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1.
Philos Trans A Math Phys Eng Sci ; 382(2283): 20240008, 2024 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-39370799

RESUMEN

Origami-inspired mechanisms provide opportunities for deployable systems, including reflectarray antennas. There is a need for approaches to deploy and stabilize such arrays. Magnetic mechanisms show promise for meeting those needs and how methods for modelling their behaviour would facilitate their design and analysis. We demonstrate the existence of bistability in select configurations of magnetically stabilized hinges and characterize their equilibrium positions as a function of parameters estimated from simulation data for these mechanisms. Other relevant information such as potential energy, axial force data, angular position of unstable equilibria and transition values from bistability to monostability are also modelled. The results are verified through experimental torque and stability data for selected configurations of the mechanisms.This article is part of the theme issue 'Origami/Kirigami-inspired structures: from fundamentals to applications'.

2.
Ultrasound Obstet Gynecol ; 58(5): 744-749, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33724570

RESUMEN

OBJECTIVE: To evaluate the influence of stomach position on postnatal outcome in cases of left congenital diaphragmatic hernia (CDH) without liver herniation, diagnosed and characterized on prenatal ultrasound (US), by comparing those with ('stomach-up' CDH) to those without ('stomach-down' CDH) intrathoracic stomach herniation. METHODS: Infants with left CDH who underwent prenatal US and postnatal repair at our institution between January 2008 and March 2017 were eligible for inclusion in this retrospective study. Detailed prenatal US examinations, fetal magnetic resonance imaging (MRI) studies, operative reports and medical records of infants enrolled in the pulmonary hypoplasia program at our institution were reviewed. Cases with liver herniation and those with an additional anomaly were excluded. Cases in which bowel loops were identified within the fetal chest on US while the stomach was intra-abdominal were categorized as having stomach-down CDH. Cases in which bowel loops and the stomach were visualized within the fetal chest on US were categorized as having stomach-up CDH. Prenatal imaging findings and postnatal outcomes were compared between the two groups. RESULTS: In total, 152 patients with left CDH were initially eligible for inclusion. Seventy-eight patients had surgically confirmed liver herniation and were excluded. Of the 74 included CDH cases without liver herniation, 28 (37.8%) had stomach-down CDH and 46 (62.2%) had stomach-up CDH. Of the 28 stomach-down CDH cases, 10 (35.7%) were referred for a suspected lung lesion. Sixty-eight (91.9%) cases had postnatal outcome data available for analysis. There was no significant difference in median observed-to-expected (o/e) lung-area-to-head-circumference ratio (LHR) between cases with stomach-down CDH and those with stomach-up CDH (41.5% vs 38.4%; P = 0.41). Furthermore, there was no difference in median MRI o/e total lung volume (TLV) between the two groups (49.5% vs 44.0%; P = 0.22). Compared with stomach-up CDH patients, stomach-down CDH patients demonstrated lower median duration of intubation (18 days vs 9.5 days; P < 0.01), median duration of extracorporeal membrane oxygenation (495 h vs 223.5 h; P < 0.05), rate of supplemental oxygen requirement at 30 days of age (20/42 (47.6%) vs 3/26 (11.5%); P < 0.01) and rate of pulmonary hypertension at initial postnatal echocardiography (28/42 (66.7%) vs 9/26 (34.6%); P = 0.01). No neonatal death occurred in stomach-down CDH patients and one neonatal death was seen in a patient with intrathoracic stomach herniation. CONCLUSIONS: In infants with left CDH without liver herniation, despite similar o/e-LHR and o/e-TLV, those with stomach-down CDH have decreased neonatal morbidity compared to those with stomach herniation. Progressive or variable physiological distension of the stomach over the course of gestation may explain these findings. Stomach-down left CDH is mistaken for a lung mass in a substantial proportion of cases. Accurate prenatal US characterization of CDH is crucial for appropriate prenatal counseling and patient management. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.


Asunto(s)
Hernias Diafragmáticas Congénitas/patología , Enfermedades del Recién Nacido/patología , Imagen por Resonancia Magnética , Estómago/patología , Ultrasonografía Prenatal , Adulto , Cefalometría , Femenino , Feto/diagnóstico por imagen , Feto/patología , Cabeza/diagnóstico por imagen , Cabeza/patología , Hernias Diafragmáticas Congénitas/diagnóstico por imagen , Hernias Diafragmáticas Congénitas/embriología , Humanos , Recién Nacido , Enfermedades del Recién Nacido/diagnóstico por imagen , Enfermedades del Recién Nacido/embriología , Pulmón/diagnóstico por imagen , Pulmón/embriología , Pulmón/patología , Masculino , Morbilidad , Embarazo , Estudios Retrospectivos , Estómago/diagnóstico por imagen , Estómago/embriología
3.
Ultrasound Obstet Gynecol ; 55(6): 740-746, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-31613408

RESUMEN

OBJECTIVE: To determine whether the presence of a myelomeningocele (MMC) sac and sac size correlate with compromised lower-extremity function in fetuses with open spinal dysraphism. METHODS: A radiology database search was performed to identify cases of MMC and myeloschisis (MS) diagnosed prenatally in a single center from 2013 to 2017. All cases were evaluated between 18 and 25 weeks. Ultrasound reports were reviewed for talipes and impaired lower-extremity motion. In MMC cases, sac volume was calculated from ultrasound measurements. Magnetic resonance imaging reports were reviewed for hindbrain herniation. The association of presence of a MMC sac and sac size with talipes and impaired lower-extremity motion was assessed. Post-hoc analysis of data from the multicenter Management of Myelomeningocele Study (MOMS) randomized controlled trial was performed to confirm the study findings. RESULTS: In total, 283 MMC and 121 MS cases were identified. MMC was associated with a lower incidence of hindbrain herniation than was MS (80.9% vs 100%; P < 0.001). Compared with MS cases, MMC cases with hindbrain herniation had a higher rate of talipes (28.4% vs 16.5%, P = 0.02) and of talipes or lower-extremity impairment (34.9% vs 19.0%, P = 0.002). Although there was a higher rate of impaired lower-extremity motion alone in MMC cases with hindbrain herniation than in MS cases, the difference was not statistically significant (6.6% vs 2.5%; P = 0.13). Among MMC cases with hindbrain herniation, mean sac volume was higher in those associated with talipes compared with those without talipes (4.7 ± 4.2 vs 3.0 ± 2.6 mL; P = 0.002). Review of the MOMS data demonstrated similar findings; cases with a sac on baseline imaging had a higher incidence of talipes than did those without a sac (28.2% vs 7.5%; P = 0.007). CONCLUSIONS: In fetuses with open spinal dysraphism, the presence of a MMC sac was associated with fetal talipes, and this effect was correlated with sac size. The presence of a larger sac in fetuses with open spinal dysraphism may result in additional injury through mechanical stretching of the nerves, suggesting another acquired mechanism of injury to the exposed spinal tissue. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.


Asunto(s)
Deformidades Congénitas de las Extremidades Inferiores/embriología , Meningomielocele/embriología , Lesiones Prenatales/etiología , Disrafia Espinal/embriología , Pie Zambo/embriología , Bases de Datos Factuales , Femenino , Edad Gestacional , Humanos , Deformidades Congénitas de las Extremidades Inferiores/diagnóstico por imagen , Meningomielocele/complicaciones , Meningomielocele/diagnóstico por imagen , Embarazo , Lesiones Prenatales/diagnóstico por imagen , Disrafia Espinal/complicaciones , Disrafia Espinal/diagnóstico por imagen , Pie Zambo/congénito , Pie Zambo/diagnóstico por imagen , Ultrasonografía Prenatal
4.
Eur J Appl Physiol ; 120(1): 67-75, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31515632

RESUMEN

PURPOSE: Blood flow to skeletal muscles and removal of metabolic by-products during a sport climb are essential to optimise performance and recovery. New Zealand blackcurrant (NZBC) extract has enhanced blood flow and performance in other exercise modalities. We examined the effect of NZBC extract on sport climbing performance and recovery. METHODS: The study employed a double-blind, randomised, crossover design. Male sport climbers (n = 18, age 24 ± 6 years, height 179 ± 6 cm, mass 71.4 ± 7.8 kg, French grade 6a-8b) undertook 7 days supplementation of NZBC extract (600 mg day-1 CurraNZ™ containing 210 mg anthocyanins) or a placebo (PL). Climbing ability was assessed through hang time (HT), pull-ups and total climbing time (TCT) in 3 intermittent climbing bouts on a Treadwall M6 rotating climbing wall to exhaustion with 20 min recovery between climbs. Heart rate (HR), blood lactate (BL), forearm girth (FG) and hand grip strength (HGS) were recorded. RESULTS: NZBC extract had no effect on pull-ups but provided a trend for higher HT and significantly improved TCT (+23%) compared to PL (-11%) over three climbs. HR, BL, FG and HGS all indicated that 20 min was insufficient for physiological recovery between the three climbing bouts indicating accumulative fatigue regardless of supplement condition. CONCLUSION: Despite indices of progressive fatigue across three bouts of climbing, NZBC extract facilitated not only a maintenance of TCT but an improved climbing endurance as compared with the PL condition. Blackcurrant anthocyanin-derived metabolites seem to affect physiological responses that facilitate sport climbing performance.


Asunto(s)
Rendimiento Atlético , Montañismo , Extractos Vegetales/farmacología , Ribes/química , Adulto , Fuerza de la Mano , Frecuencia Cardíaca , Humanos , Ácido Láctico/sangre , Masculino , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/fisiología , Extractos Vegetales/administración & dosificación , Flujo Sanguíneo Regional/efectos de los fármacos
5.
Eur J Appl Physiol ; 120(1): 77, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31776695

RESUMEN

The authors would like to correct the following errors in the online publication of the article. Incorrect values for % changes for climb duration were provided in the abstract, results and discussion session. The  % changes in climb duration was 15% with intake of New Zealand blackcurrant extract and -15% for the placebo condition. This correction does not change the conclusions derived from the study.

6.
Anal Chem ; 89(13): 6976-6983, 2017 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-28644003

RESUMEN

We introduce a chemical sensing technology, named ChIMES (Chemical Identification through Magneto-Elastic Sensing), that can detect a broad range of targets and that has the capability of untethered communication through a metallic or nonmetallic barrier. These features enable many applications in which penetrations into the sampled environment are unwanted or infeasible because of health, safety, or environmental concerns, such as following the decomposition of a dangerous material in a sealed container. The sensing element is passive and consists of a target response material hard-coupled to a magnetoelastic wire. When the response material encounters a target, it expands, imposing mechanical stress on the wire and altering its magnetic permeability. Using a remote excitation-detection coil set, the changes in permeability are observed by switching the magnetic domains in the wire and measuring the modifications in the Faraday voltage as the stress is varied. Sensors with different response materials can be arrayed and interrogated individually. We describe the sensor and its associated instrumentation, compare the performance of several types of wire, and evaluate analytical metrics of single and arrayed ChIMES sensors against a suite of volatile organic compounds.

7.
Pediatr Blood Cancer ; 62(4): 598-602, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25546733

RESUMEN

BACKGROUND: Topotecan has been variably incorporated in the treatment of patients with relapsed Wilms tumour (WT) who failed initial treatment with three or more effective drugs. Our objective was to describe outcome and to retrospectively investigate the potential role of topotecan in relapsed WT patients. METHODS: Children who were treated with topotecan as part of their chemotherapeutic regimens for relapsed WT were identified and included in our retrospective study. Patient charts were reviewed for general patient characteristics, histology and stage at initial diagnosis, number and type of relapse, salvage treatment schedules, toxicity, response to treatment and outcome. RESULTS: From 2000 to 2012, 30 children (median age at relapse 5.5 years, range 1.6-14.5 years) were identified to have received topotecan as part of their salvage regimens (primary progressive disease n = 3, first, second and third relapse n = 13, 9 and 2 respectively, partial response n = 3). Topotecan was administered as a single agent (12 patients) or in combination with other drugs (18 patients). Sixteen patients had high-risk histology according to the SIOP classification, 15 died within 12 months because of progressive disease. Fourteen patients had SIOP intermediate-risk histology of which four patients displayed objective responses to topotecan. Overall, 6 out of 14 intermediate-risk patients survived (median follow up of 6 years), however, three of whom (stage V) had bilateral nephrectomy after topotecan treatment. CONCLUSIONS: Topotecan does not seem to show effectiveness in the treatment of relapsed WT patients with initial high-risk histology. In patients with intermediate-risk histology, the role of topotecan might deserve further attention, to prove its efficacy.


Asunto(s)
Neoplasias Renales , Recurrencia Local de Neoplasia , Topotecan/administración & dosificación , Adolescente , Niño , Preescolar , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Lactante , Neoplasias Renales/tratamiento farmacológico , Neoplasias Renales/mortalidad , Neoplasias Renales/patología , Masculino , Recurrencia Local de Neoplasia/tratamiento farmacológico , Recurrencia Local de Neoplasia/mortalidad , Recurrencia Local de Neoplasia/patología , Estudios Retrospectivos , Factores de Riesgo , Tasa de Supervivencia , Inhibidores de Topoisomerasa I , Tumor de Wilms/tratamiento farmacológico , Tumor de Wilms/mortalidad , Tumor de Wilms/patología
8.
Child Care Health Dev ; 41(6): 980-8, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25495257

RESUMEN

BACKGROUND: Having a physical disability and using a wheelchair can create difficulties in navigating the physical and built environment, especially during winter when snow and ice become problematic. Little is known about the experiences of winter among youth who use an assistive mobility device. This study aimed to understand how youth with a physical disability experience winter, compared with typically developing peers. METHODS: A purposive sample of 25 youths (13 with a physical disability; 12 typically developing) completed a 2-week weather journal and photographs in two Canadian cities during winter. These data were used to guide semi-structured interviews with participants. RESULTS: Youths with disabilities experienced many similar challenges in winter, such as health and safety concerns and accessibility issues, compared with typically developing youth - but to a greater extent. Youths with disabilities reported more challenges going outdoors during winter and negative psychosocial impacts, including loneliness and increased dependence, compared with peers without a disability. They also, however, described developing several adaptive strategies to cope with these challenges. CONCLUSIONS: There is a strong need to remove physical and environmental barriers to facilitate the participation and inclusion of youth with disabilities in winter.


Asunto(s)
Personas con Discapacidad/psicología , Estaciones del Año , Participación Social , Tiempo (Meteorología) , Adaptación Fisiológica , Adolescente , Adulto , Niño , Frío , Femenino , Humanos , Masculino , Quebec , Dispositivos de Autoayuda , Aislamiento Social , Encuestas y Cuestionarios , Poblaciones Vulnerables
9.
Int J Cosmet Sci ; 37(6): 636-41, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26032853

RESUMEN

OBJECTIVE: To examine the potential of non-animal collagens as a new option for cosmetic applications. METHODS: Non-animal collagens from three species, Streptococcus pyogenes, Solibacter usitatus and Methylobacterium sp 4-46, have been expressed as recombinant proteins in Escherichia coli using a cold-shock, pCold, expression system. The proteins were purified using either metal affinity chromatography or a simple process based on precipitation and proteolytic digestion of impurities, which is suitable for large-scale production. Samples were examined using a range of analytical procedures. RESULTS: Analyses by gel electrophoresis and mass spectrometry were used to examine the purity and integrity of the products. Circular dichroism spectroscopy showed stabilities around 38°C, and calculated pI values were from 5.4 to 8.6. UV-visible light spectroscopy showed the clarity of collagen solutions. The collagens were soluble at low ionic strength between pH 5 and pH 8, but were less soluble under more acidic conditions. At lower pH, the insoluble material was well dispersed and did not form the fibrous associations and aggregates found with animal collagens. The materials were shown to be non-cytotoxic to cells in culture. CONCLUSIONS: These novel, non-animal collagens may be potential alternatives to animal collagens for inclusion in cosmetic formulations.


Asunto(s)
Acidobacteria/química , Colágeno/química , Cosméticos , Methylobacterium/química , Streptococcus pyogenes/química
10.
J Pharmacol Exp Ther ; 341(1): 81-9, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22214649

RESUMEN

Blockade of D2 family dopamine receptors (D2Rs) is a fundamental property of antipsychotics, and the degree of striatal D2R occupancy has been related to antipsychotic and motor effects of these drugs. Recent studies suggest the D2R occupancy of antipsychotics may differ in extrastriatal regions compared with the dorsal striatum. We studied this issue in macaque monkeys by using a within-subjects design. [(18)F]fallypride positron emission tomography scans were obtained on four different doses of risperidone and paliperidone (the 9-OH metabolite of risperidone) and compared with multiple off-drug scans in each animal. The half-life of the two drugs in these monkeys was determined to be between 3 and 4 h, and drug was administered by a constant infusion through an intragastric catheter. The D2R occupancy of antipsychotic was determined in the caudate, putamen, ventral striatum, and four prefrontal and temporal cortical regions and was related to serum and cerebrospinal fluid drug levels. Repeated 2-week treatment with risperidone or paliperidone did not produce lasting changes in D2R binding potential in any region examined. As expected, D2R binding potential was highest in the caudate and putamen and was approximately one-third that level in the ventral striatum and 2% of that level in the cortical regions. We found dose-dependent D2R occupancy for both risperidone and paliperidone in both basal ganglia and cortical regions of interest. We could not find evidence of regional variation in D2R occupancy of either drug. Comparison of D2R occupancy and serum drug levels supports a target of 40 to 80 ng/ml active drug for these two atypical antipsychotics.


Asunto(s)
Antipsicóticos/metabolismo , Isoxazoles/metabolismo , Pirimidinas/metabolismo , Receptores de Dopamina D2/metabolismo , Risperidona/metabolismo , Animales , Antipsicóticos/farmacología , Encéfalo/diagnóstico por imagen , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Antagonistas de los Receptores de Dopamina D2 , Relación Dosis-Respuesta a Droga , Isoxazoles/farmacología , Macaca mulatta , Masculino , Palmitato de Paliperidona , Tomografía de Emisión de Positrones/métodos , Unión Proteica/fisiología , Pirimidinas/farmacología , Risperidona/farmacología
11.
Horm Behav ; 61(2): 181-90, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22197270

RESUMEN

3,4-methylenedioxymethamphetamine (MDMA) is a substituted phenethylamine that is widely abused as the street drug "ecstasy". Racemic MDMA (S,R(+/-)-MDMA) and its stereoisomers elicit complex spectrums of psychobiological, neurochemical, and hormonal effects. In this regard, recent findings demonstrated that S,R(+/-)-MDMA and its stereoisomer R(-)-MDMA elicit increases in striatal extracellular serotonin levels and plasma levels of the hormone prolactin in rhesus monkeys. In the present mechanistic study, we evaluated the role of the serotonin transporter and the 5-HT(2A) receptor in S,R(+/-)-MDMA- and R(-)-MDMA-elicited prolactin secretion in rhesus monkeys through concurrent microdialysis and plasma analysis determinations and drug interaction experiments. Concurrent neurochemical and hormone determinations showed a strong positive temporal correlation between serotonin release and prolactin secretion. Consistent with their distinct mechanisms of action and previous studies showing that the serotonin transporter inhibitor fluoxetine attenuates the behavioral and neurochemical effects of S,R(+/-)-MDMA, pretreatment with fluoxetine attenuated serotonin release elicited by either S,R(+/-)-MDMA or R(-)-MDMA. As hypothesized, at a dose that had no significant effects on circulating prolactin levels when administered alone, fluoxetine also attenuated prolactin secretion elicited by S,R(+/-)-MDMA. In contrast, combined pretreatment with both fluoxetine and the selective 5-HT(2A) receptor antagonist M100907 was required to attenuate prolactin secretion elicited by R(-)-MDMA, suggesting that this stereoisomer of S,R(+/-)-MDMA elicits prolactin secretion through both serotonin release and direct agonism of 5-HT(2A) receptors. Accordingly, these findings inform our understanding of the neuropharmacology of both S,R(+/-)-MDMA and R(-)-MDMA and the regulation of prolactin secretion.


Asunto(s)
Alucinógenos/farmacología , N-Metil-3,4-metilenodioxianfetamina/sangre , N-Metil-3,4-metilenodioxianfetamina/farmacología , Prolactina/sangre , Prolactina/metabolismo , Serotoninérgicos/farmacología , Animales , Femenino , Fluorobencenos/farmacología , Fluoxetina/farmacología , Alucinógenos/sangre , Macaca mulatta , Microdiálisis , Piperidinas/farmacología , Serotoninérgicos/sangre , Antagonistas de la Serotonina/farmacología , Inhibidores Selectivos de la Recaptación de Serotonina/farmacocinética , Estereoisomerismo , Factores de Tiempo
12.
Mol Psychiatry ; 15(2): 185-203, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18504425

RESUMEN

The reinforcing effects and long-term consequences of cocaine self-administration have been associated with brain regions of the mesolimbic dopamine pathway, namely the nucleus accumbens (NAc). Studies of cocaine-induced biochemical adaptations in rodent models have advanced our knowledge; however, unbiased detailed assessments of intracellular alterations in the primate brain are scarce, yet essential, to develop a comprehensive understanding of cocaine addiction. To this end, two-dimensional difference in gel electrophoresis (2D-DIGE) was used to compare changes in cytosolic protein abundance in the NAc between rhesus monkeys self-administering cocaine and controls. Following image normalization, spots with significantly differential image intensities (P<0.05) were identified, excised, trypsin digested and analyzed by matrix-assisted laser-desorption ionization time-of-flight time-of-flight (MALDI-TOF-TOF). In total, 1098 spots were subjected to statistical analysis with 22 spots found to be differentially abundant of which 18 proteins were positively identified by mass spectrometry. In addition, approximately 1000 protein spots were constitutively expressed of which 21 proteins were positively identified by mass spectrometry. Increased levels of proteins in the cocaine-exposed monkeys include glial fibrillary acidic protein, syntaxin-binding protein 3, protein kinase C isoform, adenylate kinase isoenzyme 5 and mitochondrial-related proteins, whereas decreased levels of proteins included beta-soluble N-ethylmaleimide-sensitive factor attachment protein and neural and non-neural enolase. Using a complimentary proteomics approach, the differential expression of phosphorylated proteins in the cytosolic fraction of these subjects was examined. Two-dimensional gel electrophoresis (2DGE) was followed by gel staining with Pro-Q Diamond phosphoprotein gel stain, enabling differentiation of approximately 150 phosphoprotein spots between the groups. Following excision and trypsin digestions, MALDI-TOF-TOF was used to confirm the identity of 15 cocaine-altered phosphoproteins. Significant increased levels were detected for gamma-aminobutyric acid type A receptor-associated protein 1, 14-3-3 gamma-protein, glutathione S-transferase and brain-type aldolase, whereas significant decreases were observed for beta-actin, Rab GDP-dissociation inhibitor, guanine deaminase, peroxiredoxin 2 isoform b and several mitochondrial proteins. Results from these studies indicate coordinated dysregulation of proteins related to cell structure, signaling, metabolism and mitochondrial function. These data extend and compliment previous studies of cocaine-induced biochemical alterations in human postmortem brain tissue, using an animal model that closely recapitulates the human condition and provide new insight into the molecular basis of the disease and potential targets for pharmacotherapeutic intervention.


Asunto(s)
Cocaína/administración & dosificación , Inhibidores de Captación de Dopamina/administración & dosificación , Regulación de la Expresión Génica/efectos de los fármacos , Núcleo Accumbens/efectos de los fármacos , Núcleo Accumbens/metabolismo , Proteómica/métodos , Secuencia de Aminoácidos , Animales , Conducta Animal , Cocaína/farmacología , Condicionamiento Operante/efectos de los fármacos , Condicionamiento Operante/fisiología , Bases de Datos de Proteínas , Inhibidores de Captación de Dopamina/farmacología , Electroforesis en Gel Bidimensional/métodos , Regulación de la Expresión Génica/fisiología , Macaca mulatta , Masculino , Fosfoproteínas/análisis , Autoadministración/métodos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
13.
Pharmacology ; 88(1-2): 44-9, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21757974

RESUMEN

BACKGROUND/AIMS: Fluoxetine (Prozac) is a selective serotonin reuptake inhibitor currently used to treat depression and mood disorders. It has been widely studied clinically and preclinically, yet there is limited knowledge of its pharmacokinetics in nonhuman primates. METHODS: The present study characterized the pharmacokinetics of fluoxetine and its active metabolite norfluoxetine in rhesus macaques following both acute (1, 3, 5.6 and 10 mg/kg) and chronic doses (5.6 and 10 mg/kg/day) via different routes of administration (intravenous, subcutaneous, intramuscular, and oral). Blood samples were collected at multiple time points following administration and analyzed using mass spectrometry. RESULTS: Fluoxetine had a half-life of 11-16 h and norfluoxetine had a half-life of 21-29 h. Potentially functionally significant serum concentrations of norfluoxetine were present at 24 h even after a single administration of fluoxetine. Similar to observations in humans under steady state conditions, norfluoxetine accounted for the greater percentage of active drug in the blood stream. CONCLUSION: A daily dose of 10 mg/kg administered orally maintained serum concentrations in the human clinical range over the course of 6 weeks. Given the long half-lives of fluoxetine and norfluoxetine observed in this study, precautions should be taken when designing preclinical studies to prevent accumulation of drug serum concentrations.


Asunto(s)
Antidepresivos/farmacocinética , Fluoxetina/farmacocinética , Inhibidores Selectivos de la Recaptación de Serotonina/farmacocinética , Administración Oral , Animales , Antidepresivos/administración & dosificación , Antidepresivos/sangre , Antidepresivos/farmacología , Relación Dosis-Respuesta a Droga , Vías de Administración de Medicamentos , Evaluación Preclínica de Medicamentos , Femenino , Fluoxetina/administración & dosificación , Fluoxetina/análogos & derivados , Fluoxetina/sangre , Fluoxetina/farmacología , Humanos , Inyecciones Subcutáneas , Macaca mulatta , Ratones , Modelos Animales , Ratas , Inhibidores Selectivos de la Recaptación de Serotonina/administración & dosificación , Inhibidores Selectivos de la Recaptación de Serotonina/sangre , Inhibidores Selectivos de la Recaptación de Serotonina/farmacología , Especificidad de la Especie , Factores de Tiempo
14.
J Phys Chem B ; 125(6): 1667-1673, 2021 02 18.
Artículo en Inglés | MEDLINE | ID: mdl-33534567

RESUMEN

The Belousov-Zhabotinsky (BZ) reaction is an example of a homogeneous, nonequilibrium reaction used commonly as a model for the study of biological structure and morphogenesis. We report the experimental effects of temperature on spontaneously nucleated trigger waves in a quasi-two-dimensional BZ reaction-diffusion system, conducted isothermally at temperatures between 9.9 and 43.3 °C. Novel application of filter-coupled circle finding and localized pattern analysis is shown to allow the highly accurate extraction of average radial wave velocity and nucleation period. Using this, it is possible to verify a strong Arrhenius dependence of average wave velocity with temperature, which is used to find the effective activation energy of the reaction in accordance with predictions elaborated from the widely used Oregonator model of the BZ reaction. On the basis of our experimental results and existing theoretical models, the value for activation energy of the important self-catalyzed step in the Oregonator model is determined to be 86.58 ± 4.86 kJ mol-1, within range of previous theoretical prediction.

15.
PLoS One ; 16(5): e0235946, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34014933

RESUMEN

Primates form strong social bonds and depend on social relationships and networks that provide shared resources and protection critical for survival. Social deficits such as those present in autism spectrum disorder (ASD) and other psychiatric disorders hinder the individual's functioning in communities. Given that early diagnosis and intervention can improve outcomes and trajectories of ASD, there is a great need for tools to identify early markers for screening/diagnosis, and for translational animal models to uncover biological mechanisms and develop treatments. One of the most widely used screening tools for ASD in children is the Social Responsiveness Scale (SRS), a quantitative measure used to identify individuals with atypical social behaviors. The SRS has been adapted for use in adult rhesus monkeys (Macaca mulatta)-a species very close to humans in terms of social behavior, brain anatomy/connectivity and development-but has not yet been validated or adapted for a necessary downward extension to younger ages matching those for ASD diagnosis in children. The goal of the present study was to adapt and validate the adult macaque SRS (mSRS) in juvenile macaques with age equivalent to mid-childhood in humans. Expert primate coders modified the mSRS to adapt it to rate atypical social behaviors in juvenile macaques living in complex social groups at the Yerkes National Primate Research Center. Construct and face validity of this juvenile mSRS (jmSRS) was determined based on well-established and operationalized measures of social and non-social behaviors in this species using traditional behavioral observations. We found that the jmSRS identifies variability in social responsiveness of juvenile rhesus monkeys and shows strong construct/predictive validity, as well as sensitivity to detect atypical social behaviors in young male and female macaques across social status. Thus, the jmSRS provides a promising tool for translational research on macaque models of children social disorders.


Asunto(s)
Escala de Evaluación de la Conducta/normas , Conducta Animal , Macaca mulatta/psicología , Conducta Social , Animales , Trastorno de Personalidad Antisocial/psicología , Encéfalo/crecimiento & desarrollo , Niño , Femenino , Humanos , Macaca mulatta/crecimiento & desarrollo , Masculino , Especificidad de la Especie
16.
J Pharmacol Exp Ther ; 334(2): 642-50, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20466795

RESUMEN

3,4-Methylenedioxymethamphetamine (MDMA) is an amphetamine derivative that elicits complex biological effects in humans. One plausible mechanism for this phenomenon is that racemic MDMA is composed of two stereoisomers that exhibit qualitatively different pharmacological effects. In support of this, studies have shown that R(-)-MDMA tends to have hallucinogen-like effects, whereas S(+)-MDMA tends to have psychomotor stimulant-like effects. However, relatively little is known about whether these stereoisomers engender different endocrine and neurochemical effects. In the present study, the endocrine and neurochemical effects of each stereoisomer and the racemate were assessed in four rhesus monkeys after intravenous delivery at doses (1-3 mg/kg) that approximated voluntary self-administration by rhesus monkeys and human recreational users. Specifically, fluorescence-based enzyme-linked immunosorbent assay was used to assess plasma prolactin concentrations, and in vivo microdialysis was used to assess extracellular dopamine and serotonin concentrations in the dorsal striatum. R(-)-MDMA, but not S(+)-MDMA, significantly increased plasma prolactin levels and the effects of S,R(+/-)-MDMA were intermediate to each of its component stereoisomers. Although S(+)-MDMA did not alter prolactin levels, it did significantly increase extracellular serotonin concentrations. In addition, S(+)-MDMA, but not R(-)-MDMA, significantly increased dopamine concentrations. Furthermore, as in the prolactin experiment, the effects of the racemate were intermediate to each of the stereoisomers. These studies demonstrate the stereoisomers of MDMA engender qualitatively different endocrine and neurochemical effects, strengthening the inference that differences in these stereoisomers might be the mechanism producing the complex biological effects of the racemic mixture of MDMA in humans.


Asunto(s)
Estimulantes del Sistema Nervioso Central/farmacología , Cuerpo Estriado/efectos de los fármacos , Dopamina/metabolismo , Alucinógenos/farmacología , N-Metil-3,4-metilenodioxianfetamina/farmacología , Prolactina/metabolismo , Serotonina/metabolismo , Ácido 3,4-Dihidroxifenilacético/metabolismo , Animales , Estimulantes del Sistema Nervioso Central/química , Cuerpo Estriado/metabolismo , Espacio Extracelular/metabolismo , Femenino , Alucinógenos/química , Ácido Homovanílico/metabolismo , Macaca mulatta , Microdiálisis , N-Metil-3,4-metilenodioxianfetamina/química , Estereoisomerismo , Relación Estructura-Actividad
17.
AJNR Am J Neuroradiol ; 41(10): 1923-1929, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32943419

RESUMEN

BACKGROUND AND PURPOSE: Fetal imaging is crucial in the evaluation of open neural tube defects. The identification of intraventricular hemorrhage prenatally has unclear clinical implications. We aimed to explore fetal imaging findings in open neural tube defects and evaluate associations between intraventricular hemorrhage with prenatal and postnatal hindbrain herniation, postnatal intraventricular hemorrhage, and ventricular shunt placement. MATERIALS AND METHODS: After institutional review board approval, open neural tube defect cases evaluated by prenatal sonography between January 1, 2013 and April 24, 2018 were enrolled (n = 504). The presence of intraventricular hemorrhage and gray matter heterotopia by both prenatal sonography and MR imaging studies was used for classification. Cases of intraventricular hemorrhage had intraventricular hemorrhage without gray matter heterotopia (n = 33) and controls had neither intraventricular hemorrhage nor gray matter heterotopia (n = 229). A total of 135 subjects with findings of gray matter heterotopia were excluded. Outcomes were compared with regression analyses. RESULTS: Prenatal and postnatal hindbrain herniation and postnatal intraventricular hemorrhage were more frequent in cases of prenatal intraventricular hemorrhage compared with controls (97% versus 79%, 50% versus 25%, and 63% versus 12%, respectively). Increased third ventricular diameter, specifically >1 mm, predicted hindbrain herniation (OR = 3.7 [95% CI, 1.5-11]) independent of lateral ventricular size and prenatal intraventricular hemorrhage. Fetal closure (n = 86) was independently protective against postnatal hindbrain herniation (OR = 0.04 [95% CI, 0.01-0.15]) and postnatal intraventricular hemorrhage (OR = 0.2 [95% CI, 0.02-0.98]). Prenatal intraventricular hemorrhage was not associated with ventricular shunt placement. CONCLUSIONS: Intraventricular hemorrhage is relatively common in the prenatal evaluation of open neural tube defects. Hindbrain herniation is more common in cases of intraventricular hemorrhage, but in association with increased third ventricular size. Fetal closure reverses hindbrain herniation and decreases the rate of intraventricular hemorrhage postnatally, regardless of the presence of prenatal intraventricular hemorrhage.


Asunto(s)
Hemorragia Cerebral/diagnóstico por imagen , Enfermedades Fetales/diagnóstico por imagen , Defectos del Tubo Neural/diagnóstico por imagen , Hemorragia Cerebral/epidemiología , Hemorragia Cerebral/etiología , Femenino , Feto , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Defectos del Tubo Neural/complicaciones , Embarazo , Rombencéfalo/diagnóstico por imagen , Tercer Ventrículo/diagnóstico por imagen , Ultrasonografía Prenatal/métodos
18.
J Pharmacol Exp Ther ; 331(2): 717-23, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19684254

RESUMEN

3,4-Methylenedioxymethamphetamine (MDMA) is a substituted phenethylamine more commonly known as the drug of abuse "ecstasy." The acute and persistent neurochemical effects of MDMA in the mice are distinct from those in other species. MDMA shares biological effects with both amphetamine-type stimulants and mescaline-type hallucinogens, which may be attributable to distinct effects of its two enantiomers, both of which are active in vivo. In this regard, among the substituted phenethylamines, R(-)-enantiomers tend to have hallucinogen-like effects, whereas S(+)-enantiomers tend to have stimulant-like effects. In the present study, mice were trained to discriminate S(+)- or R(-)-MDMA from vehicle. Drug substitution tests were then undertaken with the structurally similar phenethylamine dopamine/norepinephrine releaser S(+)-amphetamine, the structurally dissimilar tropane nonselective monoamine reuptake inhibitor cocaine, the structurally similar phenethylamine 5-hydroxytryptamine (5-HT)(2A) agonist 2,5-dimethoxy-4-(n)-propylthiophenethylamine (2C-T-7), and the structurally dissimilar mixed action tryptamine 5-HT(2A) agonist/monoamine reuptake inhibitor N,N-dipropyltryptamine (DPT). S(+)-amphetamine fully substituted in the S(+)-MDMA-treated animals but did not substitute for the R(-)-MDMA cue. 2C-T-7 fully substituted in the R(-)-MDMA-trained animals but did not substitute for the S(+)-MDMA cue. Cocaine and DPT substituted for both training drugs, but whereas cocaine was more potent in S(+)-MDMA-trained mice, DPT was more potent in R(-)-MDMA-trained mice. These data suggest that qualitative differences in the discriminative stimulus effects of each stereoisomer of MDMA exist in mice and further our understanding of the complex nature of the interoceptive effects of MDMA.


Asunto(s)
Estimulantes del Sistema Nervioso Central/farmacología , Discriminación en Psicología/efectos de los fármacos , Alucinógenos/farmacología , N-Metil-3,4-metilenodioxianfetamina/farmacología , Anfetaminas/farmacología , Animales , Cocaína/farmacología , Condicionamiento Operante/efectos de los fármacos , Aprendizaje Discriminativo/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Masculino , Ratones , N-Metil-3,4-metilenodioxianfetamina/química , Fenetilaminas/farmacología , Inhibidores Selectivos de la Recaptación de Serotonina/farmacología , Estereoisomerismo , Triptaminas/farmacología
19.
Pharmacol Biochem Behav ; 91(3): 333-8, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18755212

RESUMEN

Cocaine blocks uptake of the monoamines dopamine, serotonin and norepinephrine, and monoamine uptake inhibitors constitute one class of drugs under consideration as candidate "agonist" medications for the treatment of cocaine abuse and dependence. The pharmacological selectivity of monoamine uptake inhibitors to block uptake of dopamine, serotonin and norepinephrine is one factor that may influence the efficacy and/or safety of these compounds as drug abuse treatment medications. To address this issue, the present study compared the effects of 7-day treatment with a non-selective monoamine uptake inhibitor (RTI-112) and a dopamine-selective uptake inhibitor (RTI-113) on cocaine- and food-maintained responding in rhesus monkeys. Monkeys (N=3) were trained to respond for cocaine injections (0.01 mg/kg/inj) and food pellets under a second-order schedule [FR2(VR16:S)] during alternating daily components of cocaine and food availability. Both RTI-112 (0.0032-0.01 mg/kg/hr) and RTI-113 (0.01-0.056 mg/kg/h) produced dose-dependent, sustained and nearly complete elimination of cocaine self-administration. However, for both drugs, the potency to reduce cocaine self-administration was similar to the potency to reduce food-maintained responding. These findings do not support the hypothesis that pharmacological selectivity to block dopamine uptake is associated with behavioral selectivity to decrease cocaine- vs. food-maintained responding in rhesus monkeys.


Asunto(s)
Cocaína/análogos & derivados , Cocaína/farmacología , Condicionamiento Operante/efectos de los fármacos , Alimentos , Inhibidores de la Monoaminooxidasa/farmacología , Tropanos/farmacología , Animales , Interpretación Estadística de Datos , Relación Dosis-Respuesta a Droga , Macaca mulatta , Masculino , Esquema de Refuerzo , Autoadministración
20.
Obes Surg ; 18(10): 1308-12, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18560946

RESUMEN

BACKGROUND: Obesity has become far more prevalent over the last few decades. In parallel, bariatric surgery has been increasingly utilized as a method of treatment. This appears to be having an impact on the rate of body contouring surgery for hanging redundant skin after the massive weight loss that usually results from bariatric surgery. Little literature is available addressing how frequently patients who have undergone bariatric surgery receive or desire body contouring surgery or regarding how satisfied these patients are with the hanging skin in certain body areas. METHODS: Seventy individuals (out of 250 who were mailed the questionnaire) who had undergone Roux-en-Y gastric bypass surgery 6-10 years previously completed a questionnaire, which obtained information regarding their experiences with as well as their desire for body contouring surgery and more general body area satisfaction. RESULTS: Thirty three of the seventy patients reported having undergone a total of 38 body contouring procedures. The most common were abdominoplasties (24.3%), breast lifts (8.6%), and thigh lifts (7.1%). However, subjects were not uniformly satisfied with body areas that had undergone body contouring surgery; some found the areas unattractive. The majority of patients, at least to some extent, desired body contouring surgery, often in several areas, most notably the waist/abdomen, rear/buttock, upper arms, and chest/breast. CONCLUSION: Paralleling the increasing use of bariatric surgery is an increasing desire for body contouring surgery. Most patients desire body contouring surgery after bariatric surgery. However, third party payors usually do not reimburse for such procedures.


Asunto(s)
Derivación Gástrica , Motivación , Obesidad Mórbida/psicología , Obesidad Mórbida/cirugía , Satisfacción Personal , Procedimientos de Cirugía Plástica , Adulto , Índice de Masa Corporal , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Satisfacción del Paciente , Autoimagen , Factores de Tiempo
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