scholarly journals Engineering strategies towards overcoming bleeding and glial scar formation around neural probes

Author(s):  
Elisabeth Otte ◽  
Andreas Vlachos ◽  
Maria Asplund

AbstractNeural probes are sophisticated electrophysiological tools used for intra-cortical recording and stimulation. These microelectrode arrays, designed to penetrate and interface the brain from within, contribute at the forefront of basic and clinical neuroscience. However, one of the challenges and currently most significant limitations is their ‘seamless’ long-term integration into the surrounding brain tissue. Following implantation, which is typically accompanied by bleeding, the tissue responds with a scarring process, resulting in a gliotic region closest to the probe. This glial scarring is often associated with neuroinflammation, neurodegeneration, and a leaky blood–brain interface (BBI). The engineering progress on minimizing this reaction in the form of improved materials, microfabrication, and surgical techniques is summarized in this review. As research over the past decade has progressed towards a more detailed understanding of the nature of this biological response, it is time to pose the question: Are penetrating probes completely free from glial scarring at all possible?

Aorta ◽  
2021 ◽  
Author(s):  
Igor Vendramin ◽  
Uberto Bortolotti ◽  
Davide Nunzio De Manna ◽  
Andrea Lechiancole ◽  
Sandro Sponga ◽  
...  

AbstractSimultaneous replacement of the ascending aorta and aortic valve has always been a challenging procedure. Introduction of composite conduits, through various ingenious procedures and their modifications, has changed the outlook of patients with aortic valve disease and ascending aorta pathology. In the past 70 years, progress of surgical techniques and prosthetic materials has allowed such patients to undergo radical procedures providing excellent early and long-term results in both young and elderly patients. This article aims to review the most important technical advances in the treatment of aortic valve disease and ascending aorta aneurysms recognizing the important contributions in this field.


2015 ◽  
Vol 9 (1) ◽  
pp. 92-102 ◽  
Author(s):  
H Derar ◽  
M Shahinpoor

Hip replacement surgery has gone through tremendous evolution since the first procedure in 1840. In the past five decades the advances that have been made in technology, advanced and smart materials innovations, surgical techniques, robotic surgery and methods of fixations and sterilization, facilitated hip implants that undergo multiple design revolutions seeking the least problematic implants and a longer survivorship. Hip surgery has become a solution for many in need of hip joint remedy and replacement across the globe. Nevertheless, there are still long-term problems that are essential to search and resolve to find the optimum implant. This paper reviews several recent patents on hip replacement surgery. The patents present various designs of prostheses, different materials as well as methods of fixation. Each of the patents presents a new design as a solution to different issues ranging from the longevity of the hip prostheses to discomfort and inconvenience experienced by patients in the long-term.


2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e15722-e15722
Author(s):  
Veronica Mariotti ◽  
Ricardo Daniel Parrondo ◽  
Miguel Gonzalez Velez ◽  
Narjust Duma ◽  
Lori Ann Leslie ◽  
...  

e15722 Background: Pancreatic cancer (PaCa) is a highly lethal disease, with a 5-year overall survival (OS) rate of approximately 6%, and a median OS of only 3–6 months (m). Despite recent improvements in surgical techniques and increased use of combination chemotherapy (CT), OS remains poor. This study aims to examine the factors that led to increased OS in PaCa patients (pts) over the past two decades in a single academic institution. Methods: All medical records of pts diagnosed with PaCa at the John Theurer Cancer Center from 1990 to 2012 were reviewed, and 916 PaCa pts were included in this analysis. We compared one group of pts diagnosed from 1990 to 2003 (G1, n = 482), with a group of pts diagnosed from 2004 to 2012 (G2, n = 434) in terms of OS, demographics, tumor features and treatment (tx). Results: Median age at diagnosis was 70.5 years (range 26-96). There was no significant difference between G1 and G2 in terms of age at diagnosis, stage of disease and number of pts who received surgery. A significantly higher percentage of pts received CT in G2 compared to G1 (66.5% vs 51.0%, p = .00). Tumors of the pancreatic head were more common in G1 compared to G2 (51.8% vs 44.4% p = .02). More pts in G2 received two or more CT agents compared to G1 (49.0% vs 34.1%, p = .00). Median OS was significantly longer in G2 compared to G1 (9m vs 5m, p = .00), in pts who received CT compared to pts who did not (3m vs 9m, p = .00) and in pts who received surgery compared to pts who did not (5m vs 19m, p = .00). Pancreatic head location was associated with improved OS compared to other locations (9m vs 5m, p = .00). No OS difference was found between pts who received combination with two or more agents vs single agent CT. Conclusions: In line with multiple studies, analysis of PaCa data from our institution showed an increase OS in pts diagnosed with PaCa in more recent years, and in those who received surgery and CT. CT was administered in a larger number of pts in G2, which might account for the better OS in this group. Pts diagnosed with tumors of the pancreatic head had better survival, which could be explained by earlier presentation leading to earlier diagnosis and tx. Further research in PaCa therapeutics is needed, as long-term OS in PaCa pts remains poor despite recent advances.


2020 ◽  
Author(s):  
Rachael L. Sumner ◽  
Meg J. Spriggs ◽  
Alexander D. Shaw

AbstractNeuroplasticity is essential to learning and memory in the brain; it has therefore also been implicated in numerous neurological and psychiatric disorders, making measuring the state of neuroplasticity of foremost importance to clinical neuroscience. Long-term potentiation (LTP) is a key mechanism of neuroplasticity and has been studied extensively, and invasively in non-human animals. Translation to human application largely relies on the validation of non-invasive measures of LTP. The current study provides validation for the use of a thalamocortical computational model of visual cortex for investigating and replicating interlaminar connectivity changes using non-invasive EEG recording of humans, and a commonly used visual sensory LTP paradigm. The model demonstrated remarkable accuracy recapitulating post-tetanus changes including increased excitatory connectivity from thalamus to layer IV and from layer IV to II/III. The findings also further validate visual sensory induced LTP and evoked potential modulation for measuring of the state of LTP in cortex.


Cancers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 592 ◽  
Author(s):  
Patrice Forget ◽  
Jose A. Aguirre ◽  
Ivanka Bencic ◽  
Alain Borgeat ◽  
Allessandro Cama ◽  
...  

The question of whether anesthetic, analgesic or other perioperative intervention during cancer resection surgery might influence long-term oncologic outcomes has generated much attention over the past 13 years. A wealth of experimental and observational clinical data have been published, but the results of prospective, randomized clinical trials are awaited. The European Union supports a pan-European network of researchers, clinicians and industry partners engaged in this question (COST Action 15204: Euro-Periscope). In this narrative review, members of the Euro-Periscope network briefly summarize the current state of evidence pertaining to the potential effects of the most commonly deployed anesthetic and analgesic techniques and other non-surgical interventions during cancer resection surgery on tumor recurrence or metastasis.


Author(s):  
Xiaoyan Feng ◽  
Illya Martynov ◽  
Anne Suttkus ◽  
Martin Lacher ◽  
Steffi Mayer

Abstract Introduction Research on esophageal atresia (EA) has been heavily published over the past decades. Herein, we aimed to study the quantity and quality as well as key topics in EA research with regards to global collaborations among countries and authors. Material and Methods Publications on EA from 1945 to 2018 were extracted from the Web of Science core collection database. Productivity (quantity) was assessed by the number of publications. Quality was estimated from the number of citations, citation rate per item and year, h-index, and impact index. Collaborative networks were evaluated using VOSviewer. All measures were analyzed for countries, authors, and journals. The 10 most cited original articles between 1969 and 2018 in 5-year intervals (n = 100) were manually screened to assess the key points of EA research. Results A total of 2,170 publications from 85 countries published in 388 journals were identified yielding 26,755 citations, both significantly increasing over time (p < 0.001). The most productive countries and authors also accounted for high-quality publications and benefited from an active global network. The most productive journals derived from the field of pediatric surgery but accounted only for one-third of EA papers. The best cited journals were unspecific for pediatric surgery. Long-term outcome remained the most important topic in EA research, followed by surgical techniques, epidemiology, associated anomalies, perioperative complications, and postnatal management. In contrast, basic science was underrepresented. Conclusion Over the past seven decades, EA publications increased tremendously. Productiveness and quality benefited from global networking. Long-term outcome remains the key interest of EA research.


2008 ◽  
Vol 2008 ◽  
pp. 1-6 ◽  
Author(s):  
Nasser Simforoosh ◽  
Mohammad H. Radfar

Significant controversy exists regarding vesicoureteral reflux (VUR) management, due to lack of sufficient prospective studies. The rationale for surgical management is that VUR can cause recurrent episodes of pyelonephritis and long-term renal damage. Several surgical techniques have been introduced during the past decades. Open anti-reflux operations have high success rate, exceeding 95%, and long durability. The goal of this article is to review the Gil-Vernet trigonoplasty technique, which is a simple and highly successful technique but has not gained the attention it deserves. The mainstay of this technique is approximation of medial aspects of ureteral orifices to midline by one mattress suture. A unique advantage of Gil-Vernet trigonoplasty is its bilateral nature, which results in prevention from contralateral new reflux. Regarding not altering the normal course of the ureter in Gil-Vernet procedure, later catheterization of and retrograde access to the ureter can be performed normally. There is no report of ureterovesical junction obstruction following Gil-Vernet procedure. Gil-Vernet trigonoplasty can be performed without inserting a bladder catheter and drain on an outpatient setting. Several exclusive advantages of Gil-Vernet trigonoplasty make it necessary to reconsider the technique role in VUR management.


2001 ◽  
Vol 8 (5) ◽  
pp. 419-426 ◽  
Author(s):  
Alan R. Shons ◽  
Gerard Mosiello

Background The techniques of breast reconstruction have evolved and matured over the past 25 years. Recent studies have proven the benefit of breast reconstruction for breast cancer patients. Methods The authors reviewed the recent literature on the techniques of breast reconstruction and the effects of reconstruction on patients following surgery for breast cancer. The findings in recent studies are correlated with the experience of the authors. Results A better understanding has been gained regarding surgical techniques of breast reconstruction as well as the proper indications for the various methods. The criteria of patient benefit have been defined by recent long-term studies. Conclusions Breast reconstruction following mastectomy has been proven to be a safe and beneficial procedure.


2019 ◽  
Vol 7 (1) ◽  
pp. e636 ◽  
Author(s):  
James M. Stankiewicz ◽  
Howard L. Weiner

Two different treatment paradigms are most often used in multiple sclerosis (MS). An escalation or induction approach is considered when treating a patient early in the disease course. An escalator prioritizes safety, whereas an inducer would favor efficacy. Our understanding of MS pathophysiology has evolved with novel in vivo and in vitro observations. The treatment landscape has also shifted significantly with the approval of over 10 new medications over the past decade alone. Here, we re-examine the treatment approach in light of these recent developments. We believe that recent work suggests that early prediction of the disease course is fraught, the amount of damage to the brain that MS causes is underappreciated, and its impact on patient function oftentimes is underestimated. These concerns, coupled with the recent availability of agents that allow a better therapeutic effect without compromising safety, lead us to believe that initiating higher efficacy treatments early is the best way to achieve the best possible long-term outcomes for people with MS.


2007 ◽  
Vol 2007 ◽  
pp. 1-6 ◽  
Author(s):  
Marian Joëls ◽  
Harm J. Krugers

When an organism is exposed to a stressful situation, corticosteroid levels in the brain rise. This rise has consequences for behavioral performance, including memory formation. Over the past decades, it has become clear that a rise in corticosteroid level is also accompanied by a reduction in hippocampal long-term potentiation (LTP). Recent studies, however, indicate that stress does not lead to a universal suppression of LTP. Many factors, including the type of stress, the phase of the stress response, the area of investigation, type of LTP, and the life history of the organism determine in which direction LTP will be changed.


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