RESUMO
Blebbistatin, para-nitroblebbistatin (NBleb), and para-aminoblebbistatin (AmBleb) are highly useful tool compounds as they selectively inhibit the ATPase activity of myosin-2 family proteins. Despite the medical importance of the myosin-2 family as drug targets, chemical optimization has not yet provided a promising lead for drug development because previous structure-activity-relationship studies were limited to a single myosin-2 isoform. Here we evaluated the potential of blebbistatin scaffold for drug development and found that D-ring substitutions can fine-tune isoform specificity, absorption-distribution-metabolism-excretion, and toxicological properties. We defined the inhibitory properties of NBleb and AmBleb on seven different myosin-2 isoforms, which revealed an unexpected potential for isoform specific inhibition. We also found that NBleb metabolizes six times slower than blebbistatin and AmBleb in rats, whereas AmBleb metabolizes two times slower than blebbistatin and NBleb in human, and that AmBleb accumulates in muscle tissues. Moreover, mutagenicity was also greatly reduced in case of AmBleb. These results demonstrate that small substitutions have beneficial functional and pharmacological consequences, which highlight the potential of the blebbistatin scaffold for drug development targeting myosin-2 family proteins and delineate a route for defining the chemical properties of further derivatives to be developed. SIGNIFICANCE STATEMENT: Small substitutions on the blebbistatin scaffold have beneficial functional and pharmacological consequences, highlighting their potential in drug development targeting myosin-2 family proteins.
Assuntos
Absorção Fisico-Química , Descoberta de Drogas , Compostos Heterocíclicos de 4 ou mais Anéis/metabolismo , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Miosinas/antagonistas & inibidores , Animais , Compostos Heterocíclicos de 4 ou mais Anéis/química , Compostos Heterocíclicos de 4 ou mais Anéis/toxicidade , Humanos , Simulação de Dinâmica Molecular , Miosinas/química , Conformação Proteica , Ratos , Distribuição TecidualRESUMO
The recent trend in electrocardiogram (ECG) device development is towards wireless body sensors applied for patient monitoring. The ultimate goal is to develop a multi-functional body sensor that will provide synchronized vital bio-signs of the monitored user. In this paper, we present an ECG sensor for long-term monitoring, which measures the surface potential difference between proximal electrodes near the heart, called differential ECG lead or differential lead, in short. The sensor has been certified as a class IIa medical device and is available on the market under the trademark Savvy ECG. An improvement from the user's perspective-immediate access to the measured data-is also implemented into the design. With appropriate placement of the device on the chest, a very clear distinction of all electrocardiographic waves can be achieved, allowing for ECG recording of high quality, sufficient for medical analysis. Experimental results that elucidate the measurements from a differential lead regarding sensors' position, the impact of artifacts, and potential diagnostic value, are shown. We demonstrate the sensors' potential by presenting results from its various areas of application: medicine, sports, veterinary, and some new fields of investigation, like hearth rate variability biofeedback assessment and biometric authentication.
Assuntos
Técnicas Biossensoriais/instrumentação , Eletrocardiografia/instrumentação , Frequência Cardíaca/fisiologia , Monitorização Fisiológica/instrumentação , Telemedicina , Animais , Identificação Biométrica/instrumentação , Identificação Biométrica/métodos , Técnicas Biossensoriais/métodos , Técnicas Biossensoriais/veterinária , Cardiotocografia/instrumentação , Eletrocardiografia/métodos , Eletrocardiografia/veterinária , Eletrodos/veterinária , Desenho de Equipamento , Feminino , Cavalos , Humanos , Aplicativos Móveis , Monitorização Ambulatorial/instrumentação , Monitorização Ambulatorial/métodos , Monitorização Ambulatorial/veterinária , Monitorização Fisiológica/métodos , Monitorização Fisiológica/veterinária , Valor Preditivo dos Testes , Gravidez , Cuidado Pré-Natal/métodos , Processamento de Sinais Assistido por Computador/instrumentação , Medicina Esportiva/instrumentação , Medicina Esportiva/métodos , Telemedicina/instrumentação , Telemedicina/métodos , Telemetria/instrumentação , Telemetria/métodos , Telemetria/veterinária , Fatores de Tempo , Medicina Veterinária/instrumentação , Medicina Veterinária/métodos , Tecnologia sem Fio/instrumentaçãoRESUMO
In response to the global trend of decreasing antibiotic usage, this study aimed to evaluate the nature and frequency of antibiotic prescriptions in conjunction with endodontic therapy in Croatia and to assess the attitudes of Croatian dental practitioners towards the endodontic treatment of patients susceptible to bacterial endocarditis. A survey questionnaire was sent to all dental practitioners in Croatia, achieving a response rate of 27%. The most frequently prescribed antibiotic was penicillin with clavulanic acid (63.4%), while standalone penicillin was less prevalent (18.6%). For patients exhibiting penicillin allergies, 90% of respondents indicated clindamycin as their preferred alternative. Antibiotics were mostly prescribed for localized acute apical abscesses without fever, followed by prophylaxis for infectious endocarditis and cellulitis. Only 1.3% of the respondents reported frequent antibiotic prescriptions without accompanying local treatment. While a substantial proportion of surveyed practitioners professed familiarity with the latest guidelines for antibiotic prophylaxis, their choice of antibiotics did not consistently reflect this claim. Most respondents conducted endodontic procedures on patients at risk of bacterial endocarditis. The findings highlight a need for targeted continuing education for dental practitioners in the Republic of Croatia, ensuring their practices align with current guidelines and global trends in antibiotic prescription.
RESUMO
The human lysosomal enzymes alpha-galactosidase (alpha-GAL, EC 3.2.1.22) and alpha-N-acetylgalactosaminidase (alpha-NAGAL, EC 3.2.1.49) share 46% amino acid sequence identity and have similar folds. The active sites of the two enzymes share 11 of 13 amino acids, differing only where they interact with the 2-position of the substrates. Using a rational protein engineering approach, we interconverted the enzymatic specificity of alpha- GAL and alpha-NAGAL. The engineered alpha-GAL (which we call alpha-GAL(SA)) retains the antigenicity of alpha-GAL but has acquired the enzymatic specificity of alpha-NAGAL. Conversely, the engineered alpha-NAGAL (which we call alpha-NAGAL(EL)) retains the antigenicity of alpha-NAGAL but has acquired the enzymatic specificity of the alpha-GAL enzyme. Comparison of the crystal structures of the designed enzyme alpha-GAL(SA) to the wild-type enzymes shows that active sites of alpha-GAL(SA) and alpha-NAGAL superimpose well, indicating success of the rational design. The designed enzymes might be useful as non-immunogenic alternatives in enzyme replacement therapy for treatment of lysosomal storage disorders such as Fabry disease.
Assuntos
Doença de Fabry/enzimologia , Doenças por Armazenamento dos Lisossomos/enzimologia , Lisossomos/enzimologia , alfa-Galactosidase/química , alfa-N-Acetilgalactosaminidase/química , Sequência de Aminoácidos , Metabolismo dos Carboidratos , Carboidratos/química , Cristalografia por Raios X/métodos , Glicoproteínas/química , Humanos , Cinética , Dados de Sequência Molecular , Dobramento de Proteína , Homologia de Sequência de Aminoácidos , Especificidade por SubstratoRESUMO
OBJECTIVE: To evaluate the type and the frequency of antibiotic prescribing along with endodontic therapy in Croatia. The aim is, also, to assess the attitudes of Croatian doctors towards endodontic treatment of patients at risk of developing bacterial endocarditis. MATERIAL AND METHODS: Data were collected by a survey questionnaire. RESULTS: 8.4% of the examined practitioners stated that they prescribe antibiotics often, and 91.6% of them stated that they prescribed them never/ very rarely/rarely. Most of them (41%) prescribe antibiotics once or twice a month, 32.5% once or twice in several months and 20.5% once or twice a week. The most commonly used antibiotic was penicillin with clavulanic acid. Also, 26.2% of examined practitioners prescribed antibiotics for gangrene pulp, 51.2% of them for localized acute apical periodontitis without swelling, 85% of them for cellulitis, 75% of them for fever and enlarged lymph nodes, 16.9% of them for tooth with fistula and 94.1% of them for prophylaxis of infectious endocarditis. According to the results of study, 54.4% of dental practitioners did not prescribe antibiotics without intervention on susceptible tooth; 76% of participants often/almost always/ always accepted endodontic treatment of patients requiring antibiotic prophylaxis to prevent infectious endocarditis, and 96.7% of participants indicated they were familiar with recent instructions for antibiotic prophylaxis. CONCLUSION: These findings point to inappropriate use of antibiotics in the practice of 83 dental practitioners questioned regarding the frequency of administration and indications. The most commonly used antibiotic was penicillin with clavulanic acid. A high percentage of surveyed practitioners stated that they were familiar with recent instructions for antibiotic prophylaxis. They also stated that they performed endodontic procedures on patients who were at risk of bacterial endocarditis. There is a noticeable need for targeted continuing education of dental practitioners in the Republic of Croatia.
RESUMO
Mice homozygous for the human GRACILE syndrome mutation (Bcs1lc.A232G) display decreased respiratory chain complex III activity, liver dysfunction, hypoglycemia, rapid loss of white adipose tissue and early death. To assess the underlying mechanism of the lipodystrophy in homozygous mice (Bcs1lp.S78G), these and wild-type control mice were subjected to a short 4-hour fast. The homozygotes had low baseline blood glucose values, but a similar decrease in response to fasting as in wild-type mice, resulting in hypoglycemia in the majority. Despite the already depleted glycogen and increased triacylglycerol content in the mutant livers, the mice responded to fasting by further depletion and increase, respectively. Increased plasma free fatty acids (FAs) upon fasting suggested normal capacity for mobilization of lipids from white adipose tissue into circulation. Strikingly, however, serum glycerol concentration was not increased concomitantly with free FAs, suggesting its rapid uptake into the liver and utilization for fuel or gluconeogenesis in the mutants. The mutant hepatocyte mitochondria were capable of responding to fasting by appropriate morphological changes, as analyzed by electron microscopy, and by increasing respiration. Mutants showed increased hepatic gene expression of major metabolic controllers typically associated with fasting response (Ppargc1a, Fgf21, Cd36) already in the fed state, suggesting a chronic starvation-like metabolic condition. Despite this, the mutant mice responded largely normally to fasting by increasing hepatic respiration and switching to FA utilization, indicating that the mechanisms driving these adaptations are not compromised by the CIII dysfunction. SUMMARY STATEMENT: Bcs1l mutant mice with severe CIII deficiency, energy deprivation and post-weaning lipolysis respond to fasting similarly to wild-type mice, suggesting largely normal systemic lipid mobilization and utilization mechanisms.
Assuntos
Complexo III da Cadeia de Transporte de Elétrons/metabolismo , Jejum/fisiologia , Mobilização Lipídica/fisiologia , Acidose Láctica/metabolismo , Animais , Glicemia/metabolismo , Colestase/metabolismo , Transporte de Elétrons/fisiologia , Feminino , Retardo do Crescimento Fetal/metabolismo , Gluconeogênese/fisiologia , Glicogênio/metabolismo , Hemossiderose/metabolismo , Hepatócitos/metabolismo , Hepatócitos/fisiologia , Homozigoto , Hipoglicemia/metabolismo , Hipoglicemia/fisiopatologia , Fígado/metabolismo , Fígado/fisiologia , Masculino , Erros Inatos do Metabolismo/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Mitocôndrias/fisiologia , Doenças Mitocondriais/congênito , Doenças Mitocondriais/metabolismo , Aminoacidúrias Renais/metabolismo , Triglicerídeos/metabolismoRESUMO
Remote patient monitoring should reduce mortality rates, improve care, and reduce costs. We present an overview of the available technologies for the remote monitoring of chronic obstructive pulmonary disease (COPD) patients, together with the most important medical information regarding COPD in a language that is adapted for engineers. Our aim is to bridge the gap between the technical and medical worlds and to facilitate and motivate future research in the field. We also present a justification, motivation, and explanation of how to monitor the most important parameters for COPD patients, together with pointers for the challenges that remain. Additionally, we propose and justify the importance of electrocardiograms (ECGs) and the arterial carbon dioxide partial pressure (PaCO2) as two crucial physiological parameters that have not been used so far to any great extent in the monitoring of COPD patients. We cover four possibilities for the remote monitoring of COPD patients: continuous monitoring during normal daily activities for the prediction and early detection of exacerbations and life-threatening events, monitoring during the home treatment of mild exacerbations, monitoring oxygen therapy applications, and monitoring exercise. We also present and discuss the current approaches to decision support at remote locations and list the normal and pathological values/ranges for all the relevant physiological parameters. The paper concludes with our insights into the future developments and remaining challenges for improvements to continuous remote monitoring systems. Graphical abstract á .
Assuntos
Monitorização Fisiológica , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Telemedicina , Eletrocardiografia/métodos , HumanosRESUMO
Presented is a wireless body sensor capable of measuring local potential differences on a body surface. By using on-sensor signal processing capabilities, and developed algorithms for off-line signal processing on a personal computing device, it is possible to record single channel ECG, heart rate, breathing rate, EMG, and when three sensors are applied, even the 12-lead ECG. The sensor is portable, unobtrusive, and suitable for both inpatient and outpatient monitoring. The paper presents the sensor's hardware and results of power consumption analysis. The sensor's capabilities of recording various physiological parameters are also presented and illustrated. The paper concludes with envisioned sensor's future developments and prospects.
Assuntos
Monitorização Fisiológica/instrumentação , Tecnologia sem Fio , Eletroencefalografia , Eletromiografia , Humanos , Monitorização Ambulatorial/instrumentação , Processamento de Sinais Assistido por Computador , Avaliação da Tecnologia Biomédica , Sinais VitaisRESUMO
Systems with reduced numbers of leads that can synthesize the 12-lead electrocardiogram (ECG) with an insignificant or a small loss of diagnostic information have been proposed. The advantage over standard 12-lead ECG systems is the smaller number of measurement sites (i.e., electrodes) and, consequently, fewer wires. In this paper, we review all the important systems with reduced numbers of leads together with the methodology for synthesizing the leads. The fundamental theoretical background necessary to understand the most important concepts related to the synthesis is included. The presented theoretical and experimental justifications for the synthesis show that it is not necessary to measure a large number of leads directly, because the standard 12-lead ECG and arbitrary additional leads can be synthesized. Various approaches to evaluating the synthesized 12-lead ECG are defined and explained, and a number of systems that synthesize 12-lead ECG are presented as they were introduced in the literature. We cover the developments and improvements from the 1940s to the present day. The systems are classified on the basis of the synthesis method used, the approach to the evaluation of the synthesized ECG (depending on the measurement sites used), and on the number and types of leads employed. Based on a detailed assessment of state-of-the-art systems, open problems and challenges are highlighted, while further developments of electrocardiographic systems are envisaged.
Assuntos
Eletrocardiografia , Eletrocardiografia/instrumentação , Eletrocardiografia/métodos , Eletrodos , Humanos , Processamento de Sinais Assistido por ComputadorRESUMO
A methodology is presented for estimating the wireless body electrode (WE) positions and for calculating the linear transformations that enable the synthesis of a 12-lead ECG or a multichannel ECG from three WEs, which in turn simplifies and improves the acquisition of ECGs. We present, compare, and evaluate three approaches to the synthesis: fully personalized, fully universal, and combined with universal leads and personalized transformations. The evaluation results show that WEs are an acceptable alternative to the standard 12-lead ECG device for patients with chronic myocardial ischemia, if either the fully personalized or combined approach is used. The median correlation coefficients are all higher than 0.94 and 0.92 for the fully personalized and combined approaches, respectively. The corresponding kappa and percentual diagnostic agreements between the synthesized and target 12-lead ECGs are 0.88 (95%) and 0.83 (92%), respectively. The evaluation additionally shows that the personalization of the transformations has more impact on the quality of the synthesized ECGs than the personalization of the WEs' positions.
Assuntos
Eletrocardiografia/métodos , Eletrodos , Processamento de Sinais Assistido por Computador/instrumentação , Tecnologia sem Fio/instrumentação , Adulto , Idoso , Feminino , Coração/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/fisiopatologiaRESUMO
A new approach is proposed for synthesizing the standard 12-lead ECG from three differential leads formed by pairs of proximal electrodes on the body surface. The method is supported by a statistical analysis that gives the best personalized positions of electrodes. The measurements from multichannel ECGs were used to calculate the differential leads. Our algorithm searches for optimal differential leads and the corresponding personalized transformation matrix that is used to synthesize the standard 12-lead ECG. The algorithm has been evaluated on 99 multichannel ECGs measured on 30 healthy subjects and 35 patients scheduled for elective cardiac surgery. It is shown that the algorithm significantly outperforms the synthesis based on the EASI lead system with medians of correlation coefficients greater than 0.954 for all 12 standard leads. To determine the optimal number of differential leads, the syntheses for two, three, and four differential leads were calculated. The analysis shows that 3 is the optimal number of differential leads for practical applications. Because of the proximity of the differential electrodes, the proposed approach offers an opportunity for the synthesis of a standard 12-lead ECG with wireless electrodes.