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1.
Oper Neurosurg (Hagerstown) ; 24(3): e223-e227, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36701558

RESUMO

BACKGROUND AND IMPORTANCE: We report a case of nail gun-related penetrating brain injury, puncturing through the anterior third of superior sagittal sinus, which remained patent and was associated with an arteriovenous (AV) shunt revealed on catheter angiogram. CLINICAL PRESENTATION: A previously well 35-year-old male patient presented with a self-inflicted pneumatic nail gun injury. Neurological examination was unremarkable. Computed tomography (CT) of the brain demonstrated the nail had penetrated through the skull, traversed the anterior third of the superior sagittal sinus (SSS), right frontal lobe parenchyma, frontal horn of right lateral ventricle, caudate, and right cerebral peduncle. CT angiogram showed no associated vascular injury, with CT venogram showing a short segment of filling defect within SSS adjacent to nail penetration. However, digital subtraction angiography revealed an associated arteriovenous shunt 8 mm anterior to the dural penetration site, which filled the SSS in arterial phase. Removal of the nail was performed using a double concentric craniotomy around the nail entry site. Before removal of the nail, the SSS anterior to the nail penetration site was tied off and divided along with coagulation and division of the falx, while the SSS posterior to the nail penetration site was also tied off to isolate the penetrated SSS segment. The patient recovered well with repeat digital subtraction angiography demonstrating no residual AV shunting. CONCLUSION: This case report aims to highlight the importance of performing a catheter angiogram and describe our stepwise considerations and approach in treating a penetrating injury involving the superior sagittal sinus with concurrent AV fistula.


Assuntos
Encéfalo , Seio Sagital Superior , Masculino , Humanos , Adulto , Seio Sagital Superior/diagnóstico por imagem , Seio Sagital Superior/cirurgia , Encéfalo/cirurgia , Procedimentos Neurocirúrgicos , Craniotomia , Dura-Máter/cirurgia
2.
Tissue Eng Part A ; 27(11-12): 648-664, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33764164

RESUMO

Positively charged oligo(poly(ethylene glycol) fumarate) (OPF+) hydrogel scaffolds, implanted into a complete transection spinal cord injury (SCI), facilitate a permissive regenerative environment and provide a platform for controlled observation of repair mechanisms. Axonal regeneration after SCI is critically dependent upon nutrients and oxygen from a newly formed blood supply. Our objective was to investigate fundamental characteristics of revascularization in association with the ingrowth of axons into hydrogel scaffolds, thereby defining spatial relationships between axons and the neovasculature. A novel combination of stereologic estimates and precision image analysis techniques quantitate neurovascular regeneration in rats. Multichannel hydrogel scaffolds containing Matrigel-only (MG), Schwann cells (SCs), or SCs with rapamycin-eluting poly(lactic co-glycolic acid) microspheres (RAPA) were implanted for 6 weeks following complete spinal cord transection. Image analysis of 72 scaffold channels identified a total of 2494 myelinated and 4173 unmyelinated axons at 10 µm circumferential intervals centered around 708 individual blood vessel profiles. Blood vessel number, density, volume, diameter, intervessel distances, total vessel surface and cross-sectional areas, and radial diffusion distances were compared. Axon number and density, blood vessel surface area, and vessel cross-sectional areas in the SC group exceeded that in the MG and RAPA groups. Individual axons were concentrated within a concentric radius of 200-250 µm from blood vessel walls, in Gaussian distributions, which identified a peak axonal number (Mean Peak Amplitude) corresponding to defined distances (Mean Peak Distance) from each vessel, the highest concentrations of axons were relatively excluded from a 25-30 µm zone immediately adjacent to the vessel, and from vessel distances >150 µm. Higher axonal densities correlated with smaller vessel cross-sectional areas. A statistical spatial algorithm was used to generate cumulative distribution F- and G-functions of axonal distribution in the reference channel space. Axons located around blood vessels were definitively organized as clusters and were not randomly distributed. A scoring system stratifies 5 direct measurements and 12 derivative parameters influencing regeneration outcomes. By providing methods to quantify the axonal-vessel relationships, these results may refine spinal cord tissue engineering strategies to optimize the regeneration of complete neurovascular bundles in their relevant spatial relationships after SCI. Impact statement Vascular disruption and impaired neovascularization contribute critically to the poor regenerative capacity of the spinal cord after injury. In this study, hydrogel scaffolds provide a detailed model system to investigate the regeneration of spinal cord axons as they directly associate with individual blood vessels, using novel methods to define their spatial relationships and the physiologic implications of that organization. These results refine future tissue engineering strategies for spinal cord repair to optimize the re-development of complete neurovascular bundles in their relevant spatial architectures.


Assuntos
Hidrogéis , Traumatismos da Medula Espinal , Animais , Axônios , Regeneração Nervosa , Ratos , Células de Schwann , Medula Espinal , Alicerces Teciduais
3.
J Neurosurg Case Lessons ; 1(10): CASE2122, 2021 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-35855437

RESUMO

BACKGROUND: Giant pituitary macroadenomas with a diameter >4 cm are rare tumors, accounting for only about 5% of pituitary adenomas. They are more difficult to maximally resect safely owing to limited access as well as encasement of adjacent structures. Acidophil stem cell adenomas are rare immature neoplasms proposed to derive from common progenitor cells of somatotroph and lactotroph cells. These adenomas comprise about 4.3% of surgically removed pituitary adenomas. No previous reports have described acidophil stem cell adenomas that grow to the size of giant macroadenomas. This rare entity poses special challenges given the need for maximal safe resection in an immature neoplasm. OBSERVATIONS: The authors report a 21-year-old female who presented with 3 years of progressive visual decline and a giant macroadenoma. She underwent endoscopic transsphenoidal surgery for decompression. Given the tumor size and involvement of adjacent critical structures, gross-total resection was not achieved. The authors review the literature on giant pituitary adenomas and provide a discussion on clinical management for this rare entity. LESSONS: The authors present a very rare case of a giant pituitary adenoma of acidophil stem cell origin and discuss the technical and management challenges in this rare entity.

4.
J Tissue Eng Regen Med ; 13(5): 857-873, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30808065

RESUMO

Hydrogel scaffolds provide a beneficial microenvironment in transected rat spinal cord. A combinatorial biomaterials-based strategy provided a microenvironment that facilitated regeneration while reducing foreign body reaction to the three-dimensional spinal cord construct. We used poly lactic-co-glycolic acid microspheres to provide sustained release of rapamycin from Schwann cell (SC)-loaded, positively charged oligo-polyethylene glycol fumarate scaffolds. The biological activity and dose-release characteristics of rapamycin from microspheres alone and from microspheres embedded in the scaffold were determined in vitro. Three dose formulations of rapamycin were compared with controls in 53 rats. We observed a dose-dependent reduction in the fibrotic reaction to the scaffold and improved functional recovery over 6 weeks. Recovery was replicated in a second cohort of 28 animals that included retransection injury. Immunohistochemical and stereological analysis demonstrated that blood vessel number, surface area, vessel diameter, basement membrane collagen, and microvessel phenotype within the regenerated tissue was dependent on the presence of SCs and rapamycin. TRITC-dextran injection demonstrated enhanced perfusion into scaffold channels. Rapamycin also increased the number of descending regenerated axons, as assessed by Fast Blue retrograde axonal tracing. These results demonstrate that normalization of the neovasculature was associated with enhanced axonal regeneration and improved function after spinal cord transection.


Assuntos
Células Imobilizadas , Microesferas , Células de Schwann , Sirolimo , Regeneração da Medula Espinal , Alicerces Teciduais/química , Animais , Linhagem Celular , Células Imobilizadas/metabolismo , Células Imobilizadas/patologia , Células Imobilizadas/transplante , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Preparações de Ação Retardada/farmacologia , Feminino , Polietilenoglicóis/química , Polietilenoglicóis/farmacocinética , Polietilenoglicóis/farmacologia , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/farmacocinética , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/farmacologia , Ratos , Ratos Endogâmicos F344 , Células de Schwann/metabolismo , Células de Schwann/patologia , Células de Schwann/transplante , Sirolimo/química , Sirolimo/farmacocinética , Sirolimo/farmacologia , Traumatismos da Medula Espinal/metabolismo , Traumatismos da Medula Espinal/patologia , Traumatismos da Medula Espinal/terapia , Engenharia Tecidual
5.
J Tissue Eng Regen Med ; 12(1): e398-e407, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28296347

RESUMO

Positively-charged oligo[poly(ethylene glycol)fumarate] (OPF+ ) is a biodegradable hydrogel used for spinal cord injury repair. We compared scaffolds containing primary Schwann cells (SCs) to scaffolds delivering SCs genetically modified to secrete high concentrations of glial cell-derived neurotrophic factor (GDNF). Multichannel OPF+ scaffolds loaded with SCs or GDNF-SCs were implanted into transected rat spinal cords for 4 weeks. GDNF-SCs promoted regeneration of more axons into OPF+ scaffolds (2773.0 ± 396.0) than primary SC OPF+ scaffolds (1666.0 ± 352.2) (p = 0.0491). This increase was most significant in central and ventral-midline channels of the scaffold. Axonal remyelination was quantitated by stereologic analysis. Increased myelination of regenerating axons was observed in the GDNF-SC group. Myelinating cell and axon complexes were formed by host SCs and not by implanted cells or host oligodendrocytes. Fast Blue retrograde tracing studies determined the rostral-caudal directionality of axonal growth. The number of neurons that projected axons rostrally through the GDNF-SC scaffolds was higher (7929 ± 1670) than in animals with SC OPF+ scaffolds (1069 ± 241.5) (p < 0.0001). The majority of ascending axons were derived from neurons located more than 15 mm from the scaffold-cord interface, and were identified to be lumbosacral intraspinal motor neurons. Transected animals with GDNF-SC OPF+ scaffolds partially recovered locomotor function at weeks 3 and 4 following surgery. Copyright © 2017 John Wiley & Sons, Ltd.


Assuntos
Axônios/fisiologia , Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Hidrogéis/farmacologia , Regeneração Nervosa/efeitos dos fármacos , Remielinização/efeitos dos fármacos , Células de Schwann/metabolismo , Traumatismos da Medula Espinal/fisiopatologia , Alicerces Teciduais/química , Animais , Axônios/efeitos dos fármacos , Fumaratos/química , Humanos , Polietilenoglicóis/química , Ratos Sprague-Dawley , Recuperação de Função Fisiológica/efeitos dos fármacos , Células de Schwann/citologia , Células de Schwann/efeitos dos fármacos
6.
Clin Neurol Neurosurg ; 152: 28-33, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27866034

RESUMO

OBJECTIVE: A single level discectomy is one of the most common procedures performed by spine surgeons. While some practitioners utilize the microscope, others do not. We postulate improved visualization with an intraoperative microscope decreases complications and inferior outcomes. METHODS: A multicenter surgical registry was utilized for this retrospective cohort analysis. Patients with degenerative spinal diagnoses undergoing elective single level discectomies from 2010 to 2014 were included. Univariate analysis was performed comparing demographics, patient characteristics, operative data, and outcomes for discectomies performed with and without a microscope. Multivariable logistic regression analysis was then applied to compare outcomes of micro- and macrodiscectomies. RESULTS: Query of the registry yielded 23,583 patients meeting inclusion criteria. On univariate analysis the microscope was used in a greater proportion of the oldest age group as well as Hispanic white patients. Patients with any functional dependency, history of congestive heart failure, chronic corticosteroid use, or anemia (hematocrit<35%) also had greater proportions of microdiscectomies. Thoracic region discectomies more frequently involved use of the microscope than cervical or lumbar discectomies (25.0% vs. 16.4% and 13.0%, respectively, p<0.001). Median operative time (IQR) was increased in microscope cases [80min (60, 108) vs. 74min (54, 102), p<0.001]. Of the patients that required reoperation within 30days, 2.5% of them had undergone a microdiscectomy compared to 1.9% who had undergone a macrodiscectomy, p=0.044. On multivariable analysis, microdiscectomies were more likely to have an operative time in the top quartile of discectomy operative times, ≥103min (OR 1.256, 95% CI 1.151-1.371, p<0.001). In regards to other multivariable outcome models for any complication, surgical site infection, dural tears, reoperation, and readmission, no significant association with microdiscectomy was found. CONCLUSIONS: The use of the microscope was found to significantly increase the odds of longer operative time, but not influence rates of postoperative complications. Thus, without evidence from this study that the microscope decreases complications, the use of the microscope should be at the surgeon's discretion, validating the use of both macro and micro approaches to discectomy as acceptable standards of care.


Assuntos
Discotomia/estatística & dados numéricos , Microcirurgia/estatística & dados numéricos , Avaliação de Processos e Resultados em Cuidados de Saúde/estatística & dados numéricos , Complicações Pós-Operatórias/epidemiologia , Sistema de Registros/estatística & dados numéricos , Idoso , Idoso de 80 Anos ou mais , Discotomia/métodos , Discotomia/normas , Feminino , Humanos , Masculino , Microcirurgia/métodos , Microcirurgia/normas , Pessoa de Meia-Idade , Estudos Retrospectivos
7.
Tissue Eng Part A ; 21(13-14): 2099-114, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25891264

RESUMO

Positively charged oligo[poly(ethylene glycol) fumarate] (OPF+) scaffolds loaded with Schwann cells bridge spinal cord injury (SCI) lesions and support axonal regeneration in rat. The regeneration achieved is not sufficient for inducing functional recovery. Attempts to increase regeneration would benefit from understanding the effects of the scaffold and transplanted cells on lesion environment. We conducted morphometric and stereological analysis of lesions in rats implanted with OPF+ scaffolds with or without loaded Schwann cells 1, 2, 3, 4, and 8 weeks after thoracic spinal cord transection. No differences were found in collagen scarring, cyst formation, astrocyte reactivity, myelin debris, or chondroitin sulfate proteoglycan (CSPG) accumulation. However, when scaffold-implanted animals were compared with animals with transection injuries only, these barriers to regeneration were significantly reduced, accompanied by increased activated macrophages/microglia. This distinctive and regeneration permissive tissue reaction to scaffold implantation was independent of Schwann cell transplantation. Although the tissue reaction was beneficial in the short term, we observed a chronic fibrotic host response, resulting in scaffolds surrounded by collagen at 8 weeks. This study demonstrates that an appropriate biomaterial scaffold improves the environment for regeneration. Future targeting of the host fibrotic response may allow increased axonal regeneration and functional recovery.


Assuntos
Fumaratos/farmacologia , Polietilenoglicóis/farmacologia , Implantação de Prótese , Traumatismos da Medula Espinal/patologia , Traumatismos da Medula Espinal/terapia , Alicerces Teciduais/química , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Feminino , Proteína Glial Fibrilar Ácida/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Proteínas dos Microfilamentos/metabolismo , Microglia/efeitos dos fármacos , Microglia/metabolismo , Proteína Básica da Mielina/metabolismo , Fenótipo , Proteoglicanas/metabolismo , Ratos Sprague-Dawley , Células de Schwann/citologia , Células de Schwann/efeitos dos fármacos , Células de Schwann/transplante , Fatores de Tempo
8.
J Neurosci Methods ; 211(2): 179-84, 2012 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-22960163

RESUMO

Techniques used to produce partial spinal cord injuries in animal models have the potential for creating variability in lesions. The amount of tissue affected may influence the functional outcomes assessed in the animals. The recording of somatosensory evoked potentials (SSEPs) may be a valuable tool for assessing the extent of lesion applied in animal models of traumatic spinal cord injury (SCI). Intraoperative tibial SSEP recordings were assessed during surgically induced lateral thoracic hemisection SCI in Sprague-Dawley rats. The transmission of SSEPs, or lack thereof, was determined and compared against the integrity of the dorsal funiculi on each side of the spinal cord upon histological sectioning. An association was found between the presence of an SSEP signal and presence of intact dorsal funiculus tissue. The relative risk is 4.50 (95% confidence interval: 1.83-11.08) for having an intact dorsal funiculus when the ipsilateral SSEP was present compared to when it was absent. Additionally, the amount of spared spinal cord tissue correlates with final functional assessments at nine weeks post injury: BBB (linear regression, R²=0.618, p<0.001) and treadmill test (linear regression, R²=0.369, p=0.016). Therefore, we propose intraoperative SSEP monitoring as a valuable tool to assess extent of lesion and reduce variability between animals in experimental studies of SCI.


Assuntos
Modelos Animais de Doenças , Potenciais Somatossensoriais Evocados/fisiologia , Monitorização Intraoperatória/métodos , Traumatismos da Medula Espinal/fisiopatologia , Animais , Feminino , Ratos , Ratos Sprague-Dawley
9.
J Clin Invest ; 120(12): 4207-19, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21060152

RESUMO

Amputation as a result of impaired wound healing is a serious complication of diabetes. Inadequate angiogenesis contributes to poor wound healing in diabetic patients. Endothelial progenitor cells (EPCs) normally augment angiogenesis and wound repair but are functionally impaired in diabetics. Here we report that decreased expression of manganese superoxide dismutase (MnSOD) in EPCs contributes to impaired would healing in a mouse model of type 2 diabetes. A decreased frequency of circulating EPCs was detected in type 2 diabetic (db/db) mice, and when isolated, these cells exhibited decreased expression and activity of MnSOD. Wound healing and angiogenesis were markedly delayed in diabetic mice compared with normal controls. For cell therapy, topical transplantation of EPCs onto excisional wounds in diabetic mice demonstrated that diabetic EPCs were less effective than normal EPCs at accelerating wound closure. Transplantation of diabetic EPCs after MnSOD gene therapy restored their ability to mediate angiogenesis and wound repair. Conversely, siRNA-mediated knockdown of MnSOD in normal EPCs reduced their activity in diabetic wound healing assays. Increasing the number of transplanted diabetic EPCs also improved the rate of wound closure. Our findings demonstrate that cell therapy using diabetic EPCs after ex vivo MnSOD gene transfer accelerates their ability to heal wounds in a mouse model of type 2 diabetes.


Assuntos
Diabetes Mellitus Tipo 2/terapia , Células Endoteliais/enzimologia , Superóxido Dismutase/genética , Cicatrização/genética , Cicatrização/fisiologia , Animais , Complicações do Diabetes/enzimologia , Complicações do Diabetes/genética , Complicações do Diabetes/patologia , Complicações do Diabetes/terapia , Diabetes Mellitus Tipo 2/enzimologia , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/patologia , Modelos Animais de Doenças , Células Endoteliais/transplante , Expressão Gênica , Técnicas de Silenciamento de Genes , Terapia Genética , Humanos , Masculino , Camundongos , Camundongos Mutantes , Transplante de Células-Tronco , Células-Tronco/enzimologia
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