scholarly journals Comparative Adenylic Acid Deaminase Activity in Choroid Plexus and Ciliary Process Tissue

Nature ◽  
1960 ◽  
Vol 185 (4710) ◽  
pp. 388-388 ◽  
Author(s):  
MORTON B. WAITZMAN
Keyword(s):  
Choroid Plexus ◽  
Ciliary Process ◽  
Adenylic Acid

ATP-stimulated adenylic acid deaminase activity at site of aqueous humor production

1960 ◽  
Vol 198 (3) ◽  
pp. 665-668 ◽  
Author(s):  
Morton B. Waitzman
Keyword(s):  
Cerebrospinal Fluid ◽  
Choroid Plexus ◽  
Aqueous Humor ◽  
Adenine Nucleotide ◽  
Amp Deaminase ◽  
Active System ◽  
Ciliary Process ◽  
General Acceptance ◽  
Adenylic Acid ◽  
Fluid Production

A specific 5-adenylic acid (5-AMP) deaminase was studied in preparations of hog ciliary process tissue. It was determined that while the activity of this deaminase is enhanced by adenosinetriphosphate (ATP), this activity is not completely blocked in the absence of ATP. Deamination proceeds only at the expense of 5-AMP, but a myokinase-like-active system may be prepared, such that 5-AMP is added to the substrate pool. In this latter case total levels of deamination are generally reflective of added 5-AMP and myokinase-like reaction accumulated 5-AMP. The general acceptance of ciliary process tissue as the site of aqueous humor production leads one to a reasonable conclusion that the very active 5-AMP deaminase studied plays some as yet unexplained role in the dynamics of aqueous secretion. Possibilities concerning the specific role(s) played are discussed. Functional analogy between aqueous humor and cerebrospinal fluid production is again suggested by the fact that an adenine nucleotide deaminase is found also in choroid plexus tissue.

Organization of tight junctions in the choroid plexus epithelium

1978 ◽  
Vol 36 (2) ◽  
pp. 336-337
Author(s):  
B. Van Deurs ◽  
J. K. Koehler
Keyword(s):  
Choroid Plexus ◽  
Present Report ◽  
Freeze Fracture ◽  
Barrier Properties ◽  
Cell Junctions ◽  
Structural Basis ◽  
Apical Surface ◽  
Choroid Plexus Epithelium ◽  
Solid Nitrogen ◽  
Special Composition

The choroid plexus epithelium constitutes a blood-cerebrospinal fluid (CSF) barrier, and is involved in regulation of the special composition of the CSF. The epithelium is provided with an ouabain-sensitive Na/K-pump located at the apical surface, actively pumping ions into the CSF. The choroid plexus epithelium has been described as “leaky” with a low transepithelial resistance, and a passive transepithelial flux following a paracellular route (intercellular spaces and cell junctions) also takes place. The present report describes the structural basis for these “barrier” properties of the choroid plexus epithelium as revealed by freeze fracture.Choroid plexus from the lateral, third and fourth ventricles of rats were used. The tissue was fixed in glutaraldehyde and stored in 30% glycerol. Freezing was performed either in liquid nitrogen-cooled Freon 22, or directly in a mixture of liquid and solid nitrogen prepared in a special vacuum chamber. The latter method was always used, and considered necessary, when preparations of complementary (double) replicas were made.

MR Findings of Choroid Plexus Papilloma: Case Report

1994 ◽  
Vol 30 (4) ◽  
pp. 643
Author(s):  
Joo Hyeong Oh ◽  
Tae Hoon Kim ◽  
Woo Suk Choi
Keyword(s):  
Case Report ◽  
Choroid Plexus ◽  
Choroid Plexus Papilloma ◽  
Plexus Papilloma

Development and evaluation of a patient-specific surgical simulator for endoscopic colloid cyst resection

2020 ◽  
Vol 133 (2) ◽  
pp. 521-529 ◽  
Author(s):  
Vivek P. Bodani ◽  
Gerben E. Breimer ◽  
Faizal A. Haji ◽  
Thomas Looi ◽  
James M. Drake
Keyword(s):  
Choroid Plexus ◽  
Computer Aided Design ◽  
Third Ventricle ◽  
Colloid Cyst ◽  
Comfort Level ◽  
Complex Case ◽  
Patient Specific ◽  
Surgical Simulator ◽  
Perceived Realism ◽  
Noncontrast Ct

OBJECTIVEEndoscopic resection of third-ventricle colloid cysts is technically challenging due to the limited dexterity and visualization provided by neuroendoscopic instruments. Extensive training and experience are required to master the learning curve. To improve the education of neurosurgical trainees in this procedure, a synthetic surgical simulator was developed and its realism, procedural content, and utility as a training instrument were evaluated.METHODSThe simulator was developed based on the neuroimaging (axial noncontrast CT and T1-weighted gadolinium-enhanced MRI) of an 8-year-old patient with a colloid cyst and hydrocephalus. Image segmentation, computer-aided design, rapid prototyping (3D printing), and silicone molding techniques were used to produce models of the skull, brain, ventricles, and colloid cyst. The cyst was filled with a viscous fluid and secured to the roof of the third ventricle. The choroid plexus and intraventricular veins were also included. Twenty-four neurosurgical trainees performed a simulated colloid cyst resection using a 30° angled endoscope, neuroendoscopic instruments, and image guidance. Using a 19-item feedback survey (5-point Likert scales), participants evaluated the simulator across 5 domains: anatomy, instrument handling, procedural content, perceived realism, and confidence and comfort level.RESULTSParticipants found the simulator’s anatomy to be highly realistic (mean 4.34 ± 0.63 [SD]) and appreciated the use of actual instruments (mean 4.38 ± 0.58). The procedural content was also rated highly (mean 4.28 ± 0.77); however, the perceived realism was rated slightly lower (mean 4.08 ± 0.63). Participants reported greater confidence in their ability to perform an endoscopic colloid cyst resection after using the simulator (mean 4.45 ± 0.68). Twenty-three participants (95.8%) indicated that they would use the simulator for additional training. Recommendations were made to develop complex case scenarios for experienced trainees (normal-sized ventricles, choroid plexus adherent to cyst wall, bleeding scenarios) and incorporate advanced instrumentation such as side-cutting aspiration devices.CONCLUSIONSA patient-specific synthetic surgical simulator for training residents and fellows in endoscopic colloid cyst resection was successfully developed. The simulator’s anatomy, instrument handling, and procedural content were found to be realistic. The simulator may serve as a valuable educational tool to learn the critical steps of endoscopic colloid cyst resection, develop a detailed understanding of intraventricular anatomy, and gain proficiency with bimanual neuroendoscopic techniques.

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