Publications by authors named "Andrew T Healy"

Study Design: Observational study.

Objectives: To evaluate the prevalence of erectile dysfunction and evaluate the effects of decompressive surgery on erectile dysfunction in cervical spinal stenosis and lumbar canal stenosis patients.

Methods: This observational, prospective analysis enrolled patients aged 18-80 with cervical spinal stenosis and/or lumbar canal stenosis that underwent respective decompressive surgery.

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The excited state dynamics in two fully characterized pyridoneBODIPY-fullerene complexes were investigated using time-resolved spectroscopy. Photoexcitation was initially localized on the pyridoneBODIPY chromophore. The energy was rapidly transferred to the fullerene, which subsequently underwent ISC to form a triplet state and returned the energy to the pyridoneBODIPY via triplet-triplet energy transfer.

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Several pyrene-boron-dipyrromethene (BODIPY) and pyrene-BODIPY-ferrocene derivatives with a fully conjugated pyrene fragment appended to the α-position(s) of the BODIPY core have been prepared by Knoevenagel condensation reaction and characterized by one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR), UV-vis, fluorescence spectroscopy, high-resolution mass spectrometry as well as X-ray crystallography. The redox properties of new donor-acceptor BODIPY dyads and triads were studied by electrochemical (cyclic voltammetry (CV) and differential pulse voltammetry (DPV)) and spectroelectrochemical approaches. Formation of weakly bonded noncovalent complexes between the new pyrene-BODIPYs and nanocarbon materials (C, C, single-walled carbon nanotube (SWCNT), and graphene) was studied by UV-vis, steady-state fluorescent, and time-resolved transient absorption spectroscopy.

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Photoactivatable protecting groups (PPGs) are useful for a broad range of applications ranging from biology to materials science. In chemical biology, induction of biological processes via photoactivation is a powerful strategy for achieving spatiotemporal control. The importance of cysteine, glutathione, and other bioactive thiols in regulating protein structure/activity and cell redox homeostasis makes modulation of thiol activity particularly useful.

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An adult with Sprengel deformity and Klippel-Feil syndrome associated with an omovertebral bone has rarely been reported in literature. The omovertebral bone is an abnormal cartilaginous connection between the scapula and the cervical spine. Limited cases have previously been reported in the literature describing surgical intervention when neurologic deficits such as cervical myelopathy or radiculopathy are present.

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The electronic communication between two ferrocene groups in the electron-deficient expanded aza-BODIPY analogue of zinc manitoba-dipyrromethene (MB-DIPY) was probed by spectroscopic, electrochemical, spectroelectrochemical, and theoretical methods. The excited-state dynamics involved sub-ps formation of the charge-separated state in the organometallic zinc MB-DIPYs, followed by recovery of the ground state via charge recombination in 12 ps. The excited-state behavior was contrasted with that observed in the parent complex that lacked the ferrocene electron donors and has a much longer excited-state lifetime (670 ps for the singlet state).

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Objective: Lateral mass fixation stabilizes the cervical spine while causing minimal morbidity and resulting in high fusion rates. Still, with 2 years of follow-up, approximately 6% of patients who have undergone posterior cervical fusion have worsening kyphosis or symptomatic adjacent-segment disease. Based on the length of the construct, the question of whether to extend the fixation system to undisrupted levels has not been answered for the cervical spine.

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We developed a simple methodology for the preparation of stable -(nitrile oxide)-substituted BODIPYs, which were characterized by spectroscopic methods and X-ray crystallography. These compounds were used for the preparation of isoxazoline- or isoxazolyl-BODIPYs by 1,3-dipolar cycloaddition reaction with dipolarophiles. Several BODIPYs possess molecular rotor behavior, including viscosity-dependent fluorescence.

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A series of covalent ferrocene-BODIPY-fullerene triads with the ferrocene groups conjugated to the BODIPY π-system and the fullerene acceptor linked at the boron hub by a common catecholpyrrolidine bridge were prepared and characterized by 1D and 2D NMR, UV/Vis, steady-state fluorescence spectroscopy, high-resolution mass spectrometry, and, for one of the derivatives, X-ray crystallography. Redox processes of the new compounds were investigated by electrochemical (CV and DPV) methods and spectroelectrochemistry. DFT calculations indicate that the HOMO in all triads was delocalized between ferrocene and BODIPY π-system, the LUMO was always fullerene-centered, and the catechol-centered occupied orbital was close in energy to the HOMO.

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The excited-state dynamics and energetics of a series of BODIPY-derived chromophores bound to a catechol at the boron position were investigated with a combination of static and time-resolved spectroscopy, electrochemistry, and density functional theory calculations. Compared with the difluoro-BODIPY-derived parent compounds, the addition of the catechol at the boron reduced the excited-state lifetime by three orders of magnitude. Deactivation of the excited state proceeded through an intermediate charge-transfer state accessed from the initial optically excited π* state in <1 ps.

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Study Design: In vitro cadaveric biomechanical study.

Objectives: Despite numerous techniques employed to establish solid lumbosacral fixation, there are little biomechanical data correlating fixation methods at L5/S1 to thoracolumbosacral (TLS) construct length. We aimed to determine the optimal construct with the hypothesis that under physiological loads, lumbosacral constructs can be stabilized by L5/S1 anterior lumbar interbody fusion (ALIF) alone, without iliac screw fixation (ISF), and that TLS constructs would require ISF, with or without ALIF.

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Study Design: A retrospective cohort study at a single tertiary care center.

Objective: To determine the impact of superior segment facet joint violation (FJV) during lumbar fusion on reoperation rates and quality of life (QOL).

Summary Of Background Data: Although lumbar fusion is an efficacious and durable treatment for numerous spinal pathologies, adjacent segment degeneration remains a serious complication.

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OBJECTIVE Improvements in imaging technology have steadily advanced surgical approaches. Within the field of spine surgery, assistance from the O-arm Multidimensional Surgical Imaging System has been established to yield superior accuracy of pedicle screw insertion compared with freehand and fluoroscopic approaches. Despite this evidence, no studies have investigated the clinical relevance associated with increased accuracy.

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OBJECTIVE The far lateral transcondylar approach to the ventral foramen magnum requires partial resection of the occipital condyle. Early biomechanical studies suggest that occipitocervical (OC) fusion should be considered if 50% of the condyle is resected. In clinical practice, however, a joint-sparing condylectomy has often been employed without the need for OC fusion.

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Background: Nodular fasciitis is a benign mesenchymal tumor arising from fascia that typically presents as a rapidly growing, subcutaneous mass. Intraneural cases are very rare and can present with neurological symptoms, requiring surgical resection.

Case Description: A 31-year-old woman presented to us with painful paresthesias in her elbow and progressive motor deficits, for which she underwent surgery.

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Study Design: Retrospective Review.

Objective: The aim of this study was to determine medical, radiographic, and surgical risk factors for the development of adjacent segment disease (ASD) after lumbar fusion.

Summary Of Background Data: ASD is a recognized outcome of spinal fusion that leads to increased costs and debilitating symptoms for patients.

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OBJECTIVE Neurosurgery is among the most competitive residencies, as evidenced by the high number of applicants for relatively few positions. Although it is important to recruit candidates who have the intellectual capacity and drive to succeed, traditional objective selection criteria, such as US Medical Licensing Examination (USMLE) (also known as Step 1) score, number of publications, and class ranking, have not been shown to consistently predict clinical and academic success. Furthermore, these traditional objective parameters have not been associated with specific personality traits.

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OBJECTIVE Cervical open-door laminoplasty (ODL) is designed to decompress the spinal cord, maintain motion, and prevent postlaminectomy kyphosis. Many traditional laminoplasty techniques involve disruption of the posterior ligamentous structures, most notably the C7-T1 supraspinous ligament and interspinales muscle complex (intraspinous and supraspinous ligaments [ISLs]). METHODS Eight human cervical cadaveric specimens (C2-T1) were used to investigate the subaxial kinematics following ODL with varying degrees of posterior element disruption.

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OBJECTIVE Pedicle and lateral mass screw placement is technically demanding due to complex 3D spinal anatomy that is not easily visualized. Neurosurgical and orthopedic surgery residents must be properly trained in such procedures, which can be associated with significant complications and associated morbidity. Current training in pedicle and lateral mass screw placement involves didactic teaching and supervised placement in the operating room.

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Transient absorption following photodetachment of a series of neat methyl-alkyl-pyrrolidinium bis(trifluoromethylsulfonyl)amides at 6.20 eV was measured with sub-picosecond time resolution in the visible and near-IR portions of the spectrum. This series spans the onset of structuring in the liquids in the form of polarity alternation.

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OBJECT The degenerative process of the spinal column results in instability followed by a progressive loss of segmental motion. Segmental degeneration is associated with intervertebral disc and facet changes, which can be quantified. Correlating this degeneration with clinical segmental motion has not been investigated in the thoracic spine.

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Study Design: Systematic review.

Objective: To evaluate literature comparing fusion rates in anterior lumbar interbody fusion (ALIF), posterior lumbar interbody/transforaminal lumbar interbody fusion (PLIF/TLIF), and posterolateral lumbar fusion (PLF) with and without recombinant human bone morphogenetic protein-2 (rhBMP-2).

Summary Of Background Data: rhBMP-2 is used for the FDA-approved indication of single-level ALIF with LT-Cage and off-label for PLIF/TLIF, and PLF.

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Background Context: Various posterolateral approaches exist to access ventral thoracic spinal canal pathologies. Selecting the optimal surgical approach requires sound understanding of the exposure and working angle afforded by each approach.

Purpose: The purpose of this study was to quantify exposure of the ventral spinal canal with various posterolateral thoracic spinal approaches and to determine how regional anatomical differences affect measurements.

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Background Context: Polyetheretherketone (PEEK) is an organic polymer thermoplastic with strong mechanical and chemical resistance properties. It has been used in industry to fabricate items for demanding applications such as bearings, piston parts, compressor plate valves, and cable insulation. Since the early 1980s, polyetheretherketone polymers have been increasingly used in orthopedic and spinal surgery applications.

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In spite of aggressive multi-modality treatments, patients diagnosed with anaplastic astrocytoma and glioblastoma continue to display poor median survival. The success of our current conventional and targeted chemotherapies are largely hindered by systemic- and neurotoxicity, as well as poor central nervous system (CNS) penetration. Interstitial drug administration via convection-enhanced delivery (CED) is an alternative that potentially overcomes systemic toxicities and CNS delivery issues by directly bypassing the blood-brain barrier (BBB).

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