Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 68
Filtrar
1.
Proteomics ; : e2100313, 2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38850190

RESUMO

Evolutionary relationships among parasites of the subfamily Leishmaniinae, which comprises pathogen agents of leishmaniasis, were inferred based on differential protein expression profiles from mass spectrometry-based quantitative data using the PhyloQuant method. Evolutionary distances following identification and quantification of protein and peptide abundances using Proteome Discoverer and MaxQuant software were estimated for 11 species from six Leishmaniinae genera. Results clustered all dixenous species of the genus Leishmania, subgenera L. (Leishmania), L. (Viannia), and L. (Mundinia), sister to the dixenous species of genera Endotrypanum and Porcisia. Placed basal to the assemblage formed by all these parasites were the species of genera Zelonia, Crithidia, and Leptomonas, so far described as monoxenous of insects although eventually reported from humans. Inferences based on protein expression profiles were congruent with currently established phylogeny using DNA sequences. Our results reinforce PhyloQuant as a valuable approach to infer evolutionary relationships within Leishmaniinae, which is comprised of very tightly related trypanosomatids that are just beginning to be phylogenetically unraveled. In addition to evolutionary history, mapping of species-specific protein expression is paramount to understand differences in infection processes, tissue tropisms, potential to jump from insects to vertebrates including humans, and targets for species-specific diagnostic and drug development.

2.
Adv Exp Med Biol ; 1443: 23-32, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38409414

RESUMO

Protein glycosylation is a post-translational modification involving the addition of carbohydrates to proteins and plays a crucial role in protein folding and various biological processes such as cell recognition, differentiation, and immune response. The vast array of natural sugars available allows the generation of plenty of unique glycan structures in proteins, adding complexity to the regulation and biological functions of glycans. The diversity is further increased by enzymatic site preferences and stereochemical conjugation, leading to an immense amount of different glycan structures. Understanding glycosylation heterogeneity is vital for unraveling the impact of glycans on different biological functions. Evaluating site occupancies and structural heterogeneity aids in comprehending glycan-related alterations in biological processes. Several software tools are available for large-scale glycoproteomics studies; however, integrating identification and quantitative data to assess heterogeneity complexity often requires extensive manual data processing. To address this challenge, we present a python script that automates the integration of Byonic and MaxQuant outputs for glycoproteomic data analysis. The script enables the calculation of site occupancy percentages by glycans and facilitates the comparison of glycan structures and site occupancies between two groups. This automated tool offers researchers a means to organize and interpret their high-throughput quantitative glycoproteomic data effectively.


Assuntos
Glicopeptídeos , Espectrometria de Massas em Tandem , Software , Glicosilação , Polissacarídeos/química
3.
Adv Exp Med Biol ; 1443: 1-22, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38409413

RESUMO

Extracellular vesicles (EVs) are bilayer membrane particles released from several cell types to the extracellular environment. EVs have a crucial role in cell-cell communication, involving different biological processes in health and diseases. Due to the potential of biomarkers for several diseases as diagnostic and therapeutic tools, it is relevant to understand the biology of the EVs and their content. One of the current challenges involving EVs is regarding the purification method, which is a critical step for EV's functional and characterization studies. Ultracentrifugation is the most used method for EV isolation, where the nanoparticles are separated in sequential centrifugation to isolate the EVs based on their size. However, for viscous biofluids such as plasma, there is a co-isolation of the most abundant proteins, which can impair the EV's protein identification due to the low abundance of these proteins and signal suppression by the most abundant plasma proteins. Emerging techniques have gained attention in recent years. Titanium dioxide (TiO2) is one of the most promising techniques due to its property for selective isolation based on the interaction with phospholipids in the EV membrane. Using a small amount of TiO2 beads and a low volume of plasma, it is possible to isolate EVs with reduced plasma protein co-isolation. This study describes a comprehensive workflow for the isolation and characterization of plasma extracellular vesicles (EVs) using mass spectrometry-based proteomics techniques. The aim of this chapter is describe the EV isolation using TiO2 beads enrichment and high-throughput mass spectrometry techniques to efficiently identify the protein composition of EVs in a fast and straightforward manner.


Assuntos
Vesículas Extracelulares , Titânio , Microesferas , Vesículas Extracelulares/metabolismo , Proteínas Sanguíneas/análise , Proteínas Sanguíneas/metabolismo , Plasma
4.
Neuromodulation ; 2023 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-37140522

RESUMO

STUDY DESIGN: This is a report of methods and tools for selection of task and individual configurations targeted for voluntary movement, standing, stepping, blood pressure stabilization, and facilitation of bladder storage and emptying using tonic-interleaved excitation of the lumbosacral spinal cord. OBJECTIVES: This study aimed to present strategies used for selection of stimulation parameters for various motor and autonomic functions. CONCLUSIONS: Tonic-interleaved functionally focused neuromodulation targets a myriad of consequences from spinal cord injury with surgical implantation of the epidural electrode at a single location. This approach indicates the sophistication of the human spinal cord circuitry and its important role in the regulation of motor and autonomic functions in humans.

5.
Curr Opin Neurol ; 35(4): 536-543, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35856918

RESUMO

PURPOSE OF REVIEW: There is a long history of neuromodulation of the spinal cord after injury in humans with recent momentum of studies showing evidence for therapeutic potential. Nonrandomized, mechanistic, hypothesis-driven, small cohort, epidural stimulation proof of principle studies provide insight into the human spinal circuitry functionality and support the pathway toward clinical treatments. RECENT FINDINGS: Individuals living with spinal cord injury can recover motor, cardiovascular, and bladder function even years after injury using neuromodulation. Integration of continuous feedback from sensory information, task-specific training, and optimized excitability state of human spinal circuitry are critical spinal mechanisms. Neuromodulation activates previously undetectable residual supraspinal pathways to allow intentional (voluntary) control of motor movements. Further discovery unveiled the human spinal circuitry integrated regulatory control of motor and autonomic systems indicating the realistic potential of neuromodulation to improve the capacity incrementally, but significantly for recovery after severe spinal cord injury. SUMMARY: The discovery that both motor and autonomic function recovers with lumbosacral spinal cord placement of the electrode reveals exciting avenues for a synergistic overall improvement in function, health, and quality of life for those who have been living with the consequences of spinal cord injury even for decades.


Assuntos
Traumatismos da Medula Espinal , Estimulação da Medula Espinal , Espaço Epidural , Humanos , Qualidade de Vida , Medula Espinal , Traumatismos da Medula Espinal/terapia
6.
Exp Brain Res ; 240(1): 279-288, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34854934

RESUMO

Spinal cord epidural stimulation (scES) is an intervention to restore motor function in those with severe spinal cord injury (SCI). Spinal cord lesion characteristics assessed via magnetic resonance imaging (MRI) may contribute to understand motor recovery. This study assessed relationships between standing ability with scES and spared spinal cord tissue characteristics at the lesion site. We hypothesized that the amount of lateral spared cord tissue would be related to independent extension in the ipsilateral lower limb. Eleven individuals with chronic, clinically motor complete SCI underwent spinal cord MRI, and were subsequently implanted with scES. Standing ability and lower limb activation patterns were assessed during an overground standing experiment with scES. This assessment occurred prior to any activity-based intervention with scES. Lesion hyperintensity was segmented from T2 axial images, and template-based analysis was used to estimate spared tissue in anterior, posterior, right, and left spinal cord regions. Regression analysis was used to assess relationships between imaging and standing outcomes. Total volume of spared tissue was related to left (p = 0.007), right (p = 0.005), and bilateral (p = 0.011) lower limb extension. Spared tissue in the left cord region was related to left lower limb extension (p = 0.019). A positive trend (p = 0.138) was also observed between right spared cord tissue and right lower limb extension. In this study, MRI measures of spared spinal cord tissue were significantly related to standing outcomes with scES. These preliminary results warrant future investigation of roles of supraspinal input and MRI-detected spared spinal cord tissue on lower limb motor responsiveness to scES.


Assuntos
Traumatismos da Medula Espinal , Estimulação da Medula Espinal , Espaço Epidural/diagnóstico por imagem , Humanos , Medula Espinal/diagnóstico por imagem , Traumatismos da Medula Espinal/diagnóstico por imagem , Traumatismos da Medula Espinal/terapia , Posição Ortostática
7.
Brain ; 144(2): 420-433, 2021 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-33367527

RESUMO

Spinal cord epidural stimulation (scES) has enabled volitional lower extremity movements in individuals with chronic and clinically motor complete spinal cord injury and no clinically detectable brain influence. The aim of this study was to understand whether the individuals' neuroanatomical characteristics or positioning of the scES electrode were important factors influencing the extent of initial recovery of lower limb voluntary movements in those with clinically motor complete paralysis. We hypothesized that there would be significant correlations between the number of joints moved during attempts with scES prior to any training interventions and the amount of cervical cord atrophy above the injury, length of post-traumatic myelomalacia and the amount of volume coverage of lumbosacral enlargement by the stimulation electrode array. The clinical and imaging records of 20 individuals with chronic and clinically motor complete spinal cord injury who underwent scES implantation were reviewed and analysed using MRI and X-ray integration, image segmentation and spinal cord volumetric reconstruction techniques. All individuals that participated in the scES study (n = 20) achieved, to some extent, lower extremity voluntary movements post scES implant and prior to any locomotor, voluntary movement or cardiovascular training. The correlation results showed that neither the cross-section area of spinal cord at C3 (n = 19, r = 0.33, P = 0.16) nor the length of severe myelomalacia (n = 18, r = -0.02, P = 0.93) correlated significantly with volitional lower limb movement ability. However, there was a significant, moderate correlation (n = 20, r = 0.59, P = 0.006) between the estimated percentage of the lumbosacral enlargement coverage by the paddle electrode as well as the position of the paddle relative to the maximal lumbosacral enlargement and the conus tip (n = 20, r = 0.50, P = 0.026) with the number of joints moved volitionally. These results suggest that greater coverage of the lumbosacral enlargement by scES may improve motor recovery prior to any training, possibly because of direct modulatory effects on the spinal networks that control lower extremity movements indicating the significant role of motor control at the level of the spinal cord.


Assuntos
Movimento , Traumatismos da Medula Espinal/diagnóstico , Traumatismos da Medula Espinal/reabilitação , Estimulação da Medula Espinal/métodos , Volição , Adulto , Espaço Epidural , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Resultado do Tratamento , Adulto Jovem
8.
J Proteome Res ; 20(10): 4693-4707, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34533964

RESUMO

Medulloblastomas (MBs) and glioblastomas (GBMs) are high-incidence central nervous system tumors. Different origin sites and changes in the tissue microenvironment have been associated with the onset and progression. Here, we describe differences between the extracellular matrix (ECM) signatures of these tumors. We compared the proteomic profiles of MB and GBM decellularized tumor samples between each other and their normal decellularized brain site counterparts. Our analysis revealed that 19, 28, and 11 ECM proteins were differentially expressed in MBs, GBMs, and in both MBs and GBMs, respectively. Next, we validated key findings by using a protein tissue array with 53 MB and 55 GBM cases and evaluated the clinical relevance of the identified differentially expressed proteins through their analysis on publicly available datasets, 763 MB samples from the GSE50161 and GSE85217 studies, and 115 GBM samples from RNAseq-TCGA. We report a shift toward a denser fibrillary ECM as well as a clear alteration in the glycoprotein signature, which influences the tumor pathophysiology. MS data have been submitted to the PRIDE repository, project accession: PXD023350.


Assuntos
Neoplasias Encefálicas , Matriz Extracelular , Glioblastoma , Meduloblastoma , Neoplasias Encefálicas/genética , Matriz Extracelular/patologia , Glioblastoma/genética , Humanos , Meduloblastoma/genética , Proteoma/genética , Proteômica , Microambiente Tumoral
9.
N Engl J Med ; 379(13): 1244-1250, 2018 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-30247091

RESUMO

Persons with motor complete spinal cord injury, signifying no voluntary movement or sphincter function below the level of injury but including retention of some sensation, do not recover independent walking. We tested intense locomotor treadmill training with weight support and simultaneous spinal cord epidural stimulation in four patients 2.5 to 3.3 years after traumatic spinal injury and after failure to improve with locomotor training alone. Two patients, one with damage to the mid-cervical region and one with damage to the high-thoracic region, achieved over-ground walking (not on a treadmill) after 278 sessions of epidural stimulation and gait training over a period of 85 weeks and 81 sessions over a period of 15 weeks, respectively, and all four achieved independent standing and trunk stability. One patient had a hip fracture during training. (Funded by the Leona M. and Harry B. Helmsley Charitable Trust and others; ClinicalTrials.gov number, NCT02339233 .).


Assuntos
Terapia por Exercício , Recuperação de Função Fisiológica , Traumatismos da Medula Espinal/reabilitação , Estimulação da Medula Espinal , Caminhada , Adulto , Doença Crônica , Eletrodos Implantados , Espaço Epidural , Humanos , Locomoção , Masculino
10.
Neuromodulation ; 24(3): 405-415, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33794042

RESUMO

STUDY DESIGN: This is a narrative review focused on specific challenges related to adequate controls that arise in neuromodulation clinical trials involving perceptible stimulation and physiological effects of stimulation activation. OBJECTIVES: 1) To present the strengths and limitations of available clinical trial research designs for the testing of epidural stimulation to improve recovery after spinal cord injury. 2) To describe how studies can control for the placebo effects that arise due to surgical implantation, the physical presence of the battery, generator, control interfaces, and rehabilitative activity aimed to promote use-dependent plasticity. 3) To mitigate Hawthorne effects that may occur in clinical trials with intensive supervised participation, including rehabilitation. MATERIALS AND METHODS: Focused literature review of neuromodulation clinical trials with integration to the specific context of epidural stimulation for persons with chronic spinal cord injury. CONCLUSIONS: Standard of care control groups fail to control for the multiple effects of knowledge of having undergone surgical procedures, having implanted stimulation systems, and being observed in a clinical trial. The irreducible effects that have been identified as "placebo" require sham controls or comparison groups in which both are implanted with potentially active devices and undergo similar rehabilitative training.


Assuntos
Traumatismos da Medula Espinal , Estimulação da Medula Espinal , Ensaios Clínicos como Assunto , Espaço Epidural , Humanos , Medula Espinal , Traumatismos da Medula Espinal/terapia
11.
J Proteome Res ; 19(11): 4496-4515, 2020 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-32686424

RESUMO

Congenital Zika syndrome was first described due to increased incidence of congenital abnormalities associated with Zika virus (ZIKV) infection. Since the eye develops as part of the embryo central nervous system (CNS) structure, it becomes a specialized compartment able to display symptoms of neurodegenerative diseases and has been proposed as a noninvasive approach to the early diagnosis of neurological diseases. Ocular lesions result from defects that occurred during embryogenesis and can become apparent in newborns exposed to ZIKV. Furthermore, the absence of microcephaly cannot exclude the occurrence of ocular lesions and other CNS manifestations. Considering the need for surveillance of newborns and infants with possible congenital exposure, we developed a method termed cellular imprinting proteomic assay (CImPA) to evaluate the ocular surface proteome specific to infants exposed to ZIKV during gestation compared to nonexposure. CImPA combines surface cells and fluid capture using membrane disks and a large-scale quantitative proteomics approach, which allowed the first-time report of molecular alterations such as neutrophil degranulation, cell death signaling, ocular and neurological pathways, which are associated with ZIKV infection with and without the development of congenital Zika syndrome, CZS. Particularly, infants exposed to ZIKV during gestation and without early clinical symptoms could be detected using the CImPA method. Lastly, this methodology has broad applicability as it could be translated in the study of several neurological diseases to identify novel diagnostic biomarkers. Data are available via ProteomeXchange with identifier PXD014038.


Assuntos
Microcefalia , Complicações Infecciosas na Gravidez , Infecção por Zika virus , Zika virus , Feminino , Humanos , Lactente , Recém-Nascido , Gravidez , Proteômica , Infecção por Zika virus/diagnóstico
12.
Glycoconj J ; 33(6): 937-951, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27234710

RESUMO

Glycosylation is a very important post-translational modification involved in various cellular processes, such as cell adhesion, signal transduction and immune response. Urine is a rich source of glycoproteins and attractive biological fluid for biomarker discovery, owing to its availability, ease of collection, and correlation with pathophysiology of diseases. Although the urinary proteomics have been explored previously, the urinary glycoproteome characterization remains challenging requiring the development and optimization of analytical and bioinformatics methods for protein glycoprofiling. This study describes the high confident identification of 472 unique N-glycosylation sites covering 256 urinary glycoproteins. Besides, 202 unique N-glycosylation sites were identified in low molecular weight endogenous glycopeptides, which belong to 90 glycoproteins. Global site-specific characterization of the N-linked glycan heterogeneity was achieved by intact glycopeptide analysis, revealing 303 unique glycopeptides most of them displaying complex/hybrid glycans composed by sialic acid and fucose. These datasets consist in a valuable resource of glycoproteins and N-glycosylation sites found in healthy human urine that can be further explored in different disorders, in which the N-linked glycosylation may be aberrant.


Assuntos
Glicopeptídeos/urina , Glicoproteínas/urina , Adulto , Glicosilação , Humanos , Masculino
13.
Brain ; 137(Pt 5): 1394-409, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24713270

RESUMO

Previously, we reported that one individual who had a motor complete, but sensory incomplete spinal cord injury regained voluntary movement after 7 months of epidural stimulation and stand training. We presumed that the residual sensory pathways were critical in this recovery. However, we now report in three more individuals voluntary movement occurred with epidural stimulation immediately after implant even in two who were diagnosed with a motor and sensory complete lesion. We demonstrate that neuromodulating the spinal circuitry with epidural stimulation, enables completely paralysed individuals to process conceptual, auditory and visual input to regain relatively fine voluntary control of paralysed muscles. We show that neuromodulation of the sub-threshold motor state of excitability of the lumbosacral spinal networks was the key to recovery of intentional movement in four of four individuals diagnosed as having complete paralysis of the legs. We have uncovered a fundamentally new intervention strategy that can dramatically affect recovery of voluntary movement in individuals with complete paralysis even years after injury.


Assuntos
Terapia por Estimulação Elétrica/métodos , Locomoção/fisiologia , Paralisia , Modalidades de Fisioterapia , Medula Espinal/fisiologia , Adulto , Doença Crônica , Eletromiografia , Potencial Evocado Motor/fisiologia , Teste de Esforço , Humanos , Masculino , Movimento/fisiologia , Músculo Esquelético/fisiopatologia , Paralisia/patologia , Paralisia/reabilitação , Paralisia/terapia , Resultado do Tratamento , Adulto Jovem
14.
J Neurophysiol ; 111(5): 1088-99, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24335213

RESUMO

Epidural stimulation (ES) of the lumbosacral spinal cord has been used to facilitate standing and voluntary movement after clinically motor-complete spinal-cord injury. It seems of importance to examine how the epidurally evoked potentials are modulated in the spinal circuitry and projected to various motor pools. We hypothesized that chronically implanted electrode arrays over the lumbosacral spinal cord can be used to assess functionally spinal circuitry linked to specific motor pools. The purpose of this study was to investigate the functional and topographic organization of compound evoked potentials induced by the stimulation. Three individuals with complete motor paralysis of the lower limbs participated in the study. The evoked potentials to epidural spinal stimulation were investigated after surgery in a supine position and in one participant, during both supine and standing, with body weight load of 60%. The stimulation was delivered with intensity from 0.5 to 10 V at a frequency of 2 Hz. Recruitment curves of evoked potentials in knee and ankle muscles were collected at three localized and two wide-field stimulation configurations. Epidural electrical stimulation of rostral and caudal areas of lumbar spinal cord resulted in a selective topographical recruitment of proximal and distal leg muscles, as revealed by both magnitude and thresholds of the evoked potentials. ES activated both afferent and efferent pathways. The components of neural pathways that can mediate motor-evoked potentials were highly dependent on the stimulation parameters and sensory conditions, suggesting a weight-bearing-induced reorganization of the spinal circuitries.


Assuntos
Terapia por Estimulação Elétrica , Potencial Evocado Motor , Músculo Esquelético/fisiopatologia , Paralisia/reabilitação , Traumatismos da Medula Espinal/reabilitação , Adulto , Eletrodos Implantados , Eletromiografia , Humanos , Vértebras Lombares/fisiopatologia , Masculino , Traumatismos da Medula Espinal/fisiopatologia , Adulto Jovem
15.
Neurotrauma Rep ; 5(1): 277-292, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38515546

RESUMO

Activity-based training and lumbosacral spinal cord epidural stimulation (scES) have the potential to restore standing and walking with self-balance assistance after motor complete spinal cord injury (SCI). However, improvements in upright postural control have not previously been addressed in this population. Here, we implemented a novel robotic postural training with scES, performed with free hands, to restore upright postural control in individuals with chronic, cervical (n = 5) or high-thoracic (n = 1) motor complete SCI, who had previously undergone stand training with scES using a walker or a standing frame for self-balance assistance. Robotic postural training re-enabled and/or largely improved the participants' ability to control steady standing, self-initiated trunk movements and upper limb reaching movements while standing with free hands, receiving only external assistance for pelvic control. These improvements were associated with neuromuscular activation pattern adaptations above and below the lesion. These findings suggest that the human spinal cord below the level of injury can generate meaningful postural responses when its excitability is modulated by scES, and can learn to improve these responses. Upright postural control improvements can enhance functional motor recovery promoted by scES after severe SCI.

16.
Malar J ; 12: 184, 2013 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-23734739

RESUMO

BACKGROUND: Isoprenoids are the most diverse and abundant group of natural products. In Plasmodium falciparum, isoprenoid synthesis proceeds through the methyl erythritol diphosphate pathway and the products are further metabolized by farnesyl diphosphate synthase (FPPS), turning this enzyme into a key branch point of the isoprenoid synthesis. Changes in FPPS activity could alter the flux of isoprenoid compounds downstream of FPPS and, hence, play a central role in the regulation of a number of essential functions in Plasmodium parasites. METHODS: The isolation and cloning of gene PF3D7_18400 was done by amplification from cDNA from mixed stage parasites of P. falciparum. After sequencing, the fragment was subcloned in pGEX2T for recombinant protein expression. To verify if the PF3D7_1128400 gene encodes a functional rPfFPPS protein, its catalytic activity was assessed using the substrate [4-14C] isopentenyl diphosphate and three different allylic substrates: dimethylallyl diphosphate, geranyl diphosphate or farnesyl diphosphate. The reaction products were identified by thin layer chromatography and reverse phase high-performance liquid chromatography. To confirm the product spectrum formed of rPfFPPS, isoprenic compounds were also identified by mass spectrometry. Apparent kinetic constants KM and Vmax for each substrate were determined by Michaelis-Menten; also, inhibition assays were performed using risedronate. RESULTS: The expressed protein of P. falciparum FPPS (rPfFPPS) catalyzes the synthesis of farnesyl diphosphate, as well as geranylgeranyl diphosphate, being therefore a bifunctional FPPS/geranylgeranyl diphosphate synthase (GGPPS) enzyme. The apparent KM values for the substrates dimethylallyl diphosphate, geranyl diphosphate and farnesyl diphosphate were, respectively, 68 ± 5 µM, 7.8 ± 1.3 µM and 2.06 ± 0.4 µM. The protein is expressed constitutively in all intra-erythrocytic stages of P. falciparum, demonstrated by using transgenic parasites with a haemagglutinin-tagged version of FPPS. Also, the present data demonstrate that the recombinant protein is inhibited by risedronate. CONCLUSIONS: The rPfFPPS is a bifunctional FPPS/GGPPS enzyme and the structure of products FOH and GGOH were confirmed mass spectrometry. Plasmodial FPPS represents a potential target for the rational design of chemotherapeutic agents to treat malaria.


Assuntos
Farnesiltranstransferase/genética , Farnesiltranstransferase/metabolismo , Plasmodium falciparum/enzimologia , Cromatografia Líquida , Clonagem Molecular , Farnesiltranstransferase/química , Plasmodium falciparum/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem , Terpenos/metabolismo
17.
ScientificWorldJournal ; 2013: 937407, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23737734

RESUMO

Amphibians are known by cutaneous glands, spread over the skin, containing toxins (proteins, peptides, biogenic amines, steroidal bufadienolides, and alkaloids) used as chemical defense against predators and microbial infection. Toads are characterized by the presence of parotoid macroglands. The common toads have lately been divided into two genera: Bufo (Europe, Asia, and Africa) and Rhinella (South America). Basal Rhaebo genus is exclusively of Central America and Amazon region. Although Rhinella and Rhaebo are related, species may share differences due to the diversity of environments that they live in. In this work, we have performed a biochemical characterization of the components of the poison of eight Rhinella species and one Rhaebo by means of RP-HPLC with either UV or MS detection and by SDS-PAGE, in order to verify whether phylogenetic and biological differences, such as habitat, diet, and defensive strategies, between them may also be reflected in poison composition. Although some components were common among the secretions, we were able to identify exclusive molecules to some species. The fact that closely related animals living in different habitats secrete different molecules into the skin is an indication that biological features, and not only evolution, seem to directly influence the skin secretion composition.


Assuntos
Alcaloides/metabolismo , Venenos de Anfíbios/metabolismo , Bufonidae/classificação , Bufonidae/metabolismo , Glândula Parótida/metabolismo , Esteroides/metabolismo , Animais , América do Sul , Especificidade da Espécie
18.
Front Bioeng Biotechnol ; 11: 1073716, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36815892

RESUMO

Introduction: Lumbosacral spinal cord neuromodulation has shown the ability to restore voluntary control and stepping in individuals with chronic spinal cord injury. Methods: We combined cervical transcutaneous and lumbar epidural stimulation to explore the brain-spinal connectomes and their influence in spinal excitability and interlimb coupling. Four individuals with a prior implanted lumbosacral spinal cord epidural stimulator participated in the study. We assessed lower extremity muscle activity and kinematics during intentional stepping in both non-weight bearing and weight-bearing environments. Results: Our results showed an inhibition of motor evoked potentials generated by spinal cord epidural stimulation when cervical transcutaneous stimulation is applied. In contrast, when intentional stepping is performed in a non-weight bearing setting, range of motion, motor output amplitude, and coordination are improved when cervical transcutaneous and lumbar epidural stimulations are combined. Similarly, with both stimulations applied, coordination is improved and motor output variability is decreased when intentional stepping is performed on a treadmill with body weight support. Discussion: Combined transcutaneous cervical and epidural lumbar stimulation demonstrated an improvement of voluntary control of stepping in individuals with chronic motor complete paralysis. The immediate functional improvement promoted by the combination of cervical and lumbar stimulation adds to the body of evidence for increasing spinal excitability and improvement of function that is possible in individuals with chronic paralysis.

19.
J Clin Med ; 12(21)2023 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-37959340

RESUMO

Motor recovery following a complete spinal cord injury is not likely. This is partially due to insurance limitations. Rehabilitation strategies for individuals with this type of severe injury focus on the compensation for the activities of daily living in the home and community and not on the restoration of function. With limited time in therapies, the initial goals must focus on getting the patient home safely without the expectation of recovery of voluntary movement below the level of injury. In this study, we report a case of an individual with a chronic, cervical (C3)-level clinically motor- and sensory-complete injury who was able to perform voluntary movements with both upper and lower extremities when positioned in a sensory-rich environment conducive to the specific motor task. We show how he is able to intentionally perform push-ups, trunk extensions and leg presses only when appropriate sensory information is available to the spinal circuitry. These data show that the human spinal circuitry, even in the absence of clinically detectable supraspinal input, can generate motor patterns effective for the execution of various upper and lower extremity tasks, only when appropriate sensory information is present. Neurorehabilitation in the right sensory-motor environment that can promote partial recovery of voluntary movements below the level of injury, even in individuals diagnosed with a clinically motor-complete spinal cord injury.

20.
Bioengineering (Basel) ; 10(9)2023 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-37760167

RESUMO

Cervical spinal cord injury (SCI) leads to impaired trunk motor control, negatively impacting the performance of activities of daily living in the affected individuals. Improved trunk control with better sitting posture has been previously observed due to neuromuscular electrical stimulation and transcutaneous spinal stimulation, while improved postural stability has been observed with spinal cord epidural stimulation (scES). Hence, we studied how trunk-specific scES impacts sitting independence and posture. Fourteen individuals with chronic, severe cervical SCI with an implanted neurostimulator performed a 5-min tall-sit task without and with trunk-specific scES. Spine posture was assessed by placing markers on five spine levels and evaluating vertical spine inclination angles. Duration of trunk manual assistance was used to assess independence along with the number of independence changes and average independence score across those changes. With scES, the sacrum-L1 inclination and number of independence changes tended to decrease by 1.64 ± 3.16° (p = 0.07; Cohen's d = 0.53) and 9.86 ± 16.8 (p = 0.047; Cohen's d = 0.59), respectively. Additionally, for the participants who had poor sitting independence without scES, level of independence tended to increase by 12.91% [0%, 31.52%] (p = 0.38; Cohen's d = 0.96) when scES was present. Hence, trunk-specific scES promoted improvements in lower spine posture and lower levels of trunk assistance.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA