Collective Euclidian distances and quantum similarity

2012 ◽  
Vol 51 (1) ◽  
pp. 338-353 ◽  
Author(s):  
Ramon Carbó-Dorca
Keyword(s):  
Quantum Similarity ◽  
Euclidian Distances

ITVT-07. Robotic alignment module Cirq for navigated brainstem tumor biopsies

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi229-vi229
Author(s):  
Kirsten van Baarsen ◽  
Peter Woerdeman ◽  
Mariam Slot ◽  
Eelco Hoving
Keyword(s):  
Brain Stem ◽  
3D Ct ◽  
Registration Accuracy ◽  
Brainstem Tumor ◽  
Intended Target ◽  
Registration Errors ◽  
Surgical Devices ◽  
Brain Stem Tumors ◽  
Tumor Biopsies ◽  
Euclidian Distances

Abstract BACKGROUND With the incorporation of the robotic alignment module Cirq (Brainlab, Germany) into our neurosurgical armamentarium, we aimed to know our baseline accuracy in stererotactic biopsies. We therefore retrospectively reviewed our data on biopsy accuracy for brain(stem) tumors using the non-robotic alignment instrument Varioguide (Brainlab, Germany). Because of unexpectedly large deviations from the intended target, we sought to improve our registration accuracy when we introduced Cirq. Intraoperative 3D CT with bone fiducials was added to the pre-operative 3D T1 MRI with skin fiducials. This made it possible to compare surgical devices as well as registration methods. AIMS To share our experience with the new robotic alignment module Cirq for navigated brain(stem) tumor biopsies and to evaluate its target accuracy with bone fiducial registration, as compared to the previously used Varioguide with skin fiducial registration. METHODS All patients (0–18 years old) that underwent a brain(stem) biopsy in our institution were included. Over 2018–2020, data were collected retrospectively (cohort Varioguide with 3D T1 MRI registration with skin fiducials). From 2021, data were collected prospectively (cohort Cirq with both 3D T1 MRI registration with skin fiducials and intraoperative CT registration with bone fiducials). For both cohorts, Euclidian distances were calculated between the intended target and the obtained target. For the prospective cohort, registration errors were calculated for bone versus skin fiducials. PRELIMINARY REUSLTS The deviation from the intended target was much smaller in the Cirq cohort versus the Varioguide cohort. Within the Cirq cohort, registration errors were submillimetric for bone fiducial registration as compared to several millimeters for skin fiducial registration. CONCLUSION: The Cirq robotic arm is convenient, safe and highly accurate, especially when combined with intraoperative 3D CT bone fiducial registration. Skin fiducial registration does not offer the level of precision that is mandatory in brainstem tumor biopsies.

Density gradient quantum similarity

2012 ◽  
Author(s):  
Ramon Carbó-Dorca ◽  
Luz Dary Mercado
Keyword(s):  
Density Gradient ◽  
Quantum Similarity

scholarly journals Study of interaction energies between residues of the active site of Hsp90 and geldanamycin analogues using quantum mechanics/molecular mechanics methods

F1000Research ◽  
2019 ◽  
Vol 8 ◽  
pp. 2040
Author(s):  
Ricardo Vivas-Reyes ◽  
Alejando Morales-Bayuelo ◽  
Carlos Gueto ◽  
Juan C. Drosos ◽  
Johana Márquez Lázaro ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Biological Activity ◽  
Active Site ◽  
Density Functional ◽  
Biological Response ◽  
Computational Techniques ◽  
Quantum Similarity ◽  
Interaction Energies ◽  
Atp Binding Site ◽  
Hsp90 Chaperone

Background: Heat shock protein (Hsp90KDa) is a molecular chaperone involved in the process of cellular oncogenesis, hence its importance as a therapeutic target in clinical trials. Geldanamycin is an inhibitor of Hsp90 chaperone activity, which binds to the ATP binding site in the N-terminal domain of Hsp90. However, geldanamycin has shown hepatotoxic damage in clinical trials; for this reason, its use is not recommended. Taking advantage that geldanamycin binds successfully to Hsp90, many efforts have focused on the search for similar analogues, which have the same or better biological response and reduce the side effects of its predecessor; 17-AAG and 17-DMAG are examples of these analogues. Methods: In order to know the chemical factors influencing the growth or decay of the biological activity of geldanamycin analogues, different computational techniques such as docking, 3DQSAR and quantum similarity were used.  Moreover, the study quantified the interaction energy between amino acids residues of active side and geldanamycin analogues, through hybrid methodologies and density functional theory (DFT) indexes. Results: The evaluation of interaction energies showed that the interaction with Lys58 residue is essential for the union of the analogues to the active site of Hsp90, and improves its biological activity. This union is formed through a substituent on C-11 of the geldanamycin macrocycle. A small and attractor group was found as the main steric and electrostatic characteristic that substituents on C11 need in order to interact with Lys 58; behavior was observed with hydroxy and methoxy series of geldanamycin analogues, under study. Conclusion: These outcomes were supported with quantum similarity and reactivity indices calculations using DFT in order to understand the non-covalent stabilization in the active site of these compounds.

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