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2.
Acta Neurochir (Wien) ; 165(12): 4183-4189, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37831227

RESUMO

PURPOSE: The population is aging, and age remains an important factor in deciding surgical candidacy for intracranial tumors. The natural history and surgical behavior of meningiomas in octogenarians are not well understood. We evaluated the surgical and functional outcomes, including survival, among octogenarians with intracranial meningiomas in a single institution. METHODS: The Tumor Registry (2004-2021) was used to identify octogenarian patients (ages 80-89) diagnosed with intracranial meningioma. Primary endpoints were 1-year survival and functional outcome measured with mRS postsurgery. Kaplan-Meier, univariable Log-rank tests, and multivariable Cox hazards proportional regression models were used for assessing factors associated with overall survival (OS) in octogenarians with meningiomas who underwent surgery; logistic regression and McNemar's were used to further characterize risk factors affecting functional surgical outcome at 1 year. RESULTS: Thirty octogenarians with intracranial meningioma who underwent surgery were identified. Median age was 82.5 years and 66.6% were female patients. The 1-year median postsurgical survival probability for all octogenarians with meningioma was 86.3% and no intraoperative mortality was observed. Frailty (mFI-5, p = 0.84), tumor grade (p = 0.11), tumor size (p = 0.22), extent of resection (p = 0.35), and Karnofsky scale on admission (p = 0.93) did not significantly affect the survival in octogenarians with meningiomas which were treated surgically. The 1-year postoperative functional status of octogenarian meningioma patients who underwent surgery was significantly improved compared to pre-op mRS (McNemar's chi-squared = 9.6, df = 1, p-value = 0.001946). CONCLUSION: In octogenarians with meningiomas, surgical intervention significantly improves the pre-operative modified Rankin Scale at 1 year postsurgery in this cohort.


Assuntos
Neoplasias Meníngeas , Meningioma , Idoso de 80 Anos ou mais , Humanos , Feminino , Masculino , Meningioma/patologia , Octogenários , Neoplasias Meníngeas/cirurgia , Neoplasias Meníngeas/patologia , Estudos Retrospectivos , Resultado do Tratamento
3.
World Neurosurg ; 148: e363-e373, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33421645

RESUMO

BACKGROUND: No large dataset-derived standard has been established for normal or pathologic human cerebral ventricular and cranial vault volumes. Automated volumetric measurements could be used to assist in diagnosis and follow-up of hydrocephalus or craniofacial syndromes. In this work, we use deep learning algorithms to measure ventricular and cranial vault volumes in a large dataset of head computed tomography (CT) scans. METHODS: A cross-sectional dataset comprising 13,851 CT scans was used to deploy U-Net deep learning networks to segment and quantify lateral cerebral ventricular and cranial vault volumes in relation to age and sex. The models were validated against manual segmentations. Corresponding radiologic reports were annotated using a rule-based natural language processing framework to identify normal scans, cerebral atrophy, or hydrocephalus. RESULTS: U-Net models had high fidelity to manual segmentations for lateral ventricular and cranial vault volume measurements (Dice index, 0.878 and 0.983, respectively). The natural language processing identified 6239 (44.7%) normal radiologic reports, 1827 (13.1%) with cerebral atrophy, and 1185 (8.5%) with hydrocephalus. Age-based and sex-based reference tables with medians, 25th and 75th percentiles for scans classified as normal, atrophy, and hydrocephalus were constructed. The median lateral ventricular volume in normal scans was significantly smaller compared with hydrocephalus (15.7 vs. 82.0 mL; P < 0.001). CONCLUSIONS: This is the first study to measure lateral ventricular and cranial vault volumes in a large dataset, made possible with artificial intelligence. We provide a robust method to establish normal values for these volumes and a tool to report these on CT scans when evaluating for hydrocephalus.


Assuntos
Algoritmos , Cefalometria/métodos , Conjuntos de Dados como Assunto , Aprendizado Profundo , Ventrículos Laterais/anatomia & histologia , Crânio/anatomia & histologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Atrofia , Encéfalo/patologia , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Hidrocefalia/diagnóstico por imagem , Hidrocefalia/patologia , Ventrículos Laterais/diagnóstico por imagem , Ventrículos Laterais/patologia , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Processamento de Linguagem Natural , Neuroimagem , Estudos Retrospectivos , Crânio/diagnóstico por imagem , Crânio/patologia , Tomografia Computadorizada por Raios X , Adulto Jovem
4.
World Neurosurg ; 133: e690-e694, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31568911

RESUMO

OBJECTIVE: Adjacent segment disease (ASD) is a long-term complication of lumbar spinal fusion. This study aims to evaluate demographic and operative factors that influence development of ASD after fusion for lumbar degenerative pathologies. METHODS: A retrospective cohort study was performed on patients undergoing instrumented lumbar fusion for degenerative disorders (spondylolisthesis, stenosis, or intervertebral disk degeneration) with a minimum follow-up of 6 months. RESULTS: Our inclusion criteria were met by 568 patients; 29.4% of patients had developed surgical ASD. Median follow-up was 2.8 years. Multivariate logistic regression analysis showed that decompression of segments outside the fusion construct had higher ASD (odds ratio = 2.6; P < 0.001), and those undergoing fusion for spondylolisthesis had lower ASD (odds ratio = 0.47; P = 0.003). CONCLUSIONS: Results of our study show that the most important surgical factor contributing to ASD is decompression beyond fused levels. Hence caution should be exercised when decompressing spinal segments outside the fusion construct. Conversely, spondylolisthesis patients had the lowest ASD rates in our cohort.


Assuntos
Descompressão Cirúrgica/efeitos adversos , Complicações Pós-Operatórias/etiologia , Fusão Vertebral/efeitos adversos , Adulto , Idoso , Estudos de Coortes , Feminino , Humanos , Vértebras Lombares , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco
5.
J Neurosurg ; : 1-4, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30497211

RESUMO

Levonorgestrel-releasing intrauterine devices (LIUDs) are thought to release this progestin locally in the uterus to limit side effects. Authors here present a case of treatment-refractory hydrocephalus and pseudomeningocele (PMC), both of which fully resolved after LIUD removal.A 35-year-old woman with an implanted LIUD developed symptomatic PMC and hydrocephalus after suboccipital craniectomy for Chiari malformation type I. Over the next 8 months, she underwent ventriculoperitoneal shunt placement and two attempts at needle decompression of the fluid collection, which did not relieve her symptoms or the PMC, except for a few days at a time. Subsequently, she had her LIUD removed. Three weeks after removal of the LIUD, her symptoms as well as the fluid collection resolved completely without any further intervention. Thus, the increased intracranial pressure and associated persistence of the PMC may be partially attributed to the LIUD.This case indicates that a persistent problem (PMC and intracranial hypertension) that may be associated with the LIUD rapidly resolves after its removal. Implication of LIUDs as the cause of intracranial hypertension is still a matter of controversy. Further studies are needed to evaluate any potential causal relationship between LIUDs and intracranial hypertension, and physicians are advised to consider this scenario in their differential diagnosis.

6.
J Neurotrauma ; 35(22): 2605-2614, 2018 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-29877141

RESUMO

Civilian gunshot wounds to the head (cGSWH) are devastating, but there is no consensus regarding prognosis and management. Therefore, we conducted a meta-analysis to identify prognostic factors associated with mortality. PubMed, EMBASE, Scopus, Web of Science, and Cochrane Library were queried for retrospective cohort studies of isolated cGSWH reporting mortality prognostic factors. Meta-Analysis Of Observational Studies in Epidemiology (MOOSE) guidelines were followed. Study quality was assessed using the Newcastle-Ottawa scale. Primary outcome was mortality. Pooled estimates of odds ratios (ORs) and 95% confidence intervals (CIs) were derived using random-effects models. Seventeen (17) observational studies (1774 patients) were identified and included. Factors associated with mortality were: age >40 years (OR, 3.44; 95% CI [1.71-6.91]), suicide attempt (5.78; [3.07-10.87]), Glasgow Coma Scale (GCS) 3-8 compared with 9-15 (38.02; [21.98-65.77]), GCS 3-5 versus 6-8 (15.38; [6.72-35.23], bilateral fixed and dilated pupils versus normal (67.12; [16.67-270.22]), and versus unilateral fixed and dilated pupil (25.35; [5.82-110.41]), dural penetration (29.07; [4.30-196.53]) and bihemispheric (4.23; [2.32-7.68]), and multi-lobar injuries (6.53; [1.99-21.42]). Selection for operative management, according to expert neurosurgical opinion, was protective (0.06; [0.01-0.22]). This is the first meta-analysis on cGSWH mortality prognostic factors. Increasing age, suicide attempt, lower GCS, bilateral mydriasis, dural penetration, and bihemispheric and multi-lobar injury are associated with increased mortality. This study can serve as a guide to clinicians and will provide directions for future research to develop evidence-based management algorithms.


Assuntos
Traumatismos Cranianos Penetrantes/mortalidade , Ferimentos por Arma de Fogo/mortalidade , Humanos , Prognóstico
8.
World Neurosurg ; 102: 695.e7-695.e10, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28385656

RESUMO

BACKGROUND: Intracranial silicone migration is a rare complication of ocular silicone oil endotamponade and may resemble intraventricular hemorrhage. The etiology of the phenomenon is challenging to understand. CASE DESCRIPTION: In an effort to shed light on this phenomenon, we report a case of a 67-year-old woman with ocular silicone oil endotamponade on the left eye due to retinal detachment who presented with headache to the emergency department. The imaging work-up revealed intraventricular silicone oil migration. CONCLUSIONS: The literature is reviewed through the perspective of pathophysiology. The migration of intraocular silicone oil into the ventricular system provides both an important complication for clinicians to be aware of, as well as a paradigm reminding us that cerebrospinal fluid spaces may have more extensive communications with other body compartments than previously thought.


Assuntos
Sistema Nervoso Central , Hemorragia Cerebral/diagnóstico , Corpos Estranhos no Olho/diagnóstico , Migração de Corpo Estranho/diagnóstico , Óleos de Silicone , Idoso , Diagnóstico Diferencial , Tamponamento Interno/métodos , Feminino , Transtornos da Cefaleia/etiologia , Humanos , Imageamento por Ressonância Magnética , Tomografia Computadorizada por Raios X
9.
Int J Mol Sci ; 18(1)2016 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-28036023

RESUMO

The aquaporin (AQP) family of water channels are a group of small, membrane-spanning proteins that are vital for the rapid transport of water across the plasma membrane. These proteins are widely expressed, from tissues such as the renal epithelium and erythrocytes to the various cells of the central nervous system. This review will elucidate the basic structure and distribution of aquaporins and discuss the role of aquaporins in various neuropathologies. AQP1 and AQP4, the two primary aquaporin molecules of the central nervous system, regulate brain water and CSF movement and contribute to cytotoxic and vasogenic edema, where they control the size of the intracellular and extracellular fluid volumes, respectively. AQP4 expression is vital to the cellular migration and angiogenesis at the heart of tumor growth; AQP4 is central to dysfunctions in glutamate metabolism, synaptogenesis, and memory consolidation; and AQP1 and AQP4 adaptations have been seen in obstructive and non-obstructive hydrocephalus and may be therapeutic targets.


Assuntos
Aquaporinas/metabolismo , Edema Encefálico/metabolismo , Epilepsia/metabolismo , Hidrocefalia/metabolismo , Animais , Edema Encefálico/patologia , Movimento Celular , Epilepsia/patologia , Humanos , Hidrocefalia/patologia , Equilíbrio Hidroeletrolítico
10.
Clin Biochem ; 49(9): 726-728, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26874199

RESUMO

OBJECTIVES: Sestrin-2 (Sesn2) belongs to a family of highly conserved antioxidant proteins that were discovered as p53-inducible proteins and inhibits cell growth and proliferation. Our aim was to assess the levels of Sesn2 in malignant pleural effusions of lung cancer patients compared to benign pleural effusions. DESIGN AND METHODS: We enrolled 73 patients (55/males and 18/females) diagnosed with pleural effusion (PE). PEs were grouped as 44 malignant pleural effusions (MPEs; lung cancer) and 29 benign (BPE; 7 congestive heart failure, 9 tuberculosis, 13 parapneumonic). Pleural fluid (PF) Sesn2 levels were determined by enzyme-linked immunosorbent assay (ELISA) kit. Standard biochemical PF analysis was also performed and Sesn2 levels were correlated with PF lactate dehydrogenase (LDH), protein, cell counts and age. RESULTS: Sesn2 was detected in 24/44 patients with MPEs and in 3/29 patients with BPEs (p=0.0001). The mean value (mean±SEM) of Sesn2 in patients with MPEs was 0.54±0.22ng/mL while in BPEs it was 0.12±0.04ng/mL (p=0.0004). In MPEs Sesn2 pleural fluid levels did not correlate with PF LDH and cell counts (p=0.89 and p=0.64 respectively). CONCLUSIONS: Our study shows that Sesn2 is significantly increased in MPEs compared to BPEs. Moreover, the lack of correlation of Sesn2 levels with PF cell counts and PF LDH suggests that it is potentially secreted by pleural mesothelial cells.


Assuntos
Biomarcadores/metabolismo , Epitélio/metabolismo , Exsudatos e Transudatos/metabolismo , Neoplasias Pulmonares/complicações , Proteínas Nucleares/metabolismo , Derrame Pleural Maligno/metabolismo , Ensaio de Imunoadsorção Enzimática , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Derrame Pleural Maligno/etiologia , Derrame Pleural Maligno/patologia , Prognóstico
11.
World Neurosurg ; 88: 631-639, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26578351

RESUMO

BACKGROUND: Cerebral cavernous malformations are more common than generally thought, affecting approximately 1 in every 250 adults. Most of these lesions are asymptomatic or have a relatively benign course, but a small minority behave aggressively and present with recurrent episodes of symptomatic hemorrhage. A safe and effective medical treatment option for the management of this latter group would be useful. Propranolol has recently been shown to be effective in the treatment of infantile hemangioma, a close pathologic counterpart of cavernous malformations. These results suggest a potential role for propranolol treatment in the management of patients with symptomatic cavernous malformations. METHODS: Low-dose propranolol (20 mg, three times daily) was used to treat 2 adult female patients in their mid- to late fifties, both of whom had symptomatic cavernous malformations and a history of repeated hemorrhage. Serial magnetic resonance imaging studies after the initiation of propranolol demonstrated regression of the lesions and no evidence of recurrent hemorrhage. CONCLUSIONS: Propranolol may offer a safe and effective treatment for patients who have cavernous malformations with symptomatic hemorrhage. Additional studies are needed to confirm these findings.


Assuntos
Neoplasias Encefálicas/tratamento farmacológico , Hemorragia Cerebral/prevenção & controle , Hemangioma Cavernoso do Sistema Nervoso Central/tratamento farmacológico , Propranolol/administração & dosagem , Antagonistas Adrenérgicos beta/administração & dosagem , Adulto , Neoplasias Encefálicas/complicações , Neoplasias Encefálicas/diagnóstico , Hemorragia Cerebral/diagnóstico , Hemorragia Cerebral/etiologia , Feminino , Hemangioma Cavernoso do Sistema Nervoso Central/complicações , Hemangioma Cavernoso do Sistema Nervoso Central/diagnóstico , Humanos , Pessoa de Meia-Idade , Resultado do Tratamento
12.
Brain Res ; 1581: 89-102, 2014 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-24933327

RESUMO

A secondary and often lethal consequence of traumatic brain injury is cellular edema that we posit is due to astrocytic swelling caused by transmembrane water fluxes augmented by vasopressin-regulated aquaporin-4 (AQP4). We therefore tested whether vasopressin 1a receptor (V1aR) inhibition would suppress astrocyte AQP4, reduce astrocytic edema, and thereby diminish TBI-induced edematous changes. V1aR inhibition by SR49059 significantly reduced brain edema after cortical contusion injury (CCI) in rat 5h post-injury. Injured-hemisphere brain water content (n=6 animals/group) and astrocytic area (n=3/group) were significantly higher in CCI-vehicle (80.5±0.3%; 18.0±1.4 µm(2)) versus sham groups (78.3±0.1%; 9.5±0.9 µm(2)), and SR49059 blunted CCI-induced increases in brain edema (79.0±0.2%; 9.4±0.8µm(2)). CCI significantly up-regulated GFAP, V1aR and AQP4 protein levels and SR49059 suppressed injury induced up regulation (n=6/group). In CCI-vehicle, sham and CCI-SR49059 groups, GFAP was 1.58±0.04, 0.47±0.02, and 0.81±0.03, respectively; V1aR was 1.00±0.06, 0.45±0.05, and 0.46±0.09; and AQP4 was 2.03±0.34, 0.49±0.04, and 0.92±0.22. Confocal immunohistochemistry gave analogous results. In CCI-vehicle, sham and CCI-SR49059 groups, fluorescence intensity of GFAP was 349±38, 56±5, and 244±30, respectively, V1aR was 601±71, 117.8±14, and 390±76, and AQP4 was 818±117, 158±5, and 458±55 (n=3/group). The results support that edema was predominantly cellular following CCI and documented that V1aR inhibition with SR49059 suppressed injury-induced up regulation of GFAP, V1A and AQP4, blunting edematous changes. Our findings suggest V1aR inhibitors may be potential therapeutic tools to prevent cellular swelling and provide treatment for post-traumatic brain edema.


Assuntos
Edema Encefálico/prevenção & controle , Lesões Encefálicas/tratamento farmacológico , Indóis/farmacologia , Fármacos Neuroprotetores/farmacologia , Pirrolidinas/farmacologia , Animais , Antagonistas dos Receptores de Hormônios Antidiuréticos/farmacologia , Aquaporina 4/metabolismo , Astrócitos/efeitos dos fármacos , Astrócitos/patologia , Astrócitos/fisiologia , Edema Encefálico/etiologia , Edema Encefálico/patologia , Edema Encefálico/fisiopatologia , Lesões Encefálicas/complicações , Lesões Encefálicas/patologia , Lesões Encefálicas/fisiopatologia , Modelos Animais de Doenças , Expressão Gênica/efeitos dos fármacos , Proteína Glial Fibrilar Ácida/metabolismo , Imuno-Histoquímica , Masculino , Microscopia Confocal , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Receptores de Vasopressinas/metabolismo
13.
J Neurotrauma ; 31(14): 1258-67, 2014 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-24635833

RESUMO

Brain swelling and increased intracranial pressure (ICP) following traumatic brain injury (TBI) contribute to poor outcome. Vasopressin-1a receptors (V1aR) and aquaporin-4 (AQP4) regulate water transport and brain edema formation, perhaps in part by modulating cation fluxes. After focal TBI, V1aR inhibitors diminish V1aR and AQP4, reduce astrocytic swelling and brain edema. We determined whether V1aR inhibition with SR49059 after lateral controlled-cortical-impact (CCI) injury affects extracellular Na(+) and K(+) concentrations ([Na(+)]e; [K(+)]e). Ion-selective Na(+) and K(+) electrodes (ISE) and an ICP probe were implanted in rat parietal cortex, and [Na(+)]e, [K(+)]e, and physiological parameters were monitored for 5 h post-CCI. Sham-vehicle-ISE, CCI-vehicle-ISE and CCI-SR49059-ISE groups were studied, and SR49059 was administered 5 min to 5 h post-injury. We found a significant injury-induced decrease in [Na(+)]e to 80.1 ± 15 and 87.9 ± 7.9 mM and increase in [K(+)]e to 20.9 ± 3.8 and 13.4 ± 3.4 mM at 5 min post-CCI in CCI-vehicle-ISE and CCI-SR49059-ISE groups, respectively (p<0.001 vs. baseline; ns between groups). Importantly, [Na(+)]e in CCI-SR49059-ISE was reduced 5-20 min post-injury and increased to baseline at 25 min, whereas recovery in CCI-vehicle-ISE required more than 1 hr, suggesting SR49059 accelerated [Na(+)]e recovery. In contrast, [K(+)]e recovery took 45 min in both groups. Further, ICP was lower in the CCI-SR49059-ISE group. Thus, selective V1aR inhibition allowed faster [Na(+)]e recovery and reduced ICP. By augmenting the [Na(+)]e recovery rate, SR49059 may reduce trauma-induced ionic imbalance, blunting cellular water influx and edema after TBI. These findings suggest SR49059 and V1aR inhibitors are potential tools for treating cellular edema post-TBI.


Assuntos
Edema Encefálico/metabolismo , Lesões Encefálicas/metabolismo , Potássio/metabolismo , Receptores de Vasopressinas/metabolismo , Sódio/metabolismo , Animais , Antagonistas dos Receptores de Hormônios Antidiuréticos/farmacologia , Aquaporina 4/metabolismo , Edema Encefálico/fisiopatologia , Lesões Encefálicas/fisiopatologia , Modelos Animais de Doenças , Potássio/análise , Ratos , Ratos Sprague-Dawley , Sódio/análise
14.
Respir Physiol Neurobiol ; 185(2): 454-60, 2013 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-22947217

RESUMO

Titanium dioxide engineered nanoparticles (nano-TiO(2)) are widely used in the manufacturing of a number of products. Due to their size (<100 nm), when inhaled they may be deposited in the distal lung regions and damage Clara cells. We investigated the mechanisms by which short-term (1-h) incubation of human airway Clara-like (H441) cells to nano-TiO(2) (6 nm in diameter) alters the ability of H441 cells to adhere to extracellular matrix. Our results show that 1h post-incubation, there was a 3-fold increase of extracellular H(2)O(2), increased intracellular oxidative stress as demonstrated by 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) oxidation, and a 5-fold increase of phosphor-ERK1/2 as measured by Western blotting. These changes were accompanied by a 25% decrease of H441 adherence to fibronectin (p<0.05 compared to vehicle incubated H441 cells). Pretreatment with the ERK1/2 inhibitor U0126 for 3h, partially prevented this effect. In conclusion, short-term exposure of H441 cells to nano-TiO(2) appears to reduce adherence to fibronectin due to oxidative stress and activation of ERK1/2.


Assuntos
Adesão Celular/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Nanopartículas Metálicas , Titânio/farmacologia , Adenocarcinoma/patologia , Análise de Variância , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Humanos , Peróxido de Hidrogênio/metabolismo , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Varredura , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Espectrofotometria Infravermelho , Fatores de Tempo , Fatores de Transcrição/metabolismo
15.
Childs Nerv Syst ; 28(4): 533-40, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22252717

RESUMO

PURPOSE: The purpose of this paper is to study the ionic permeability of the leptomeninges related to the effect of ouabain (sodium-potassium-ATPase inhibitor) and amiloride (epithelial sodium channel (ENaC) inhibitor) on the tissue, as well as identify the presence of ion channels. METHODS: Cranial leptomeningeal samples from 26 adult sheep were isolated. Electrophysiological measurements were performed with Ussing system and transmembrane resistance values (R(TM) in Ω*cm(2)) obtained over time. Experiments were conducted with the application of ouabain 10(-3) M or amiloride 10(-5) M at the arachnoidal and pial sides. Immunohistochemical studies of leptomeningeal tissue were prepared with alpha-1 sodium-potassium-ATPase (ATP1A1), beta-ENaC, and delta-ENaC subunit antibodies. RESULTS: The application of ouabain at the arachnoidal side raised the transmembrane resistance statistically significantly and thus decreased its ionic permeability. The addition of ouabain at the pial side led also to a significant but less profound increment in transmembrane resistance. The addition of amiloride at the arachnoidal or pial side did not produce any statistical significant change in the R(TM) from controls (p > 0.05). Immunohistochemistry confirmed the presence of the ATP1A1 and beta- and delta-ENaC subunits at the leptomeninges. CONCLUSIONS: In summary, leptomeningeal tissue possesses sodium-potassium-ATPase and ENaC ion channels. The application of ouabain alters the ionic permeability of the leptomeninges thus reflecting the role of sodium-potassium-ATPase. Amiloride application did not alter the ionic permeability of leptomeninges possibly due to localization of ENaC channels towards the subarachnoid space, away from the experimental application sites. The above properties of the tissue could potentially be related to cerebrospinal fluid turnover at this interface.


Assuntos
Aracnoide-Máter/metabolismo , Permeabilidade da Membrana Celular/fisiologia , Canais Epiteliais de Sódio/fisiologia , Pia-Máter/metabolismo , ATPase Trocadora de Sódio-Potássio/fisiologia , Amilorida/farmacologia , Animais , Aracnoide-Máter/efeitos dos fármacos , Permeabilidade da Membrana Celular/efeitos dos fármacos , Canais Epiteliais de Sódio/metabolismo , Feminino , Masculino , Ouabaína/farmacologia , Pia-Máter/efeitos dos fármacos , Ovinos , ATPase Trocadora de Sódio-Potássio/metabolismo
16.
J Appl Physiol (1985) ; 112(6): 1064-72, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22207722

RESUMO

Assessment of locomotion following exposure of animals to noxious or painful stimuli can offer significant insights into underlying mechanisms of injury and the effectiveness of various treatments. We developed a novel method to track the movement of mice in two dimensions using computer vision and neural network algorithms. By using this system we demonstrated that mice exposed to chlorine (Cl(2)) gas developed impaired locomotion and increased immobility for up to 9 h postexposure. Postexposure administration of buprenorphine, a common analgesic agent, increased locomotion and decreased immobility times in Cl(2)- but not air-exposed mice, most likely by decreasing Cl(2)-induced pain. This method can be adapted to assess the effectiveness of various therapies following exposure to a variety of chemical and behavioral noxious stimuli.


Assuntos
Inteligência Artificial , Cloro/toxicidade , Exposição por Inalação/efeitos adversos , Locomoção/efeitos dos fármacos , Redes Neurais de Computação , Algoritmos , Animais , Buprenorfina/farmacologia , Computadores , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Dor/induzido quimicamente , Dor/fisiopatologia , Software
17.
J Neurosurg ; 115(5): 1031-7, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21800965

RESUMO

OBJECT: Negative-pressure and low-pressure hydrocephalus are rare clinical entities that are frequently misdiagnosed. They are characterized by recurrent episodes of shunt failure because the intracranial pressure is lower than the opening pressure of the valve. In this report the authors discuss iatrogenic CSF leaks as a cause of low- or negative-pressure hydrocephalus after approaches to the cranial base. METHODS: The authors retrospectively reviewed cases of low-pressure or negative-pressure hydrocephalus presenting after cranial approaches complicated with a CSF leak at their institution. RESULTS: Three patients were identified. Symptoms of high intracranial pressure and ventriculomegaly were present, although the measured pressures were low or negative. A blocked communication between the ventricles and the subarachnoid space was documented in 2 of the cases and presumed in the third. Shunt revisions failed repeatedly. In all cases, temporary clinical and radiographic improvement resulted from external ventricular drainage at subatmospheric pressures. The CSF leaks were sealed and CSF communication was reestablished operatively. In 1 case, neck wrapping was used with temporary success. CONCLUSIONS: Negative-pressure or low-pressure hydrocephalus associated with CSF leaks, especially after cranial base approaches, is difficult to treat. The solution often requires the utilization of subatmospheric external ventricular drains to establish a lower ventricular drainage pressure than the drainage pressure created in the subarachnoid space, where the pressure is artificially lowered by the CSF leak. Treatment involves correction of the CSF leak, neck wrapping to increase brain turgor and allow the pressure in the ventricles to rise to the level of the opening pressure of the valve, and reestablishing the CSF route.


Assuntos
Rinorreia de Líquido Cefalorraquidiano/etiologia , Hidrocefalia/cirurgia , Procedimentos Neurocirúrgicos/efeitos adversos , Base do Crânio/cirurgia , Idoso , Vazamento de Líquido Cefalorraquidiano , Pressão do Líquido Cefalorraquidiano , Derivações do Líquido Cefalorraquidiano , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Neurocirúrgicos/métodos
18.
ASAIO J ; 57(5): 388-94, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21709544

RESUMO

The vascular surface distribution of the subarachnoid space has not been studied extensively. The aim of our study was to develop a method of computer-assisted estimation of the distribution of the vascular network in the cortical leptomeninges and subarachnoid space and model it to aid the study of the physiology of brain surface dialysis. Nine sheets of leptomeningeal tissue were obtained from adult sheep. Fourteen image sample areas of 4 cm² each were acquired and processed with ImageJ. The vascular and nonvascular areas of the cortical subarachnoid space were identified using a "projected surface" approach. The modeling equations were used to predict the behavior of brain surface dialysis processes. The mean surface area of identified subarachnoid vessels was 0.354 ± 0.02 cm² per 1 cm² of tissue. The mean meningeal area with unidentified vessels was 0.646 ± 0.02 cm²/1 cm², and the difference between these surfaces was significant (p < 0.0001). The modeling equations used predict that modifying the vessel diameter of the subarachnoid space could alter the efficiency of brain surface dialysis. The computer-assisted modeling of the vascular surface of the cortical subarachnoid space may be a useful tool in depicting its morphology and assessing the physiology during brain surface dialysis.


Assuntos
Encéfalo/irrigação sanguínea , Encéfalo/patologia , Meninges/patologia , Animais , Autopsia , Encéfalo/anatomia & histologia , Calibragem , Diálise , Humanos , Processamento de Imagem Assistida por Computador , Microcirculação , Modelos Animais , Modelos Teóricos , Ovinos , Espaço Subaracnóideo/patologia
20.
Childs Nerv Syst ; 27(1): 27-33, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20625739

RESUMO

PURPOSE: Hydrocephalus is a common disorder of defective cerebrospinal fluid (CSF) turnover. The identification of the aquaporin water channels (AQPs) led to the study of their role in the composition of biological fluids including CSF. The purpose of this study is to review the potential role of aquaporins in the pathogenesis, compensation, and possibly treatment of hydrocephalus. METHODS: We performed a MEDLINE search using the terms "aquaporin AND hydrocephalus." The search returned a total of 20 titles. Eleven studies fulfilled the criteria for this review. RESULTS: Most studies were performed in animal models. The expression of AQPs in hydrocephalus is significantly altered. Aquaporin-1 levels at the choroid plexus are decreased in most models of hydrocephalus while CSF production and intracranial pressure are reduced in AQP1 knockout mice. In contrast, the expression of AQP4 in hydrocephalus is increased at its sites of expression. Aquaporin-4 knockout mice show a decreased clearance of brain edema via blood-CSF and blood-brain barrier (BBB) pathways and decreased survival in hydrocephalus models. CONCLUSIONS: Aquaporin-1 is highly expressed at the choroid plexus and is related to CSF production. Aquaporin-4 is expressed at the ependyma, glia limitans, and at the perivascular end feet processes of astrocytes of the BBB, facilitating the water movement across these tissue interfaces. The observations obtained from animal studies and few cases in humans indicate an adaptive and protective role of AQPs in hydrocephalus by decreasing CSF production and increasing edema clearance. Aquaporins are attractive targets for the pharmaceutical treatment of hydrocephalus.


Assuntos
Aquaporinas/metabolismo , Hidrocefalia/metabolismo , Animais , Transporte Biológico , Humanos
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