ABSTRACT
This study reports a facile approach for constructing low-cost and remarkable electroactivity iron vanadate (Fe-V-O) semiconductor material to be used as a photoelectrochemical sensor for dopamine detection. The structure and morphology of the iron vanadate obtained by the Successive Ionic Adsorption and Reaction process were critically characterized, and the photoelectrochemical characterization showed a high photoelectroactivity of the photoanode in visible light irradiation. Under best conditions, dopamine was detected by chronoamperometry at +0.35 V vs. Ag/AgCl, achieving two linear response ranges (between 1.21 and 30.32 µmol L-1, and between 30.32 and 72.77 µmol L-1). The limits of detection and quantification were 0.34 and 1.12 µmol L-1, respectively. Besides, the accuracy of the proposed electrode was assessed by determining dopamine in artificial cerebrospinal fluid, obtaining recovery values ranging from 98.7 to 102.4%. The selectivity was also evaluated by dopamine detection against several interferent species, demonstrating good precision and promising application for the proposed method. Furthermore, DFT-based electronic structure calculations were also conducted to help the interpretation. The dominant dopamine species were determined according to the experimental conditions, and their interaction with the iron vanadate photoanode was proposed. The improved light-induced DOP detection was likewise evaluated regarding the charge transfer process.
Subject(s)
Biosensing Techniques , Dopamine , Biosensing Techniques/methods , Dopamine/chemistry , Electrochemical Techniques/methods , Electrodes , Iron , Light , Limit of Detection , VanadatesABSTRACT
Hyperammonemia in adults is generally associated with cerebral edema, decreased cerebral metabolism, and increased cerebral blood flow. The aim of this study was to evaluate the association between non-hepatic hyperammonemia and intracranial hypertension assessed by Doppler flowmetry and measurement of the optic nerve sheath. A prospective cohort study in critically ill patients hospitalized in intensive care units of a University Hospital between March 2015 and February 2016. Clinical data and severity scores were collected and the Glasgow coma scale was recorded. Serial serum ammonia dosages were performed in all study patients. Transcranial Doppler evaluation was carried out for the first 50 consecutive results of each stratum of ammonemia: normal (<35 µmol/L), mild hyperammonemia (≥35 µmol/L and < 50 µmol/L), moderate hyperammonemia (≥50 µmol/L and < 100 µmol/L), and severe hyperammonemia (≥100 µmol/L). The measurement of the optic nerve sheath was performed at the same time as the Doppler examination if the patient scored less than 8 on the Glasgow coma scale. There was no difference in flow velocity in the cerebral arteries between patients with and without hyperammonemia. Patients with hyperammonemia presented longer ICU stay. Optic nerve sheath thickness was higher in the group with severe hyperammonemia and this group presented an association with intracranial hypertension. Higher mortality was observed in the severe hyperammonemia group. There was an association between severe hyperammonemia and signs of intracranial hypertension. No correlation was found between ammonia levels and cerebral blood flow velocity through the Doppler examination.
Subject(s)
Cerebrovascular Circulation/physiology , Hyperammonemia/diagnostic imaging , Intracranial Hypertension/diagnostic imaging , Optic Nerve/diagnostic imaging , Adult , Aged , Critical Illness , Female , Glasgow Coma Scale , Humans , Hyperammonemia/physiopathology , Intracranial Hypertension/physiopathology , Intracranial Pressure/physiology , Male , Middle Aged , Optic Nerve/physiopathology , Prospective Studies , Severity of Illness Index , Ultrasonography, Doppler, TranscranialABSTRACT
Cordotomy consists in the discontinuation of the spinothalamic tract in the anterolateral quadrant of the spinal cord and aims to reduce the transference of nociceptive information in the dorsal horn of the grey matter of the spinal cord (CPME) for rostral units at the neural axis. Many modalities of cordotomy may be employed: anterior transdiscal between C4-C5; endoscopic infra mastoid tip between C1-C2; percutaneous guided by fluoroscopy infra mastoid tip between C1-C2; percutaneous guided by CT infra mastoid tip between C1-C2; open cordotomy by means of laminectomy. The main indication is for patients in advanced cancer disease with severe neuropathic pain bellow the neck in whom the period of survival due to cancer disease is inferior to 3-4 months. The results for immediate pain relieve ranges from 69% to 100% of the cases, while preoperative Karnofsky scores were 20 and 70, respectively versus post operative Karnofsky scores of 20 and 100 respectively; the difference was determined to be highly significant (p < 0.001).
A cordotomia consiste na discontinuação do trato espinotâmico no quadrante ântero-lateral da medula espinal e visa reduzir a transferência de informação nociceptiva no corno dorsal da substância cinzenta da medula espinal (CPME) para as unidades rostrais no neuroeixo. Muitas modalidades de cordotomia podem ser empregadas: transdiscal anterior entre C4-C5; endoscópica inframastoidea entre C1-C2; Percutânea inframastoidea entre C1-C2 guiada por fluoroscopia; percutânea inframastoidea entre C1-C2 guiada por TC; cordotomia aberta por laminectomia. A principal indicação é para pacientes com câncer avançado com dor neuropática severa abaixo do pescoço nos quais a sobrevida devido ao câncer é inferior a 3-4 meses. Os resultados para alívio imediato da dor varia de 69% a 100% dos casos, enquanto os escores de Karnofsky foram de 20 e 70 no período pré-operatório, para 20 e 100 no período pós-opertaório; a diferença foi estatisticamente significativa (p < 0.001).
Subject(s)
Spinothalamic Tracts/surgery , Cervical Vertebrae/pathology , Cordotomy/methods , Neck Pain , Electrocoagulation/methods , Pulsed Radiofrequency TreatmentABSTRACT
A displasia septo-óptica (DSO) é uma síndrome do desenvolvimento considerada heterogênea, pois envolve anomalias da linhamédia do cérebro associadas a disfunções oftalmológicas, neurológicas e do eixo hipotálamo-hipófise. O fenótipo é altamentevariável dificultando a classificação da doença. Relatamos um caso de hipopituitarismo neonatal grave que levou à descobertade malformações cerebrais e hipoplasia do nervo óptico, sendo caracterizada assim a síndrome DSO-like. Mesmo em presençade um septo pelúcido normal e com poucas alterações na ressonância magnética, este paciente apresentou um fenótipo endócrinode alto risco de morte no período neonatal. Mutações genéticas têm sido raramente descritas no HESX1 e estão associadas avárias deficiências hormonais hipofisárias combinadas com a DSO. O gene HESX1 codifica um fator de transcrição pertencenteà classe de genes chamados homeobox. A partir deste gene candidato, foi isolada a região codificadora no DNA para análise porsequenciamento. Este relato de caso com seguimento clínico de 7 anos e estudo genético preliminar apresenta uma discussãoda investigação diagnóstica a partir do quadro inicial, destacando as alterações de neuroimagem encontradas nesta síndrome.
Subject(s)
Hypopituitarism , Septo-Optic Dysplasia , Septum PellucidumABSTRACT
The ankyrin-repeat transient receptor potential 1 (TRPA1) has been implicated in pathological conditions of the bladder, but its role in overactive bladder (OAB) following spinal cord injury (SCI) remains unknown. In this study, using a rat SCI model, we assessed the relevance of TRPA1 in OAB induced by SCI. SCI resulted in tissue damage, inflammation, and changes in bladder contractility and in voiding behavior. Moreover, SCI caused upregulation of TRPA1 protein and mRNA levels, in bladder and in dorsal root ganglion (DRG; L6-S1), but not in corresponding segment of spinal cord. Alteration in bladder contractility following SCI was evidenced by enhancement in cinnamaldehyde-, capsaicin-, or carbachol-induced bladder contraction as well as in its spontaneous phasic activity. Of relevance to voiding behavior, SCI induced increase in the number of nonvoiding contractions (NVCs), an important parameter associated with the OAB etiology, besides alterations in other urodynamic parameters. HC-030031 (TRPA1 antagonist) treatment decreased the number and the amplitude of NVCs while the TRPA1 antisense oligodeoxynucleotide (AS-ODN) treatment normalized the spontaneous phasic activity, decreased the cinnamaldehyde-induced bladder contraction and the number of NVCs in SCI rats. In addition, the cinnamaldehyde-induced bladder contraction was reduced by exposure of the bladder preparations to HC-030031. The efficacy of TRPA1 AS-ODN treatment was confirmed by means of the reduction of TRPA1 expression in the DRG, in the corresponding segment of the spinal cord and in the bladder, specifically in detrusor muscle. The present data show that the TRPA1 activation and upregulation seem to exert an important role in OAB following SCI.
