Evidence map›Paper›PMID 25206026›Full record

ArticleAnnals of neurosciences2013

Convection Enhanced Delivery: A Comparison of infusion characteristics in ex vivo and in vivo non-human primate brain tissue.

Gurwattan Miranpuri, Angelica Hinchman, Anyi Wang, Dominic Schomberg, Ken Kubota, Martin Brady, Raghu Raghavan, Kevin Bruner, Ethan Brodsky, Walter Block and 6 more

Open access · greenAbstract read
In one paragraph

Article in Annals of neurosciences, 2013. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
0.4field-weighted citation impact, top 32% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed, 13 citations in OpenAlex.

  1. Observational
  2. Article
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

16 authors at 5 institutions in 2 countries.

Gurwattan MiranpuriDepartment of Neurological Surgery, School of Medicine and Public Health ; Kinetics Foundation.
Angelica HinchmanDepartment of Neurological Surgery, School of Medicine and Public Health.
Anyi WangDepartment of Neurological Surgery, School of Medicine and Public Health ; Department of Biomedical Engineering at the University of Wisconsin-Madison.
Dominic SchombergDepartment of Neurological Surgery, School of Medicine and Public Health.
Ken KubotaKinetics Foundation.
Martin BradyTherataxis.
Raghu RaghavanTherataxis.
Kevin BrunerWisconsin National Primate Research Center.
Ethan BrodskyDepartment of Biomedical Engineering at the University of Wisconsin-Madison.
Walter BlockDepartment of Biomedical Engineering at the University of Wisconsin-Madison.
Ben GrabowDepartment of Biomedical Engineering at the University of Wisconsin-Madison.
Jim RaschkeKinetics Foundation.
Andrew AlexanderWeismann Center at the UW Madison, USA.
Chris RossEngineering Resources Group Inc.
Heather SimmonsWisconsin National Primate Research Center.
Karl SillayDepartment of Neurological Surgery, School of Medicine and Public Health ; Department of Biomedical Engineering at the University of Wisconsin-Madison.
University of Wisconsin–Madison · USNeurological Surgery · USKinetic Foundation · GBApplied Resources (United States) · USWest Virginia Wesleyan College · US

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundConvection enhanced delivery (CED) is emerging as a promising infusion toolto facilitate delivery of therapeutic agents into the brain via mechanically controlled pumps. Infusion protocols and catheter design have an important impact on delivery. CED is a valid alternative for systemic administration of agents in clinical trials for cell and gene therapies. Where gel and ex vivo models are not sufficient in modeling the disease, in vivo models allow researchers to better understand the underlying mechanisms of neuron degeneration, which is helpful in finding novel approaches to control the process or reverse the progression. Determining the risks, benefits, and efficacy of new gene therapies introduced via CED will pave a way to enter human clinical trial. PURPOSE: The objective of this study is to compare volume distribution (Vd)/ volume infused (Vi) ratios and backflow measurements following CED infusions in ex vivo versus in vivo non-human primate brain tissue, based on infusion protocols developed in vitro.

methodsIn ex vivo infusions, the first brain received 2 infusions using a balloon catheter at rates of 1 μL/min and 2 μL/min for 30 minutes. The second and third brains received infusions using a valve-tip (VT) catheter at 1 μL/min for 30 minutes. The fourth brain received a total of 45 μL infused at a rate of 1 μL/min for 15 minutes followed by 2 μL/min for 15 minutes. Imaging was performed (SPGR FA34) every 3 minutes. In the in vivo group, 4 subjects received a total of 8 infusions of 50 μL. Subjects 1 and 2 received infusions at 1.0 μL/min using a VT catheter in the left hemisphere and a smart-flow (SF) catheter in the right hemisphere. Subjects 3 and 4 each received 1 infusion in the left and right hemisphere at 1.0 μL/min.

resultsMRI calculations of Vd/Vi did not significantly differ from those obtained on post-mortem pathology. The mean measured Vd/Vi of in vivo (5.23 + /-1.67) compared to ex vivo (2.17 + /-1.39) demonstrated a significantly larger Vd/Vi for in vivo by 2.4 times (p = 0.0017).

conclusionWe detected higher ratios in the in vivo subjects than in ex vivo. This difference could be explained by the extra cellular space volume fraction. Studies evaluating backflow and morphology use in vivo tissue as a medium are recommended. Further investigation is warranted to evaluate the role blood pressure and heart rate may play in human CED clinical trials.

Indexed as

BackflowConvection enhanced delivery (CED)NeurocatheterNon-human primateVolume distribution volume infused ratio (Vd/Vi)

Identifiers

PMID25206026
PMCPMC4117126
OpenAlexW2108079080

What OpenQuestion holds

Textmetadata
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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.