15 results on '"Snyder LA"'
Search Results
2. ACR Appropriateness Criteria® Myelopathy: 2021 Update.
- Author
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Agarwal V, Shah LM, Parsons MS, Boulter DJ, Cassidy RC, Hutchins TA, Jamlik-Omari Johnson, Kendi AT, Khan MA, Liebeskind DS, Moritani T, Ortiz AO, Reitman C, Shah VN, Snyder LA, Timpone VM, and Corey AS
- Subjects
- Diagnosis, Differential, Evidence-Based Medicine, Humans, Magnetic Resonance Imaging, United States, Societies, Medical, Spinal Cord Diseases diagnostic imaging
- Abstract
Myelopathy is a clinical diagnosis with localization of the neurological findings to the spinal cord, rather than the brain or the peripheral nervous system, and then to a particular segment of the spinal cord. Myelopathy can be the result of primary intrinsic disorders of the spinal cord or from secondary conditions, which result in extrinsic compression of the spinal cord. While the causes of myelopathy may be multiple, the acuity of presentation and symptom onset frame a practical approach to the differential diagnosis. Imaging plays a crucial role in the evaluation of myelopathy with MRI the preferred modality. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment., (Copyright © 2021 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2021
- Full Text
- View/download PDF
3. Management of Extracranial Blunt Cerebrovascular Injuries: Experience with an Aspirin-Based Approach.
- Author
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Catapano JS, Israr S, Whiting AC, Hussain OM, Snyder LA, Albuquerque FC, Ducruet AF, Nakaji P, Lawton MT, Weinberg JA, and Zabramski JM
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- Adolescent, Adult, Aged, Aortic Dissection etiology, Anticoagulants adverse effects, Anticoagulants therapeutic use, Aspirin adverse effects, Carotid Artery Injuries drug therapy, Carotid Artery, Internal, Cerebrovascular Trauma complications, Cerebrovascular Trauma epidemiology, Disease Management, Drug Evaluation, Female, Hemorrhage chemically induced, Hospital Mortality, Humans, Injury Severity Score, Length of Stay, Male, Middle Aged, Multiple Trauma epidemiology, Platelet Aggregation Inhibitors adverse effects, Retrospective Studies, Stroke etiology, Vertebral Artery injuries, Wounds, Nonpenetrating complications, Wounds, Nonpenetrating epidemiology, Young Adult, Aspirin therapeutic use, Cerebrovascular Trauma drug therapy, Platelet Aggregation Inhibitors therapeutic use, Wounds, Nonpenetrating drug therapy
- Abstract
Background: Optimal management of patients with extracranial blunt cerebrovascular injury (BCVI) remains controversial, with both anticoagulation and antiplatelet therapy being recommended. The purpose of this study was to evaluate the efficacy and safety of using acetylsalicylic acid (ASA) in the management of BCVI., Methods: Patients with BCVI were identified from the registry of a Level 1 trauma center between 2010 and 2017. Digital imaging and electronic medical records were reviewed for patient information including demographic characteristics, injury type, therapy, outcomes, and follow-up., Results: Over the study period, 13,578 patients were admitted following blunt trauma, with 94 (0.7%) having confirmed BCVI (mean age, 42 years; 72% male). Mean Injury Severity Score and Glasgow Coma Score were 27 and 10, respectively. BCVI was identified in 130 vessels with Biffl grade I (38%) and grade II injury (29%) being most common. Twelve (13%) patients experienced an ischemic event, but only 3 events occurred after diagnosis. ASA was primary treatment for 56 (60%) patients. Thirty patients (32%) received no treatment; 21 patients died within 24 hours of primary injury. Only 4 patients had ASA contraindications. Four patients (7%) had ASA-related complications; there were 2 cases of intracranial hemorrhage progression and 2 cases of gastrointestinal bleeding. Follow-up vascular imaging at a mean of 36 days demonstrated stable or improved levels of BCVI in 94% of patients., Conclusions: An ASA-based management strategy for BCVI was efficacious and relatively safe in this study. This approach may be the preferred treatment for BCVI, but confirmation is needed., (Copyright © 2019 Elsevier Inc. All rights reserved.)
- Published
- 2020
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4. ACR Appropriateness Criteria ® Cervical Neck Pain or Cervical Radiculopathy.
- Author
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McDonald MA, Kirsch CFE, Amin BY, Aulino JM, Bell AM, Cassidy RC, Chakraborty S, Choudhri AF, Gemme S, Lee RK, Luttrull MD, Metter DF, Moritani T, Reitman C, Shah LM, Sharma A, Shih RY, Snyder LA, Symko SC, Thiele R, and Bykowski J
- Subjects
- Contrast Media, Diagnosis, Differential, Evidence-Based Medicine, Humans, Societies, Medical, United States, Neck Pain diagnostic imaging, Radiculopathy diagnostic imaging
- Abstract
Nontraumatic neck pain is a leading cause of disability, with nearly 50% of individuals experiencing ongoing or recurrent symptoms. Radiographs are appropriate as initial imaging for cervical or neck pain in the absence of "red flag" symptoms or if there are unchanging chronic symptoms; however, spondylotic changes are commonly identified and may result in both false-positive and false-negative findings. Noncontrast CT can be complementary to radiographs for evaluation of new or changing symptoms in the setting of prior cervical spine surgery or in the assessment of extent of ossification in the posterior longitudinal ligament. Noncontrast MRI is usually appropriate for assessment of new or increasing radiculopathy due to improved nerve root definition. MRI without and with contrast is usually appropriate in patients with new or increasing cervical or neck pain or radiculopathy in the setting of suspected infection or known malignancy. Imaging may be appropriate; however, it is not always indicated for evaluation of cervicogenic headache without neurologic deficit. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment., (Copyright © 2019 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2019
- Full Text
- View/download PDF
5. Barrow Innovation Center Case Series: Early Clinical Experience with Novel Surgical Instrument Used To Prevent Intraoperative Spinal Cord Injuries.
- Author
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Bohl MA, Baranoski JF, Sexton D, Nakaji P, Snyder LA, Kakarla UK, and Porter RW
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- Aged, Cadaver, Equipment Design, Female, Humans, Iatrogenic Disease, Internship and Residency, Magnetic Resonance Imaging, Male, Middle Aged, Neurosurgery education, Patents as Topic legislation & jurisprudence, Postoperative Complications therapy, Spinal Cord surgery, Spinal Cord Injuries diagnostic imaging, Spinal Stenosis surgery, Surgical Instruments, Intraoperative Complications prevention & control, Neurosurgical Procedures adverse effects, Neurosurgical Procedures instrumentation, Spinal Cord Injuries prevention & control
- Abstract
Objective: The Barrow Innovation Center comprises an educational program in medical innovation that enables residents to identify problems in patient care and rapidly develop and implement solutions to these problems. Residents involved in this program noted an elevated risk of iatrogenic spinal cord injury during posterior cervical and thoracic procedures. The objective of this study was to describe this complication, and a novel solution was developed through a new innovation training program., Methods: A case report demonstrates the risk of iatrogenic spinal cord injury during posterior cervical decompression and fusion. Solutions to this problem were developed at the innovation center via an iterative process of prototype creation, cadaveric testing, and redesign. Patent law students who partnered with the center wrote and filed a provisional patent protecting the novel prototype designs., Results: The concept of a protective shield for the spinal cord was developed, and within only 6 weeks the devices were provisionally patented and used in the operating room. This device was named the Myeloshield. Initial clinical experience indicates that the Myeloshield can be used without impeding the flow of surgery and has the potential to prevent iatrogenic spinal cord injury; this experience is presented through 2 case reports demonstrating the use of Myeloshields in the operating room., Conclusions: This report demonstrates how programs like the Barrow Innovation Center can provide neurosurgery residents with a unique educational experience in medical device innovation and intellectual property development and can serve as an avenue of surgical quality improvement and problem solving., (Copyright © 2018 Elsevier Inc. All rights reserved.)
- Published
- 2018
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6. Improving Intraoperative Fluoroscopic Visualization in Cervical Spine Surgery.
- Author
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Snyder LA
- Subjects
- Humans, Cervical Vertebrae surgery, Fluoroscopy
- Published
- 2016
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7. Lumbar Spinal Fixation with Cortical Bone Trajectory Pedicle Screws in 79 Patients with Degenerative Disease: Perioperative Outcomes and Complications.
- Author
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Snyder LA, Martinez-Del-Campo E, Neal MT, Zaidi HA, Awad AW, Bina R, Ponce FA, Kaibara T, and Chang SW
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- Adult, Aged, Aged, 80 and over, Arizona epidemiology, Causality, Comorbidity, Female, Humans, Length of Stay, Male, Middle Aged, Perioperative Care statistics & numerical data, Postoperative Complications prevention & control, Prevalence, Retrospective Studies, Risk Factors, Spinal Fusion instrumentation, Intervertebral Disc Degeneration epidemiology, Intervertebral Disc Degeneration surgery, Lumbar Vertebrae surgery, Pedicle Screws statistics & numerical data, Postoperative Complications epidemiology, Spinal Fusion statistics & numerical data
- Abstract
Objective: Biomechanical studies demonstrate that cortical bone trajectory pedicle screws (CBTPS) have greater pullout strength than traditional pedicle screws with a lateral-medial trajectory. CBTPS start on the pars and angulate in a mediolateral-caudocranial direction. To our knowledge, no large series exists evaluating the perioperative outcomes and safety of CBTPS., Methods: We retrospectively reviewed all patients who received lumbar CBTPS at our institution. Data were collected regarding patient demographics, use of image guidance, operative blood loss, hospital stay, and postoperative complications., Results: A total of 79 patients undergoing CBTPS fusion for degenerative lumbosacral disease with back pain were included in the analysis (42 female, 37 male; October 2011-January 2015). Twenty patients (25.3%) had previous lumbar spine surgery, 39 (49.4%) had a smoking history, and mean body mass index was 28.7. Mean length of stay was 3.5 days, and mean operative blood loss was 306.3 mL. Image guidance was used in 69 (87.3%) cases. A total of 66 (83.5%) fusions were single level, and 54 (68.4%) fusions were single level without previous surgery. There were 9 complications in 7 (8.9%) patients; these included hardware failure, pseudarthrosis, deep vein thrombosis, pulmonary embolism, epidural hematoma, and wound infection. No complications were caused by misplaced screws. Mean follow-up was 13.2 months., Conclusions: As CBTPS becomes increasingly popular among spine surgeons performing lumbar fusion, this report provides an important evaluation of technique safety and acceptable perioperative outcomes., (Copyright © 2016 Elsevier Inc. All rights reserved.)
- Published
- 2016
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8. Transcriptional, translational, and physiological signatures of undernourished honey bees (Apis mellifera) suggest a role for hormonal factors in hypopharyngeal gland degradation.
- Author
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Corby-Harris V, Meador CA, Snyder LA, Schwan MR, Maes P, Jones BM, Walton A, and Anderson KE
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- Animals, Bees growth & development, Bees metabolism, Female, Hypopharynx growth & development, Hypopharynx metabolism, Insect Proteins metabolism, Male, Bees genetics, Insect Hormones metabolism, Insect Proteins genetics, Protein Biosynthesis, Transcription, Genetic
- Abstract
Honey bee colonies function as a superorganism, where facultatively sterile female workers perform various tasks that support the hive. Nurse workers undergo numerous anatomical and physiological changes in preparation for brood rearing, including the growth of hypopharyngeal glands (HGs). These glands produce the major protein fraction of a protein- and lipid-rich jelly used to sustain developing larvae. Pollen intake is positively correlated with HG growth, but growth in the first three days is similar regardless of diet, suggesting that initial growth is a pre-determined process while later HG development depends on nutrient availability during a critical window in early adulthood (>3 d). It is unclear whether the resultant size differences in nurse HG are simply due to growth arrest or active degradation of the tissue. To determine what processes cause such differences in HG size, we catalogued the differential expression of both gene transcripts and proteins in the HGs of 8 d old bees that were fed diets containing pollen or no pollen. 3438 genes and 367 proteins were differentially regulated due to nutrition. Of the genes and proteins differentially expressed, undernourished bees exhibited more gene and protein up-regulation compared to well-nourished bees, with the affected processes including salivary gland apoptosis, oogenesis, and hormone signaling. Protein secretion was virtually the only process up-regulated in well-nourished bees. Further assays demonstrated that inhibition of ultraspiracle, one component of the ecdysteroid receptor, in the fat body caused larger HGs. Undernourished bees also had higher acid phosphatase activity, a physiological marker of cell death, compared to well-nourished bees. These results support a connection between poor nutrition, hormonal signaling, and HG degradation., (Published by Elsevier Ltd.)
- Published
- 2016
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9. Resection of sporadic spinal hemangioblastomas.
- Author
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Snyder LA and Spetzler RF
- Subjects
- Female, Humans, Male, Hemangioblastoma surgery, Microsurgery methods, Neurosurgical Procedures methods, Spinal Cord Neoplasms surgery
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- 2014
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10. Awareness of potential treatment sequelae of orbital and periorbital dural arteriovenous fistulas and arteriovenous malformations.
- Author
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Snyder LA and Spetzler RF
- Subjects
- Female, Humans, Male, Intracranial Arteriovenous Malformations complications, Intracranial Arteriovenous Malformations therapy, Orbit pathology
- Published
- 2014
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11. Current indications for indocyanine green angiography.
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Snyder LA and Spetzler RF
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- Female, Humans, Cerebral Angiography methods, Indocyanine Green, Intracranial Aneurysm surgery, Microscopy, Video methods, Monitoring, Intraoperative methods, Vascular Surgical Procedures methods
- Published
- 2011
- Full Text
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12. Expression of human tissue factor under the control of the mouse tissue factor promoter mediates normal hemostasis in knock-in mice.
- Author
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Snyder LA, Rudnick KA, Tawadros R, Volk A, Tam SH, Anderson GM, Bugelski PJ, and Yang J
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- Animals, Antibodies, Monoclonal immunology, Antibodies, Monoclonal toxicity, Brain metabolism, Cardiomyopathies chemically induced, Epitopes immunology, Female, Gene Expression Regulation, Genes, Synthetic, Hemorrhage chemically induced, Humans, Immunoglobulin G immunology, Immunoglobulin G toxicity, Kidney metabolism, Male, Mice, Mice, Knockout, Mice, Transgenic, Myocardium metabolism, Organ Specificity, Pericytes metabolism, Regulatory Sequences, Nucleic Acid, Species Specificity, Thromboplastin antagonists & inhibitors, Thromboplastin biosynthesis, Thromboplastin genetics, Thromboplastin immunology, Hemostasis physiology, Thromboplastin physiology
- Abstract
Background: Tissue factor (TF) is expressed widely at the subluminal surface of blood vessels and serves as the primary cellular initiator of the extrinsic pathway of blood coagulation. Lack of TF in mice resulted in lethality in utero, but human TF (huTF) expressed at low levels from a human minigene rescued null mice from prenatal death. Although these low-TF expressing transgenic mice developed to term, they had a significantly shorter life span and exhibited hemorrhage and fibrosis in the heart., Methods: Human TF knock-in (TFKI) mice were generated by replacing the first two exons of the mouse (murine) TF (muTF) gene with the huTF complete coding sequence, thus placing it under the control of the endogenous muTF promoter., Results: Expression of huTF in the TFKI mice was similar to muTF in wild-type (wt) mice. The TFKI mice showed no microscopic evidence of spontaneous hemorrhage in the heart, nor cardiac fibrosis at up to 18 months of age. Immunohistochemistry showed that huTF was expressed in cells surrounding blood vessels in TFKI mice. Coagulation activity of brain homogenates from TFKI mice was comparable with that from wt brain. Cardiac hemorrhage similar to that of the low-TF transgenic mice occurred in the TFKI mice when huTF was blocked by a neutralizing anti-huTF monoclonal antibody., Conclusion: We generated a transgenic mouse line that expresses huTF under the control of the endogenous muTF promoter at physiological levels. Our results suggest that huTF can fully reconstitute the murine coagulation system and mediate normal hemostasis.
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- 2008
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13. CCL2 as an important mediator of prostate cancer growth in vivo through the regulation of macrophage infiltration.
- Author
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Loberg RD, Ying C, Craig M, Yan L, Snyder LA, and Pienta KJ
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- Animals, Antibodies, Monoclonal pharmacology, Chemokine CCL2 antagonists & inhibitors, Humans, Male, Mice, Mice, SCID, Prostatic Neoplasms immunology, Xenograft Model Antitumor Assays, Chemokine CCL2 physiology, Chemotaxis drug effects, Macrophages immunology, Prostatic Neoplasms pathology
- Abstract
The ability of CCL2 to influence prostate cancer tumorigenesis and metastasis may occur through two distinct mechanisms: 1) a direct effect on tumor cell growth and function, and 2) an indirect effect on the tumor microenvironment by the regulation of macrophage mobilization and infiltration into the tumor bed. We have previously demonstrated that CCL2 exerts a direct effect on prostate cancer epithelial cells by the regulation of their growth, invasion, and migration, resulting in enhanced tumorigenesis and metastasis. Here we describe an indirect effect of CCL2 on prostate cancer growth and metastasis by regulating monocyte/macrophage infiltration into the tumor microenvironment and by stimulating a phenotypic change within these immune cells to promote tumor growth (tumor-associated macrophages). VCaP prostate cancer cells were subcutaneously injected in male SCID mice and monitored for tumor volume, CD68(+) macrophage infiltration, and microvascular density. Systemic administration of anti-CCL2 neutralizing antibodies (CNTO888 and C1142) significantly retarded tumor growth and attenuated CD68(+) macrophage infiltration, which was accompanied by a significant decrease in microvascular density. These data suggest that CCL2 contributes to prostate cancer growth through the regulation of macrophage infiltration and enhanced angiogenesis within the tumor.
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- 2007
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14. Alternative transcripts of the rat and human dopamine D3 receptor.
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Snyder LA, Roberts JL, and Sealfon SC
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- Amino Acid Sequence, Animals, Base Sequence, Brain metabolism, Chromosome Deletion, Humans, Molecular Sequence Data, Oligodeoxyribonucleotides, Polymerase Chain Reaction, RNA, Messenger isolation & purification, Rats, Rats, Inbred Strains, Receptors, Dopamine D3, Restriction Mapping, Sequence Homology, Nucleic Acid, RNA Splicing, RNA, Messenger genetics, Receptors, Dopamine genetics, Receptors, Dopamine D2, Transcription, Genetic
- Abstract
A cDNA for the rat dopamine D3 receptor containing a 113 bp deletion has been isolated. The segment deleted, encompassing the first extracellular loop and third transmembrane domain, alters the reading frame, introducing 19 amino acids not found in the full length receptor followed by a premature stop codon. This novel mRNA encodes a 109 amino acid protein containing two putative transmembrane domains. A similar variant cDNA for the human D3 receptor has also been identified.
- Published
- 1991
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15. The mutagenic effects of two monofunctional alkylating chemicals on mature spermatozoa of drosophila.
- Author
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Lim JK and Snyder LA
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- Animals, Drosophila, Genes, Lethal drug effects, Genes, Recessive drug effects, Male, Sex Chromosomes drug effects, Spermatozoa drug effects, Alkylating Agents pharmacology, Azirines pharmacology, Chromosome Aberrations drug effects, Mutation drug effects, Sulfonic Acids pharmacology
- Published
- 1968
- Full Text
- View/download PDF
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