48 research outputs found
Ophthalmic aspects of idiopathic intracranial hypertension syndrome (pseudotumor cerebri)
A síndrome do pseudotumor cerebral é uma condição caracterizada por elevação da pressão intracraniana na ausência de lesões expansivas e de ventriculomegalia e com a constituição do líquor normal em um paciente sem alterações no nível de consciência. A terminologia desta afecção modificou nos últimos anos acompanhando os avanços nos métodos diagnósticos e no conhecimento da sua fisiopatogenia. Quando nenhuma causa é identificada a condição é denominada hipertensão intracraniana idiopática. Os pacientes freqüentemente são examinados pelo oftalmologista, já que apresentam achados como papiledema, diplopia e perda visual, uma complicação freqüentemente grave e irreversível. Neste artigo, revisamos os critérios diagnósticos, as alterações oftalmológicas, em especial a perda visual, bem como o tratamento enfatizando a importância do oftalmologista no diagnóstico e na monitoração da visão durante o tratamento clínico desta afecção, bem como na realização do tratamento cirúrgico pela descompressão da bainha do nervo óptico.Pseudotumor cerebri is a syndrome of increased intra-cranial pressure without a space-occupying lesion or ventriculomegaly in a patient with normal level of conscience and normal cerebrospinal fluid constitution. The terminology for the disorder has changed over the years in accordance with advances in diagnostic technology and insights into the disease process. When no secondary cause is identified, the syndrome is termed idiopathic intracranial hypertension. Patients are not uncommonly seen by ophthamologists since they present with papiledema, double vision and visual loss, a frequently severe and irreversible complication. In this paper we review the diagnostic criteria and the ophthalmic manifestations of this condition. We also emphasize the importance of the ophthalmlogist in the diagnosis and monitoring of visual function during the medical treatment of this condition as well as in the in the event of surgical treatment performed using optic nerve sheath decompression
Optic nerve meningioma mimicking progression of glaucomatous axonal damage: a case report
O objetivo é relatar um caso de meningioma da bainha do nervo óptico localizado na região do canal óptico simulando progressão de dano axonal glaucomatoso. Paciente de 60 anos em tratamento para glaucoma primário de ângulo aberto apresentou perda progressiva do campo visual e aumento da escavação do disco óptico à esquerda. Devido à rapidez e à assimetria da progressão do dano axonal, por causa da redução da acuidade visual e do aparente bom controle pressórico uma lesão compressiva do nervo óptico foi suspeitada. A tomografia computadorizada de órbitas foi normal, entretanto a imagem por ressonância magnética evidenciou um meningioma da bainha do nervo óptico na região do canal óptico. Afecções compressivas da via óptica anterior são causas incomuns de escavação do disco óptico, entretanto podem simular uma neuropatia glaucomatosa e devem ser lembradas nos pacientes com suspeita de glaucoma de baixa pressão intra-ocular ou em tratamento para glaucoma que apresentem evolução atípica da perda visual.To report a case of an optic nerve sheath meningioma located at the optic canal area mimicking the progression of a glaucomatous axonal damage. A 60-year-old female patient developed progressive visual field loss and enlargement of the optic disc cup in the left eye while in treatment for primary open-angle glaucoma. Because of the rapid progression of axonal loss, the asymmetry of the visual field defect and the fact that intraocular pressure had been under control, a compressive optic neuropathy was suspected. A computerized tomography scan of the orbit was normal but a high-resolution magnetic resonance imaging demonstrated an optic nerve sheath meningioma located at the optic canal area. Compressive lesions of the anterior visual pathways are uncommon causes of optic disc cupping but should be considered in patients suspected of or undergoing treatment for glaucoma that present with atypical progression of visual loss
Orbital involvement in Rosai-Dorfman disease
A doença de Rosai-Dorfman (DRD) ou histiocitose sinusal com linfadenopatia maciça é uma entidade clínica idiopática, rara e benigna, caracterizada pela proliferação histiocitária com linfofagocitose. Geralmente se apresenta com linfoadenomegalia cervical, no entanto pode haver acometimento extranodal, sendo a região orbitária um dos locais de possível acometimento. Na maioria dos casos é uma doença autolimitada com melhora espontânea, entretanto pode ser necessária exérese cirúrgica da lesão ou tratamento com corticosteróides e radioterapia.Neste trabalho, relatamos o caso de um paciente masculino de 29 anos, com queixa de tumoração em pálpebra inferior direita por 6 meses e história de acometimento sinusal prévio pela doença de Rosai Dorfmann. Ao exame oftalmológico apresentava proptose de olho direito e aumento de volume de pálpebra inferior direita. O exame de tomografia computadorizada de órbitas evidenciou lesão sólida extraconal em órbita direita. Após a exérese da lesão houve melhora importante do quadro clínico. O exame histopatológico associado à imuno-histoquímica confirmou o envolvimento orbitário na DRD. Revisamos também o quadro clínico, diagnóstico diferencial e tratamento desta afecção.Rosai-Dorfman disease or sinus histiocytosis with massive lymphadenopathy is a rare idiopathic and benign clinical entity, characterized by histiocytic proliferation with linfofagocitosis. It usually presents with cervical lymphadenopathy although extranodal involvement may occur. The orbital region is one of the most common extranodal sites. It is usually a self-limiting disease with spontaneous resolution but surgical excision, corticosteroids and radiotherapy may be necessary. We describe the case of a 29-years-old male patient complaining of an orbital mass sensation for 6 months and a history of previous sinus involvement from Rosai-Dorfman disease. Ophthalmic examination showed proptosis of the right eye and swelling of right lower eyelid. Computed tomography of the orbits disclosed a solid extraconal lesion in the inferior right orbit. After surgical excision there was a significant clinical improvement. Histopathologic examination confirmed the diagnosis of Rosai-Dorfman disease. We also review the clinical picture and differential diagnosis of this condition
Effects of glycosaminoglycan supplementation in the chondrogenic differentiation of bone marrow- and synovial- derived mesenchymal stem/stromal cells on 3D-extruded poly (ε-caprolactone) scaffolds
The lack of effective and long-term treatments for articular cartilage defects has increased the interest for innovative tissue engineering strategies. Such approaches, combining cells, biomaterial matrices and external biochemical/physical cues, hold promise for generating fully functional cartilage tissue. Herein, this study aims at exploring the use of the major cartilage glycosaminoglycans (GAGs), chondroitin sulfate (CS) and hyaluronic acid (HA), as external biochemical cues to promote the chondrogenic differentiation of human bone marrow- and synovium-derived mesenchymal stem/stromal cells (hBMSC/hSMSC) on custom-made 3 D porous poly (ε-caprolactone) (PCL) scaffolds. The culture conditions, namely the chondrogenic medium and hypoxic environment (5% O2 tension), were firstly optimized by culturing hBMSCs on PCL scaffolds without GAG supplementation. For both MSC sources, GAG supplemented media, particularly with HA, promoted significantly cartilage-like extracellular matrix (ECM) production (higher sulfated GAG amounts) and chondrogenic gene expression. Remarkably, in contrast to tissues generated using hBMSCs, the hSMSC-based constructs showed decreased expression of hypertrophic marker COL X. Histological, immunohistochemical and transmission electron microscopy (TEM) analysis confirmed the presence of typical articular cartilage ECM components (GAGs, aggrecan, collagen fibers) in all the tissue constructs produced. Overall, our results highlight the potential of integrating GAG supplementation, hSMSCs and customizable 3 D scaffolds toward the fabrication of bioengineered cartilage tissue substitutes with reduced hypertrophy.info:eu-repo/semantics/publishedVersio
Additive manufactured Poly("-caprolactone)-graphene scaffolds: Lamellar crystal orientation, mechanical properties and biological performance
Understanding the mechano–biological coupling mechanisms of biomaterials for tissue engineering is of major importance to assure proper scaffold performance in situ. Therefore, it is of paramount importance to establish correlations between biomaterials, their processing conditions, and their mechanical behaviour, as well as their biological performance. With this work, it was possible to infer a correlation between the addition of graphene nanoparticles (GPN) in a concentration of 0.25, 0.5, and 0.75% (w/w) (GPN0.25, GPN0.5, and GPN0.75, respectively) in three-dimensional poly("-caprolactone) (PCL)-based scaffolds, the extrusion-based processing parameters, and the lamellar crystal orientation through small-angle X-ray scattering experiments of extruded samples of PCL and PCL/GPN. Results revealed a significant impact on the scaffold’s mechanical properties to
a maximum of 0.5% of GPN content, with a significant improvement in the compressive modulus of 59 MPa to 93 MPa. In vitro cell culture experiments showed the scaffold’s ability to support the adhesion and proliferation of L929 fibroblasts (fold increase of 28, 22, 23, and 13 at day 13 (in relation to day 1) for PCL, GPN0.25, GPN0.5, and GPN0.75, respectively) and bone marrow mesenchymal stem/stromal cells (seven-fold increase for all sample groups at day 21 in relation to day 1). Moreover, the cells maintained high viability, regular morphology, and migration capacity in all the different experimental groups, assuring the potential of PCL/GPN scaffolds for tissue engineering (TE) applications.info:eu-repo/semantics/publishedVersio
A multimodal stimulation cell culture bioreactor for tissue engineering: A numerical modelling approach
This research was funded by the Fundação para a Ciência e a Tecnologia (FCT) and Centro2020 through
the following Projects: UIDP/04044/2020, PAMI—ROTEIRO/0328/2013 (No 022158) and Stimuli2BioScaffold—
Stimuli modelling for BioScaffolds: from numerical modelling to in vitro tests co-financed by COMPETE2020
under the PT2020 programme, and supported by FCT (02/SAICT/2017). Ref. POCI-01-0145-FEDER-032554;
Bone2Move—Development of “in vivo” experimental techniques and modeling methodologies for the evaluation
of 4D scaffolds on bone defect in sheep model: an integrative research approach co-financed by COMPETE2020 under the PT2020 programme, and supported by FCT (02/SAICT/2017), Project nº 31146; MATIS—MATERIALS AND SUSTAINABLE INDUSTRIAL TECHNOLOGIES (CENTRO-01-0145-FEDER-000014-3362); Instituto de Biofísica e Engenharia Biomédica (IBEB) is supported by Fundação para a Ciência e Tecnologia (FCT), Portugal, under Grant n UIDB/00645/2020. Also supported by UID/BIO/04565/2020.The use of digital twins in tissue engineering (TE) applications is of paramount importance to reduce the number of in vitro and in vivo tests. To pursue this aim, a novel multimodal bioreactor is developed, combining 3D design with numerical stimulation. This approach will facilitate the reproducibility between studies and the platforms optimisation (physical and digital) to enhance TE. The new bioreactor was specifically designed to be additive manufactured, which could not be reproduced with conventional techniques. Specifically, the design suggested allows the application of dual stimulation (electrical and mechanical) of a scaffold cell culture. For the selection of the most appropriate material for bioreactor manufacturing several materials were assessed for their cytotoxicity. Numerical modelling methods were then applied to the new bioreactor using one of the
most appropriate material (Polyethylene Terephthalate Glycol-modified (PETG)) to find the optimal
stimulation input parameters for bone TE based on two reported in vitro studies.info:eu-repo/semantics/publishedVersio
Monitoring Yeast Cultures Grown on Corn Stover Hydrolysate for Lipid Production
ABSTRACT: Microbial oils can be used as an alternative sustainable and renewable feedstock to fossil reserves for producing lubricants and polyurethane materials. Two oleaginous yeasts were grown on non-detoxified corn stover hydrolysate supplemented with corn steep liquor and mineral medium in shake flasks. Trichosporon oleaginosus DSM 11815 displayed the highest lipid production. This strain was further cultivated in a bench bioreactor, using the same culture medium, under a batch regime. Flow cytometry was used to monitor the T. oleaginosus culture using the dual staining technique (SYBR Green and PI) for cell membrane integrity detection. Values of 42.28% (w/w) and 0.06 g/Lh lipid content and lipid productivity, respectively, were recorded for T. oleaginosus cultivated in the bench bioreactor operated under a batch regime. During the cultivation, most of the yeast cells maintained their integrity. T. oleaginosus has the potential to be used as an oil microbial source for a wide range of industrial applications. In addition, it is robust in adverse conditions such as lignocellulosic hydrolysate exposure and oxygen-limiting conditions. Flow cytometry is a powerful and useful tool for monitoring yeast cultivations on lignocellulosic hydrolysates for cell count, size, granularity, and membrane integrity detection.info:eu-repo/semantics/publishedVersio