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Li C, Gui S, Zhang Y. Compare the safety and efficacy of endoscopic third ventriculostomy and ventriculoperitoneal shunt placement in infants and children with hydrocephalus: a systematic review and meta-analysis. Int J Neurosci 2024; 134:1-10. [PMID: 28697664 DOI: 10.1080/00207454.2017.1348352] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 06/24/2017] [Indexed: 10/19/2022]
Abstract
PURPOSE Endoscopic third ventriculostomy (ETV) and ventriculoperitoneal shunt placement are two surgical options used for treatment of non-communicating hydrocephalus. The purpose of this study was to compare the efficiency and safety of these techniques in pediatric patients. MATERIALS AND METHODS An extensive literature review regarding the clinical outcome, safety and efficiency of ETV and shunting in treatment of hydrocephalus was conducted in Medline, PubMed, Cochrane and Google Scholar databases up to 27 November 2015. Patient demographics, ETV and shunting success and failure rates were extracted. RESULTS A total of seven two-arm studies were included for quantitative analysis and 25 single-arm studies were included for systematic review. The two-arm studies recruited a total of 6995 patients: 1046 in the ETV group and 5949 in the shunt group. The pooled results showed that the 1 year success rate of ETV and shunt-placement procedure were similar (pooled RR = 0.870, 95% CI = 0.680-1.112, P = 0.266). The failure rate in the ETV treatment group was 0.9 times higher than in the shunt group; however, the results did not reach statistical significance (pooled RR = 0.893, 95% CI = 0.576-1.383, P = 0.611). CONCLUSIONS Both ETV and shunts are associated with similar 1 year success and failure rates. Therefore, there are no current indications to recommend one mode of treatment over the other. Future studies designed to assess the effectiveness of ETV and shunt procedures depending on patient's age and etiology are warranted.
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Affiliation(s)
- Chuzhong Li
- Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
- Beijing Institute for Brain Disorders Brain Tumor Center, Beijing, China
- China National Clinical Research Center for Neurological Diseases, Beijing, China
| | - Songbai Gui
- Department of Neurosurgery, Beijing Tiantan Hospital affiliated to Capital Medical University, Beijing, China
| | - Yazhuo Zhang
- Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
- Beijing Institute for Brain Disorders Brain Tumor Center, Beijing, China
- China National Clinical Research Center for Neurological Diseases, Beijing, China
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Munthe S, Pedersen CB, Poulsen FR, Andersen MS, Børgesen SE. Ventriculosinus shunt: a pilot study to investigate new technology to treat hydrocephalus and mimic physiological principles of cerebrospinal fluid drainage. J Neurosurg 2023; 139:1412-1419. [PMID: 37086160 DOI: 10.3171/2023.3.jns222858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 03/06/2023] [Indexed: 04/23/2023]
Abstract
OBJECTIVE Devices draining CSF to the intracranial venous sinus for the treatment of hydrocephalus have been tested in the past, and while clinically effective, have not shown efficacy in the long term. The majority of these devices become obstructed within 3 months due to endothelial overgrowth. In this study, the authors investigated a newly developed ventriculosinus (VS) shunt outlet device with the objective of showing it would remain patent for at least 6 months. METHODS Twelve patients in need of shunting for hydrocephalus underwent an operation using the investigational device and were followed for 6 months to record patency of the shunt. RESULTS In 10 patients, the shunt was patent at 6 months, with the outlet device remaining unobstructed. In the remaining 2 patients, one died just before reaching the 6-month endpoint, and in the other the outlet was misplaced during surgery and therefore ceased to function after 3 months. No occlusion of the internal jugular vein or thrombus formation was noted in any of the 12 cases. CONCLUSIONS These findings indicate that the outlet device can remain patent and has the capability to mimic physiological drainage by diverting CSF to the intracranial sinus. Additional confirmation of its potential as part of a new VS shunt system and ultimately as a viable alternative for ventriculoperitoneal and ventriculoatrial shunting to reduce complication rates requires further clinical trials.
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Affiliation(s)
- Sune Munthe
- 1Department of Neurosurgery, Odense University Hospital, Odense
- 2Department of Clinical Research and BRIDGE (Brain Research Inter-Disciplinary Guided Excellence), University of Southern Denmark, Odense; and
| | - Christian Bonde Pedersen
- 1Department of Neurosurgery, Odense University Hospital, Odense
- 2Department of Clinical Research and BRIDGE (Brain Research Inter-Disciplinary Guided Excellence), University of Southern Denmark, Odense; and
| | - Frantz Rom Poulsen
- 1Department of Neurosurgery, Odense University Hospital, Odense
- 2Department of Clinical Research and BRIDGE (Brain Research Inter-Disciplinary Guided Excellence), University of Southern Denmark, Odense; and
| | - Mikkel Schou Andersen
- 1Department of Neurosurgery, Odense University Hospital, Odense
- 2Department of Clinical Research and BRIDGE (Brain Research Inter-Disciplinary Guided Excellence), University of Southern Denmark, Odense; and
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DeBeer T, Jordan LC, Waddle S, Lee C, Patel NJ, Garza M, Davis LT, Pruthi S, Jones S, Donahue MJ. Red cell exchange transfusions increase cerebral capillary transit times and may alter oxygen extraction in sickle cell disease. NMR Biomed 2023; 36:e4889. [PMID: 36468659 PMCID: PMC10106384 DOI: 10.1002/nbm.4889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 11/30/2022] [Accepted: 12/02/2022] [Indexed: 05/17/2023]
Abstract
Persons with sickle cell disease (SCD) suffer from chronic hemolytic anemia, reduced blood oxygen content, and lifelong risk of silent and overt stroke. Major conventional stroke risk factors are absent in most individuals with SCD, yet nearly 50% have evidence of brain infarcts by the age of 30 years, indicating alternative etiologies for ischemia. We investigated whether radiological evidence of accelerated blood water transit through capillaries, visible on arterial spin labeling (ASL) magnetic resonance imaging, reduces following transfusion-induced increases in hemoglobin and relates to oxygen extraction fraction (OEF). Neurological evaluation along with anatomical and hemodynamic imaging with cerebral blood flow (CBF)-weighted pseudocontinuous ASL and OEF imaging with T2 -relaxation-under-spin-tagging were applied in sequence before and after blood transfusion therapy (n = 32) and in a comparator cohort of nontransfused SCD participants on hydroxyurea therapy scanned at two time points to assess stability without interim intervention (n = 13). OEF was calculated separately using models derived from human hemoglobin-F, hemoglobin-A, and hemoglobin-S. Gray matter CBF and dural sinus signal, indicative of rapid blood transit, were evaluated at each time point and compared with OEF using paired statistical tests (significance: two-sided p < 0.05). No significant change in sinus signal was observed in nontransfused participants (p = 0.650), but a reduction was observed in transfused participants (p = 0.034), consistent with slower red cell transit following transfusion. The dural sinus signal intensity was inversely associated with OEF pretransfusion (p = 0.011), but not posttransfusion. Study findings suggest that transfusion-induced increases in total hemoglobin may lengthen blood transit times through cerebral capillaries and alter cerebral OEF in SCD.
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Affiliation(s)
- Tonner DeBeer
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Lori C. Jordan
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Spencer Waddle
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Chelsea Lee
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Niral J. Patel
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Maria Garza
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - L. Taylor Davis
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Sumit Pruthi
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Sky Jones
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Manus J. Donahue
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
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Luciano M, Holubkov R, Williams MA, Malm J, Nagel S, Moghekar A, Eklund A, Zwimpfer T, Katzen H, Hanley DF, Hamilton MG. Placebo-Controlled Effectiveness of Idiopathic Normal Pressure Hydrocephalus Shunting: A Randomized Pilot Trial. Neurosurgery 2023; 92:481-489. [PMID: 36700738 PMCID: PMC9904195 DOI: 10.1227/neu.0000000000002225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 09/11/2022] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Multiple prospective nonrandomized studies have shown 60% to 70% of patients with idiopathic normal pressure hydrocephalus (iNPH) improve with shunt surgery, but multicenter placebo-controlled trial data are necessary to determine its effectiveness. OBJECTIVE To evaluate the effectiveness of cerebrospinal fluid shunting in iNPH through comparison of open vs placebo shunting groups at 4 months using a pilot study. METHODS Patients were randomized to a Codman Certas Plus valve (Integra LifeSciences) set at 4 (open shunt group) or 8 ("virtual off"; placebo group). Patients and assessors were blinded to treatment group. The primary outcome measure was 10-m gait velocity. Secondary outcome measures included functional scales for bladder control, activities of daily living, depression, and quality of life. Immediately after 4-month evaluation, all shunts were adjusted in a blinded fashion to an active setting and followed to 12 months after shunting. RESULTS A total of 18 patients were randomized. At the 4-month evaluation, gait velocity increased by 0.28 ± 0.28 m/s in the open shunt group vs 0.04 ± 0.17 m/s in the placebo group. The estimated treatment difference was 0.22 m/s ([ P = .071], 95% CI -0.02 to 0.46). Overactive Bladder Short Form symptom bother questionnaire significantly improved in open shunt vs placebo ( P = .007). The 4-month treatment delay did not reduce the subsequent response to active shunting, nor did it increase the adverse advents rate at 12 months. CONCLUSION This multicenter, randomized pilot study demonstrates the effectiveness, safety, and feasibility of a placebo-controlled trial in iNPH, and found a trend suggesting gait velocity improves more in the open shunt group than in the placebo group.
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Affiliation(s)
- Mark Luciano
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Adult Hydrocephalus Clinical Research Network, Department of Pediatrics, Division of Critical Care, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Richard Holubkov
- Adult Hydrocephalus Clinical Research Network, Department of Pediatrics, Division of Critical Care, University of Utah School of Medicine, Salt Lake City, Utah, USA
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Michael A. Williams
- Adult Hydrocephalus Clinical Research Network, Department of Pediatrics, Division of Critical Care, University of Utah School of Medicine, Salt Lake City, Utah, USA
- Departments of Neurology and Neurological Surgery, University of Washington School of Medicine, Seattle, Washington, USA
| | - Jan Malm
- Department of Clinical Science, Neurosciences, Umeå University, Umeå, Sweden
| | - Sean Nagel
- Adult Hydrocephalus Clinical Research Network, Department of Pediatrics, Division of Critical Care, University of Utah School of Medicine, Salt Lake City, Utah, USA
- Center for Neurological Restoration, Cleveland Clinic, Cleveland, Ohio, USA
- Department of Neurosurgery, Cleveland Clinic, Cleveland, Ohio, USA
| | - Abhay Moghekar
- Adult Hydrocephalus Clinical Research Network, Department of Pediatrics, Division of Critical Care, University of Utah School of Medicine, Salt Lake City, Utah, USA
- Department of Neurology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Anders Eklund
- Department of Radiation Sciences, Biomedical Engineering, Umeå University, Umeå, Sweden
| | - Thomas Zwimpfer
- Adult Hydrocephalus Clinical Research Network, Department of Pediatrics, Division of Critical Care, University of Utah School of Medicine, Salt Lake City, Utah, USA
- Division of Neurosurgery, Department of Surgery, University of British Columbia, Vancouver, Canada
| | - Heather Katzen
- Adult Hydrocephalus Clinical Research Network, Department of Pediatrics, Division of Critical Care, University of Utah School of Medicine, Salt Lake City, Utah, USA
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Daniel F. Hanley
- Department of Neurology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Mark G. Hamilton
- Adult Hydrocephalus Clinical Research Network, Department of Pediatrics, Division of Critical Care, University of Utah School of Medicine, Salt Lake City, Utah, USA
- Division of Neurosurgery, Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Canada
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5
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Vuurberg NE, Post ICJH, Keller BPJA, Schaafsma A, Vos CG. A systematic review & meta-analysis on perioperative cerebral and hemodynamic monitoring methods during carotid endarterectomy. Ann Vasc Surg 2022; 88:385-409. [PMID: 36100123 DOI: 10.1016/j.avsg.2022.08.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 08/23/2022] [Accepted: 08/31/2022] [Indexed: 11/01/2022]
Abstract
OBJECTIVE To compare outcomes between different strategies of perioperative cerebral and hemodynamic monitoring during carotid endarterectomy. DATA SOURCES MEDLINE, EMBASE, CINAHL, and Cochrane CENTRAL databases were searched. METHODS This review was performed according to the PRISMA guidelines and prospectively registered in the international prospective register of systematic reviews (CRD42021241891). The GRADE approach was used to describe the methodological quality of the studies and certainty of the evidence. The primary outcome was 30-day stroke rate. Secondary outcomes measures are 30-day ipsilateral stroke, 30-day mortality, shunt rate and complication rates. RESULTS The search identified 3 460 articles. Seventeen RCTs, three prospective observational studies and seven registries were included, reporting on 236 983 patients. The overall pooled 30-day stroke rate is 1.8% (95% CI 1.4 - 2.2%), ranging from 0 - 12.6%. In RCT's the pooled 30-day stroke rate is 2.7% (95% CI 1.6 - 3.7%) compared to 1.3% (95%CI 0.8 - 1.8%) in the registries. The overall stroke risk decreased from 3.7% before the year 2000 to 1.6% after 2000. No significant differences could be identified between different monitoring and shunting strategies, although a trend to higher stroke rates in routine no shunting arms of RCTs was observed. Overall 30-day mortality, myocardial infarction and nerve injury rates are 0.6% (95%CI 0.4 - 0.8), 0.8% (95%CI 0.6-1.0) and 1.3% (95%CI 0.4-2.2), respectively. CONCLUSIONS No significant differences between the compared shunting and monitoring strategies are found. However, routine no shunting is not recommended. The available data is too limited to prefer one method of neuromonitoring over another method when selective shunting is applied.
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Affiliation(s)
| | - Ivo C J H Post
- Department of Surgery, Martini Hospital, Groningen, The Netherlands
| | | | - Arjen Schaafsma
- Department of Clinical Neurophysiology & Neurology, Martini Hospital, Groningen, The Netherlands
| | - Cornelis G Vos
- Department of Surgery, Martini Hospital, Groningen, The Netherlands.
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Refardt J, den Hoed CM, Langendonk J, Zandee WT, Charehbili A, Feelders RA, de Herder WW, Brabander T, Hofland J. Prognostic significance of hyperammonemia in neuroendocrine neoplasm patients with liver metastases. Endocr Relat Cancer 2022; 29:241-250. [PMID: 35171111 DOI: 10.1530/erc-21-0346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 02/16/2022] [Indexed: 11/08/2022]
Abstract
Neuroendocrine neoplasms (NENs) are rare, usually slow-growing tumors, often presenting with extensive liver metastases. Hyperammonemia due to insufficient hepatic clearance has been described in NEN cases; however, no systematic evaluation of risk factors and outcomes of NEN-associated hyperammonemia exists so far. This case report and retrospective review of NEN patients developing hyperammonemia from the years 2000 to 2020 at the Erasmus Medical Center in Rotterdam, the Netherlands, aimed to describe these patients and determine prognostic factors to improve evaluation and treatment. Forty-four NEN patients with documented hyperammonemia were identified. All patients had liver metastases with 30% (n = 13) showing signs of portal hypertension. Patients who developed encephalopathy had higher median ammonia levels, but there was no association between the severity of hyperammonemia and liver tumor burden or presence of liver insufficiency. Eighty-four percent (n = 37) of patients died during follow-up. The median (IQR) time from diagnosis of hyperammonemia to death was 1.7 months (0.1-22.7). Hyperbilirubinemia, hypoalbuminemia, elevated international normalized ratio, presence of liver insufficiency, encephalopathy and ascites were associated with worse outcomes. Their role as independent risk factors for mortality was confirmed using the Child-Pugh score as a summary factor (P < 0.001). No difference was seen concerning overall survival between our hyperammonemia patients and a propensity score-matched control stage IV NEN cohort. In conclusion, hyperammonemia comprises a relevant and potentially underdiagnosed complication of NEN liver metastases and is associated with worse outcomes. Assessment of signs of encephalopathy, risk factors and the Child-Pugh score could be helpful in selecting patients in whom ammonia levels should be measured.
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Affiliation(s)
- Julie Refardt
- ENETS Center of Excellence, Department of Internal Medicine, Section of Endocrinology, Erasmus Medical Center and Erasmus Cancer Institute, Rotterdam, The Netherlands
- ENETS Center of Excellence, Department of Endocrinology, University Hospital Basel, Basel, Switzerland
| | - Caroline M den Hoed
- Department of Gastroenterology and Hepatology, Erasmus MC Transplant Institute, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Janneke Langendonk
- Department of Internal Medicine, Center for Lysosomal and Metabolic Diseases, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Wouter T Zandee
- Division of Endocrinology, Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Ayoub Charehbili
- ENETS Center of Excellence, Department of Radiology & Nuclear Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Richard A Feelders
- ENETS Center of Excellence, Department of Internal Medicine, Section of Endocrinology, Erasmus Medical Center and Erasmus Cancer Institute, Rotterdam, The Netherlands
| | - Wouter W de Herder
- ENETS Center of Excellence, Department of Internal Medicine, Section of Endocrinology, Erasmus Medical Center and Erasmus Cancer Institute, Rotterdam, The Netherlands
| | - Tessa Brabander
- ENETS Center of Excellence, Department of Radiology & Nuclear Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Johannes Hofland
- ENETS Center of Excellence, Department of Internal Medicine, Section of Endocrinology, Erasmus Medical Center and Erasmus Cancer Institute, Rotterdam, The Netherlands
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Kambara A, Kajimoto Y, Yagi R, Ikeda N, Furuse M, Nonoguchi N, Kawabata S, Kuroiwa T, Kuroda K, Tsuji S, Saura R, Wanibuchi M. Long-Term Prognosis of Cognitive Function in Patients With Idiopathic Normal Pressure Hydrocephalus After Shunt Surgery. Front Aging Neurosci 2021; 12:617150. [PMID: 33551791 PMCID: PMC7854532 DOI: 10.3389/fnagi.2020.617150] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 12/15/2020] [Indexed: 11/24/2022] Open
Abstract
The long-term prognosis of cognitive function in patients with idiopathic normal pressure hydrocephalus (iNPH) remains unclear. This study aimed to determine the long-term prognosis of cognitive function in patients with iNPH, as well as the factors related to it. It included 48 patients with iNPH who were treated with cerebrospinal fluid shunting between January 2015 and December 2017 at Osaka Medical College Hospital, with follow-up evaluation of their cognitive function for >2 years. Cognitive function was measured using the Mini-Mental State Examination (MMSE) preoperatively and at 3 months, 1 and 2 years post-operatively. The mean MMSE score (22.4 ± 5.4 preoperatively) improved at 3 months [23.8 ± 5.0 (p = 0.0002)] and 1 year [23.7 ± 4.8 (p = 0.004)] post-operatively. At 2 years post-operatively, they were able to maintain their preoperative level (22.6 ± 5.3). The patients were classified in to the cognitive decline group [11 (23%) patients; a decrease in the MMSE score by ≥ 2 points 2 years after surgery] and the maintenance/improvement group [37 (77%) patients]. Univariate and receiver operating characteristic analyses were performed for the two groups to identify factors associated with cognitive prognosis. In both groups, the patients who were younger (p = 0.009) or had milder symptoms (p = 0.035) had a better long-term prognosis of cognitive function. The cutoffs for age and disease severity (idiopathic normal-pressure hydrocephalus grading scale; INPHGS) were 78 years (area under the curve = 0.77) and 5 points (area under the curve = 0.71), respectively. In conclusion, most patients (77%) were able to improve and maintain cognitive function for at least 2 years after surgery. The fact that disease severity and age are associated with cognitive prognosis suggests that early iNPH intervention is desirable to improve cognitive prognosis.
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Affiliation(s)
- Akihiro Kambara
- Department of Neurosurgery, Osaka Medical College, Takatsuki, Japan
| | | | - Ryokichi Yagi
- Department of Neurosurgery, Osaka Medical College, Takatsuki, Japan
| | - Naokado Ikeda
- Department of Neurosurgery, Osaka Medical College, Takatsuki, Japan
| | - Motomasa Furuse
- Department of Neurosurgery, Osaka Medical College, Takatsuki, Japan
| | | | - Shinji Kawabata
- Department of Neurosurgery, Osaka Medical College, Takatsuki, Japan
| | - Toshihiko Kuroiwa
- Department of Neurosurgery, Tesseikai Neurosurgery Hospital, Shijonawate, Japan
| | - Kenji Kuroda
- Clinical Department of Rehabilitation, Osaka Medical College, Takatsuki, Japan
| | - Shohei Tsuji
- Clinical Department of Rehabilitation, Osaka Medical College, Takatsuki, Japan
| | - Ryuichi Saura
- Department of Physical and Rehabilitation Medicine, Osaka Medical College, Takatsuki, Japan
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Shadabipour P, Raithel AL, Hamann TW. Charge-Carrier Dynamics at the CuWO 4/Electrocatalyst Interface for Photoelectrochemical Water Oxidation. ACS Appl Mater Interfaces 2020; 12:50592-50599. [PMID: 33119249 DOI: 10.1021/acsami.0c14705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Unraveling the charge-carrier dynamics at electrocatalyst/electrode interfaces is critical for the development of efficient photoelectrochemical (PEC) water oxidation. Unlike the majority of photoanodes investigated for PEC water oxidation, the integration of electrocatalysts with CuWO4 electrodes generally results in comparable or worse performance compared to the bare electrode. This is despite the fact that the surface state recombination limits the water oxidation efficiency with CuWO4 electrodes, and an electrocatalyst ought to bypass this reaction and improve performance. Here, we present results that deepen the understanding of the energetics and electron-transfer processes at the CuWO4/electrocatalyst interface, which controls the performance of such systems. Ni0.75Fe0.25Oy (denoted as Ni75) was chosen as a model electrocatalyst, and through dual-working electrode experiments, we have been able to provide significant insight into the role of the electrocatalyst on the charge-transfer process at the CuWO4/Ni75 interface. We have shown a lack of performance improvement for CuWO4/Ni75 relative to the bare electrode to water oxidation. We attribute this surprising result to water oxidation on the CuWO4 surface kinetically outcompeting hole transfer to the Ni75 electrocatalyst interface.
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Affiliation(s)
- Parisa Shadabipour
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824-1322, United States
| | - Austin L Raithel
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824-1322, United States
| | - Thomas W Hamann
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824-1322, United States
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9
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Vivas-Buitrago T, Domingo R, Tripathi S, Herrera JP, Heemskerk J, Grewal S, Zalewski NL, Quinones-Hinojosa A, Reimer R, Wharen RE, Graff-Radford NR. In NPH, setting valve opening pressure close to lumbar puncture opening pressure decreases overdrainage. Neurol Neurochir Pol 2020; 54:531-537. [PMID: 33047786 DOI: 10.5603/pjnns.a2020.0077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 08/25/2020] [Accepted: 08/25/2020] [Indexed: 11/25/2022]
Abstract
BACKGROUND The management of normal pressure hydrocephalus (NPH) can be difficult, partly because there are frequent treatment complications such as overdrainage which, when serious, may require surgical intervention. We previously reported a correlation between the difference of lumbar puncture opening pressure minus the valve opening pressure setting (LPOP-VOP) (which we refer to as the delta) and increased rates of overdrainage. This led to a modification in our practice, whereby we now set the VOP equal to, or close to, the LPOP, resulting in lower deltas. OBJECTIVE In this new study, our aim was to compare the rate of overdrainage in our patients with higher and lower deltas and assess the significance of setting the VOP equal, or close, to the patient's LPOP. METHODS 1. We reproduced the association between delta and overdrainage. 2. We compared the incidence of overdrainage in those whose VOP was set close to LPOP (low delta) versus those with VOP setting distant from the LPOP (higher delta). 3. We compared symptom improvement in those with a low versus higher delta. RESULTS We confirmed the relation between high delta and an increased rate of overdrainage, lower rates of overdrainage in those whose VOP was set close to the LPOP (Delta Adjusted Practice), and better improvement of symptoms when the VOP was set closer to the LPOP. CONCLUSION We propose that the initial VOP should be set as close as possible to the patient's LPOP to decrease overdrainage without compromising symptom improvement.
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Affiliation(s)
| | - Ricardo Domingo
- Mayo Clinic, 4500 san pablo rd, 32224 Jacksonville, United States
| | | | | | - Johan Heemskerk
- Mayo Clinic, 4500 san pablo rd, 32224 Jacksonville, United States
| | - Sanjeet Grewal
- Mayo Clinic, 4500 san pablo rd, 32224 Jacksonville, United States
| | | | | | - Ronald Reimer
- Mayo Clinic, 4500 san pablo rd, 32224 Jacksonville, United States
| | - Robert E Wharen
- Mayo Clinic, 4500 san pablo rd, 32224 Jacksonville, United States
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Kryukov AI, Kunelskaya NL, Ivoylov AY, Kunelskaya VY, Pakina VR, Yanovsky VV, Morozova ZN. [On the issue of treatment of exudative otitis media in children]. Vestn Otorinolaringol 2020; 85:14-21. [PMID: 32241982 DOI: 10.17116/otorino20208501114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
AIM To increase the effectiveness of treatment of children with catarrhal and secretory stages of exudative otitis media (EOM) through the development of a therapeutic and diagnostic algorithm for the management of children with this condition. MATERIAL AND METHOD From 2008 to 2017, 346 children (682 ears) aged from 3 to 13 years with exudative otitis media were examined and treated. Two groups of patients were formed: Group 1 (150 children, 298 ears) - with a catarrhal stage of EOM, group 2 (196 children, 384 ears) - with a secretory stage of EOM. Diagnosis and treatment algorithm was created for such patients based on the results of the examination. RESULTS Depending on the treatment, 3 groups of patients were formed: Group I - 150 children with a catarrhal stage of EOM who received conservative and surgical treatment for upper respiratory tract conditions; Group II - 146 children with an a secretory stage of EOM, who underwent conservative and surgical treatment: myringotomy / installation of a shunt in the eardrum simultaneously with surgical removal of the block of the auditory tube ostium, a course of conservative treatment for children who did not require surgical treatment; Group III - 50 children with a secretory stage of EOM and grade III adenoids, whose parents, contrary to the doctor's advice, refused the proposed myringotomy / installation of a shunt in the eardrum simultaneously with surgical removal of the block of the auditory tube ostium. These children underwent only adenotomy. CONCLUSION The developed treatment algorithm for children with EOM, depending on the stage of the disease, demonstrated high clinical efficacy and made it possible to achieve stable positive results in 94.7% of cases in patients with the catarrhal stage of ESO and in 84.8% of cases in patients with the secretory stage of ESO, which makes it possible for us to recommend it as an integrated method that improves the quality of treatment for children with EOM.
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Affiliation(s)
- A I Kryukov
- Sverzhevsky Research Clinical Institute of Otorhinolaryngology of the Moscow Healthcare Department, Moscow, Russia, 117152; Pirogov Russian National Research Medical University of the Ministry of Health of Russia, Department of Otolaryngology of Cure Faculty, Moscow, Russia, 117997
| | - N L Kunelskaya
- Sverzhevsky Research Clinical Institute of Otorhinolaryngology of the Moscow Healthcare Department, Moscow, Russia, 117152; Pirogov Russian National Research Medical University of the Ministry of Health of Russia, Department of Otolaryngology of Cure Faculty, Moscow, Russia, 117997
| | - A Yu Ivoylov
- Sverzhevsky Research Clinical Institute of Otorhinolaryngology of the Moscow Healthcare Department, Moscow, Russia, 117152; Pirogov Russian National Research Medical University of the Ministry of Health of Russia, Department of Otolaryngology of Pediatric Faculty, Moscow, Russia, 117997; Speransky Pediatric Municipal Clinical Hospital No. 9 of the Moscow Healthcare Department, Moscow, Russia, 123317
| | - V Ya Kunelskaya
- Sverzhevsky Research Clinical Institute of Otorhinolaryngology of the Moscow Healthcare Department, Moscow, Russia, 117152
| | - V R Pakina
- Sverzhevsky Research Clinical Institute of Otorhinolaryngology of the Moscow Healthcare Department, Moscow, Russia, 117152
| | - V V Yanovsky
- Sverzhevsky Research Clinical Institute of Otorhinolaryngology of the Moscow Healthcare Department, Moscow, Russia, 117152
| | - Z N Morozova
- Sverzhevsky Research Clinical Institute of Otorhinolaryngology of the Moscow Healthcare Department, Moscow, Russia, 117152
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Müller J, Röttgers L, Neidenbach RC, Oberhoffer R, Ewert P, Hager A. Reduced Handgrip Strength in Congenital Heart Disease With Regard to the Shunt Procedure in Infancy. Front Pediatr 2018; 6:247. [PMID: 30238000 PMCID: PMC6135915 DOI: 10.3389/fped.2018.00247] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 08/20/2018] [Indexed: 11/23/2022] Open
Abstract
Objective: In many patients with congenital heart disease (CHD) arterial blood flow to the arms is inhibited due to shunt surgery in infancy. This study investigates the handgrip strength of patients with CHD in regard to previous shunt procedures. Patients and Methods: Handgrip was evaluated in 424 patients with various CHD (189 female, age 28.1 ± 13.4 years) including 63 with shunt procedures in infancy; and 123 controls (51 female, 35.6 ± 14.2 years) using a Jamar dynamometer adjusted for hand size. The best of three repetitions was recorded for each side and the right-to-left hand ratio was calculated. The 63 shunted patients were grouped considering the side of the shunt: 14 right, 35 central and 14 left. Results: Patients with CHD, especially shunts, had significantly lower handgrip strength in the dominant hand than controls (controls: 43.2 ± 14.8 kg, CHD: 36.8 ± 14.8 kg, left shunt: 33.6 ± 14.6 kg, central shunt: 30.7 ± 15.2 kg and right shunt 27.8 ± 13.6 kg; p < 0.001). In controls the right hand was 8.3% stronger, comparable to patients with either no shunt or central shunt (controls: 8.3 ± 13.2%; no shunt: 7.9 ± 15.3%; central shunt: 9.5 ± 18.1% p = 0.820). In patients with a left shunt the right hand was 22.5 ± 17.8% stronger than the left (p = 0.027 compared to central) while in those with a right shunt the right hand was 2.3 ± 18.3% weaker (p = 0.049 compared to central). Conclusions: Shunt procedures in infancy cause reduced handgrip strength in adulthood and diminished handgrip strength of the ipsilateral site.
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Affiliation(s)
- Jan Müller
- Department of Sport and Health Sciences, Institute of Preventive Pediatrics, Technische Universität München, Munich, Germany
| | - Leopold Röttgers
- Department of Pediatric Cardiology and Congenital Heart Disease, Deutsches Herzzentrum München, Technische Universität München, Munich, Germany
| | - Rhoia C. Neidenbach
- Department of Pediatric Cardiology and Congenital Heart Disease, Deutsches Herzzentrum München, Technische Universität München, Munich, Germany
| | - Renate Oberhoffer
- Department of Sport and Health Sciences, Institute of Preventive Pediatrics, Technische Universität München, Munich, Germany
- Department of Pediatric Cardiology and Congenital Heart Disease, Deutsches Herzzentrum München, Technische Universität München, Munich, Germany
| | - Peter Ewert
- Department of Pediatric Cardiology and Congenital Heart Disease, Deutsches Herzzentrum München, Technische Universität München, Munich, Germany
| | - Alfred Hager
- Department of Pediatric Cardiology and Congenital Heart Disease, Deutsches Herzzentrum München, Technische Universität München, Munich, Germany
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McCaughan AN, Toomey E, Schneider M, Berggren KK, Nam SW. A kinetic-inductance-based superconducting memory element with shunting and sub-nanosecond write times. Supercond Sci Technol 2018; 32:10.1088/1361-6668/aae50d. [PMID: 32116414 PMCID: PMC7047614 DOI: 10.1088/1361-6668/aae50d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We present a kinetic-inductance-based superconducting memory element with non-destructive readout, femtojoule read and write energies, both read and write shunts, which is writeable with pulses shorter than 400 ps. The element utilizes both a high-kinetic-inductance layer made from tungsten silicide as well as a low-kinetic-inductance layer made from niobium. By using tungsten silicide-which has a long (20 ns) thermal time constant-and measuring bit error rates from 10 MHz to 1 GHz, we were able to verify that the thin-film elements could be operated at a data rate at least as fast as the material thermal time constant with a bit error ratio less than 10-6. We also analyze the margins of the device, and outline the characteristics by which a more efficient device may be designed.
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Affiliation(s)
- Adam N McCaughan
- National Institute of Standards and Technology, 325 Broadway St, Boulder, CO 80305, United States of America
| | - Emily Toomey
- Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, Cambridge, MA 02139, United States of America
| | - Michael Schneider
- National Institute of Standards and Technology, 325 Broadway St, Boulder, CO 80305, United States of America
| | - Karl K Berggren
- Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, Cambridge, MA 02139, United States of America
| | - Sae Woo Nam
- National Institute of Standards and Technology, 325 Broadway St, Boulder, CO 80305, United States of America
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13
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Klimov VS, Gulay YS, Evsyukov AV, Moysak GI. [Syringosubarachnoid shunting in treatment of syringomyelia: a literature review and a clinical case report]. Zh Vopr Neirokhir Im N N Burdenko 2017; 81:58-65. [PMID: 28665389 DOI: 10.17116/neiro201781358-65] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
In the article, we describe a clinical case of syringomyelia associated with an Arnold-Chiari type 1 malformation, evaluate the efficacy of syringosubarachnoid shunting, and analyze the literature data of domestic and international researchers involved in investigation and treatment of the pathology. Application of syringosubarachnoid shunting in the described case resulted in a clinical improvement in the form of regression of paresis and hypoesthesia, which demonstrated the efficacy of the shunting technique for correction of the syringomyelia symptoms.
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Affiliation(s)
- V S Klimov
- Federal Neurosurgical Center, Novosibirsk, Russia
| | - Yu S Gulay
- Evdokimov Moscow State University of Medicine and Dentistry, Moscow, Russia
| | - A V Evsyukov
- Federal Neurosurgical Center, Novosibirsk, Russia
| | - G I Moysak
- Federal Neurosurgical Center, Novosibirsk, Russia
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14
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Shaw R, Mahant N, Jacobson E, Owler B. A Review of Clinical Outcomes for Gait and Other Variables in the Surgical Treatment of Idiopathic Normal Pressure Hydrocephalus. Mov Disord Clin Pract 2016; 3:331-341. [PMID: 30363503 PMCID: PMC6178707 DOI: 10.1002/mdc3.12335] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 01/07/2016] [Accepted: 01/09/2016] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Idiopathic normal pressure hydrocephalus (INPH) is a treatable cause of gait disturbance, cognitive impairment, and urinary incontinence. This clinical triad of symptoms occurs in association with ventriculomegaly and normal cerebrospinal fluid (CSF) pressure. Although the treatment outcomes after CSF shunting for INPH have improved significantly since its first description in 1965, shortcomings in our understanding still remain. Not all INPH patients exhibit clinical improvement after shunting, and it is challenging to identify patients who are more likely to benefit from shunting. METHODS The Cochrane Library, Medline, Embase, and PubMed databases were searched for English-language publications between 1965 and October 2015. Reference lists of publications were also manually searched for additional publications. RESULTS The findings of this review indicate that, despite efforts to improve patient selection, the degree of clinical improvement after shunting continues to demonstrate significant variability both within and between studies. These discrepancies in treatment outcomes are the result of controversies in 3 distinct but interrelated domains: the underlying pathophysiology of INPH, the diagnosis of INPH, and the identification of likely shunt-responders. CONCLUSIONS This review focuses on these 3 areas and their relation to surgical treatment outcomes. Despite the limitations of published outcome studies and limitations in our understanding of INPH pathophysiology, shunting is a safe and effective means of achieving meaningful clinical improvement in most patients with INPH.
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Affiliation(s)
- Richard Shaw
- Faculty of MedicineUniversity of New South WalesSydneyAustralia
| | - Neil Mahant
- Department of NeurologyWestmead HospitalSydneyAustralia
- Western Clinical School: Medicine (Westmead)University of SydneySydneyAustralia
| | - Erica Jacobson
- Department of NeurosurgeryPrince of Wales HospitalSydneyAustralia
| | - Brian Owler
- Department of NeurosurgerySydney Adventist HospitalSydneyAustralia
- Department of SurgeryUniversity of SydneySydneyAustralia
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15
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Kapoor R, Evins AI, Marcus J, Rigante L, Kubota M, Stieg PE. Selective Patch Angioplasty and Intraoperative Shunting in Carotid Endarterectomy: A Single-Center Review of 141 Procedures. Cureus 2015; 7:e367. [PMID: 26623222 PMCID: PMC4659576 DOI: 10.7759/cureus.367] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Objective: Open surgical treatment of carotid artery stenosis, namely, carotid endarterectomy (CEA), has evolved since its inception in 1953. Despite improvements in the treatment of carotid occlusive disease through technological and surgical innovations, the use of patch grafting in CEA’s remains controversial. We evaluate the durability of the primary closure and the safety of selective shunting during carotid endarterectomy (CEA) as determined by intraoperative EEG and postoperative outcomes. Methods: A consecutive series of CEA’s performed by the senior author at a single academic medical center from 2001 to 2012 were reviewed. All cases were performed under continuous intraoperative electroencephalography (EEG). Patch angioplasty was used in cases where there was tortuosity of the vessel within the region of the endarterectomy and narrow vessel diameter at the distal end of the arteriotomy. Shunting was used when intraoperative EEG showed a > 50% reduction in a waveform in any lead. Patients were evaluated for restenosis via imaging or ultrasound at six months and subsequently annual follow-up. Results: One hundred and forty-one CEA’s were performed on 132 (76 male, 56 female) patients with an average age of 71 years (range: 40–95 years). Four (3%) cases required patch angioplasty and three (2%) required intraoperative shunts. The cross-clamp time ranged from 22 to 74 minutes, and the duration increased with the use of shunts and patches. Complications were rare and included recurrent stenosis (n=2), postoperative transient ischemic attack (n=1), ischemic stroke in (n=1), temporary hypoglossal nerve weakness (n=2), temporary marginal mandibular nerve weakness (n=6), and neck hematoma (n=1). Conclusion: Intraoperative EEG data suggests that primary closure and selective shunting in CEA can result in outcomes comparable with routine patch angioplasty and shunting.
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Affiliation(s)
- Rahul Kapoor
- Department of Neurological Surgery, Weill Cornell Medical College, New York Presbyterian Hospital, New York
| | - Alexander I Evins
- Department of Neurological Surgery, Weill Cornell Medical College, New York Presbyterian Hospital, New York
| | - Joshua Marcus
- Department of Neurological Surgery, Weill Cornell Medical College, New York Presbyterian Hospital, New York
| | - Luigi Rigante
- Department of Neurological Surgery, Weill Cornell Medical College, New York Presbyterian Hospital, New York
| | - Mayumi Kubota
- Department of Neurological Surgery, Weill Cornell Medical College, New York Presbyterian Hospital, New York
| | - Philip E Stieg
- Department of Neurological Surgery, Weill Cornell Medical College, New York Presbyterian Hospital, New York
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16
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Egger R, Schmitt AC, Wallace DJ, Sakmann B, Oberlaender M, Kerr JN. Robustness of sensory-evoked excitation is increased by inhibitory inputs to distal apical tuft dendrites. Proc Natl Acad Sci U S A 2015; 112:14072-7. [PMID: 26512104 DOI: 10.1073/pnas.1518773112] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cortical inhibitory interneurons (INs) are subdivided into a variety of morphologically and functionally specialized cell types. How the respective specific properties translate into mechanisms that regulate sensory-evoked responses of pyramidal neurons (PNs) remains unknown. Here, we investigated how INs located in cortical layer 1 (L1) of rat barrel cortex affect whisker-evoked responses of L2 PNs. To do so we combined in vivo electrophysiology and morphological reconstructions with computational modeling. We show that whisker-evoked membrane depolarization in L2 PNs arises from highly specialized spatiotemporal synaptic input patterns. Temporally L1 INs and L2-5 PNs provide near synchronous synaptic input. Spatially synaptic contacts from L1 INs target distal apical tuft dendrites, whereas PNs primarily innervate basal and proximal apical dendrites. Simulations of such constrained synaptic input patterns predicted that inactivation of L1 INs increases trial-to-trial variability of whisker-evoked responses in L2 PNs. The in silico predictions were confirmed in vivo by L1-specific pharmacological manipulations. We present a mechanism-consistent with the theory of distal dendritic shunting-that can regulate the robustness of sensory-evoked responses in PNs without affecting response amplitude or latency.
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Abstract
The 35S promoter of cauliflower mosaic virus and that of other plant pararetroviruses gives rise to an RNA, which is both a pre-genome and a polycistronic mRNA. The 600 nucleotide long very structured leader of this RNA is also transcribed separately. The resulting 8S RNA is then converted to a double strand giving rise to a huge set of siRNAs, which suppress silencing. In this Mini-Review I discuss how this versatile stretch of 600 nts constitutes a masterpiece of evolution.
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Affiliation(s)
- Thomas Hohn
- Botanical Institute, University of BaselBasel, Switzerland
- Friedrich Miescher InstituteBasel, Switzerland
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18
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Biglino G, Giardini A, Hsia TY, Figliola R, Taylor AM, Schievano S. Modeling single ventricle physiology: review of engineering tools to study first stage palliation of hypoplastic left heart syndrome. Front Pediatr 2013; 1:31. [PMID: 24400277 PMCID: PMC3864195 DOI: 10.3389/fped.2013.00031] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 10/11/2013] [Indexed: 12/27/2022] Open
Abstract
First stage palliation of hypoplastic left heart syndrome, i.e., the Norwood operation, results in a complex physiological arrangement, involving different shunting options (modified Blalock-Taussig, RV-PA conduit, central shunt from the ascending aorta) and enlargement of the hypoplastic ascending aorta. Engineering techniques, both computational and experimental, can aid in the understanding of the Norwood physiology and their correct implementation can potentially lead to refinement of the decision-making process, by means of patient-specific simulations. This paper presents some of the available tools that can corroborate clinical evidence by providing detailed insight into the fluid dynamics of the Norwood circulation as well as alternative surgical scenarios (i.e., virtual surgery). Patient-specific anatomies can be manufactured by means of rapid prototyping and such models can be inserted in experimental set-ups (mock circulatory loops) that can provide a valuable source of validation data as well as hydrodynamic information. Such models can be tuned to respond to differing the patient physiologies. Experimental set-ups can also be compatible with visualization techniques, like particle image velocimetry and cardiovascular magnetic resonance, further adding to the knowledge of the local fluid dynamics. Multi-scale computational models include detailed three-dimensional (3D) anatomical information coupled to a lumped parameter network representing the remainder of the circulation. These models output both overall hemodynamic parameters while also enabling to investigate the local fluid dynamics of the aortic arch or the shunt. As an alternative, pure lumped parameter models can also be employed to model Stage 1 palliation, taking advantage of a much lower computational cost, albeit missing the 3D anatomical component. Finally, analytical techniques, such as wave intensity analysis, can be employed to study the Norwood physiology, providing a mechanistic perspective on the ventriculo-arterial coupling for this specific surgical scenario.
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Affiliation(s)
- Giovanni Biglino
- Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science , London , UK ; Cardiorespiratory Unit, Great Ormond Street Hospital for Children, NHS Foundation Trust , London , UK
| | - Alessandro Giardini
- Cardiorespiratory Unit, Great Ormond Street Hospital for Children, NHS Foundation Trust , London , UK
| | - Tain-Yen Hsia
- Cardiorespiratory Unit, Great Ormond Street Hospital for Children, NHS Foundation Trust , London , UK
| | - Richard Figliola
- Departments of Bioengineering and Mechanical Engineering, Clemson University , Clemson, SC , USA
| | - Andrew M Taylor
- Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science , London , UK ; Cardiorespiratory Unit, Great Ormond Street Hospital for Children, NHS Foundation Trust , London , UK
| | - Silvia Schievano
- Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science , London , UK ; Cardiorespiratory Unit, Great Ormond Street Hospital for Children, NHS Foundation Trust , London , UK
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Szemes M, Davies RL, Garden CLP, Usowicz MM. Weaker control of the electrical properties of cerebellar granule cells by tonically active GABAA receptors in the Ts65Dn mouse model of Down's syndrome. Mol Brain 2013; 6:33. [PMID: 23870245 PMCID: PMC3723448 DOI: 10.1186/1756-6606-6-33] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 07/14/2013] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Down's syndrome (DS) is caused by triplication of all or part of human chromosome 21 and is characterized by a decrease in the overall size of the brain. One of the brain regions most affected is the cerebellum, in which the number of granule cells (GCs) is markedly decreased. GCs process sensory information entering the cerebellum via mossy fibres and pass it on to Purkinje cells and inhibitory interneurons. How GCs transform incoming signals depends on their input-output relationship, which is adjusted by tonically active GABA(A) receptor channels. RESULTS We report that in the Ts65Dn mouse model of DS, in which cerebellar volume and GC number are decreased as in DS, the tonic GABA(A) receptor current in GCs is smaller than in wild-type mice and is less effective in moderating input resistance and raising the minimum current required for action potential firing. We also find that tonically active GABA(A) receptors curb the height and broaden the width of action potentials in wild-type GCs but not in Ts65Dn GCs. Single-cell real-time quantitative PCR reveals that these electrical differences are accompanied by decreased expression of the gene encoding the GABA(A) receptor β3 subunit but not genes coding for some of the other GABA(A) receptor subunits expressed in GCs (α1, α6, β2 and δ). CONCLUSIONS Weaker moderation of excitability and action potential waveform in GCs of the Ts65Dn mouse by tonically active GABA(A) receptors is likely to contribute to atypical transfer of information through the cerebellum. Similar changes may occur in DS.
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Affiliation(s)
- Marianna Szemes
- Present address: School of Cellular and Molecular Medicine, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Rachel L Davies
- Present address: Research & Enterprise Development, University of Bristol, Senate House, Tyndall Avenue, Bristol BS8 1TH, UK
| | - Claire LP Garden
- Present address: School of Life, Sport and Social Sciences, Edinburgh Napier University, Sighthill Court, Edinburgh EH11 4BN, UK
| | - Maria M Usowicz
- School of Physiology & Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK
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Goutman SA, Katzan IL, Gupta R. Transcranial Doppler with bubble study as a method to detect extracardiac right-to-left shunts in patients with ischemic stroke. J Neuroimaging 2012; 23:523-5. [PMID: 22928688 DOI: 10.1111/j.1552-6569.2012.00738.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 05/12/2012] [Accepted: 05/22/2012] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND AND PURPOSE Paradoxical embolism through extracardiac right-to-left shunts (ECRLS) may represent an under-detected stroke mechanism. Stroke patients without evidence of cardiac right-to-left shunt (RLS) on echocardiogram may benefit from transcranial Doppler with bubble study (TCD-b) to aid in recognition of stroke etiology. This study assesses the usefulness of TCD-b in the stroke evaluation. METHODS Retrospective cohort study of consecutive patients undergoing TCD-b performed in our neurovascular laboratory from February 2005 to August 2009. Echocardiography results were reviewed in patients with positive TCD-b. Detailed medical record review was performed on patients with positive TCD-b and negative echocardiogram findings for RLS. RESULTS Of 502 patients undergoing TCD-b, 48.4% (n = 243) had a positive study suggesting the presence of RLS. Of these, 59.2% (n = 144) had an echocardiogram demonstrating a cardiac RLS, 26% (n = 63) had echocardiograms without evidence of cardiac RLS, and 14.8% (n = 36) had no echocardiogram. Data on the evaluation to determine source of potential shunting in patients with discrepant findings was available in 11(17.5%). Of these, 63.6% (7/11) had potential mechanisms for positive TCD-b: one pulmonary arteriovenous malformation (AVM), one arteriovenous fistula thrombus, one parietal AVM, and four had malignancy. CONCLUSIONS TCD-bubble studies may prove useful in uncovering treatable causes of stroke.
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Kolind J, Hounsgaard J, Berg RW. Opposing Effects of Intrinsic Conductance and Correlated Synaptic Input on V-Fluctuations during Network Activity. Front Comput Neurosci 2012; 6:40. [PMID: 22783184 PMCID: PMC3389371 DOI: 10.3389/fncom.2012.00040] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Accepted: 06/08/2012] [Indexed: 11/13/2022] Open
Abstract
Neurons often receive massive concurrent bombardment of synaptic inhibition and excitation during functional network activity. This increases membrane conductance and causes fluctuations in membrane potential (Vm) and spike timing. The conductance increase is commonly attributed to synaptic conductance, but also includes the intrinsic conductances recruited during network activity. These two sources of conductance have contrasting dynamic properties at sub-threshold membrane potentials. Synaptic transmitter gated conductance changes abruptly and briefly with each presynaptic action potential. If the spikes arrive at random times the changes in synaptic conductance are therefore stochastic and rapid during intense network activity. In comparison, sub-threshold intrinsic conductances vary smoothly in time. In the present study this discrepancy is investigated using two conductance-based models: a (1) compartment model and a (2) compartment with realistic slow intrinsic conductances. We examine the effects of varying the relative contributions of non-fluctuating intrinsic conductance with fluctuating concurrent inhibitory and excitatory synaptic conductance. For given levels of correlation in the synaptic input we find that the magnitude of the membrane fluctuations uniquely determines the relative contribution of synaptic and intrinsic conductance. We also quantify how Vm-fluctuations vary with synaptic correlations for fixed ratios of synaptic and intrinsic conductance. Interestingly, the levels of Vm -fluctuations and conductance observed experimentally during functional network activity leave little room for intrinsic conductance to contribute. Even without intrinsic conductances the variance in Vm -fluctuations can only be explained by a high degree of correlated firing among presynaptic neurons.
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Affiliation(s)
- Jens Kolind
- Faculty of Health Sciences, Department of Neuroscience and Pharmacology, University of Copenhagen Copenhagen, Denmark
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Govani SM, Higgins PDR. Combination of thiopurines and allopurinol: adverse events and clinical benefit in IBD. J Crohns Colitis 2010; 4:444-9. [PMID: 21122542 PMCID: PMC3157326 DOI: 10.1016/j.crohns.2010.02.009] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2009] [Revised: 02/01/2010] [Accepted: 02/22/2010] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND AIMS Allopurinol has been presented as a safe and effective adjunct to thiopurine therapy in inflammatory bowel disease (IBD). We aimed to determine the rate of infectious complications and clinical successes with a combination of thiopurine/allopurinol in IBD, and to identify which variables predict 6-thioguanine, 6-methylmercaptopurine, and white blood cell levels. Additionally we aimed to identify which variables predict complications. METHODS A retrospective database search identified patients with inflammatory bowel disease on both thiopurines and allopurinol. Regression modeling was used to identify which variables predicted metabolite levels, white blood cell levels, and complications. RESULTS Twenty-seven subjects were found, with 20 treated intentionally and 7 inadvertently after a concurrent gout diagnosis. Thirteen of 20 patients had a major clinical improvement and 7 of 16 stopped steroids. Five infectious complications occurred. These included 2 cases of shingles, and one each of PCP, EBV, and viral meningitis. Significant predictors of metabolite levels included the dose of thiopurine and allopurinol, age, and BMI. Low white blood cell count levels were associated with increased doses, high BMI, and older age. Despite having only 5 events, there was a difference in absolute lymphocyte count between patients with and without infection (median 200 per mm³ vs 850 per mm³ respectively, p=0.0503). CONCLUSIONS Adjunctive allopurinol therapy in shunting patients produced major clinical improvement in 48% of patients. However, a surprising number of opportunistic infections have occurred. Low absolute lymphocyte count may be a previously unrecognized indicator of risk of opportunistic infections.
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Affiliation(s)
- Shail M Govani
- University of Michigan, Department of Internal Medicine, Division of General Medicine, United States
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Theodorakis NG, Wang YN, Wu J, Maluccio MA, Skill NJ. Tumor necrosis factor alpha signaling in the development of experimental murine pre-hepatic portal hypertension. Int J Physiol Pathophysiol Pharmacol 2010; 2:104-110. [PMID: 21383890 PMCID: PMC3047261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Accepted: 03/20/2010] [Indexed: 05/30/2023]
Abstract
The cytokine tumor necrosis factor alpha (TNFa) has previously been identified in the development of portal hypertension (PHT) by facilitating portal venous and systemic hyperemia. TNFa is reported to contribute to hyperemia via endothelial nitric oxide synthase (eNOS) induction and nitric oxide (NO) production. This study examines this hypothesis by utilizing TNFa receptor knockout mice and a murine model of pre-hepatic PHT. Plasma TNFa and NOx and tissue TNFa mRNA levels were determined in wild-type mice 0-7d post induction of pre-hepatic PHT by partial portal vein ligation (PVL). TNFa receptor knockout mice also received PVL or sham surgery and splenic pulp pressure, abdominal aortic flow and portal-systemic shunting were recorded 7d following. Portal pressure and systemic hyperemia developed rapidly following PVL. Plasma NOx was increased temporarily 2-3 days following PVL and returned to baseline by day 7. Circulating TNFa was below detectable limits of the ELISA used, as such no increase was observed. Hepatic and vascular TNFa mRNA levels were transiently changed after PVL otherwise there was no significant change. TNFa receptor targeted gene deletion did not ameliorate plasma NOx following PVL and had no effect on the development of PHT. TNFa receptor signaling plays no detectable role in the development of systemic hyperemia in the murine model of pre-hepatic PHT. Consequently, increased TNFa observed in intra-hepatic inflammatory models (CCl(4)) and in patients is probably related to inflammation associated with intra-hepatic pathology. Alternatively, TNFa may be signaling via a TNFa receptor independent mechanism.
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Abstract
OBJECTIVES : To determine the prevalence of portopulmonary hypertension, hepatopulmonary syndrome (HPS), and intrapulmonary vascular shunting (IPVS) in children with clinically stable portal hypertension and to assess the value of vasoactive peptide levels, biochemical tests and clinical signs or symptoms to predict these conditions. PATIENTS AND METHODS : A prospective, cross-sectional analysis was conducted on 33 children, ages 4 to 17 years, with stable cirrhosis (n = 28) or extrahepatic portal hypertension (n = 5). The children were screened for IPVS and hypoxia with contrast-enhanced echocardiography (cECHO) and pulse oximetry, and screened for pulmonary hypertension with Doppler echocardiography. Chemistries, radiographs, physical examinations, and levels of vasoactive peptides were compared between subjects with IPVS and those with normal cECHO. RESULTS : No subject had pulmonary hypertension. Six (19%) had IPVS, all of which had intrahepatic causes of portal hypertension, and 1 of whom had HPS. Compared with subjects with normal cECHO, those with IPVS had biochemical evidence of more advanced liver disease and higher b-type natriuretic peptide levels. CONCLUSIONS : Prevalence of portopulmonary hypertension and HPS appear to be rare in clinically stable children with portal hypertension. Intrapulmonary vascular shunting was present in 19% of these patients. A novel finding of this study is the elevation of b-type natriuretic peptide in children with IPVS.
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Affiliation(s)
- John R. Whitworth
- Pediatric Gastroenterology, Hepatology and Nutrition, University of Colorado Denver School of Medicine, Aurora, CO, USA
| | - D. Dunbar Ivy
- Pediatric Cardiology, University of Colorado Denver School of Medicine, Aurora, CO, USA
| | - Jane Gralla
- Pediatric Clinical Translational Research Center, University of Colorado Denver School of Medicine, Aurora, CO, USA
| | - Michael R. Narkewicz
- Pediatric Gastroenterology, Hepatology and Nutrition, University of Colorado Denver School of Medicine, Aurora, CO, USA
| | - Ronald J. Sokol
- Pediatric Gastroenterology, Hepatology and Nutrition, University of Colorado Denver School of Medicine, Aurora, CO, USA
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