 natural basaltic glasses to unravel the limitations of the synthetic models on natural samples, and to determine the suitability of "universal" Raman-model applications in scenarios where prior chemical contextualization of the target sample is possible. This study represents the first time Raman spectra of amorphous silicates have been paired with PLS, offering a foundation for future improvements utilizing these systems.

3.
Clin Gastroenterol Hepatol ; 22(3): 642-652.e2, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37879520

RESUMO

BACKGROUND & AIMS: We describe the experience of Lynch syndrome (LS) diagnosis in the province of Manitoba, Canada, over the past 20 years. METHODS: We performed a retrospective review of charts from the provincial Genetics Clinic from January 1, 2000, to May 31, 2023. We extracted data on individuals identified to carry a germline pathogenic or likely pathogenic LS gene variant, the mode of ascertainment, family history, and cascade genetic testing (CGT). Data were stratified and compared before and after the year of implementation (October 2013) of the provincial LS screening program (LSSP) and ascertainment by the LSSP vs clinic referrals (CRs). RESULTS: Between 2014 and 2021, 50 of 101 (49.5%) index cases were identified by the LSSP compared with 51 of 101 (50.5%) from CRs. The proportion of PMS2 variants was 34% (17 of 50) for LSSP index cases compared with 21.6% (11 of 51) for CRs from 2014 to 2021 (P < .001). Among CRs from 2014 to 2021, 24 of 51 (47.1%) families met the Amsterdam criteria, compared with 11 of 50 (22.0%) for the LSSP (P = .01). CGT occurred among 46.8% (95 of 203; average, 1.9 relatives/index) of first-degree relatives of CR index cases vs 36.5% (84 of 230; average, 1.7 relatives/index) of first-degree relatives of LSSP index cases (P = .03). Daughters were most likely to undergo CGT. CONCLUSIONS: A tumor screening program is more effective at detecting individuals with lower penetrant gene variants and families who do not meet traditional family history-based criteria. Cascade genetic testing is higher among clinic referrals compared with the screening program. These findings suggest a complementary role of these 2 ascertainment methods for Lynch syndrome.


Assuntos
Neoplasias Colorretais Hereditárias sem Polipose , Humanos , Neoplasias Colorretais Hereditárias sem Polipose/diagnóstico , Neoplasias Colorretais Hereditárias sem Polipose/epidemiologia , Neoplasias Colorretais Hereditárias sem Polipose/genética , Manitoba/epidemiologia , Estudos Retrospectivos , Mutação em Linhagem Germinativa , Testes Genéticos/métodos , Reparo de Erro de Pareamento de DNA
4.
Curr Probl Cardiol ; 49(1 Pt C): 102179, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37923029

RESUMO

Gut microbiota, which comprises a broad range of bacteria inhabiting the human intestines, plays a crucial role in establishing a mutually beneficial relationship with the host body. Dysbiosis refers to the perturbations in the composition or functioning of the microbial community, which can result in a shift from a balanced microbiota to an impaired state. This alteration has the potential to contribute to the development of chronic systemic inflammation. Heart failure (HF) is a largely prevalent clinical condition that has been demonstrated to have variations in the gut microbiome, indicating a potential active involvement in the pathogenesis and advancement of the disease. The exploration of the complex interplay between the gut microbiome and HF presents a potential avenue for the discovery of innovative biomarkers, preventive measures, and therapeutic targets. This review aims to investigate the impact of gut bacteria on HF.


Assuntos
Microbioma Gastrointestinal , Insuficiência Cardíaca , Microbiota , Humanos , Insuficiência Cardíaca/terapia , Inflamação , Disbiose/complicações , Disbiose/microbiologia
5.
Dis Mon ; 69(5): 101557, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37031059

RESUMO

Dementia is a chronic progressive cognitive decline illness that results in functional impairment. Vascular dementia (VaD), second only to Alzheimer's disease (AD), is one of the most prevalent forms of dementia in the elderly (aged over 65 years), with a varied presentation and unpredictable disease development caused by cerebrovascular or cardiovascular illness. To get a better understanding of the changes occurring in the brain and to drive therapy efforts, new biomarkers for early and precise diagnosis of AD and VaD are required. In this review, Firstly, we describe the subtypes of vascular dementia, their clinical features, pathogenesis, genetics implemented, and their associated neuroimaging and biomarkers, while describing extensively the recent biomarkers discovered in the literature. Secondly, we describe some of the well-documented and other less-defined risk factors and their association and pathophysiology in relation to vascular dementia. Finally, we follow recent updates in the management of vascular dementia along with its association and differentiation from Alzheimer's disease. The aim of this review is to gather the scattered updates and the most recent changes in blood, CSF, and neuroimaging biomarkers related to the multiple subtypes of vascular dementia along with its association with Alzheimer's dementia and diabetes mellitus.


Assuntos
Doença de Alzheimer , Demência Vascular , Diabetes Mellitus , Idoso , Humanos , Doença de Alzheimer/complicações , Doença de Alzheimer/genética , Doença de Alzheimer/diagnóstico , Demência Vascular/terapia , Demência Vascular/complicações , Biomarcadores , Neuroimagem
6.
Dis Mon ; 69(5): 101545, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36925418

RESUMO

Frontotemporal Dementia, also known by the name Pick's disease, is a rare form of dementia that can run for several generations. The two key characteristics are argyrophilic, spherical intraneuronal inclusions, which most frequently impact the frontal and temporal poles, and localized cortical atrophy (Pick bodies). Although personality decline and memory loss are frequently more severe than the visuospatial and apraxia disorders that are common in Alzheimer's disease, clinical overlap with other non-Alzheimer degenerative disorders is being increasingly recognized. The limbic system, which includes the hippocampus, entorhinal cortex, and amygdala, typically experiences the greatest levels of neuronal loss and degeneration. In the hippocampus's dentate fascia, several Pick bodies are frequently seen. Leukoencephalopathy and inflated cortical neurons are less specific symptoms (Pick cells). In this paper, we review the factors leading to Picks disease along with its pathophysiology, clinical manifestations, diagnosis, imaging, treatment, prognosis, and a comprehensive discussion on the same. We have also discussed the relationship of frontotemporal dementia with glucose metabolism, bipolar disorder, and amyotrophic lateral sclerosis, all of which are emerging fields of interest and need more studies.


Assuntos
Esclerose Lateral Amiotrófica , Transtorno Bipolar , Demência Frontotemporal , Doença de Pick , Humanos , Demência Frontotemporal/diagnóstico , Demência Frontotemporal/genética , Esclerose Lateral Amiotrófica/diagnóstico , Esclerose Lateral Amiotrófica/genética , Transtorno Bipolar/diagnóstico , Transtorno Bipolar/genética , Encéfalo/diagnóstico por imagem , Glucose
7.
Cureus ; 14(10): e30028, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36348872

RESUMO

Emphysematous cystitis (EC) is a rare type of complicated urinary tract infection mostly seen in elderly females with diabetes, characterized by gas within the bladder lumen and wall. The presenting symptoms are variable, ranging from no symptoms to severe sepsis. The commonly isolated organisms in urine cultures are Escherichia coli and Klebsiella pneumoniae. Imaging studies, namely plain conventional abdominal radiography and computed tomography, are necessary to make a definitive diagnosis of EC. The management includes medical treatment with culture-guided antibiotics, whereas surgical intervention such as cystectomy is rarely required in severe cases. Here, we have a case of a 48-year-old diabetic female diagnosed with EC on radio imaging. The patient was aggressively treated with higher antibiotics such as piperacillin/tazobactam, clindamycin, and fosfomycin along with measures to control blood sugars. However, she developed severe sepsis and succumbed to death. Our report presents one of the rare cases of EC as a life-threatening complication in diabetics, suggesting that every case of urinary tract infection in uncontrolled diabetics should be thoroughly investigated and treated to prevent fatal complications.

8.
Cureus ; 14(9): e28786, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36225423

RESUMO

Sturge-Weber syndrome (SWS) is a rare sporadic neurocutaneous syndrome characterized by angiomas involving the face, eyes, and brain (leptomeninges). Classical port-wine stains are seen in the ophthalmic and maxillary division of the trigeminal nerve. The most common presenting feature is seizures, the onset of which ranges from birth to late adulthood. Diagnosis is mainly done by brain radio imaging (CT scan and MRI with gadolinium contrast) where characteristic features of calcification and leptomeningeal enhancement are seen. We report a newly diagnosed case of SWS in a 31-year-old female patient who presented to our hospital with a complaint of generalized tonic-clonic (GTCS) type of convulsion two days prior to the admission with purple discoloration of the skin on the right side of the face, trunk, and right upper limb since birth. During the evaluation of past medical history, the patient was found to have a known case of epilepsy since the age of three months and on was on irregular treatment. To find out the cause of the seizure and skin lesions, further investigations were done which were suggestive of SWS in MRI and CT scanning of the brain. The patient was counseled about the syndrome and discharged on anti-convulsion treatment with advice for dye laser photocoagulation for port-wine stain.  SWS is a rare sporadic genetic disease and diagnosis is primarily done by evaluating history, the presence of port-wine stain, and characteristic features on brain radio imaging. As no definitive treatment is available yet, patients are being treated by medical and surgical interventions for symptoms as well as for associated complications.

9.
Blood Purif ; 51(8): 649-659, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35468595

RESUMO

BACKGROUND: Pediatric sepsis is a significant public health issue. This condition is exacerbated by rising serum creatinine and inflammatory cytokines that lead to deleterious effects upon the body. The current standard of care involves the use of continuous kidney replacement therapy to remove harmful cytokines until the body returns to homeostasis. In order to promote faster clearance and reduced stay in the ICU, high-volume hemofiltration (HVHF) has shown promise. However, there is a paucity of studies to fully elucidate its benefits. METHODS: A literature search was done using PubMed/ MEDLINE and Embase. The literature was reviewed by two independent reviewers, who independently assessed the quality of randomized controlled trials by using the Cochrane risk of bias tool for RCTs and Newcastle-Ottawa Scale (NOS) for assessing the quality of nonrandomized controlled trials. Data were combined from studies with a similar design. RESULTS: The primary endpoint of all-cause mortality was found to be reduced by 40% across all of the pooled studies. For secondary endpoints, significant reductions of serum creatinine were found. Additionally, duration of ICU stays and treatment course was found to be significantly shorter in HVHF patients than the current standard of care. The rate of adverse effects was analyzed, and there was no difference in the proportion of patients developing hypokalemia, hyperkalemia, hypernatremia, or hyponatremia. The proportion of patients developing hyperglycemia was higher in patients undergoing HVHF, whereas the proportions of patients developing bleeding were significantly less in patients undergoing HVHF. One study reported a total number of adverse events between the two groups which were significantly lesser in patients undergoing HVHF. CONCLUSION: HVHF shows promise as a modality to treat pediatric patients with sepsis. In order to confirm the benefits of this modality, future studies need significantly more patients for analysis.


Assuntos
Hemofiltração , Sepse , Criança , Creatinina , Estado Terminal/terapia , Citocinas , Humanos , Sepse/terapia
10.
Laryngoscope ; 132(10): 1984-1992, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35191537

RESUMO

OBJECTIVES: Investigate outcomes following oral cavity and oropharyngeal salvage surgery. METHODS: Adult patients who underwent salvage surgery for recurrent squamous cell carcinoma of the oral cavity and oropharynx from 1996 to 2018 were analyzed using multivariable Cox proportional hazards regression. Disease-free survival (DFS), overall survival (OS), associated factors, and basic quality measures were analyzed. RESULTS: One hundred and eight patients (72% oral cavity, 28% oropharynx) were followed for a median of 17.9 months. Median DFS and OS were 9.9 and 21 months, respectively. Surgery with adjuvant chemoradiotherapy compared to surgery alone (hazard ratio [HR] = 0.15, 95% confidence interval [CI]: 0.03-0.78) and negative margins (HR = 0.36, 95% CI: 0.14-0.90) were associated with better DFS, while lymphovascular space invasion (LVSI) (HR = 2.66, 95% CI: 1.14-6.19) and higher stage (III vs. I-II, HR = 3.94, 95% CI: 1.22-12.71) were associated with worse DFS. Higher stage was associated with worse OS (HR = 3.79, 95% CI: 1.09-13.19). Patients were hospitalized for a median of 8 days with 24% readmitted within 30 days. A total of 72% and 38% of patients, respectively, underwent placement of a feeding tube or tracheostomy. CONCLUSIONS: After oral cavity and oropharyngeal salvage surgery, adjuvant chemoradiotherapy, negative margins, negative LVSI, and lower stage were associated with a lower risk of recurrence. Only lower-stage disease was associated with improved survival. The majority of patients had feeding tubes, half underwent free tissue transfer, a third required tracheostomy, and a quarter was readmitted. LEVEL OF EVIDENCE: 3 Laryngoscope, 132:1984-1992, 2022.


Assuntos
Neoplasias Orofaríngeas , Adulto , Humanos , Margens de Excisão , Boca/patologia , Recidiva Local de Neoplasia/cirurgia , Neoplasias Orofaríngeas/patologia , Neoplasias Orofaríngeas/cirurgia , Estudos Retrospectivos , Terapia de Salvação
11.
Analyst ; 146(20): 6288-6296, 2021 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-34549732

RESUMO

Increased acidification of aquatic habitats due to climate change is damaging mollusks. Non-destructive methods for analysis are necessary to study these endangered species. We analyzed five Unionidae gastropods using Raman spectroscopy. Shells were primarily composed of aragonite, a polymorph of calcium carbonate found in shell microstructure. Lattice mode Raman peaks from vaterite, a thought to be rare polymorph of calcium carbonate, were identified in each mollusk. Vaterite is present in mollusks at instances of shell damage and subsequent repair. We demonstrate that Raman spectroscopy is sensitive to vaterite, and it may not be as rare as previously thought. We also collected Raman spectra across the interior of Lampsillis fasciola. This data was analyzed through multivariate analysis, combining Principal Component Analysis with Linear Discriminant Analysis (PCA-LDA). Results of PCA-LDA correlate with growth of the mollusks, demonstrating that Raman spectroscopy combined with multivariate analysis could be used to monitor shell growth.


Assuntos
Moluscos , Análise Espectral Raman , Animais , Carbonato de Cálcio , Análise Discriminante , Água Doce , Análise de Componente Principal
12.
Nat Commun ; 12(1): 4722, 2021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34354059

RESUMO

Mutations in the LaminA gene are a common cause of monogenic dilated cardiomyopathy. Here we show that mice with a cardiomyocyte-specific Lmna deletion develop cardiac failure and die within 3-4 weeks after inducing the mutation. When the same Lmna mutations are induced in mice genetically deficient in the LINC complex protein SUN1, life is extended to more than one year. Disruption of SUN1's function is also accomplished by transducing and expressing a dominant-negative SUN1 miniprotein in Lmna deficient cardiomyocytes, using the cardiotrophic Adeno Associated Viral Vector 9. The SUN1 miniprotein disrupts binding between the endogenous LINC complex SUN and KASH domains, displacing the cardiomyocyte KASH complexes from the nuclear periphery, resulting in at least a fivefold extension in lifespan. Cardiomyocyte-specific expression of the SUN1 miniprotein prevents cardiomyopathy progression, potentially avoiding the necessity of developing a specific therapeutic tailored to treating each different LMNA cardiomyopathy-inducing mutation of which there are more than 450.


Assuntos
Cardiomiopatia Dilatada/genética , Lamina Tipo A/genética , Lamina Tipo A/metabolismo , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Animais , Cardiomiopatia Dilatada/patologia , Cardiomiopatia Dilatada/fisiopatologia , Dependovirus/genética , Feminino , Humanos , Lamina Tipo A/deficiência , Masculino , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Associadas aos Microtúbulos/deficiência , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Transdução Genética
14.
J Vis Exp ; (159)2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32420993

RESUMO

It has been shown that in vivo tissues are highly crowded by proteins, nucleic acids, ribonucleoproteins, polysaccharides, etc. The following protocol applies a macromolecular crowding (MMC) technique to mimic this physiological crowding through the addition of neutral polymers (crowders) to cell cultures in vitro. Previous studies using Ficoll or dextran as crowders demonstrate that the expression of collagen I and fibronectin in WI38 and WS-1 cell lines are significantly enhanced using the MMC technique. However, this technique has not been validated in primary hypertrophic scar-derived human skin fibroblasts (hHSFs). As hypertrophic scarring arises from the excessive deposition of collagen, this protocol aims to construct a collagen-rich in vitro hypertrophic scar model by applying the MMC technique with hHSFs. This optimized MMC model has been shown to possess more similarities with in vivo scar tissue compared to traditional 2-dimensional (2-D) cell culture systems. In addition, it is cost-effective, time-efficient, and ethically desirable compared to animal models. Therefore, the optimized model reported here offers an advanced "in vivo-like" model for hypertrophic scar-related studies.


Assuntos
Cicatriz Hipertrófica/patologia , Substâncias Macromoleculares/metabolismo , Modelos Biológicos , Animais , Células Cultivadas , Cicatriz Hipertrófica/genética , Colágeno Tipo I/metabolismo , Fibroblastos/metabolismo , Fibroblastos/patologia , Fibronectinas , Regulação da Expressão Gênica , Humanos , Pele/patologia
15.
Artigo em Inglês | MEDLINE | ID: mdl-32328468

RESUMO

Malassezia is the most abundant eukaryotic microbial genus on human skin. Similar to many human-residing fungi, Malassezia has high metabolic potential and secretes a plethora of hydrolytic enzymes that can potentially modify and structure the external skin environment. Here we show that the dominant secreted Malassezia protease isolated from cultured Malassezia furfur is an aspartyl protease that is secreted and active at all phases of culture growth. We observed that this protease, herein named as MfSAP1 (M. furfur secreted aspartyl protease 1) has a broader substrate cleavage profile and higher catalytic efficiency than the previously reported protease homolog in Malassezia globosa. We demonstrate that MfSAP1 is capable of degrading a wide range of human skin associated extracellular matrix (ECM) proteins and ECM isolated directly from keratinocytes and fibroblasts. Using a 3-D wound model with primary keratinocytes grown on human de-epidermized dermis, we show that MfSAP1 protease can potentially interfere with wound re-epithelization in an acute wound model. Taken together, our work demonstrates that Malassezia proteases have host-associated substrates and play important roles in cutaneous wound healing.


Assuntos
Ácido Aspártico Proteases , Malassezia , Matriz Extracelular , Humanos , Peptídeo Hidrolases , Pele
16.
Analyst ; 145(10): 3461-3480, 2020 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-32301450

RESUMO

Neuroscience would directly benefit from more effective detection techniques, leading to earlier diagnosis of disease. The specificity of Raman spectroscopy is unparalleled, given that a molecular fingerprint is attained for each species. It also allows for label-free detection with relatively inexpensive instrumentation, minimal sample preparation, and rapid sample analysis. This review summarizes Raman spectroscopy-based techniques that have been used to advance the field of neuroscience in recent years.


Assuntos
Diagnóstico por Imagem/métodos , Neurociências/métodos , Análise Espectral Raman/métodos , Humanos
17.
Analyst ; 145(5): 1885-1893, 2020 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-31971169

RESUMO

Detection techniques for neurotransmitters that are rapid, label-free, and non-invasive are needed to move towards earlier diagnosis of neurological disease. Surface-enhanced Raman spectroscopy (SERS) allows for sensitive and selective detection of target analytes. The combination of SERS with spatially offset Raman spectroscopy (SORS) in a technique termed surface enhanced spatially offset Raman spectroscopy (SESORS) permits a sensitive and selective detection of neurotransmitters through the skull. Here, we present the SESORS detection of individual neurotransmitters and mixtures of neurotransmitters at physiologically relevant concentrations, while also establishing limits of detection.


Assuntos
Encéfalo/metabolismo , Neurotransmissores/análise , Crânio , Animais , Ouro/química , Limite de Detecção , Masculino , Nanopartículas Metálicas/química , Camundongos Endogâmicos BALB C , Ratos , Análise Espectral Raman/métodos
18.
Anal Chem ; 92(2): 2052-2057, 2020 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-31874025

RESUMO

Cortisol is an important steroid hormone in human physiology. Variations or abnormalities in the physiological cortisol levels control acute and chronic stress response, as well as contribute to diseases and syndromes including Addison's disease and Cushing syndrome. The ability to monitor cortisol levels in the physiological range is key in diagnosis and monitoring of these conditions, where current methodology for determination of cortisol levels relies on instrumentation that requires extensive sample preparation, long run times, and is destructive to the sample. Raman spectroscopy provides rapid sample analysis with relatively simple instrumentation; however, Raman spectroscopy is an inherently weak technique. To provide an enhanced Raman signal, we use surface enhanced Raman spectroscopy (SERS) which utilizes oscillating electric fields of metal nanoparticles, enhancing the overall electric field and therefore resulting in an enhanced signal. We demonstrate SERS-based detection of cortisol in the physiologically relevant range using colloidal silver nanoparticles in ethanolic solutions and bovine serum albumin. The SERS spectra obtained in an ethanol matrix demonstrate a sigmoidal concentration response over the physiologically relevant concentration range, with a limit of detection established at 177 nM. Analysis of cortisol solutions in a complex matrix (bovine serum albumin in phosphate buffered saline) is also demonstrated through the use of principal components analysis, a multivariate technique, which shows the separation of cortisol in a linear fashion with respect to cortisol concentration.


Assuntos
Hidrocortisona/análise , Animais , Bovinos , Teoria da Densidade Funcional , Hidroxilamina/química , Nanopartículas Metálicas/química , Conformação Molecular , Soroalbumina Bovina/química , Prata/química , Análise Espectral Raman , Propriedades de Superfície
19.
Biosensors (Basel) ; 8(2)2018 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-29751641

RESUMO

For many disease states, positive outcomes are directly linked to early diagnosis, where therapeutic intervention would be most effective. Recently, trends in disease diagnosis have focused on the development of label-free sensing techniques that are sensitive to low analyte concentrations found in the physiological environment. Surface-enhanced Raman spectroscopy (SERS) is a powerful vibrational spectroscopy that allows for label-free, highly sensitive, and selective detection of analytes through the amplification of localized electric fields on the surface of a plasmonic material when excited with monochromatic light. This results in enhancement of the Raman scattering signal, which allows for the detection of low concentration analytes, giving rise to the use of SERS as a diagnostic tool for disease. Here, we present a review of recent developments in the field of in vivo and in vitro SERS biosensing for a range of disease states including neurological disease, diabetes, cardiovascular disease, cancer, and viral disease.


Assuntos
Técnicas Biossensoriais/métodos , Técnicas e Procedimentos Diagnósticos , Doença/etiologia , Análise Espectral Raman/métodos
20.
ACS Chem Neurosci ; 9(6): 1380-1387, 2018 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-29601719

RESUMO

The development of a sensor for the rapid and sensitive detection of neurotransmitters could provide a pathway for the diagnosis of neurological diseases, leading to the discovery of more effective treatment methods. We investigate the use of surface enhanced Raman spectroscopy (SERS) based sensors for the rapid detection of melatonin, serotonin, glutamate, dopamine, GABA, norepinephrine, and epinephrine. Previous studies have demonstrated SERS detection of neurotransmitters; however, there has been no comprehensive study on the effect of the metal used as the SERS substrate or the excitation wavelength used for detection. Here, we present the detection of 7 neurotransmitters using both silver and gold nanoparticles at excitation wavelengths of 532, 633, and 785 nm. Over the range of wavelengths investigated, the SERS enhancement on the silver and gold nanoparticles varies, with an average enhancement factor of 105-106. The maximum SERS enhancement occurs at an excitation wavelength of 785 nm for the gold nanoparticles and at 633 nm for the silver nanoparticles.


Assuntos
Dopamina/metabolismo , Neurotransmissores/metabolismo , Análise Espectral Raman , Propriedades de Superfície , Ácido Glutâmico/metabolismo , Ouro/química , Melatonina/metabolismo , Nanopartículas Metálicas/química , Prata/química , Análise Espectral Raman/métodos
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