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1.
J Chem Theory Comput ; 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38950444

RESUMEN

We consider the question of how correlated the system hardness is between classical algorithms of electronic structure theory in ground state estimation and quantum algorithms. To define the system hardness for classical algorithms, we employ empirical criterion based on the deviation of electronic energies produced by coupled cluster and configuration interaction methods from the exact ones along multiple bonds dissociation in a set of molecular systems. For quantum algorithms, we have selected the Variational Quantum Eigensolver (VQE) and Quantum Phase Estimation (QPE) methods. As characteristics of the system hardness for quantum methods, we analyzed circuit depths for the state preparation, the number of quantum measurements needed for the energy expectation value, and various cost characteristics for the Hamiltonian encodings via Trotter approximation and linear combination of unitaries (LCU). Our results show that the quantum resource requirements are mostly unaffected by classical hardness, with the only exception being the state preparation part, which contributes to both VQE and QPE algorithm costs. However, there are clear indications that constructing the initial state with a significant overlap with the true ground state is easier than obtaining the state with an energy expectation value within chemical precision. These results support optimism regarding the identification of a molecular system where a quantum algorithm excels over its classical counterpart, as quantum methods can maintain efficiency in classically challenging systems.

2.
Pediatr Surg Int ; 39(1): 267, 2023 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-37676327

RESUMEN

PURPOSE: This study analyzes the implementation of the routine use of quadratus lumborum blocks (QLBs) on postoperative pain and opioid consumption among children undergoing laparoscopic appendectomy compared to those not receiving regional anesthesia. METHODS: Children undergoing laparoscopic appendectomy within a multi-hospital children's healthcare system were retrospectively reviewed from 2017 to 2021. Patients were stratified by appendicitis type (uncomplicated vs. complicated). Pain scores and opioid consumption in the post-anesthesia care unit (PACU) and within the first 24 h postoperatively were compared by block status (no block [NB] vs. QLB) and appendicitis type. RESULTS: 2033 patients were reviewed, and 610 received a QLB. The frequency of rescue opioid use was reduced in the PACU (uncomplicated: QLB 46.6% vs. NB 54.6%, p = 0.005; complicated: QLB 28.5% vs. NB 39.9%, p = 0.01) and postoperatively (complicated: QLB 33.7% vs. NB 52.9%, p < 0.001) for those who received a QLB. This resulted in reduced opioid consumption as measured by morphine milligram equivalents per kilogram postoperatively. CONCLUSION: QLBs can be safely administered in children and provide improvements in opioid consumption postoperatively. QLBs should remain a strongly favored regional anesthetic technique because of their wide applicability for abdominal surgeries to minimize rescue opioid analgesic use. TYPE OF STUDY: Retrospective comparative study. LEVEL OF EVIDENCE: Level III.


Asunto(s)
Apendicitis , Bloqueo Nervioso , Niño , Humanos , Analgésicos Opioides/uso terapéutico , Apendicitis/cirugía , Mejoramiento de la Calidad , Estudios Retrospectivos
3.
J Chem Theory Comput ; 19(19): 6656-6667, 2023 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-37715716

RESUMEN

Accurately solving the electronic structure problem through the variational quantum eigensolver (VQE) is hindered by the available quantum resources of current and near-term devices. One approach to relieving the circuit depth requirements for VQE is to "pre-process" the electronic Hamiltonian by a similarity transformation incorporating some degree of electronic correlation, with the remaining correlation left to be addressed by the circuit ansatz. This often comes at the price of a substantial increase in the number of terms to measure in the similarity-transformed Hamiltonian. In this work, we propose an efficient approach to sampling elements from the complete Pauli group for N qubits which minimizes the onset of new terms in the transformed Hamiltonian while facilitating substantial energy lowering. We benchmark the growth-mitigating generator selection technique for ground state energy estimations applied to models of the H4, N2, and H2O molecular systems. It is found that utilizing a selection procedure which obtains the growth-minimizing generator from the set of operators with the maximal energy gradient is the most competitive approach to reducing the onset of Hamiltonian terms while achieving systematic energy lowering of the reference state.

4.
J Pediatr Urol ; 19(5): 621.e1-621.e9, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37487883

RESUMEN

INTRODUCTION: Available literature comparing spinal anesthesia (SA) to general anesthesia (GA) in the pediatric population describes multiple benefits in appropriately selected patients including cost reduction, lower incidence of complications, and shorter operative times. In patients undergoing urologic procedures, data are sparse. OBJECTIVE: Our goal was to expand on the paucity of existing urologic literature as SA appears to be uniquely suited for a substantial number of its common pediatric procedures. METHODS: Within a single institution, patients who had a urologic procedure performed under SA between May 2019 and July 2021 and were less than 18 months old were compared with a matched cohort of patients who had GA. The SA and GA groups were compared by two-sample t-tests, chi-square test for independence, and Fisher's exact test. RESULTS: There were a total of 184 SA and 202 GA patients. There was no significant difference in the demographics except that SA patients were younger and weighed less than GA patients. The patients in the SA group needed less opioids both during the surgery (0% vs 26.1% p N/A) and in the immediate postoperative period when compared with GA patients (0% vs 18.2% p N/A). The patients who had SA had fewer complications necessitating PICU admission, or cancellation of surgery (0% vs 6.8% p = 0.03). Total anesthesia and emergence time were lower for SA patients (41 vs 50.2 p = 0.001 & 3.4 vs 6.1 p = 0.001). Both surgery and total OR time were not different between the groups (37.6 vs 35.5 p = 0.35 and 56.3 vs 54.4 p = 0.49). Overall, raw material cost was also found to be lower per procedure in the SA group vs the GA group ($8.90 vs $38.8: 77% reduction). Adjusted total mean costs for the surgery were not different between groups. The reduction in opioid use postoperatively also suggests reduced cost in the management of postoperative pain in the SA group. DISCUSSION: Total anesthesia time, opioid use, and serious complications were all significantly lower in the SA group. We did not find significant difference in total surgery cost between two groups. However, patients who had SA had better pain control and needed less rescue analgesics in the immediate postoperative period. No patients in either group were sent home with opioids. CONCLUSION: Spinal anesthesia was found to be an equally effective and appropriate alternative to GA with many proposed benefits for common pediatric urologic procedures. With further research, SA may prove to be a safer alternative in patients at risk for complications related to GA general anesthesia while also offering a cost benefit.


Asunto(s)
Analgésicos Opioides , Anestesia Raquidea , Humanos , Niño , Lactante , Estudios Retrospectivos , Anestesia General , Anestesia Raquidea/métodos , Dolor Postoperatorio
5.
J Pediatr Surg ; 58(9): 1816-1823, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-36894445

RESUMEN

BACKGROUND: Many studies evaluating opioid stewardship interventions' effects on postoperative pain rely on emergency department (ED) visits or readmissions, but patient-reported pain scores represent a more complete picture of the postoperative experience. This study compares patient-reported pain scores after ambulatory pediatric and urologic procedures and the effect of an opioid stewardship intervention that nearly eliminated the use of outpatient narcotics. METHODS: This is a retrospective comparative study including 3173 pediatric patients who underwent ambulatory procedures from 2015 to 2019, during which there was an intervention to reduce narcotic prescriptions. Postoperative day one phone calls assessed pain levels using a four-point scale (no pain, mild pain, moderate pain controlled with medication, or severe pain uncontrolled with medication). We quantified the proportion of patients prescribed opioids pre-versus post-intervention and compared pain scores for patients receiving opioid versus non-opioid regimens. RESULTS: Opioid prescription rates demonstrated a 6.5-fold reduction after opioid stewardship efforts. The majority of patients (2838) received non-opioids, with only 335 patients receiving opioids. Opioid patients reported moderate/severe pain slightly more than non-opioid patients (14.1% vs. 10.4%, p = 0.04). On by-procedure analyses, there were no subgroups in which non-opioid patients reported significantly higher pain scores. CONCLUSIONS: Non-opioid postoperative pain regimens appear to be effective, with only 10.4% of patients reporting moderate/severe pain after ambulatory procedures. Future studies assessing patient-reported outcomes are necessary to optimize pain control for all patients and to determine whether there is ever an indication for opioid prescription after ambulatory general pediatric or urologic surgery. TYPE OF STUDY: Retrospective comparative study. LEVEL OF EVIDENCE: Level III.


Asunto(s)
Analgésicos Opioides , Manejo del Dolor , Niño , Humanos , Estudios Retrospectivos , Manejo del Dolor/métodos , Analgésicos Opioides/uso terapéutico , Narcóticos/uso terapéutico , Dolor Postoperatorio/tratamiento farmacológico , Dolor Postoperatorio/etiología , Medición de Resultados Informados por el Paciente , Pautas de la Práctica en Medicina , Procedimientos Quirúrgicos Ambulatorios/efectos adversos
6.
Adv Sci (Weinh) ; 9(28): e2105016, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35896946

RESUMEN

Origami is the art of paper folding that allows a single flat piece of paper to assume different 3D shapes depending on the fold patterns and the sequence of folding. Using the principles of origami along with computation imaging technique the authors demonstrate a versatile shape-morphing microwave imaging array with reconfigurable field-of-view and scene-adaptive imaging capability. Microwave/millimeter-wave based array imaging systems are expected to be the workhorse for sensory perception of future autonomous intelligent systems. The imaging capability of a planar array-based systems operating in complex scattering conditions have limited field-of-view and lack the ability to adaptively reconfigure resolution. To overcome this, here, deviations from planarity and isometry are allowed, and a shape-morphing computational imaging system is demonstrated. Implemented on a reconfigurable Waterbomb origami surface with 22 active metasurface panels that radiate near-orthogonal modes across 17-27 GHz, capability to image complex 3D objects in full details minimizing the effects of specular reflections in diffraction-limited sparse imaging with scene adaptability, reconfigurable cross-range resolution, and field-of-view is demonstrated. Such electromagnetic origami surfaces, through simultaneous surface shape-morphing ability (potentially with shape-shifting electronic materials) and electromagnetic field programmability, opens up new avenues for intelligent and robust sensing and imaging systems for a wide range of applications.


Asunto(s)
Imágenes de Microonda , Diagnóstico por Imagen , Microondas
7.
Adv Mater Technol ; 7(5)2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35754760

RESUMEN

The design and manufacture of an origami-based liver-on-a-chip device are presented, together with demonstrations of the chip's effectiveness at recapitulating some of the liver's key in vivo architecture, physical microenvironment, and functions. Laser-cut layers of polyimide tape are folded together with polycarbonate nanoporous membranes to create a stack of three adjacent flow chambers separated by the membranes. Endothelial cells are seeded in the upper and lower flow chambers to simulate sinusoids, and hepatocytes are seeded in the middle flow chamber. Nutrients and metabolites flow through the simulated sinusoids and diffuse between the vascular pathways and the hepatocyte layers, mimicking physiological microcirculation. Studies of cell viability, metabolic functions, and hepatotoxicity of pharmaceutical compounds show that the endothelialized liver-on-a-chip model is conducive to maintaining hepatocyte functions and evaluation of the hepatotoxicity of drugs. Our unique origami approach speeds chip development and optimization, effectively simplifying the laboratory-scale fabrication of on-chip models of human tissues without necessarily reducing their structural and functional sophistication.

8.
J Chem Theory Comput ; 17(7): 4392-4402, 2021 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-34110818

RESUMEN

A formalism for expansions of all Jahn-Teller and pseudo-Jahn-Teller Hamiltonian operators in all axial symmetries is presented. The formalism provides Hamiltonian expansions up to arbitrarily high order and including an arbitrary number of vibrational modes, which are of arbitrary types. It consists of three equations and two tables. The formalism is user-friendly since it can be used without understanding its derivation. An example of E3″⊗e1' Jahn-Teller interaction is used to demonstrate the correctness of the formalism. A Python program is developed to automate the generation of Hamiltonian expansions for all axial Jahn-Teller and pseodo-Jahn-Teller problems and interface the expansions to the MCTDH quantum dynamics simulation program. This is the first unified Hamiltonian formalism for axial Jahn-Teller and pseudo-Jahn-Teller problems. Also it is the only one.

9.
J Chem Theory Comput ; 17(1): 66-78, 2021 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-33295175

RESUMEN

The application of current and near-term quantum hardware to the electronic structure problem is highly limited by qubit counts, coherence times, and gate fidelities. To address these restrictions within the variational quantum eigensolver (VQE) framework, many recent contributions have suggested dressing the electronic Hamiltonian to include a part of electron correlation, leaving the rest to VQE state preparation. We present a new dressing scheme that combines the preservation of the Hamiltonian hermiticity and an exact quadratic truncation of the Baker-Campbell-Hausdorff expansion. The new transformation is constructed as the exponent of an involutory linear combination (ILC) of anti-commuting Pauli products. It incorporates important strong correlation effects in the dressed Hamiltonian and can be viewed as a classical preprocessing step to alleviate the resource requirements of the subsequent VQE application. The assessment of the new computational scheme for the electronic structure of the LiH, H2O, and N2 molecules shows a significant increase in efficiency compared to the conventional qubit coupled cluster dressings.

10.
Phys Chem Chem Phys ; 22(23): 12980-12986, 2020 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-32510066

RESUMEN

One of the main challenges in the variational quantum eigensolver (VQE) framework is construction of the unitary transformation. The dimensionality of the space for unitary rotations of N qubits is 4N- 1, which makes the choice of a polynomial subset of generators an exponentially difficult process. Moreover, due to non-commutativity of generators, the order in which they are used strongly affects results. Choosing the optimal order in a particular subset of generators requires testing the factorial number of combinations. We propose an approach based on the Lie algebra-Lie group connection and corresponding closure relations that systematically eliminates the order problem.

11.
Nano Lett ; 20(7): 4850-4856, 2020 07 08.
Artículo en Inglés | MEDLINE | ID: mdl-32525319

RESUMEN

Origami design principles are scale invariant and enable direct miniaturization of origami structures provided the sheets used for folding have equal thickness to length ratios. Recently, seminal steps have been taken to fabricate microscale origami using unidirectionally actuated sheets with nanoscale thickness. Here, we extend the full power of origami-inspired fabrication to nanoscale sheets by engineering bidirectional folding with 4 nm thick atomic layer deposition (ALD) SiNx-SiO2 bilayer films. Strain differentials within these bilayers result in bending, producing microscopic radii of curvature. We lithographically pattern these bilayers and localize the bending using rigid panels to fabricate a variety of complex micro-origami devices. Upon release, these devices self-fold according to prescribed patterns. Our approach combines planar semiconductor microfabrication methods with computerized origami design, making it easy to fabricate and deploy such microstructures en masse. These devices represent an important step forward in the fabrication and assembly of deployable micromechanical systems that can interact with and manipulate micro- and nanoscale environments.

12.
J Chem Theory Comput ; 16(2): 1055-1063, 2020 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-31935085

RESUMEN

An iterative version of the qubit coupled cluster (QCC) method [I. G. Ryabinkin et al., J. Chem. Theory Comput. 2019, 14, 6317] is proposed. The new method seeks to find ground electronic energies of molecules on noisy intermediate-scale quantum devices. Each iteration involves a canonical transformation of the Hamiltonian and employs constant-size quantum circuits at the expense of increasing the Hamiltonian size. We numerically studied the convergence of the method on ground-state calculations for LiH, H2O, and N2 molecules and found that the exact ground-state energies can be systematically approached only if the generators of the QCC ansatz are sampled from a specific set of operators. We report an algorithm for constructing this set that scales linearly with the size of the Hamiltonian.

13.
J Chem Theory Comput ; 16(1): 190-195, 2020 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-31747266

RESUMEN

To obtain estimates of electronic energies, the Variational Quantum Eigensolver (VQE) technique performs separate measurements for multiple parts of the system Hamiltonian. Current quantum hardware is restricted to projective single-qubit measurements, and, thus, only parts of the Hamiltonian that form mutually qubit-wise commuting groups can be measured simultaneously. The number of such groups in the electronic structure Hamiltonians grows as N4, where N is the number of qubits, thereby putting serious restrictions on the size of the systems that can be studied. Using a partitioning of the system Hamiltonian as a linear combination of unitary operators, we found a circuit formulation of the VQE algorithm that allows one to measure a group of fully anticommuting terms of the Hamiltonian in a single series of single-qubit measurements. Numerical comparison of the unitary partitioning to previously used grouping of Hamiltonian terms based on their qubit-wise commutativity is consistent with an N-fold reduction in the number of measurable groups.

14.
J Chem Phys ; 151(16): 164111, 2019 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-31675900

RESUMEN

Solving the electronic structure problem on a universal-gate quantum computer within the variational quantum eigensolver (VQE) methodology requires constraining the search procedure to a subspace defined by relevant physical symmetries. Ignoring symmetries results in convergence to the lowest eigenstate of the Fock space for the second quantized electronic Hamiltonian. Moreover, this eigenstate can be symmetry broken due to limitations of the wavefunction ansatz. To address this VQE problem, we introduce and assess methods of exact and approximate projectors to irreducible eigensubspaces of available physical symmetries. Feasibility of symmetry projectors in the VQE framework is discussed, and their efficiency is compared with symmetry constraint optimization procedures. Generally, projectors introduce a higher number of terms for VQE measurement compared to the constraint approach. On the other hand, the projection formalism improves accuracy of the variational wavefunction ansatz without introducing additional unitary transformations, which is beneficial for reducing depths of quantum circuits.

15.
Tumour Biol ; 41(3): 1010428319827223, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30907281

RESUMEN

Prostate cancer represents a major cause of cancer death in men worldwide. Novel non-invasive methods are still required for differentiation of non-aggressive from aggressive tumors. Recently, changes in prostate-specific antigen glycosylation pattern, such as core-fucosylation, have been described in prostate cancer. The objective of this study was to evaluate whether the core-fucosylation determinant of serum prostate-specific antigen may serve as refined marker for differentiation between benign prostate hyperplasia and prostate cancer or identification of aggressive prostate cancer. A previously developed liquid chromatography-mass spectrometry/mass spectrometry-based strategy was used for multiplex analysis of core-fucosylated prostate-specific antigen (fuc-PSA) and total prostate-specific antigen levels in sera from 50 benign prostate hyperplasia and 100 prostate cancer patients of different aggressiveness (Gleason scores, 5-10) covering the critical gray area (2-10 ng/mL). For identification of aggressive prostate cancer, the ratio of fuc-PSA to total prostate-specific antigen (%-fuc-PSA) yielded a 5%-8% increase in the area under the curve (0.60) compared to the currently used total prostate-specific antigen (area under the curve = 0.52) and %-free prostate-specific antigen (area under the curve = 0.55) tests. However, our data showed that aggressive prostate cancer (Gleason score > 6) and non-aggressive prostate cancer (Gleason score ≤ 6) could not significantly (p-value = 0.08) be differentiated by usage of %-fuc-PSA. In addition, both non-standardized fuc-PSA and standardized %-fuc-PSA had no diagnostic value for differentiation of benign prostate hyperplasia from prostate cancer. The %-fuc-PSA serum levels could not improve the differentiation of non-aggressive and aggressive prostate cancer compared to conventional diagnostic prostate cancer markers. Still, it is unclear whether these limitations come from the biomarker, the used patient cohort, or the imprecision of the applied method itself. Therefore, %-fuc-PSA should be further investigated, especially by more precise methods whether it could be clinically used in prostate cancer diagnosis.


Asunto(s)
Biomarcadores de Tumor/química , Antígeno Prostático Específico/química , Hiperplasia Prostática/diagnóstico , Hiperplasia Prostática/patología , Neoplasias de la Próstata/diagnóstico , Neoplasias de la Próstata/patología , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/sangre , Cromatografía Liquida , Diagnóstico Diferencial , Glicosilación , Humanos , Masculino , Persona de Mediana Edad , Clasificación del Tumor , Próstata/patología , Antígeno Prostático Específico/sangre , Espectrometría de Masas en Tándem
16.
Sci Robot ; 4(27)2019 02 13.
Artículo en Inglés | MEDLINE | ID: mdl-33137737

RESUMEN

The trend toward smaller mechanism footprints and volumes, while maintaining the ability to perform complex tasks, presents the opportunity for exploration of hypercompact mechanical systems integrated with curved surfaces. Developable surfaces are shapes that a flat sheet can take without tearing or stretching, and they represent a wide range of manufactured surfaces. This work introduces "developable mechanisms" as devices that emerge from or conform to developable surfaces. They are made possible by aligning hinge axes with developable surface ruling lines to enable mobility. Because rigid-link motion depends on the relative orientation of hinge axes and not link geometry, links can take the shape of the corresponding developable surface. Mechanisms are classified by their associated surface type, and these relationships are defined and demonstrated by example. Developable mechanisms show promise for meeting unfilled needs using systems not previously envisioned.

17.
Sci Rep ; 8(1): 12936, 2018 08 28.
Artículo en Inglés | MEDLINE | ID: mdl-30154577

RESUMEN

Origami concepts show promise for creating complex deployable systems. However, translating origami to thick (non-paper) materials introduces challenges, including that thick panels do not flex to facilitate folding and the chances for self-intersection of components increase. This work introduces methods for creating permutations of linkage-based, origami-inspired mechanisms that retain desired kinematics but avoid self-intersection and enable their connection into deployable networks. Methods for reconfiguring overconstrained linkages and implementing them as modified origami-inspired mechanisms are proved and demonstrated for multiple linkage examples. Equations are derived describing the folding behavior of these implementations. An approach for designing networks of linkage-based origami vertices is demonstrated and applications for tessellations are described. The results offer the opportunity to exploit origami principles to create deployable systems not previously feasible.

18.
Phys Chem Chem Phys ; 20(17): 12312-12322, 2018 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-29688237

RESUMEN

We derive general expansion formulas in vibrational coordinates for all bimodal Jahn-Teller and pseudo-Jahn-Teller Hamiltonians in tetragonal symmetry. Symmetry information of all the vibronic Hamiltonian matrix elements is fully carried by up to only 4 eigenvalues of symmetry operators. This problem-to-eigenvalue reduction enables us to handle thousands of vibronic problems in one work. The derived bimodal formulas can be easily extended to cover problems with one or more than two vibrational modes. They lay a solid foundation for future vibronic coupling studies of tetragonal systems. More importantly, the efficient derivation can be applied to handle (pseudo-)Jahn-Teller Hamiltonians for all problems with one principal symmetry axis.

19.
Clin Chim Acta ; 480: 1-8, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29408166

RESUMEN

Recently, site-specific fucosylation of glycoproteins has attracted attention as it can be associated with several types of cancers including prostate cancer. However, individual glycoproteins, which might serve as potential cancer markers, often are very low-concentrated in complex serum matrices and distinct glycan structures are hard to detect by immunoassays. Here, we present a mass spectrometry-based strategy for the simultaneous analysis of core-fucosylated and total prostate-specific antigen (PSA) in human serum in the low ng/ml concentration range. Sample preparation comprised an immunoaffinity capture step to enrich total PSA from human serum using anti-PSA antibody coated magnetic beads followed by consecutive two-step on-bead partial deglycosylation with endoglycosidase F3 and tryptic digestion prior to LC-MS/MS analysis. The method was shown to be linear from 0.5 to 60 ng/ml total PSA concentrations and allows the simultaneous quantification of core-fucosylated PSA down to 1 ng/ml and total PSA lower than 0.5 ng/ml. The imprecision of the method over two days ranged from 9.7-23.2% for core-fucosylated PSA and 10.3-18.3% for total PSA depending on the PSA level. The feasibility of the method in native sera was shown using three human specimens. To our knowledge, this is the first MS-based method for quantification of core-fucosylated PSA in the low ng/ml concentration range in human serum. This method could be used in large patient cohorts as core-fucosylated PSA may be a diagnostic biomarker for the differentiation of prostate cancer and other prostatic diseases, such as benign prostatic hyperplasia (BPH). Furthermore, the described strategy could be used to monitor potential changes in site-specific core-fucosylation of other low-concentrated glycoproteins, which could serve as more specific markers ("marker refinement") in cancer research.


Asunto(s)
Glicoproteínas/sangre , Glicósido Hidrolasas/metabolismo , Antígeno Prostático Específico/sangre , Cromatografía Liquida , Glicoproteínas/metabolismo , Glicosilación , Humanos , Antígeno Prostático Específico/metabolismo , Espectrometría de Masas en Tándem
20.
Clin Chim Acta ; 464: 211-217, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27871844

RESUMEN

BACKGROUND: Accurate measurement of gentamicin concentration in serum and plasma is required for therapeutic drug monitoring to ensure appropriate treatment of patients. In this work, we present a validated LC-MS/MS-based candidate reference measurement procedure for total gentamicin quantification to be used for standardization and harmonization of routine assays applied for therapeutic drug monitoring of this compound. Total gentamicin is the sum of the concentrations of five known congeners C1, C1a, C2, C2a and C2b. To our knowledge, there is so far no LC-MS method for quantification of total gentamicin in human serum described in literature. METHODS: Sample preparation was based on sample dilution with an aqueous internal standard solution followed by protein precipitation. Stable derivatives of gentamicin-glycine congeners were prepared by chemical synthesis and used as internal standards. The primary calibration material used in this assay was characterized by NMR spectroscopy and the pattern of the gentamicin congeners was determined. The total gentamicin was reported as the sum of the congeners which were quantified individually by LC-MS/MS. RESULTS: The method allows the measurement of total gentamicin in human serum and plasma in the concentration range of 0.1 to 12.0µg/ml with an assay imprecision of ≤6% CV and an assay accuracy between 96% and 114%. LOD and LOQ for the total gentamicin were 0.04µg/ml and 0.13µg/ml, respectively. Comparative measurement of 128 native patient samples using this method implemented at two laboratory sites showed an excellent agreement. CONCLUSIONS: Validation results proved that this protocol describes a robust and reliable method which is suggested as reference measurement procedure for the standardization and harmonization of routine assays for the quantification of total gentamicin.


Asunto(s)
Análisis Químico de la Sangre/normas , Gentamicinas/sangre , Espectroscopía de Resonancia Magnética/normas , Plasma/química , Suero/química , Espectrometría de Masas en Tándem , Calibración , Cromatografía Liquida , Humanos , Límite de Detección , Modelos Lineales , Estándares de Referencia , Incertidumbre
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