scholarly journals A neural transplantation cannula and microinjector system: experimental and clinical experience

1999 ◽  
Vol 7 (3) ◽  
pp. E4
Author(s):  
Ivar Mendez ◽  
Murray Hong ◽  
Stephen Smith ◽  
Alain Dagher ◽  
Jacques Desrosiers
Keyword(s):  
Perioperative Complications ◽  
Neural Transplantation ◽  
Positron Emission ◽  
Minimal Trauma ◽  
Experimental Rat Model ◽  
Ventral Mesencephalic ◽  
Neurological Conditions ◽  
The Brain ◽  
Transplantation Procedures ◽  
Experimental Stage

The authors present a simple, reliable, and safe system for performing neural transplantation in the human brain. The device consists of a transplantation cannula and microinjector system that has been specifically designed to reduce implantation-related trauma and to maximize the number of graft deposits for each injection. The system was evaluated first in an experimental rat model of Parkinson's disease (PD). Animal transplantation with this system showed excellent graft survival with minimal trauma to the brain. Following this experimental stage, the cannula and microinjector system was used in eight patients with PD enrolled in the Halifax Neural Transplantation Program who received bilateral putaminal transplants of fetal ventral mesencephalic tissue. A total of 16 transplantation operations and 64 trajectories were performed in the eight patients, and there were no intra- or perioperative complications. Magnetic resonance imaging studies obtained 24 hours after surgery revealed no evidence of tissue damage or hemorrhage. Transplant survival was confirmed on fluorodopa positron emission tomography scans 6 and 12 months after surgery. As neural transplantation procedures for the treatment of neurological conditions evolve, the ability to deliver viable grafts safely will become of critical importance. The device presented here has been proven to be of value in maximizing the number of graft deposits while minimizing implantation-related trauma to the host brain.

Neural transplantation cannula and microinjector system: experimental and clinical experience

2000 ◽  
Vol 92 (3) ◽  
pp. 493-499 ◽  
Author(s):  
Ivar Mendez ◽  
Murray Hong ◽  
Stephen Smith ◽  
Alain Dagher ◽  
Jacques Desrosiers
Keyword(s):  
Perioperative Complications ◽  
Neural Transplantation ◽  
Content Type ◽  
Positron Emission ◽  
Minimal Trauma ◽  
Experimental Rat Model ◽  
Ventral Mesencephalic ◽  
The Brain ◽  
Transplantation Procedures ◽  
Fine Print

✓ The authors present a simple, reliable, and safe system for performing neural transplantation in the human brain. The device consists of a transplantation cannula and microinjector system that has been specifically designed to reduce implantation-related trauma and to maximize the number of graft deposits per injection. The system was evaluated first in an experimental rat model of Parkinson's disease (PD). Animals in which transplantation with this system had been performed showed excellent graft survival with minimal trauma to the brain. Following this experimental stage, the cannula and microinjector system were used in eight patients with PD enrolled in the Halifax Neural Transplantation Program who received bilateral putaminal transplants of fetal ventral mesencephalic tissue. A total of 16 transplantation operations and 64 trajectories were performed in the eight patients, and there were no intraoperative or perioperative complications. Magnetic resonance imaging studies obtained 24 hours after surgery revealed no evidence of tissue damage or hemorrhage. Transplant survival was confirmed by fluorodopa positron emission tomography scans obtained 6 and 12 months after surgery.As neural transplantation procedures for the treatment of neurological conditions evolve, the ability to deliver viable grafts safely will become critically important. The device presented here has proved to be of value in maximizing the number of graft deposits while minimizing implantation-related trauma to the host brain.

Simultaneous intrastriatal and intranigral fetal dopaminergic grafts in patients with Parkinson disease: a pilot study

2002 ◽  
Vol 96 (3) ◽  
pp. 589-596 ◽  
Author(s):  
Ivar Mendez ◽  
Alain Dagher ◽  
Murray Hong ◽  
Paula Gaudet ◽  
Swarna Weerasinghe ◽  
...  
Keyword(s):  
Pilot Study ◽  
Parkinson Disease ◽  
Rating Scale ◽  
Perioperative Complications ◽  
Clinical Results ◽  
Neural Transplantation ◽  
Content Type ◽  
Intracerebral Transplantation ◽  
Positron Emission ◽  
Fine Print

✓ The main neural transplantation strategy in Parkinson disease (PD) has been focused on reinnervating the striatum. The clinical results reported in patients who receive transplants have been limited and do not justify the use of neural transplantation as a routine therapeutic procedure for PD. Identifying the optimal target for transplantation may be one of the critical factors for optimizing clinical outcomes. Evidence from preclinical studies indicates that simultaneous intrastriatal and intranigral grafts (double grafts) may produce a more complete functional recovery. The authors report the clinical and positron emission tomography (PET) scanning results in three patients enrolled in a safety and feasibility pilot study who received double grafts and who have been followed for up to 13 months posttransplantation. Patients included in the study had idiopathic PD. All patients underwent detailed assessments before and after surgery, in accordance with the Core Assessment Program for Intracerebral Transplantation. The patients received implants of fetal mesencephalic cell suspensions in the putamen and substantia nigra (SN) bilaterally. There were no intraoperative or perioperative complications. Follow-up PET scans demonstrated an increase in the mean fluorodopa uptake constant values in the putamen and SN 12 months postsurgery. Improvements were also noted in the total Unified Parkinson′s Disease Rating Scale, Hoehn and Yahr, Schwab and England, and pronation/supination scores after transplantation. The authors demonstrate the feasibility of reinnervating the SN and striatum by using a double transplant strategy in humans.

Brain FDG PET for the Etiological Diagnosis of Clinically Uncertain Cognitive Impairment During Delirium in Remission

2020 ◽  
Vol 77 (4) ◽  
pp. 1609-1622
Author(s):  
Franziska Mathies ◽  
Catharina Lange ◽  
Anja Mäurer ◽  
Ivayla Apostolova ◽  
Susanne Klutmann ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Fdg Pet ◽  
False Negative ◽  
Ground Truth ◽  
Etiological Diagnosis ◽  
Geriatric Unit ◽  
Positron Emission ◽  
The Brain ◽  
Hospitalized Geriatric Patients

Background: Positron emission tomography (PET) of the brain with 2-[F-18]-fluoro-2-deoxy-D-glucose (FDG) is widely used for the etiological diagnosis of clinically uncertain cognitive impairment (CUCI). Acute full-blown delirium can cause reversible alterations of FDG uptake that mimic neurodegenerative disease. Objective: This study tested whether delirium in remission affects the performance of FDG PET for differentiation between neurodegenerative and non-neurodegenerative etiology of CUCI. Methods: The study included 88 patients (82.0±5.7 y) with newly detected CUCI during hospitalization in a geriatric unit. Twenty-seven (31%) of the patients were diagnosed with delirium during their current hospital stay, which, however, at time of enrollment was in remission so that delirium was not considered the primary cause of the CUCI. Cases were categorized as neurodegenerative or non-neurodegenerative etiology based on visual inspection of FDG PET. The diagnosis at clinical follow-up after ≥12 months served as ground truth to evaluate the diagnostic performance of FDG PET. Results: FDG PET was categorized as neurodegenerative in 51 (58%) of the patients. Follow-up after 16±3 months was obtained in 68 (77%) of the patients. The clinical follow-up diagnosis confirmed the FDG PET-based categorization in 60 patients (88%, 4 false negative and 4 false positive cases with respect to detection of neurodegeneration). The fraction of correct PET-based categorization did not differ between patients with delirium in remission and patients without delirium (86% versus 89%, p = 0.666). Conclusion: Brain FDG PET is useful for the etiological diagnosis of CUCI in hospitalized geriatric patients, as well as in patients with delirium in remission.

Dissecting the Therapeutic Relevance of Gene Therapy in NeuroAIDS: An Evolving Epidemic

2020 ◽  
Vol 20 (3) ◽  
pp. 174-183
Author(s):  
Bushra Nabi ◽  
Saleha Rehman ◽  
Faheem Hyder Pottoo ◽  
Sanjula Baboota ◽  
Javed Ali
Keyword(s):  
Viral Entry ◽  
Due Process ◽  
Intrinsic Property ◽  
Antiretroviral Drugs ◽  
Viral Reservoir ◽  
Primary Concern ◽  
Cellular Delivery ◽  
Formidable Challenge ◽  
Neurological Conditions ◽  
The Brain

: NeuroAIDS, a disease incorporating both infectious and neurodegenerative pathways, is still a formidable challenge for the researchers to deal with. The primary concern for the treatment of neuroAIDS still remains the inaccessibility of the viral reservoir, making it indispensable for novel techniques to be continuously innovated. Since the brain serves as a reservoir for viral replication, it is pragmatic and a prerequisite to overcome the related barriers in order to improve the drug delivery to the brain. The current treatment ideology is based on the combinatorial approach of a mocktail of antiretroviral drugs. However, complete eradication of the disease could not be achieved. Thereby the arena of gene-based cellular delivery is trending and has created a niche for itself in the present scenario. To establish the supremacy of gene delivery, it is advisable to have a better understanding of the molecular mechanism involved in the due process. The mechanism associated with the activity of the anti-HIV gene lies in their intrinsic property to impart resistance to the HIV infection by targeting the viral entry channels. This review principally emphasizes on different types of gene therapies explored so far for the management of AIDS and its associated neurological conditions. Therefore it could rightly be said that we are at the crossroad where the need of the hour is to develop novel strategies for curbing AIDS and its associated neurological conditions.

scholarly journals Development of [18F]LU14 for PET Imaging of Cannabinoid Receptor Type 2 in the Brain

2021 ◽  
Vol 22 (15) ◽  
pp. 8051
Author(s):  
Rodrigo Teodoro ◽  
Daniel Gündel ◽  
Winnie Deuther-Conrad ◽  
Lea Ueberham ◽  
Magali Toussaint ◽  
...  
Keyword(s):  
Cannabinoid Receptors ◽  
Cannabinoid Receptor ◽  
Biological Evaluation ◽  
Emission Tomography ◽  
Tailored Therapy ◽  
Positron Emission ◽  
Cannabinoid Receptor Type 2 ◽  
Attractive Therapeutic Target ◽  
The Brain

Cannabinoid receptors type 2 (CB2R) represent an attractive therapeutic target for neurodegenerative diseases and cancer. Aiming at the development of a positron emission tomography (PET) radiotracer to monitor receptor density and/or occupancy during a CB2R-tailored therapy, we herein describe the radiosynthesis of cis-[18F]1-(4-fluorobutyl-N-((1s,4s)-4-methylcyclohexyl)-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxamide ([18F]LU14) starting from the corresponding mesylate precursor. The first biological evaluation revealed that [18F]LU14 is a highly affine CB2R radioligand with >80% intact tracer in the brain at 30 min p.i. Its further evaluation by PET in a well-established rat model of CB2R overexpression demonstrated its ability to selectively image the CB2R in the brain and its potential as a tracer to further investigate disease-related changes in CB2R expression.

scholarly journals Cognitive trajectories of patients with focal ß-amyloid deposition

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Si Eun Kim ◽  
Byungju Lee ◽  
Hyemin Jang ◽  
Juhee Chin ◽  
Ching Soong Khoo ◽  
...  
Keyword(s):  
Cognitive Decline ◽  
Neuropsychological Tests ◽  
Mixed Effects ◽  
Amnestic Mild Cognitive Impairment ◽  
Emission Tomography ◽  
Amyloid Pet ◽  
Cognitive Level ◽  
Visual Rating ◽  
Positron Emission ◽  
The Brain

Abstract Background The presence of ß-amyloid (Aß) in the brain can be identified using amyloid PET. In clinical practice, the amyloid PET is interpreted based on dichotomous visual rating, which renders focal Aß accumulation be read as positive for Aß. However, the prognosis of patients with focal Aß deposition is not well established. Thus, we investigated cognitive trajectories of patients with focal Aß deposition. Methods We followed up 240 participants (112 cognitively unimpaired [CU], 78 amnestic mild cognitive impairment [aMCI], and 50 Alzheimer’s disease (AD) dementia [ADD]) for 2 years from 9 referral centers in South Korea. Participants were assessed with neuropsychological tests and 18F-flutemetamol (FMM) positron emission tomography (PET). Ten regions (frontal, precuneus/posterior cingulate (PPC), lateral temporal, parietal, and striatum of each hemisphere) were visually examined in the FMM scan, and participants were divided into three groups: No-FMM, Focal-FMM (FMM uptake in 1–9 regions), and Diffuse-FMM. We used mixed-effects model to investigate the speed of cognitive decline in the Focal-FMM group according to the cognitive level, extent, and location of Aß involvement, in comparison with the No- or Diffuse-FMM group. Results Forty-five of 240 (18.8%) individuals were categorized as Focal-FMM. The rate of cognitive decline in the Focal-FMM group was faster than the No-FMM group (especially in the CU and aMCI stage) and slower than the Diffuse-FMM group (in particular in the CU stage). Within the Focal-FMM group, participants with FMM uptake to a larger extent (7–9 regions) showed faster cognitive decline compared to those with uptake to a smaller extent (1–3 or 4–6 regions). The Focal-FMM group was found to have faster cognitive decline in comparison with the No-FMM when there was uptake in the PPC, striatum, and frontal cortex. Conclusions When predicting cognitive decline of patients with focal Aß deposition, the patients’ cognitive level, extent, and location of the focal involvement are important.

scholarly journals Synthesis and pharmacokinetic characterisation of a fluorine-18 labelled brain shuttle peptide fusion dimeric affibody

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Takahiro Morito ◽  
Ryuichi Harada ◽  
Ren Iwata ◽  
Yiqing Du ◽  
Nobuyuki Okamura ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Post Injection ◽  
Affibody Molecule ◽  
Positron Emission ◽  
A Cell ◽  
Protein Binders ◽  
Rapid Clearance ◽  
Labelling Method ◽  
The Brain ◽  
Ex Vivo Study

AbstractBrain positron emission tomography (PET) imaging with radiolabelled proteins is an emerging concept that potentially enables visualization of unique molecular targets in the brain. However, the pharmacokinetics and protein radiolabelling methods remain challenging. Here, we report the performance of an engineered, blood–brain barrier (BBB)-permeable affibody molecule that exhibits rapid clearance from the brain, which was radiolabelled using a unique fluorine-18 labelling method, a cell-free protein radiosynthesis (CFPRS) system. AS69, a small (14 kDa) dimeric affibody molecule that binds to the monomeric and oligomeric states of α-synuclein, was newly designed for brain delivery with an apolipoprotein E (ApoE)-derived brain shuttle peptide as AS69-ApoE (22 kDa). The radiolabelled products 18F-AS69 and 18F-AS69-ApoE were successfully synthesised using the CFPRS system. Notably, 18F-AS69-ApoE showed higher BBB permeability than 18F-AS69 in an ex vivo study at 10 and 30 min post injection and was partially cleared from the brain at 120 min post injection. These results suggest that small, a brain shuttle peptide-fused fluorine-18 labelled protein binders can potentially be utilised for brain molecular imaging.

scholarly journals PET evaluation of light-induced modulation of microglial activation and GLP-1R expression in depressive rats

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yu Liu ◽  
Lizhen Wang ◽  
Donghui Pan ◽  
Mingzhu Li ◽  
Yaoqi Li ◽  
...  
Keyword(s):  
Microglial Activation ◽  
Light Therapy ◽  
Emission Tomography ◽  
Noninvasive Evaluation ◽  
Mild Stress ◽  
Positron Emission ◽  
Therapeutic Choice ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1 ◽  
The Brain

AbstractLight therapy has been accepted as a promising therapeutic choice for depression. Positron emission tomography (PET) combined with specific radiotracers has great benefits for revealing pathogenesis and developing therapeutics. This study aimed to investigate the influences of light therapy on microglial activation and glucagon-like peptide-1 receptor (GLP-1R) expression in the brain of depressive rats using [18F]DPA-714 and [18F]exendin-4 PET. The results showed that chronic unpredictable mild stress (CUMS)-induced depressive rats had poorer performance in behavioral tests compared to normal rats (p < 0.05) and the depressive-like behavior could be ameliorated by light therapy. Besides, depressive rats had significantly higher [18F]DPA-714 uptake and lower [18F]FDG uptake compare to normal rats in 11 and 9 regions of interest (ROIs) of the brain, respectively (p < 0.05). After 5 weeks of light therapy, higher [18F]FDG and [18F]exendin-4 uptake was observed in most ROIs of light therapy-treated depressive rats compared to untreated depressive rats (p < 0.05) and no significant differences existed in [18F]DPA-714 uptake between the two groups. This study demonstrated that light therapy can ameliorate depressive-like behavior, improve glucose metabolism, and halt the decline of brain GLP-1R expression of depressive rats, but have no effects on microglial activation caused by CUMS. Besides, this study validated that [18F]DPA-714 and [18F]exendin-4 PET have the potential for noninvasive evaluation of microglial activation and GLP-1R expression in the brain of depression.

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