•A detailed protocol for culturing adult human brain slices is presented.•Cell viability and neurotransmitter release are only slightly affected in vitro.•Cultured slices are sensitive to Alzheimer’s ...disease-associated Aβ oligomers.•These cultures may represent a preferred model to study neurodegenerative diseases.
Slice cultures have been prepared from several organs. With respect to the brain, advantages of slice cultures over dissociated cell cultures include maintenance of the cytoarchitecture and neuronal connectivity. Slice cultures from adult human brain have been reported and constitute a promising method to study neurological diseases. Despite this potential, few studies have characterized in detail cell survival and function along time in short-term, free-floating cultures.
We used tissue from adult human brain cortex from patients undergoing temporal lobectomy to prepare 200 μm-thick slices. Along the period in culture, we evaluated neuronal survival, histological modifications, and neurotransmitter release. The toxicity of Alzheimer’s-associated Aβ oligomers (AβOs) to cultured slices was also analyzed.
Neurons in human brain slices remain viable and neurochemically active for at least four days in vitro, which allowed detection of binding of AβOs. We further found that slices exposed to AβOs presented elevated levels of hyperphosphorylated Tau, a hallmark of Alzheimer’s disease.
Although slice cultures from adult human brain have been previously prepared, this is the first report to analyze cell viability and neuronal activity in short-term free-floating cultures as a function of days in vitro.
Once surgical tissue is available, the current protocol is easy to perform and produces functional slices from adult human brain. These slice cultures may represent a preferred model for translational studies of neurodegenerative disorders when long term culturing in not required, as in investigations on AβO neurotoxicity.
•Hippocampal MTR in TLE does not add to volume or T2 signal regarding lateralization.•Extracellular CSPG are the most relevant correlate to MTR in hippocampal sclerosis.•Increased CSPG ...counterbalances neuron loss over the reduction in hippocampal MTR.
Temporal lobe epilepsy patients (TLE) often present with hippocampal atrophy, increased T2 relaxation, and reduced magnetization transfer ratio (MTR) in magnetic resonance images (MRI). The histological correlates of the reduced hippocampal MTR are so far unknown. Since MTR is dependent on the tissue’s macromolecules, our aim was to evaluate the correlations between cellular populations, extracellular matrix molecules and the MTR in TLE patients.
Patients with TLE (n = 26) and voluntaries (=20) were scanned in a 3 Tesla MRI scanner, and MTR images were calculated from 3DT1 sequences with magnetization pulse on resonance. Immunohistochemistry for neurons, reactive astrocytes, activated microglia, and extracellular matrix chondroitin sulfate were performed in formalin fixed, paraffin embedded tissues of TLE and autopsy controls (n = 10). Results were considered significant with adjusted p < 0.05.
Compared to the respective controls, TLE patients had reduced hippocampal MTR, increased reactive astrocytes and activated microglia, increased extracellular chondroitin sulfate, and reduced neuron density, compares to controls. MTR correlated positively with neuron density in CA3 and with chondroitin sulfate in CA3 and CA1. Multiple linear regressions reinforced the correlations between chondroitin sulfate and MTR.
Our data indicate that extracellular matrix molecules are the most significant histological correlates of magnetization transfer ratio in the hippocampus of TLE patients.
The term “paraclinoid aneurysms”, has been used for aneurysms of the internal carotid artery (ICA) between the cavernous sinus and the posterior communicating artery. Due to their complex anatomical ...relationship at the skull base and because they are frequently large/giant, their surgical treatment remains a challenge. Ninety-five patients harboring 106 paraclinoid aneurysms underwent surgery (1990–2010). Age, 11–72 years old. Sex, 74:21 female/male. Follow-up; 1–192 months (mean = 51.7 months). Eighty-six patients had single and 9 had multiple paraclinoid aneurysms. Sixty-six were ophthalmic, 14 were in the ICA superior wall, 13 in the inferior, 10 in the medial, and 3 in the ICA lateral wall. Eleven were giant, 29 were large, and 66 were small. Sixty-three patients had ruptured and 32 had unruptured aneurysms. Two patients with bilateral aneurysms had bilateral approaches, totaling 97 procedures. A total of 98.2 % of aneurysms were clipped (complete exclusion in 93.8 %). ICA occlusion occurred in 10 (5.6 %). There was no patient rebleeding during the follow-up period. A good outcome was achieved in 76.8 %, with better results for unruptured aneurysms, worse results for patients with vasospasm, and with no difference according to size. Thirty-six (37.9 %) patients had transient/permanent postoperative neurological deficits (25.4 % ruptured vs. 62.5 % unruptured aneurysms). The most frequent deficits were visual impairment and third cranial nerve palsies. Operative mortality was 11.6 %, all in patients presenting with ruptured aneurysms. Despite relatively high morbidity/mortality, especially for patients with ruptured aneurysms, microsurgical treatment of paraclinoid aneurysm has high efficacy, with better outcome for unruptured aneurysms and worse outcome for patients with vasospasm.
In the central nervous system, zinc is released along with glutamate during neurotransmission and, in excess, can promote neuronal death. Experimental studies have shown that metallothioneins I/II ...(MT-I/II), which chelate free zinc, can affect seizures and reduce neuronal death after status epilepticus. Our aim was to evaluate the expression of MT-I/II in the hippocampus of patients with temporal lobe epilepsy (TLE). Hippocampi from patients with pharmacoresistant mesial temporal lobe epilepsy (MTLE) and patients with TLE associated with tumor or dysplasia (TLE-TD) were evaluated for expression of MT-I/II, for the vesicular zinc levels, and for neuronal, astroglial, and microglial populations. Compared to control cases, MTLE group displayed widespread increase in MT-I/II expression, astrogliosis, microgliosis and reduced neuronal population. In TLE-TD, the same changes were observed, except that were mainly confined to fascia dentata. Increased vesicular zinc was observed only in the inner molecular layer of MTLE patients, when compared to control cases. Correlation and linear regression analyses indicated an association between increased MT-I/II and increased astrogliosis in TLE. MT-I/II levels did not correlate with any clinical variables, but MTLE patients with secondary generalized seizures (SGS) had less MT-I/II than MTLE patients without SGS. In conclusion, MT-I/II expression was increased in hippocampi from TLE patients and our data suggest that it is associated with astrogliosis and may be associated with different seizure spread patterns.
Objective
Drebrins are crucial for synaptic function and dendritic spine development, remodeling, and maintenance. In temporal lobe epilepsy (TLE) patients, a significant hippocampal synaptic ...reorganization occurs, and synaptic reorganization has been associated with hippocampal hyperexcitability. This study aimed to evaluate, in TLE patients, the hippocampal expression of drebrin using immunohistochemistry with DAS2 or M2F6 antibodies that recognize adult (drebrin A) or adult and embryonic (pan‐drebrin) isoforms, respectively.
Methods
Hippocampal sections from drug‐resistant TLE patients with hippocampal sclerosis (HS; TLE, n = 33), of whom 31 presented with type 1 HS and two with type 2 HS, and autopsy control cases (n = 20) were assayed by immunohistochemistry and evaluated for neuron density, and drebrin A and pan‐drebrin expression. Double‐labeling immunofluorescences were performed to localize drebrin A–positive spines in dendrites (MAP2), and to evaluate whether drebrin colocalizes with inhibitory (GAD65) and excitatory (VGlut1) presynaptic markers.
Results
Compared to controls, TLE patients had increased pan‐drebrin in all hippocampal subfields and increased drebrin A–immunopositive area in all hippocampal subfields but CA1. Drebrin‐positive spine density followed the same pattern as total drebrin quantification. Confocal microscopy indicated juxtaposition of drebrin‐positive spines with VGlut1‐positive puncta, but not with GAD65‐positive puncta. Drebrin expression in the dentate gyrus of TLE cases was associated negatively with seizure frequency and positively with verbal memory. TLE patients with lower drebrin‐immunopositive area in inner molecular layer (IML) than in outer molecular layer (OML) had a lower seizure frequency than those with higher or comparable drebrin‐immunopositive area in IML compared with OML.
Significance
Our results suggest that changes in drebrin‐positive spines and drebrin expression in the dentate gyrus of TLE patients are associated with lower seizure frequency, more preserved verbal memory, and a better postsurgical outcome.
Summary
Objective
Increased T2 relaxation time is often seen in temporal lobe epilepsy (TLE) with hippocampal sclerosis. Water content directly affects the effective T2 in a voxel. Our aim was to ...evaluate the relation between T2 values and two molecules associated with brain water homeostasis aquaporin 4 (AQP4) and chondroitin sulfate proteoglycan (CSPG), as well as cellular populations in the hippocampal region of patients with TLE.
Methods
Hippocampal T2 imaging and diffusion tensor imaging (DTI) were obtained from 42 drug‐resistant patients with TLE and 20 healthy volunteers (radiologic controls, RCs). A similar protocol (ex vivo) was applied to hippocampal sections from the same TLE cases and 14 autopsy control hippocampi (histologic and radiologic controls, HRCs), and each hippocampal subfield was evaluated. Hippocampal sections from TLE cases and HRC controls were submitted to immunohistochemistry for neurons (neuron nuclei NeuN), reactive astrocytes (glial fibrillary acidic protein GFAP), activated microglia (human leukocyte antigen‐D–related HLA‐DR), polarized AQP4, and CSPG.
Results
Patients with TLE had higher in vivo and ex vivo hippocampal T2 relaxation time. Hippocampi from epilepsy cases had lower neuron density, higher gliosis, decreased AQP4 polarization, and increased CSPG immunoreactive area. In vivo relaxation correlated with astrogliosis in the subiculum and extracellular CSPG in the hilus. Ex vivo T2 relaxation time correlated with astrogliosis in the hilus, CA4, and subiculum, and with microgliosis in CA1. The difference between in vivo and ex vivo relaxation ratio correlated with mean diffusivity and with the immunopositive area for CSPG in the hilus.
Significance
Our data indicate that astrogliosis, microgliosis, and CSPG expression correlate with the increased T2 relaxation time seen in the hippocampi of patients with TLE.
To analyze the clinical outcome of patients with foramen magnum (FM) meningiomas.
Thirteen patients (11 Feminine / 2 Masculine with FM meningiomas operated on through lateral suboccipital approach ...were studied. Clinical outcome were analyzed using survival (SC) and recurrence-free survival curves (RFSC).
All tumors were World Health Organization grade I. Total, subtotal and partial resections were acchieved in 69.2%, 23.1% and 7.7%, respectively, and SC was better for males and RFSC for females. Tumor location, extent of resection and involvement of vertebral artery/lower cranial nerves did not influence SC and RFSC. Recurrence rate was 7.7%. Operative mortality was 0. Main complications were transient (38.5%) and permanent (7.7%) lower cranial nerve deficits, cerebrospinal fluid fistula (30.8%), and transient and permanent respiratory difficulties in 7.7% each.
FM meningiomas can be adequately treated in public hospitals in developing countries if a multidisciplinary team is available for managing postoperative lower cranial nerve deficits.
Atypical/anaplastic (World Health Organization (WHO) grades II and III) are less common and have poorer outcomes than benign meningiomas. This study aimed to analyze the outcome of patients with ...these tumors.
Overall/recurrence-free survivals (RFS) and the Karnofsky Performance Scale of 52 patients with grades II (42) and III (9) meningiomas surgically treated were analyzed (uni/multivariate analysis).
Total/subtotal resections were 60.8%/35.3%. Patients <60 years-old and grade II tumors had longer survival. Grade II tumors, total resection and de novo meningioma had better RFS (univariate analysis). Patients >60 years-old, de novo meningioma and radiotherapy had longer survival and patients <60 years-old and with grade II tumors had longer RFS (multivariate analysis). Recurrence rate was 51% (39.2% Grade II and 66.7% Grade III). Operative mortality was 1.9%.
Age <60 years-old, grade II tumors and de novo meningiomas were the main predictors for better prognosis among patients with grades II and III meningiomas.
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