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1.
Microb Pathog ; 187: 106499, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38097117

RESUMO

Antimicrobial resistance arises over time, usually due to genetic modifications. Global observations of high resistance rates to popular antibiotics used to treat common bacterial diseases, such as diarrhea, STIs, sepsis, and urinary tract infections, indicate that our supply of effective antibiotics is running low. The mechanisms of action of several antibiotic groups are covered in this review. Antimicrobials disrupt the development and metabolism of bacteria, leading to their eventual death. However, in recent years, microorganisms become resistant to the drugs. Bacteria encode resistant genes against antibiotics and inhibit the function of antibiotics by reducing the uptake of drugs, modifying the enzyme's active site, synthesizing enzymes to degrade antibiotics, and changing the structure of ribosomal subunits. Additionally, the methods of action of resistant bacteria against different kinds of antibiotics as well as their modes of action are discussed. Besides, the resistant pathogenic bacteria which get the most priority by World Health Organisation (WHO) for synthesizing new drugs, have also been incorporated. To overcome antimicrobial resistance, nanomaterials are used to increase the efficacy of antimicrobial drugs. Metallic, inorganic, and polymer-based nanoparticles once conjugated with antibacterial drugs, exhibit synergistic effects by increasing the efficacy of the drugs by inhibiting bacterial growth. Nanomaterial's toxic properties are proportional to their concentrations. Higher concentration nanomaterials are more toxic to the cells. In this review, the toxic properties of nanomaterials on lung cells, lymph nodes, and neuronal cells are also summarized.


Assuntos
Anti-Infecciosos , Infecções Bacterianas , Nanopartículas , Humanos , Antibacterianos/química , Bactérias , Anti-Infecciosos/farmacologia , Infecções Bacterianas/tratamento farmacológico
2.
Anal Biochem ; 687: 115412, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38040173

RESUMO

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders affecting many women of reproductive age all over the world. PCOS is associated with the onset of enduring health complications, notably diabetes and cardiovascular diseases. Furthermore, PCOS escalates the propensity for conditions such as obesity, insulin resistance, and dyslipidemia, which can potentially culminate in life-threatening scenarios. A pervasive predicament surrounding PCOS pertains to its underdiagnosis due to discrepancies in diagnostic criteria and the intricacy of available testing methodologies. Consequently, many women encounter substantial delays in diagnosis with traditional diagnostic approaches. Prompt identification is imperative, as any delay can precipitate severe consequences. The conventional techniques employed for PCOS detection typically suffer from suboptimal accuracy, protracted assay times, and inherent limitations, thereby constraining their widespread applicability and accessibility. In response to these challenges, various electrochemical methods leveraging nanotechnology have been documented. In this concise review, we endeavor to delineate the deficiencies associated with established conventional methodologies while accentuating the distinctive attributes and benefits inherent to contemporary biosensors. We place particular emphasis on elucidating the pivotal advancements and recent breakthroughs in the realm of nanotechnology-facilitated biosensors for the detection of PCOS.


Assuntos
Diabetes Mellitus Tipo 2 , Resistência à Insulina , Síndrome do Ovário Policístico , Feminino , Humanos , Síndrome do Ovário Policístico/diagnóstico , Síndrome do Ovário Policístico/complicações , Resistência à Insulina/fisiologia , Obesidade/complicações
3.
Bioorg Chem ; 145: 107151, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38359706

RESUMO

Antimicrobial peptides (AMPs) are a group of polypeptide chains that have the property to target and kill a myriad of microbial organisms including viruses, bacteria, protists, etc. The first discovered AMP was named gramicidin, an extract of aerobic soil bacteria. Further studies discovered that these peptides are present not only in prokaryotes but in eukaryotes as well. They play a vital role in human innate immunity and wound repair. Consequently, they have maintained a high level of intrigue among scientists in the field of immunology, especially so with the rise of antibiotic-resistant pathogens decreasing the reliability of antibiotics in healthcare. While AMPs have promising potential to substitute for common antibiotics, their use as effective replacements is barred by certain limitations. First, they have the potential to be cytotoxic to human cells. Second, they are unstable in the blood due to action by various proteolytic agents and ions that cause their degradation. This review provides an overview of the mechanism of AMPs, their limitations, and developments in recent years that provide techniques to overcome those limitations. We also discuss the advantages and drawbacks of AMPs as a replacement for antibiotics as compared to other alternatives such as synthetically modified bacteriophages, traditional medicine, and probiotics.


Assuntos
Peptídeos Catiônicos Antimicrobianos , Peptídeos Antimicrobianos , Humanos , Peptídeos Catiônicos Antimicrobianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/uso terapêutico , Peptídeos Catiônicos Antimicrobianos/química , Reprodutibilidade dos Testes , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Antibacterianos/química , Bactérias
4.
Anal Biochem ; 663: 115015, 2023 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-36496002

RESUMO

A DNA-based electrochemical biosensor has been developed herein for the detection of Human papillomavirus-16 (HPV-16). HPV-16 is a double-stranded, non-enveloped, epitheliotropic DNA virus which responsible for cervical cancer. In this proposed biosensor, an indium tin oxide (ITO) coated glass electrode was modified for sensing HPV-16 using graphene oxide and silver coated gold nanoparticles. Subsequently, HPV-16 specific DNA probes were immobilized on a modified ITO surface. The synthesized nanocomposites were characterized by FE-SEM and UV-VIS spectroscopy techniques. Electrochemical characterization was performed by using cyclic voltammetry and electrochemical Impedance Spectroscopy methods. The hybridization between the probe and target DNA was analyzed by a reduction in current, mediated by methylene blue. The biosensor showed a qualitative inequity between the probe and target HPV-16 DNA. The developed biosensor showed high sensitivity as 0.54 mA/aM for the detection of HPV-16. In a linear range of 100 aM to 1 µM with 100 aM LOD, the proposed biosensor exhibited excellent performance with the rapid diagnosis. Thus, the results indicate that the developed HPV DNA biosensor shows good consistency with the present approaches and opens new opportunities for developing point-of-care devices. The diagnosis of HPV-16 infection in its early stage may also be possible with this detection system.


Assuntos
Técnicas Biossensoriais , Grafite , Nanopartículas Metálicas , Humanos , Papillomavirus Humano 16/genética , Papillomavirus Humano , Ouro/química , Nanopartículas Metálicas/química , DNA/química , Grafite/química , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Eletrodos
5.
J Med Virol ; 94(1): 99-109, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34570905

RESUMO

A severe pandemic of Coronavirus Disease (COVID-19) has been sweeping the globe since 2019, and this time, it did not stop, with frequent mutations transforming into virulent strains, for instance, B.1.1.7, B.1.351, and B.1.427. In recent months, a fungal infection, mucormycosis has emerged with more fatal responses and significantly increased mortality rate. To measure the severity and potential alternative approaches against black fungus coinfection in COVID-19 patients, PubMed, Google Scholar, World Health Organization (WHO) newsletters, and other online resources, based on the cases reported and retrospective observational analysis were searched from the years 2015-2021. The studies reporting mucormycosis with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) coinfection and/or demonstrating potential risk factors, such as a history of diabetes mellitus or suppressed immune system were included, and reports published in non-English language were excluded. More than 20 case reports and observational studies on black fungus coinfection in COVID-19 patients were eligible for inclusion. The results indicated that diabetes mellitus, hyperglycemic, and immunocompromised COVID-19 patients with mucormycosis were at a higher risk. We found that it was prudent to assess the potential risk factors and severity of invasive mycosis via standardized diagnostic and clinical settings. Large-scale studies need to be conducted to identify early biomarkers and optimization of diagnostic methods has to be established per population and geographical variation. This will not only help clinicians around the world to detect the coinfection in time but also will prepare them for future outbreaks of other potential pandemics.


Assuntos
COVID-19/epidemiologia , Coinfecção/epidemiologia , Mucormicose/epidemiologia , Mucormicose/mortalidade , SARS-CoV-2/isolamento & purificação , Diabetes Mellitus/patologia , Humanos , Hiperglicemia/patologia , Hospedeiro Imunocomprometido/fisiologia , Mucorales/crescimento & desenvolvimento , Mucorales/isolamento & purificação , Mucormicose/patologia , Estudos Retrospectivos , Fatores de Risco
6.
J Med Virol ; 93(4): 1967-1982, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33270225

RESUMO

The year 2020 started with the emergence of novel coronavirus, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which causes COVID-19 infection. Soon after the first evidence was reported in Wuhan, China, the World Health Organization declared global public health emergency and imminent need to understand the pathogenicity of the virus was required in limited time. Once the genome sequence of the virus was delineated, scientists across the world started working on the development of vaccines. Although, some laboratories have been using previously developed vaccine platforms from severe acute respiratory syndrome coronavirus (SARS) and middle east respiratory syndrome-related coronavirus and apply them in COVID-19 vaccines due to genetic similarities between coronaviruses. We have conducted a literature review to assess the background and current status of COVID-19 vaccines. The worldwide implementation and strategies for COVID-19 vaccine development are summarized from studies reported in years 2015-2020. While discussing the vaccine candidates, we have also explained interpretative immune responses of SARS-CoV-2 infection. There are several vaccine candidates at preclinical and clinical stages; however, only 42 vaccines are under clinical trials. Therefore, more industry collaborations and financial supports to COVID-19 studies are needed for mass-scale vaccine development. To develop effective vaccine platforms against SARS-CoV-2, the genetic resemblance with other coronaviruses are being evaluated which may further promote fast-track trials on previously developed SARS-CoV vaccines.


Assuntos
Vacinas contra COVID-19 , COVID-19/prevenção & controle , Humanos , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Vacinas de DNA , Vacinas de Produtos Inativados , Vacinas Vivas não Atenuadas , Vacinas de Subunidades Antigênicas
7.
Anal Biochem ; 630: 114325, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34352253

RESUMO

Invasive as well as non-invasive conventional techniques for the detection of Helicobacter pylori (H. pylori) have several limitations that are being overcome by the development of novel, rapid and reliable biosensors. Herein, we describe several biosensors fabricated for the detection of H. pylori. This review aims to provide the principles of biosensors and their components including in the context to H. pylori detection. The major biorecognition elements in H. pylori detection include antigen/antibodies, oligonucleotides and enzymes. Furthermore, the review describes the transducers, such as electrochemical, optical and piezoelectric, also including microfluidics approaches. An overview of the biomarkers associated with H. pylori pathogenesis is also discussed. Finally, the prospects of advancement and commercialization of point-of-care tools are summarized.


Assuntos
Técnicas Biossensoriais , Helicobacter pylori/isolamento & purificação , Sistemas Automatizados de Assistência Junto ao Leito , Humanos
8.
Helicobacter ; 26(3): e12796, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33666321

RESUMO

BACKGROUND: Gastric cancer is the third leading cause of cancer-related deaths worldwide. Approximately 70% of cases are caused by a microaerophilic gram-negative bacteria, Helicobacter pylori (H. pylori), which potentially infect almost 50% of world's population. H. pylori is mainly responsible for persistent oxidative stress in stomach and induction of chronic immune responses which ultimately result into DNA damage that eventually can lead to gastric cancer. Oxidative stress is the result of excessive release of ROS/RNS by activated neutrophils whereas bacteria itself also produce ROS in host cells. Therefore, ROS detection is an important factor for development of new strategies related to identification of H. pylori infection. METHODS: The review summarizes the various available techniques for ROS detection with their advantages, disadvantages, and limitations. All of the information included in this review have been retrieved from published studies on ROS generation and its detection methods. RESULTS: Precisely, 71 articles have been incorporated and evaluated for this review. The studied articles were divided into two major categories including articles on H. pylori-related pathogenesis and various ROS detection methods for example probe-based methods, immunoassays, gene expression profiling, and other techniques. The major part of probe activity is based on fluorescence, chemiluminescence, or bioluminescence and detected by complementary techniques such as LC-MS, HPLC, EPR, and redox blotting. CONCLUSION: The review describes the methods for ROS detection but due to some limitations in conventional methods, there is a need of cost-effective, early and fast detection methods like biosensors to diagnose the infection at its initial stage.


Assuntos
Infecções por Helicobacter , Estresse Oxidativo , Espécies Reativas de Oxigênio , Mucosa Gástrica/metabolismo , Mucosa Gástrica/microbiologia , Infecções por Helicobacter/diagnóstico , Infecções por Helicobacter/metabolismo , Helicobacter pylori , Humanos , Espécies Reativas de Oxigênio/análise , Espécies Reativas de Oxigênio/metabolismo , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/microbiologia
9.
Bioprocess Biosyst Eng ; 44(12): 2469-2479, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34386846

RESUMO

Cefepime and Meropenem are the new class of antibiotics, which are particularly used as last potent defender or the antibiotics of the last resort against multi-resistant bacterial species. In this paper, an impedance-based electrochemical biosensor was fabricated for identifying antibiotics of last resort in the forensic samples including gastric lavage and other body fluids. The sensor was developed using platinum nanoparticles (PtNPs) and electrodeposited zinc oxide- zinc hexacyanoferrate hybrid film (ZnO/ZnHCF) on the surface of a fluorine-doped glass electrode (FTO). Further, penicillinase was immobilized onto the modified electrode using penicillinase enzyme. The developed biosensor exhibits a good analytical response for the detection of antibiotics evaluated using electrochemistry studies. The linear response of the fabricated electrode was observed from 0.1 to 750 µM and the electrode limit of detection (LOD) was observed as 0.1 µM. The sensor confirms good accuracy, is highly selective, and sensitive for the target. While storing the modified electrode at 4 °C, the stability of biosensor was evaluated for 45 days, and activity loss of 30-40% was observed. The highly sensitive interface of Penicillinase@CHIT/PtNP-ZnO/ZnHCF/FTO electrode shows a promising future in forensic studies.


Assuntos
Antibacterianos/análise , Eletrodos , Ferrocianetos/química , Flúor/química , Nanopartículas Metálicas/química , Penicilinase/química , Platina/química , Óxido de Zinco/química , Cefepima/análise , Enzimas Imobilizadas/química , Limite de Detecção
10.
J Clin Psychopharmacol ; 40(1): 18-29, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31804452

RESUMO

BACKGROUND: Attitudes toward medication treatment are thought to significantly influence adherence in bipolar disorder (BD) and schizophrenia. However, the actual impact of patients' treatment attitudes on adherence and determinants of attitudes is still uncertain. METHODS: A longitudinal examination of treatment attitudes and their correlates was conducted among patients with BD and their caregivers compared with those with schizophrenia. Structured assessments of symptom severity, functioning, insight, medication side effects, knowledge of illness, medication adherence, treatment attitudes, and treatment satisfaction were performed among 176 selected patients (106 with BD and 70 with schizophrenia) and their caregivers. Participants were reassessed on these parameters at 3 and 6 months. RESULTS: Rates of nonadherence at baseline varied widely between self-reports, clinician ratings, and serum levels. Though symptoms and functioning improved with treatment, overall rates of nonadherence increased in the first 3 months because of early dropouts and remained stable thereafter. However, treatment attitudes and treatment satisfaction remained largely unchanged among patients and caregivers. Both positive and negative attitudes were commonly held and patients' attitudes did not differ between BD and schizophrenia. Patients' attitudes were significantly associated with adherence, insight, knowledge about illness, treatment satisfaction, symptom severity, social disadvantage, and side effects together with caregivers' knowledge, attitudes, and satisfaction. Caregivers of patients with schizophrenia were more knowledgeable and had more positive attitudes than patients. CONCLUSIONS: Patients' attitudes to medication treatment are associated with adherence over time. They are relatively enduring and mainly associated with insight, knowledge of illness, and treatment satisfaction among patients and their caregivers. These findings could inform psychosocial interventions aiming to improve treatment attitudes and adherence in BD and schizophrenia.


Assuntos
Antimaníacos/uso terapêutico , Antipsicóticos/uso terapêutico , Transtorno Bipolar/tratamento farmacológico , Cuidadores/psicologia , Conhecimentos, Atitudes e Prática em Saúde , Adesão à Medicação , Pacientes/psicologia , Esquizofrenia/tratamento farmacológico , Adolescente , Adulto , Idoso , Antimaníacos/efeitos adversos , Antipsicóticos/efeitos adversos , Transtorno Bipolar/diagnóstico , Transtorno Bipolar/psicologia , Feminino , Humanos , Índia , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Esquizofrenia/diagnóstico , Psicologia do Esquizofrênico , Índice de Gravidade de Doença , Fatores Socioeconômicos , Fatores de Tempo , Adulto Jovem
11.
Helicobacter ; 25(4): e12706, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32468682

RESUMO

BACKGROUND: Helicobacter pylori (H pylori) is gram-negative, spiral, and microaerophilic bacteria which can survive in ~2%-10% oxygen level. It was reported to populate in human gastric mucosa and leads to gastric cancer without any age or gender difference. MATERIALS AND METHODS: In this study, we are targeting label-free electrochemical immunosensor development for rapid H pylori detection after covalently immobilizing the antibody (CagA) over the nanomaterials modified Au electrode. Titanium oxide nanoparticles (TiO2 NPs), carboxylated multi-walled carbon nanotubes (c-MWCNT), and conducting polymer polyindole carboxylic acid (Pin5COOH) composites (TiO2 NPs/c-MWCNT/Pin5COOH) were synthesized and further utilized in immunosensor development as an electrochemical interface onto Au electrode. The stepwise modifications of CagAantibody/TiO2 NPs/c-MWNCT/Pin5COOH/Au electrode were electrochemically studied. RESULTS: Possessing the unique features of advanced materials, the proposed immunosensor reported low sensing limit of 0.1 ng/mL in dynamic linear range of 0.1-8.0 ng/mL with higher stability and reproducibility. Furthermore, developed sensor-based determination of H pylori in five human stool specimens has shown good results with suitable accuracy. CONCLUSIONS: This work lays strong foundation toward developing nanotechnology-enabled electrochemical sensor for ultrasensitive and early detection of H pylori in noninvasively collected clinical samples.


Assuntos
Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Técnicas Bacteriológicas/métodos , Infecções por Helicobacter/diagnóstico , Helicobacter pylori/isolamento & purificação , Imunoensaio/métodos , Nanoestruturas/química , Anticorpos Imobilizados/química , Anticorpos Imobilizados/imunologia , Técnicas Eletroquímicas , Eletrodos , Fezes/microbiologia , Helicobacter pylori/imunologia , Humanos , Nanopartículas Metálicas/química , Nanotubos de Carbono/química , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Titânio/química
12.
Helicobacter ; 24(1): e12544, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30324717

RESUMO

BACKGROUND: Helicobacter pylori, gastric cancer-causing bacteria, survive in their gastric environment of more than 50% of the world population. The presence of H. pylori in the gastric vicinity promotes the development of various diseases including peptic ulcer and gastric carcinoma. H. pylori produce and secret Vacuolating cytotoxin A (VacA), a major toxin facilitating the bacteria against the host defense system. The toxin causes multiple effects in epithelial cells and immune cells, especially T cells, B cells, and Macrophages. METHODS: This review describes the diverse functionalities of protein toxin VacA. The specific objective of this review is to address the overall structure, mechanism, and functions of VacA in various cell types. The recent advancements are summarized and discussed and thus conclusion is drawn based on the overall reported evidences. RESULTS: The searched articles on H. pylori VacA were evaluated and limited up to 66 articles for this review. The articles were divided into four major categories including articles on vacA gene, VacA toxin, distinct effects of VacA toxin, and their effects on various cells. Based on these studies, the review article was prepared. CONCLUSIONS: This review describes an overview of how VacA is secreted by H. pylori and contributes to colonization and virulence in multiple ways by affecting epithelial cells, T cells, Dendritic cells, B cells, and Macrophages. The reported evidence suggests that the comprehensive outlook need to be developed for understanding distinctive functionalities of VacA.


Assuntos
Proteínas de Bactérias/metabolismo , Toxinas Bacterianas/metabolismo , Citotoxinas/metabolismo , Helicobacter pylori/química , Helicobacter pylori/patogenicidade , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Toxinas Bacterianas/química , Toxinas Bacterianas/genética , Citotoxinas/química , Citotoxinas/genética , Células Epiteliais , Helicobacter pylori/crescimento & desenvolvimento , Humanos , Linfócitos , Macrófagos , Vacúolos/metabolismo , Virulência
13.
Anal Biochem ; 547: 19-25, 2018 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-29452104

RESUMO

Copper oxide nanoparticles (nano CuO) provide Cu2+ ions which can be easily harnessed for protein determination as an alternative to the use of copper sulfate (CuSO4). In the present work, nano CuO of size <25 nm were substituted for CuSO4 in two of the well-known protein assays viz. Lowry method and bicinchoninic acid (BCA) method. Use of nano CuO in the Lowry's assay had no effect on the assay time (30 min) but significantly lowered the limit of detection (LOD) from 0.01 to 0.001 µg/ml, while the BCA method when performed using nano CuO resulted in notable reduction of not only the assay time from 30 to 20 min but also the LOD from 0.1 to 0.001 µg/ml. Nano CuO based protein determination in the human serum and urd bean seeds extract produced reliable, reproducible and consistent results. Nano CuO also alleviated the inhibition of both the methods by common interfering substances such as ammonium sulfate, glucose, EDTA, SDS, Triton X-100, dithiothreitol and 2-mercaptoethanol. Hence, successful modification and improvement of Lowry and BCA methods by substitution of CuSO4 with nano CuO for protein determination has been demonstrated.


Assuntos
Sulfato de Cobre/química , Cobre/química , Nanopartículas/química , Soroalbumina Bovina/análise , Animais , Bovinos , Quinolinas/química
14.
Microb Pathog ; 107: 234-242, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28377234

RESUMO

Neonatal sepsis, a clinical disorder developed by bacterial blood stream infections (BSI) in neonates, is one of the serious global public health problems that must be addressed. More than one million of the estimated global newborn deaths per year are occurred due to severe infections. The genesis of the infection is divided into early-onset sepsis (EOS) and late-onset sepsis (LOS) of the disease. The clinical complications of neonatal sepsis may be associated with bronchopulmonary dysplasia, ductus arteriosus and necrotizing enterocolitis. The clinical diagnosis and treatment of neonatal sepsis is highly complicated. Over the past few years distinct biomarkers have been identified. Most widely used biomarkers are C-reactive protein, Procalcitonin (PCT) and Serum amyloid A (SAA). Until recently, many potential biomarkers including Cell Surface antigens and Bacterial surface antigens and genetic biomarkers are being investigated. Protein biomarkers, cytokines and chemokines are getting much interest for identification of neonatal sepsis infection.


Assuntos
Infecções Bacterianas/diagnóstico , Biomarcadores/sangue , Marcadores Genéticos/genética , Sepse Neonatal/diagnóstico , Antígenos de Bactérias/genética , Antígenos de Superfície/genética , Bactérias/classificação , Bactérias/genética , Bactérias/patogenicidade , Infecções Bacterianas/microbiologia , Infecções Bacterianas/fisiopatologia , Infecções Bacterianas/terapia , Proteínas de Bactérias/sangue , Proteínas de Bactérias/genética , Proteína C-Reativa/genética , Calcitonina/genética , Quimiocinas/sangue , Quimiocinas/genética , Citocinas/sangue , Citocinas/genética , Genes Bacterianos/genética , Humanos , Interleucina-6/genética , Interleucina-8/genética , Metanálise como Assunto , Sepse Neonatal/microbiologia , Sepse Neonatal/fisiopatologia , Sepse Neonatal/terapia , Proteína Amiloide A Sérica/genética , Fator de Necrose Tumoral alfa/genética
15.
Analyst ; 140(6): 1988-94, 2015 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-25674632

RESUMO

Determining the concentrations of acetylcholine (ACh) and choline (Ch) is clinically important. ACh is a neurotransmitter that acts as a key link in the communication between neurons in the spinal cord and in nerve skeletal junctions in vertebrates, and plays an important role in transmitting signals in the brain. A bienzymatic sensor for the detection of ACh was prepared by co-immobilizing choline oxidase (ChO) and acetylcholinesterase (AChE) on graphene matrix/platinum nanoparticles, and then electrodepositing them on an ITO-coated glass plate. Graphene nanoparticles were decorated with platinum nanoparticles and were electrodeposited on a modified ITO-coated glass plate to form a modified electrode. The modified electrode was characterized by scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) studies. The optimum response of the enzyme electrode was obtained at pH 7.0 and 35 °C. The response time of this ACh-sensing system was shown to be 4 s. The linear range of responses to ACh was 0.005-700 µM. This biosensor exhibits excellent anti-interferential abilities and good stability, retaining 50% of its original current even after 4 months. It has been applied for the detection of ACh levels in human serum samples.


Assuntos
Acetilcolina/sangue , Técnicas Biossensoriais/métodos , Grafite/química , Nanopartículas/química , Platina/química , Acetilcolina/metabolismo , Acetilcolinesterase/metabolismo , Alcaligenes/enzimologia , Oxirredutases do Álcool/metabolismo , Doença de Alzheimer/sangue , Animais , Espectroscopia Dielétrica/métodos , Técnicas Eletroquímicas/métodos , Eletrodos , Electrophorus , Enzimas Imobilizadas/metabolismo , Humanos , Limite de Detecção , Modelos Moleculares
16.
Indian J Med Res ; 139(4): 603-9, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24927348

RESUMO

BACKGROUND & OBJECTIVES: Reusable biostrip consisting enzymes immobilized onto alkylamine glass beads affixed on plasticized PVC strip for determination of triglyceride (TG) suffers from high cost of beads and their detachments during washings for reuse, leading to loss of activity. The purpose of this study was to develop a cheaper and stable biostrip for investigation of TG levels in serum. METHODS: A reusable enzyme-strip was prepared for TG determination by co-immobilizing lipase, glycerol kinase (GK), glycerol-3-phosphate oxidase (GPO) and peroxidase (HRP) directly onto plasticized polyvinyl chloride (PVC) strip through glutaraldehyde coupling. The method was evaluated by studying its recovery, precision and reusability. RESULTS: The enzyme-strip showed optimum activity at pH 7.0, 35 o C and a linear relationship between its activity and triolein concentration in the range 0.1 to 15 mM. The strip was used for determination of serum TG. The detection limit of the method was 0.1 mM. Analytical recovery of added triolein was 96 per cent. Within and between batch coefficients of variation (CV) were 2.2 and 3.7 per cent, respectively. A good correlation (r=0.99) was found between TG values by standard enzymic colrimetric method employing free enzymes and the present method. The strip lost 50 per cent of its initial activity after its 200 uses during the span of 100 days, when stored at 4 o C. INTERPRETATION & CONCLUSIONS: The nitrating acidic treatment of plasticized PVC strip led to glutaraldehyde coupling of four enzymes used for enzymic colourimetric determination of serum TG. The strip provided 200 reuses of enzymes with only 50 per cent loss of its initial activity. The method could be used for preparation of other enzyme strips also.


Assuntos
Análise Química do Sangue/instrumentação , Enzimas Imobilizadas/metabolismo , Cloreto de Polivinila/metabolismo , Fitas Reagentes/metabolismo , Triglicerídeos/sangue , Glicerol Quinase/metabolismo , Glicerolfosfato Desidrogenase/metabolismo , Peroxidase do Rábano Silvestre/metabolismo , Concentração de Íons de Hidrogênio , Cinética , Lipase/metabolismo , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura
17.
Bioprocess Biosyst Eng ; 36(11): 1545-54, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23411873

RESUMO

A method is described for the construction of a highly sensitive amperometric sensor for the detection of tyrosine, employing a magnetic nanoparticles-zinc oxide/zinc hexacyanoferrate (Fe3O4NP-ZnO/ZnHCF) hybrid film electrodeposited on the surface of a Pt electrode as working electrode. The sensor is based on electrocatalytic mechanism initiated by electrochemical oxidation of the reduced form of the hybrid film at +0.2 V vs. Ag/AgCl followed by completion of chemical oxidation of tyrosine. The sensor showed optimum response within 2 s at pH 2. The working/linear range of the sensor was 0.02-2.76 mM with a detection limit of 4 µM. The sensor measured tyrosine level in serum, a potential biomarker of phenylketonuria. The working electrode lost only 5 % of its initial activity, when stored at 4 °C, after its regular use over a period of 100 days.


Assuntos
Técnicas Eletroquímicas/métodos , Ferrocianetos/química , Magnetismo , Nanopartículas , Tirosina/análise , Óxido de Zinco/química , Catálise , Limite de Detecção , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Oxirredução , Reprodutibilidade dos Testes , Difração de Raios X
18.
Bioprocess Biosyst Eng ; 36(4): 425-32, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22903594

RESUMO

A method is described for construction of an amperometric triglyceride (TG) biosensor based on covalent co-immobilization of lipase, glycerol kinase and glycerol-3-phosphate oxidase onto gold polypyrrole nanocomposite decorated poly indole-5-carboxylic acid electrodeposited on the surface of a gold electrode. The enzyme electrode was characterized by transmission electron microscopy, scanning electron microscopy, electrochemical impedance studies, Fourier transform infrared spectroscopy and cyclic voltammetry. Biosensor showed optimum response within 4 s at pH 6.5 and 35 °C, when polarized at +0.1 V against Ag/AgCl. There was a linear relationship between sensor response and triolein concentration in the range 50-700 mg/dl. Biosensor was employed for determination of TG in serum. Detection limit of the biosensor was 20 mg/dl. Biosensor was evaluated with 91-95 % recovery of added triolein in sera and 4.14 and 5.85 % within and between batch coefficients of variation, respectively. There was a good correlation (r = 0.99) between sera TG values by standard method (Enzymic colorimetric) and the present method. The biosensor was unaffected by a number of serum substances at their physiological concentration. Biosensor lost 50 % of its initial activity after its 100 uses over 7 months, when stored at 4 °C.


Assuntos
Técnicas Biossensoriais/instrumentação , Nanopartículas Metálicas , Nanocompostos , Triglicerídeos/sangue , Adulto , Técnicas Biossensoriais/métodos , Análise Química do Sangue/instrumentação , Análise Química do Sangue/métodos , Espectroscopia Dielétrica , Enzimas Imobilizadas , Glicerol Quinase , Glicerolfosfato Desidrogenase , Ouro , Humanos , Indóis , Lipase , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica , Nanocompostos/química , Nanocompostos/ultraestrutura , Polímeros , Pirróis , Espectroscopia de Infravermelho com Transformada de Fourier
19.
J Curr Glaucoma Pract ; 17(3): 111-112, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37920376

RESUMO

How to cite this article: Dada T, Chauhan N. Optimizing Glaucoma Care: A Holistic Approach. J Curr Glaucoma Pract 2023;17(3):111-112.

20.
Ind Psychiatry J ; 32(2): 380-389, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38161480

RESUMO

Background: The rates of medication non-adherence among Indian patients with schizophrenia are high, and its detection poses problems. Comparisons of suitable measures to detect medication non-adherence in schizophrenia from Indian outpatient settings are scarce. Aim: This study compared simple and inexpensive methods of detecting medication non-adherence in schizophrenia among outpatients from a tertiary-care center in North India. Materials and Method: A longitudinal comparison of two self-reports, the Morisky Medication Adherence Questionnaire and the Drug Attitude Inventory-10, clinicians' ratings employing the Compliance Rating Scale, and clinic-based pill counts was conducted among 70 outpatients with schizophrenia. The rates and detection of medication non-adherence, associations with determinants of treatment non-adherence, and agreement between measures were examined at intake and after six months of follow-up (n = 53). Results: The self-reports had greater ability to detect medication adherence (specificity 41-65%; positive predictive values 25-51%; negative likelihood ratios 0.86-1.14) and moderate ability to detect medication non-adherence (sensitivity 27-65%; negative predictive values 49-69%; positive likelihood ratios 0.78-1.10). They yielded higher medication non-adherence rates, detected changes in medication non-adherence over time, and were associated with the other measures and the well-known correlates of medication non-adherence. Clinicians' ratings and pill counts had high sensitivity (56-90%) but low specificity (35-49%) to detect medication non-adherence. Conclusion: Self-reports are comparatively better screening options for detecting medication non-adherence among Indian outpatients with schizophrenia. However, the sequential use of different measures could lead to better recognition of medication non-adherence.

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