Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 152
Filtrar
1.
Biomater Sci ; 12(18): 4650-4663, 2024 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-39150405

RESUMEN

Upconversion nanoparticles (UCNPs) are a class of nanomaterials composed of lanthanide ions with great potential for paraclinical applications, especially in laboratory and imaging sciences. UCNPs have tunable optical properties and the ability to convert long-wavelength (low energy) excitation light into short-wavelength (high energy) emission in the ultraviolet (UV)-visible and near-infrared (NIR) spectral regions. The core-shell structure of UCNPs can be customized through chemical synthesis to meet the needs of different applications. The surface of UCNPs can also be tailored by conjugating small molecules and/or targeting ligands to achieve high specificity and selectivity, which are indispensable elements in biomedical applications. Specifically, coatings can enhance the water dispersion, biocompatibility, and efficiency of UCNPs, thereby optimizing their functionality and boosting their performance. In this context, multimodal imaging can provide more accurate in vivo information when combined with nuclear imaging. This article intends to provide a comprehensive review of the core structure, structure optimization, surface modification, and various recent applications of UCNPs in biomolecular detection, cell imaging, tumor diagnosis, and deep tissue imaging. We also present and discuss some of their critical challenges, limitations, and potential future directions.


Asunto(s)
Elementos de la Serie de los Lantanoides , Nanopartículas , Elementos de la Serie de los Lantanoides/química , Nanopartículas/química , Humanos , Animales , Neoplasias/diagnóstico por imagen
2.
PLoS One ; 19(4): e0301430, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38578715

RESUMEN

BACKGROUND: SCI is a time-sensitive debilitating neurological condition without treatment options. Although the central nervous system is not programmed for effective endogenous repairs or regeneration, neuroplasticity partially compensates for the dysfunction consequences of SCI. OBJECTIVE AND HYPOTHESIS: The purpose of our study is to investigate whether early induction of hypothermia impacts neuronal tissue compensatory mechanisms. Our hypothesis is that although neuroplasticity happens within the neuropathways, both above (forelimbs) and below (hindlimbs) the site of spinal cord injury (SCI), hypothermia further influences the upper limbs' SSEP signals, even when the SCI is mid-thoracic. STUDY DESIGN: A total of 30 male and female adult rats are randomly assigned to four groups (n = 7): sham group, control group undergoing only laminectomy, injury group with normothermia (37°C), and injury group with hypothermia (32°C +/-0.5°C). METHODS: The NYU-Impactor is used to induce mid-thoracic (T8) moderate (12.5 mm) midline contusive injury in rats. Somatosensory evoked potential (SSEP) is an objective and non-invasive procedure to assess the functionality of selective neuropathways. SSEP monitoring of baseline, and on days 4 and 7 post-SCI are performed. RESULTS: Statistical analysis shows that there are significant differences between the SSEP signal amplitudes recorded when stimulating either forelimb in the group of rats with normothermia compared to the rats treated with 2h of hypothermia on day 4 (left forelimb, p = 0.0417 and right forelimb, p = 0.0012) and on day 7 (left forelimb, p = 0.0332 and right forelimb, p = 0.0133) post-SCI. CONCLUSION: Our results show that the forelimbs SSEP signals from the two groups of injuries with and without hypothermia have statistically significant differences on days 4 and 7. This indicates the neuroprotective effect of early hypothermia and its influences on stimulating further the neuroplasticity within the upper limbs neural network post-SCI. Timely detection of neuroplasticity and identifying the endogenous and exogenous factors have clinical applications in planning a more effective rehabilitation and functional electrical stimulation (FES) interventions in SCI patients.


Asunto(s)
Hipotermia , Traumatismos de la Médula Espinal , Humanos , Ratas , Masculino , Femenino , Animales , Traumatismos de la Médula Espinal/terapia , Potenciales Evocados Somatosensoriales/fisiología , Sistema Nervioso Central , Plasticidad Neuronal/fisiología , Médula Espinal
3.
Hepatology ; 80(3): 742-753, 2024 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-38536021

RESUMEN

The liver transplantation (LT) evaluation and waitlisting process is subject to variations in care that can impede quality. The American Association for the Study of Liver Diseases (AASLD) Practice Metrics Committee (PMC) developed quality measures and patient-reported experience measures along the continuum of pre-LT care to reduce care variation and guide patient-centered care. Following a systematic literature review, candidate pre-LT measures were grouped into 4 phases of care: referral, evaluation and waitlisting, waitlist management, and organ acceptance. A modified Delphi panel with content expertise in hepatology, transplant surgery, psychiatry, transplant infectious disease, palliative care, and social work selected the final set. Candidate patient-reported experience measures spanned domains of cognitive health, emotional health, social well-being, and understanding the LT process. Of the 71 candidate measures, 41 were selected: 9 for referral; 20 for evaluation and waitlisting; 7 for waitlist management; and 5 for organ acceptance. A total of 14 were related to structure, 17 were process measures, and 10 were outcome measures that focused on elements not typically measured in routine care. Among the patient-reported experience measures, candidates of LT rated items from understanding the LT process domain as the most important. The proposed pre-LT measures provide a framework for quality improvement and care standardization among candidates of LT. Select measures apply to various stakeholders such as referring practitioners in the community and LT centers. Clinically meaningful measures that are distinct from those used for regulatory transplant reporting may facilitate local quality improvement initiatives to improve access and quality of care.


Asunto(s)
Trasplante de Hígado , Listas de Espera , Humanos , Trasplante de Hígado/normas , Estados Unidos , Cuidados Preoperatorios/normas , Cuidados Preoperatorios/métodos , Técnica Delphi , Indicadores de Calidad de la Atención de Salud
4.
Small ; 18(45): e2203629, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36084240

RESUMEN

Dendrimers are polymers with well-defined 3D branched structures that are vastly utilized in various neurotheranostics and biomedical applications, particularly as nanocarrier vectors. Imaging agents can be loaded into dendrimers to improve the accuracy of diagnostic imaging processes. Likewise, combining pharmaceutical agents and anticancer drugs with dendrimers can enhance their solubility, biocompatibility, and efficiency. Practically, by modifying ligands on the surface of dendrimers, effective therapeutic and diagnostic platforms can be constructed and implemented for targeted delivery. Dendrimer-based nanocarriers also show great potential in gene delivery. Since enzymes can degrade genetic materials during their blood circulation, dendrimers exhibit promising packaging and delivery alternatives, particularly for central nervous system (CNS) treatments. The DNA and RNA encapsulated in dendrimers represented by polyamidoamine that are used for targeted brain delivery, via chemical-structural adjustments and appropriate generation, significantly improve the correlation between transfection efficiency and cytotoxicity. This article reports a comprehensive review of dendrimers' structures, synthesis processes, and biological applications. Recent progress in diagnostic imaging processes and therapeutic applications for cancers and other CNS diseases are presented. Potential challenges and future directions in the development of dendrimers, which provide the theoretical basis for their broader applications in healthcare, are also discussed.


Asunto(s)
Dendrímeros , Dendrímeros/química , Portadores de Fármacos/química , Técnicas de Transferencia de Gen , Transfección , Solubilidad , Sistemas de Liberación de Medicamentos
5.
Adv Healthc Mater ; 11(11): e2102610, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35166052

RESUMEN

Intravenous delivery of nanomaterials containing therapeutic agents and various cargos for treating neurological disorders is often constrained by low delivery efficacy due to difficulties in passing the blood-brain barrier (BBB). Nanoparticles (NPs) administered intranasally can move along olfactory and trigeminal nerves so that they do not need to pass through the BBB, allowing non-invasive, direct access to selective neural pathways within the brain. Hence, intranasal (IN) administration of NPs can effectively deliver drugs and genes into targeted regions of the brain, holding potential for efficacious disease treatment in the central nervous system (CNS). In this review, current methods for delivering conjugated NPs to the brain are primarily discussed. Distinctive potential mechanisms of therapeutic nanocomposites delivered via IN pathways to the brain are then discussed. Recent progress in developing functional NPs for applications in multimodal bioimaging, drug delivery, diagnostics, and therapeutics is also reviewed. This review is then concluded by discussing existing challenges, new directions, and future perspectives in IN delivery of nanomaterials.


Asunto(s)
Encéfalo , Nanopartículas , Administración Intranasal , Barrera Hematoencefálica/metabolismo , Encéfalo/metabolismo , Sistemas de Liberación de Medicamentos/métodos , Polímeros/farmacología
6.
Biomedicines ; 10(1)2022 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-35052784

RESUMEN

Even nowadays, the question of whether hypothermia can genuinely be considered therapeutic care for patients with traumatic spinal cord injury (SCI) remains unanswered. Although the mechanisms of hypothermia action are yet to be fully explored, early hypothermia for patients suffering from acute SCI has already been implemented in clinical settings. This article discusses measures for inducing various forms of hypothermia and summarizes several hypotheses describing the likelihood of hypothermia mechanisms of action. We present our objective neuro-electrophysiological results and demonstrate that early hypothermia manifests neuroprotective effects mainly during the first- and second-month post-SCI, depending on the severity of the injury, time of intervening, duration, degree, and modality of inducing hypothermia. Nevertheless, eventually, its beneficial effects gradually but consistently diminish. In addition, we report potential complications and side effects for the administration of general hypothermia with a unique referment to the local hypothermia. We also provide evidence that instead of considering early hypothermia post-SCI a therapeutic approach, it is more a neuroprotective strategy in acute and sub-acute phases of SCI that mostly delay, but not entirely avoid, the natural history of the pathophysiological events. Indeed, the most crucial rationale for inducing early hypothermia is to halt these devastating inflammatory and apoptotic events as early and as much as possible. This, in turn, creates a larger time-window of opportunity for physicians to formulate and administer a well-designed personalized treatment for patients suffering from acute traumatic SCI.

7.
Korean J Gastroenterol ; 78(3): 161-167, 2021 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-34565785

RESUMEN

BACKGROUNDS/AIMS: Nonalcoholic fatty liver disease (NAFLD) encompasses a range of diseases from nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH) and has been linked to cardiovascular disease and sub-clinical cardiac remodeling. This paper presents a retrospective study of biopsy-proven NAFL and NASH to examine the differences in subclinical cardiac remodeling. METHODS: Patients were recruited from an institutional repository of patients with liver-biopsy-confirmed NAFLD. Patients with a transthoracic echocardiogram (TTE) within 12 months of the liver biopsy were included. The parameters of the diastolic dysfunction were reviewed for the differences between NAFL and NASH as well as between the stages and grades of NASH. RESULTS: Thirty-three patients were included in the study, 17 with NAFL and 16 with NASH. The NASH patients were more likely to have lower platelets, higher AST, higher ALT, and higher rates of type 2 diabetes mellitus, coronary artery disease, and hypertension than the NAFL patients. The E/e' ratio on transthoracic echocardiogram was significantly higher in NASH compared to NAFL, advanced-stage NASH compared to early stage, and high-grade NASH compared to low-grade. The E/e' ratio was also significantly higher in NASH than NAFL in patients without diabetes mellitus. The presence of diastolic dysfunction trended toward significance. The other markers of diastolic dysfunction were similar. Logistic regression revealed a statistical association with E/e' and NASH. CONCLUSIONS: NASH patients had evidence of a higher E/e' ratio than NAFL, and there was a trend towards a significant diastolic dysfunction. Patients with NASH compared to NAFL should be closely monitored for signs and symptoms of cardiac dysfunction.


Asunto(s)
Diabetes Mellitus Tipo 2 , Cardiopatías , Enfermedad del Hígado Graso no Alcohólico , Biopsia , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/diagnóstico , Humanos , Hígado/diagnóstico por imagen , Enfermedad del Hígado Graso no Alcohólico/complicaciones , Enfermedad del Hígado Graso no Alcohólico/diagnóstico , Estudios Retrospectivos
8.
Spinal Cord ; 59(11): 1206-1209, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34493803

RESUMEN

STUDY DESIGN: Descriptive secondary analysis of two spinal cord injury (SCI) animal models. OBJECTIVES: To compare the somatosensory evoked potential (SSEP) and motor behavioral (BBB) assessments of the two most used rodent SCI models (contusion and transection), to elucidate their functional similarity and differences over the acute phase of 3 weeks. SETTING: Neuro-electrophysiology SSEP and motor behavioral BBB assessments are used to provide a comparative analysis of the functional changes among various severities of contusion and transection SCI. METHODS: Adult male and female rats randomly grouped (n = 5) as following: mild (6.25 mm), moderate (12.5 mm), severe (25 mm), and very severe (50 mm) contusion as well as right T10 hemi-transection (RxI), left T8 and right T10 double hemi-transection (DxI), and T8 complete transection (CxI) injuries, plus the control group (laminectomy with no injury). Animal weight, body temperature, anesthesia, surgical procedures, electrophysiological SSEP monitoring, locomotion BBB scoring, and statistical analysis were identical among all animal groups. RESULTS: Statistical analysis of the SSEP and BBB data from both contusion and transection injury models indicate significant differences (P < 0.05). The results also show remarkable similarity for the severe and very severe contusion injuries to the complete transection, the moderate contusion injury to the double hemi-transection, and the mild contusion injury to the T10 hemi-transection injury. CONCLUSION: Although contusion and transection spinal cord injuries have two completely different pathophysiologies, their injury progress during acute phase follow a similar trend.


Asunto(s)
Contusiones , Traumatismos de la Médula Espinal , Animales , Femenino , Masculino , Ratas , Modelos Animales de Enfermedad , Potenciales Evocados Somatosensoriales/fisiología , Locomoción , Ratas Sprague-Dawley , Médula Espinal , Traumatismos de la Médula Espinal/diagnóstico
9.
Brain Res Bull ; 173: 22-27, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33991605

RESUMEN

In this paper, we investigate the forelimbs somatosensory evoked potential (SSEP) signals, which are representative of the integrity of ascending sensory pathways and their stability as well as function, recorded from corresponding cortices, post thoracic spinal cord injury (SCI). We designed a series of distinctive transection SCI to investigate whether forelimbs SSEPs change after right T10 hemi-transection, T8 and T10 double hemi-transection and T8 complete transection in rat model of SCI. We used electrical stimuli to stimulate median nerves and recorded SSEPs from left and right somatosensory areas of both cortices. We monitored pre-injury baseline and verified changes in forelimbs SSEP signals on Days 4, 7, 14, and 21 post-injury. We previously characterized hindlimb SSEP changes for the abovementioned transection injuries. The focus of this article is to investigate the quality and quantity of changes that may occur in the forelimb somatosensory pathways post-thoracic transection SCI. It is important to test the stability of forelimb SSEPs following thoracic SCI because of their potential utility as a proxy baseline for the traumatic SCIs in clinical cases wherein there is no opportunity to gather baseline of the lower extremities. We observed that the forelimb SSEP amplitudes increased following thoracic SCI but gradually returned to the baseline. Despite changes found in the raw signals, statistical analysis found forelimb SSEP signals become stable relatively soon. In summary, though there are changes in value (with p > 0.05), they are not statistically significant. Therefore, the null hypothesis that the mean of the forelimb SSEP signals are the same across multiple days after injury onset cannot be rejected during the acute phase.


Asunto(s)
Potenciales Evocados Somatosensoriales/fisiología , Miembro Anterior/fisiopatología , Corteza Somatosensorial/fisiopatología , Traumatismos de la Médula Espinal/fisiopatología , Vértebras Torácicas/fisiopatología , Animales , Modelos Animales de Enfermedad , Femenino , Masculino , Ratas , Ratas Sprague-Dawley
10.
J Hepatol ; 75(2): 284-291, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33746083

RESUMEN

BACKGROUND & AIMS: Large prospective studies to establish the prevalence of non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH), are lacking. We prospectively assessed the prevalence and severity of NAFLD/NASH in a cohort of asymptomatic middle-aged Americans attending a colonoscopy class at a gastroenterology clinic. METHODS: Screening for NAFLD was performed using magnetic resonance (MR)-based LiverMultiScan® proton density fat fraction (LMS-PDFF). MR exams also included corrected T1 and elastography for liver stiffness measurement (LSM). FibroScan® was also used to measure LSM. Participants with predetermined abnormal imaging parameters were offered a liver biopsy. Biopsies were read in a blinded fashion with results based on the consensus by 2 expert pathologists. The prevalence of NAFLD was determined by PDFF ≥5% or by histological diagnosis of NAFLD (if biopsy data were available). The prevalence of NASH was defined by biopsy. RESULTS: Of 835 participants, 664 met the inclusion and exclusion criteria. The mean age was 56 ± 6.4 years, 50% were male, the mean BMI was 30.48 ± 5.46 kg/m2, and 52% were obese. The prevalence of NAFLD was 38% (95% CI 34-41%) and the prevalence of NASH was 14% (95% CI 12-17%). While no patient had cirrhosis on biopsy, significant fibrosis (F ≥2) was present in 5.9% (95% CI 4-8%) and bridging fibrosis in 1.6% (95% CI 1-3%). In a multivariable analysis, factors associated with the presence of NASH were race, obesity, and diabetes. CONCLUSION: Using state-of-the-art liver imaging modalities and reference biopsy, this study establishes an overall prevalence of NAFLD of 38% and NASH by biopsy of 14% in this cohort of asymptomatic middle-aged US adults. LAY SUMMARY: There are no prospective studies to determine how common is nonalcoholic steatohepatitis (NASH), the severe form of non-alcoholic fatty liver disease (NAFLD). In a large number of asymptomatic middle-aged Americans, we used a combination of state-of-the-art liver imaging methods and liver biopsy to prospectively determine the prevalence of NAFLD and NASH. NAFLD was diagnosed in 38%, NASH in 14%, and significant liver fibrosis in 6% of asymptomatic middle-aged Americans.


Asunto(s)
Hígado Graso/diagnóstico , Enfermedad del Hígado Graso no Alcohólico/diagnóstico , Estudios de Cohortes , Hígado Graso/epidemiología , Femenino , Humanos , Modelos Logísticos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Enfermedad del Hígado Graso no Alcohólico/epidemiología , Prevalencia , Estudios Prospectivos , Estadísticas no Paramétricas , Estados Unidos/epidemiología
11.
Adv Exp Med Biol ; 1293: 641-657, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33398847

RESUMEN

Upconversion nanoparticle-mediated optogenetics enables remote delivery of upconverted visible light from a near-infrared light source to targeted neurons or areas, with the precision of a pulse of laser light in vivo for effective deep-tissue neuromodulation. Compared to conventional optogenetic tools, upconversion nanoparticle-based optogenetic techniques are less invasive and cause reduced inflammation with minimal levels of tissue damage. In addition to the optical stimulation, this design offers simultaneously temperature recording in proximity to the stimulated area. This chapter strives to provide life science researchers with an introduction to upconversion optogenetics, starting from the fundamental concept of photon upconversion and nanoparticle fabrication to the current state-of-the-art of surface engineering and device integration for minimally invasive neuromodulation.


Asunto(s)
Nanopartículas , Optogenética , Rayos Infrarrojos , Neuronas , Fotones
12.
Gastroenterology ; 160(1): 219-231.e1, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32781086

RESUMEN

BACKGROUND & AIMS: Aldafermin, an engineered analog of fibroblast growth factor 19, inhibits bile acid synthesis and regulates metabolic homeostasis. We report results from a 24-week, phase 2 study, with serial liver biopsies, of patients with nonalcoholic steatohepatitis (NASH). METHODS: We performed a double-blind study of 78 patients with NASH at 9 centers in the United States. Key inclusion criteria were biopsy-proven NASH with Nonalcoholic Fatty Liver Disease Activity Score ≥4, stage 2 or 3 fibrosis by NASH Clinical Research Network classification, and absolute liver fat content ≥8%, measured by magnetic resonance imaging-proton density fat fraction. Patients were randomly assigned (1:2) to groups given subcutaneous placebo (n = 25) or aldafermin 1 mg (n = 53) daily for 24 weeks. The primary outcome was change in absolute liver fat content from baseline at week 24. Secondary outcomes included serum markers and histologic measures of fibrosis improvement and NASH resolution. RESULTS: At week 24, the aldafermin group had a significant reduction in absolute liver fat content (reduction of 7.7%) compared with placebo (reduction of 2.7%; difference, reduction of 5.0%; 95% confidence interval, reduction of 8.0%-1.9%; P = .002). Aldafermin produced significantly greater decreases in levels of 7α-hydroxy-4-cholesten-3-one, bile acids, alanine and aspartate aminotransferases, and neoepitope-specific N-terminal pro-peptide of type III collagen (Pro-C3) than placebo. Fibrosis improvement (≥1 stage) with no worsening of NASH was achieved in 38% of patients receiving aldafermin vs 18% of patients receiving placebo (P = .10). NASH resolution with no worsening of fibrosis was observed in 24% of patients given aldafermin vs 9% of patients given placebo (P = .20). Discontinuations due to adverse events occurred in no patients in the aldafermin group and 4% of patients in the placebo group. CONCLUSIONS: In a phase 2 trial of patients with NASH, aldafermin reduced liver fat and produced a trend toward fibrosis improvement. ClinicalTrials.gov, Number: NCT02443116.


Asunto(s)
Factores de Crecimiento de Fibroblastos/análisis , Factores de Crecimiento de Fibroblastos/uso terapéutico , Cirrosis Hepática/tratamiento farmacológico , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Adulto , Anciano , Método Doble Ciego , Femenino , Humanos , Cirrosis Hepática/metabolismo , Cirrosis Hepática/patología , Masculino , Persona de Mediana Edad , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Enfermedad del Hígado Graso no Alcohólico/patología , Resultado del Tratamiento
13.
Ann Biomed Eng ; 49(1): 57-74, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33140242

RESUMEN

Current developments being made in upper limb prostheses are focused on replacing lost sensory information to the amputees. Providing sensory stimulation from the prosthesis can directly improve control over the prosthetic and provide a sense of body ownership. The focus of this review article is on recent developments while including foundational knowledge for some of the critical concepts in neural prostheses. Reported concepts follow the flow of information from sensors to signal processing, with emphasis on texture recognition, and then to sensory stimulation strategies that reestablish the lost sensory feedback loop. Prosthetic sensors are used to detect the physical environment, converting pressure, force, and position into electrical signals. The electrical signals can then be processed in an effort to identify the surrounding environment using distinctive characteristics such as stiffness and texture. In order for the amputee to use this information in a natural manner, there must be real-time sensory stimulation, perception, and motor control of the prosthesis. Although truly complete sensory replacement has not yet been realized, some basic percepts can be partially restored, allowing progress towards a more realistic prosthesis with natural sensations.


Asunto(s)
Miembros Artificiales , Retroalimentación Sensorial , Extremidad Superior/fisiología , Estimulación Eléctrica , Humanos , Extremidad Superior/inervación
14.
J Chromatogr A ; 1636: 461783, 2021 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-33340744

RESUMEN

New Psychoactive Substances (NPS) are quickly developing to evade legislation, posing unprecedented challenges to public health and law enforcement authorities around the world. The aim of this work was to develop and validate a simple and reliable non-target gas chromatography/mass spectrometry (GC/MS) analytical method based on linear retention indexes for the expeditious identification of NPS without the need of analytical standards. The method was optimized and validated for 22 different drugs covering ten categories: phenethylamines (amphetamine, MDMA, methamphetamine, 25CNBOMe, 2-FA, 5-MAPB), "classic" drugs (cocaine, ephedrine, THC, heroine), synthetic cannabinoids (JWH-081, AM-2201, JWH-210, MAM-2201), piperazines (o-CPP, p-CPP), tryptamines (5-MeO-MiPT), synthetic cathinones (N-ethylpentylone), synthetic opioids (U-47700), aminoindanes (5-IAI), plant-based substances (Salvinorin-A) and "other" (methiopropamine). Three figures of merit (Selectivity, Precision and Robustness) were evaluated with retention index confidence intervals ranging from 0.5 to 20.6 i.u. and relative standard deviations in the range of 0.003% to 0.027% (repeatability) and 0.02% to 0.29% (intermediate precision). A general equation for estimating linear retention index variation as a function of retention time tolerance has been derived. This result in combination with a 2III6-3 fractional factorial design allowed to conclude column polarity to be only statistically relevant factor as compared to gas flow, split ratio, injection temperature, temperature program offset and column brand.


Asunto(s)
Cromatografía de Gases y Espectrometría de Masas/métodos , Psicotrópicos/análisis , Analgésicos Opioides/análisis , Cannabinoides/análisis , Humanos , Modelos Teóricos , Fenetilaminas/análisis , Reproducibilidad de los Resultados
15.
J Neurosci Methods ; 343: 108858, 2020 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-32653385

RESUMEN

Patients who suffered from spinal cord injury (SCI) that come to healthcare professionals for diagnosis and treatment do not have electrophysiology baseline of somatosensory evoked potential (SSEP). The SSEP has always been used in research for data comparison to detect onset and severity of the SCI as well as for assessing its progress, endogenous and therapeutic recovery. This unmet need has motivated us to develop a new tool to substitute the baseline data with forelimb SSEP data of the same day. In this study, we report the development and investigation of three distinctive thoracic transections (right T10 hemi-transection (Rxl), left T8 and right T10 double hemi-transection (Dxl) and T8 complete transection (Cxl)) spinal cord injuries in an adult rat model. We used our well-established monitoring methods to obtain SSEP baselines as well as post-injury signals from days 4, 7, 14 and 21. We observed that spectral coherences obtained from non-injured spinal cord pathways are always above 0.8. The spectral coherence is dimensionless measure with values between 0 and 1 and measures the correlation between two time signals in the frequency domain. Analysis of variance (ANOVA) results also showed that there is a significant difference between the spectral coherence componanet means before and after injury with reaching p = 0.05 for Rxl, p = 0.02 for DxI, and p = 0.00 for CxI. Our signal processing enables us to replicate comparable detection of the natural history of injuries longitudinally without the implication of baseline SSEP signals, highlighting the potential of this analysis method for clinical studies.


Asunto(s)
Potenciales Evocados Somatosensoriales , Traumatismos de la Médula Espinal , Animales , Miembro Anterior , Humanos , Ratas , Procesamiento de Señales Asistido por Computador , Médula Espinal
16.
Osteoporos Int ; 31(9): 1733-1740, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32346774

RESUMEN

The effects of sedentary behavior on adolescents' bone health are controversial because, even in normal weight individuals, the excessive time spent in some specific types of these behaviors appears to have no negative effect on bone health. PURPOSE: To analyze the relationship between sedentary behaviors and bone mass in adolescents. METHODS: One hundred four adolescent boys and girls, aged 10 to 14 years, were divided into normal weight and overweight according to weight status. Specific sedentary behaviors (time spent on the Internet for school and non-school purposes, using the computer, watching television, and playing videogames) were assessed by questionnaire, and the total sedentary behavior time by accelerometry. Bone parameters were collected using X-ray absorptiometry, using total and lumbar bone mineral density (BMD) and total and lumbar bone mineral content (BMC) values. RESULTS: In both groups, the time spent on the Internet for non-school purposes was positively correlated to the total and lumbar BMD. Also, while in the overweight group, the time spent using the computer was negatively correlated to lumbar BMD, and the time spent on the Internet for non-school purposes was positively correlated to the total and lumbar BMC, and in the normal weight group, the time spent on the Internet for non-school purposes was positively correlated to lumbar BMC. CONCLUSIONS: Adolescents who spend more time in sedentary behavior, especially using the Internet for non-school purposes, have higher BMD and BMC, while normal weight adolescents who spend more time on the computer have lower BMD.


Asunto(s)
Densidad Ósea , Conducta Sedentaria , Absorciometría de Fotón , Adolescente , Peso Corporal , Huesos , Niño , Femenino , Humanos , Vértebras Lumbares , Masculino
17.
Neuromolecular Med ; 22(4): 447-463, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-31916220

RESUMEN

Functional electrical stimulation (FES) has been widely adopted to elicit muscle contraction in rehabilitation training after spinal cord injury (SCI). Conventional FES modalities include stimulations coupled with rowing, cycling, assisted walking and other derivatives. In this review, we studied thirteen clinical reports from the past 5 years and evaluated the effects of various FES aided rehabilitation plans on the functional recovery after SCI, highlighting upper and lower extremity strength, cardiopulmonary function, and balder control. We further explored potential mechanisms of FES using the Hebbian theory and lumbar locomotor central pattern generators. Overall, FES can be used to improve respiration, circulation, hand strength, mobility, and metabolism after SCI.


Asunto(s)
Terapia por Estimulación Eléctrica/métodos , Rehabilitación Neurológica/métodos , Traumatismos de la Médula Espinal/terapia , Animales , Gatos , Generadores de Patrones Centrales/fisiología , Terapia Combinada , Terapia por Estimulación Eléctrica/instrumentación , Prueba de Esfuerzo , Terapia por Ejercicio , Regulación de la Expresión Génica , Humanos , Masculino , Modelos Neurológicos , Fatiga Muscular , Fibras Musculares de Contracción Rápida/metabolismo , Fibras Musculares de Contracción Lenta/metabolismo , Músculo Esquelético/fisiopatología , Rehabilitación Neurológica/instrumentación , Traumatismos de la Médula Espinal/complicaciones , Traumatismos de la Médula Espinal/fisiopatología , Traumatismos de la Médula Espinal/rehabilitación , Vejiga Urinaria/fisiopatología , Trastornos Urinarios/etiología , Trastornos Urinarios/rehabilitación
18.
Magn Reson Chem ; 58(1): 31-40, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31254358

RESUMEN

2-methyl-5,6,7,8-tetrahydro-2H-chromen-4(3H)-one (called 6-oxo) is presented as a new AI-1 quorum sensing inhibitor for Vibrio harveyi. The development of a chemical process to afford traceable materials for new biological assays demands the development of analytical methods to ensure their purity and quality. This work describes the use of quantitative 1 H nuclear magnetic resonance (NMR) spectroscopy (qNMR) to assess the purity of a sample of 6-oxo (99.88%) and a sample of its major process impurity (E)-1-(2-hydroxycyclohex-2-en-1-yl)but-2-en-1-one (called HCB; 98.28%). To explore the scope of the use of qNMR to quantify the amount of low-content components in samples related to the chemical process for 6-oxo synthesis, this work also determined the amount of 6-oxo in two HCB samples: (a) the high-purity HCB sample described above and (b) a crude HCB sample collected during the chemical process. Despite the complexity of the crude sample, the amount of 6-oxo was readily assessed and could help to estimate the extent to which 6-oxo was already formed during the HCB synthesis. This information can help the understanding of how the process parameters can be modified to improve the performance of the whole process, by controlling the reaction mechanisms working at each step of this chemical process. In this context, our results reinforce qNMR as a complementary analytical tool for the quantification of the main component found in a sample, contributing to the standardization of reference materials and thus allowing the development of analytical methods for process control and traceability of the samples used for biological assays.

19.
Brain Res Bull ; 156: 150-163, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31866455

RESUMEN

Standardization of spinal cord injury (SCI) models is crucial for reproducible injury in research settings and their objective assessments. Basso, Beattie and Bresnahan (BBB) scoring, the traditional behavioral evaluation method, is subjective and susceptible to human error. On the other hand, neuro-electrophysiological monitoring, such as somatosensory evoked potential (SSEP), is an objective assessment method that can be performed continuously for longitudinal studies. We implemented both SSEP and BBB assessments on transection SCI model. Five experimental groups are designed as follows: left hemi-transection at T8, right hemi-transection at T10, double hemi-transection at left T8 and right T10, complete transection at T8 and control group which receives only laminectomy with intact dura and no injury on spinal cord parenchyma. On days 4, 7, 14 and 21 post-injury, first BBB scores in awake and then SSEP signals in anesthetized rats were obtained. Our results show SSEP signals and BBB scores are both closely associated with transection model and injury progression. However, the two assessment modalities demonstrate different sensitivity in measuring injury progression when it comes to late-stage double hemi-transection, complete transection and hemi-transection injury. Furthermore, SSEP amplitudes are found to be distinct in different injury groups and the progress of their attenuation is increasingly rapid with more severe transection injuries. It is evident from our findings that SSEP and BBB methods provide distinctive and valuable information and could be complementary of each other. We propose incorporating both SSEP monitoring and conventional BBB scoring in SCI research to more effectively standardize injury progression.


Asunto(s)
Potenciales Evocados Somatosensoriales/fisiología , Actividad Motora/fisiología , Traumatismos de la Médula Espinal/fisiopatología , Animales , Potenciales Evocados Motores/fisiología , Femenino , Masculino , Modelos Animales , Ratas , Ratas Sprague-Dawley , Médula Espinal/patología , Traumatismos de la Médula Espinal/metabolismo
20.
Hepatology ; 71(4): 1198-1212, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-30805949

RESUMEN

NGM282, an engineered fibroblast growth factor 19 analogue, rapidly and significantly reduced liver fat content in a multicenter, randomized, double-blind, placebo-controlled study in patients with biopsy-confirmed nonalcoholic steatohepatitis (NASH). However, it is unclear whether these changes would be accompanied by histological improvement. In this open-label study, we assessed the histological efficacy of NGM282 in patients with biopsy-confirmed nonalcoholic steatohepatitis. Paired liver biopsies from 43 patients who received subcutaneous NGM282 (1 mg, n = 24; 3 mg, n = 19) once daily for 12 weeks were evaluated blinded to time point, subject, and clinical information. At week 12, NGM282 significantly reduced nonalcoholic fatty liver disease activity score (NAS; -1.9; 95% confidence interval, -2.6 to -1.2; P < 0.001 in the 1 mg group; -2.2, -3.1 to -1.3; P < 0.001 in the 3 mg group) and fibrosis (-0.5; -0.9 to 0; P = 0.035 in the 3 mg group) scores. Overall, 50% and 63% of the patients receiving NGM282 1 mg or 3 mg, respectively, improved NAS by 2 or more points without fibrosis worsening. Of the patients receiving NGM282 1 mg or 3 mg, 25% and 42%, respectively, improved liver fibrosis by one stage or more without worsening of steatohepatitis. Treatment with NGM282 led to relative reductions in liver fat content (-58% and -67% in the 1 mg and 3 mg groups, respectively), corrected T1 (cT1; -8% and -9%), alanine aminotransferase (ALT) (-67% and -60%), aspartate aminotransferase (-57% and -52%), and fibrogenesis biomarkers neoepitope-specific N-terminal propeptide of type III collagen (Pro-C3; -22% and -33%) and enhanced liver fibrosis score (ELF; -3% and -6%) at week 12. Greater reductions in Pro-C3, ELF, and cT1, but not in liver fat content, 7alpha-hydroxy-4-cholesten-3-one, or ALT, were observed in histological responders than in nonresponders. Conclusion: In this open-label study, NGM282 improved the histological features of NASH in 12 weeks with significant reductions in NAS and fibrosis scores, accompanied by improvements in noninvasive imaging and serum markers.


Asunto(s)
Factores de Crecimiento de Fibroblastos/uso terapéutico , Cirrosis Hepática/tratamiento farmacológico , Cirrosis Hepática/patología , Enfermedad del Hígado Graso no Alcohólico/complicaciones , Adolescente , Adulto , Anciano , Biomarcadores/sangre , Femenino , Factores de Crecimiento de Fibroblastos/administración & dosificación , Humanos , Inyecciones Subcutáneas , Cirrosis Hepática/etiología , Masculino , Persona de Mediana Edad , Adulto Joven
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...