Hasil untuk "Surgery"

Shuo Wang, Jinhua Chi, Yanting Wang et al.

Vitrectomy is a common clinical treatment for fundus disease. Due to the non-renewable nature of the vitreous, artificial vitreous are usually required to replace natural vitreous to perform functions post operation. Silicone oil and gas, as the most commonly used vitreous substitutes, have obvious drawbacks, which may lead to postoperative posture maintenance, visual impairment, cataract formation and secondary surgery. In this study, an in situ cross-linked bionic hydrogel (OAHA-CDHA/Col) based on hyaluronic acid (HA) and collagen (Col) with available gelling time for clinical operation, excellent self-healing and fatigue resistance, as well as suitable mechanical and optical properties is constructed. The compatibility and degradability of OAHA-CDHA/Col hydrogel are verified, as well as the feasibility as vitreous substitute in rabbit vitrectomy model. Notably, the hydrogel demonstrates improved intraocular tolerance compared with silicone oil, with no cataracts, endophthalmitis, fundus lesions and other complications observed. These findings position the OAHA-CDHA/Col hydrogel as a promising candidate for an ideal vitreous substitute.

Prerak Deep, Dheeraj Kulkarni

We introduce the notion of round surgery diagrams in $S^3$ for representing 3-manifolds similar to Dehn surgery diagrams. We give a correspondence between a certain class of round surgery diagrams and Dehn surgery diagrams for 3-manifolds. As a consequence, we recover Asimov's result, stating that any closed connected oriented 3-manifold can be obtained by a round surgery on a framed link in $S^3$. There may be more than one round surgery diagram giving rise to the same 3-manifold. Thus, it is natural to ask whether there is a version of Kirby Calculus for round surgery diagrams, similar to the case of Dehn surgery diagrams with integral framings. In this direction, we define four types of moves on round surgery diagrams such that any two round surgery diagrams corresponding to the same 3-manifold can be obtained one from another by a finite sequence of these moves, thereby establishing a version of Kirby Calculus. As an application, we prove the existence of taut foliations, hence the existence of tight contact structures on 3-manifolds obtained by round 1-surgery on fibred links with two components on $S^3$.

Kristen Hendricks, Abhishek Mallick, Matthew Stoffregen et al.

We prove an equivariant version of the Heegaard Floer link surgery formula. As a special case, this gives an equivariant knot surgery formula for equivariant knots in $S^3$. Our proof goes by way of a naturality theorem for certain bordered modules described by the last author. As a sample application, we prove the kernel of the forgetful map from the equivariant homology cobordism group to the homology cobordism group contains a $\Z^\infty$-summand.

Marc Kegel, Isacco Nonino, Monika Yadav

In this article, we define the contact surgery distance of two contact 3-manifolds $(M,ξ)$ and $(M',ξ')$ as the minimal number of contact surgeries needed to obtain $(M,ξ)$ from $(M',ξ')$. Our main result states that the contact surgery distance between two contact $3$-manifolds is at most $5$ larger than the topological surgery distance between the underlying smooth manifolds. As a byproduct of our proof, we classify the rational homology $3$-spheres on which the $d_3$-invariant of a $2$-plane field already determines its $Γ$-invariant and Euler class.

A. V. Novozhilov, S. E. Grigoriev, O. Yu. Yakovleva et al.

Introduction. Kidney transplantation (KT) is often considered the best option for renal replacement therapy (RRT), significantly improving patient outcomes. Post-transplant, life expectancy doubles, and mortality decreases more than 4-fold compared to other RRT modalities. This article presents KT outcomes in Irkutsk Region from 2018 to 2023. All procedures were performed at a single center – the Irkutsk Regional Clinical Hospital.Objective: to analyze the immediate and long-term outcomes of KT in Irkutsk Region.Material and methods. A retrospective analysis was conducted on the treatment outcomes of 125 patients with kidney failure (KF). Among them, 74 were men with a median age of 42 (35–49) years, and 51 were women with a median age of 46 (37–55) years. The median transplant waitlist time was 15.5 (range: 6–32) months. The leading cause of KF was chronic glomerulonephritis, observed in 60 patients (48%). There were no HLA matches in 36 patients (28.8%), while 38 patients (30.4%) had one match. Arterial anastomosis was primarily performed end-to-end with the external iliac artery in 121 cases (96.8%), while in 3 cases (2.4%), the internal iliac artery was used due to external iliac artery spasm. Cold ischemia time was 222 minutes (range: 162–360), and warm ischemia time was 39 minutes (range: 30–46).Results. Length of hospital stay was 16 (range: 13–25) bed days. Primary renal function was achieved in 95 patients (77%), while 25 patients (20%) experienced delayed graft function. Blood tacrolimus reached target levels by postoperative days 9–12. Creatinine level at discharge was 120 μmol/L (range: 97–165). Surgical complications occurred in 24 patients (19.2%), while urinary tract infections were observed in 36 patients (28.8%), with 17 cases (13.6%) presenting clinical symptoms. Immunosuppressive therapy was initiated in 124 patients (99.2%) using a standard triple-drug regimen (calcineurin inhibitors, mycophenolates, and glucocorticoids). One patient (0.8%) succumbed to complications from COVID-19. One-year graft survival was 94.1%.Conclusion. The immediate outcomes align with national averages. There is a consistent upward trend in the number of kidney transplants performed. Further development of the regional transplant program will enhance access to this high-tech medical service, meeting the needs of the local population.

Alicia Hüls

This paper examines Audre Lorde’s The Cancer Journals (2020) and her journey post-mastectomy, in relation to José Muñoz’s theory of disidentification, which he discusses in his book Disidentifications: Queers of Color and the Performance of Politics (1999). For Muñoz, disidentification is a survival strategy of stepping away from predominant societal ideologies. Muñoz’s theory is particularly fruitful for analyzing Lorde’s intersectional experiences and identity struggles of being a queer woman of color with breast cancer, but lacks an element of reidentification. This paper expands on the concept of disidentification and claims that Lorde does not take this passive stand Muñoz proposes but instead reidentifies herself in the face of prevailing gender norms.

Alan Du

Two Dehn surgeries on a knot are called cosmetic if they yield homeomorphic three-manifolds. We show for a certain family of null-homologous knots in any closed orientable three-manifold, if the knot admits cosmetic surgeries with a pair of positive surgery coefficients, then the coefficients are both greater than $1$. In addition, for this family of knots, we show that $1/q$ Dehn surgery for $q$ at least $2$ is not homeomorphic to the original three-manifold. The proofs of these results use the mapping cone formula for the Heegaard Floer homology of Dehn surgery in terms of the knot Floer homology of the knot; we provide a new proof of this formula for integer surgeries in $\text{Spin}^c$ structures with nontorsion first Chern class.

Kenneth L. Baker, Marc Kegel, Duncan McCoy

Surgery on a knot in $S^3$ is said to be an alternating surgery if it yields the double branched cover of an alternating link. The main theoretical contribution is to show that the set of alternating surgery slopes is algorithmically computable and to establish several structural results. Furthermore, we calculate the set of alternating surgery slopes for many examples of knots, including all hyperbolic knots in the SnapPy census. These examples exhibit several interesting phenomena including strongly invertible knots with a unique alternating surgery and asymmetric knots with two alternating surgery slopes. We also establish upper bounds on the set of alternating surgeries, showing that an alternating surgery slope on a hyperbolic knot satisfies $|p/q| \leq 3g(K)+4$. Notably, this bound applies to lens space surgeries, thereby strengthening the known genus bounds from the conjecture of Goda and Teragaito.

John B. Etnyre, Tanushree Shah

We demonstrate that the contact cosmetic surgery conjecture holds true for all non-trivial Legendrian knots, with the possible exception of Lagrangian slice knots. We also discuss the contact cosmetic surgeries on Legendrian unknots and make the surprising observation that there are some Legendrian unknots that have a contact surgery with no cosmetic pair, while all other contact surgeries are contactomorphic to infinitely many other contact surgeries on the knot.

Tobias Ekholm

This is an overview paper that describes Eliashberg's Legendrian surgery approach to wrapped Floer cohomology and use it to derive the basic relations between various holomorphic curve theories with additional algebraic constructions. We also give a brief discussion of further results that use the surgery perspective, e.g., for holomorphic curve invariants of singular Legendrians and Lagrangians.

Tatsuya Yamazaki, Kenta Iwasaki, Susumu Tomono et al.

Summary: Detecting antibodies, particularly those targeting donor human leukocyte antigens in organ transplantation and self-antigens in autoimmune diseases, is crucial for diagnosis and therapy. Radioprotective 105 (RP105), a Toll-like receptor family protein, is expressed in immune-competent cells, such as B cells. Studies in mice have shown that the anti-mouse RP105 antibody strongly activates B cells and triggers an adjuvant effect against viral infections. However, the anti-human RP105 antibody (ɑhRP105) weakly activates human B cells. This study established new culture conditions under, which human B cells are strongly activated by the ɑhRP105. When combined with CpGDNA, specific antibody production against blood group carbohydrates, ɑGal, and SARS-CoV-2 was successfully detected in human B cell cultures. Furthermore, comprehensive analysis using liquid chromatography-electrospray ionization tandem mass spectrometry, single-cell RNA sequencing, and quantitative real-time PCR revealed that ɑhRP105 triggered a different activation stimulus compared to CpGDNA. These findings could help identify antibody-producing B cells in cases of transplant rejection and autoimmune diseases.

Ruibang Wu, Leizhen Huang, Qinghong Xia et al.

Intervertebral disc degeneration (IDD) is a major contributing factor to both lower back and neck pain. As IDD progresses, the intervertebral disc (IVD) loses its ability to maintain its disc height when subjected to axial loading. This failure in the weight-bearing capacity of the IVD is a characteristic feature of degeneration. Natural polymer-based hydrogel, derived from biological polymers, possesses biocompatibility and is able to mimic the structure of extracellular matrix, enabling them to support cellular behavior. However, their mechanical performance is relatively poor, thus limiting their application in IVD regeneration. In this study, we developed an injectable composite hydrogel, namely, Mel-MBG/SA, which is similar to natural weight-bearing IVD. Mesoporous bioactive glasses not only enhance hydrogels, but also act as carriers for melatonin (Mel) to suppress inflammation during IDD. The Mel-MBG/SA hydrogel further provides a mixed system with sustained Mel release to alleviate IL-1β-induced oxidative stress and relieve inflammation associated with IDD pathology. Furthermore, our study shows that this delivery system can effectively suppress inflammation in the rat tail model, which is expected to further promote IVD regeneration. This approach presents a novel strategy for promoting tissue regeneration by effectively modulating the inflammatory environment while harnessing the mechanical properties of the material.

Stephen Doxey, DO, Arthur J. Only, MD, Michael Milshteyn, MD et al.

Abstract. Objectives:. The purpose of this study was to obtain information on Canadian orthopaedic trauma surgeon practices and salary demographics. It was hypothesized that most of the practicing surgeons recognize specific practice aspects (compensation, call schedule, operating room availability, and provided support staff) as key factors in employment opportunity evaluation. Design:. Cross-sectional survey study. Setting:. Orthopaedic Trauma Association (OTA) practice surveys. Participants:. All active Canadian members of the OTA were eligible to participate. Main Outcome Measurement:. A 50-question survey was sent through email to OTA members assessing physician, practice, and compensation metrics of Canadian orthopaedic traumatologists. Results:. Fifty-two of 113 Canadian OTA members participated giving a response rate of 46%. All surgeons worked in an academic practice, either for a university (83%) or community hospital (17%). Only 2% of surgeons have changed jobs in the last 5 years, and over 73% of surgeons maintain the same place of employment during their careers. Most had an available dedicated orthopaedic trauma operating room (73%). The majority indicated having residents (71%) and fellows (63%) as support staff. Many reported completing 300–500 cases per year (42%), which decreased during COVID-19 for 50% of surgeons. The most common reported compensation was between $400,000 and $600,000 US dollars (25%) with many working 4–6 call shifts a month (48%) and 51–70 hours a week (48%). Conclusion:. This study demonstrated the varying practice and physician economic variables currently in Canada. The identification and continued surveillance of these employment variables will allow for transparency in job market evaluation by applicants. Level of Evidence:. Level V.

Oliver Attie, Sylvain Cappell

In this paper, we set up two surgery theories and two kinds of Whitehead torsion for foliations. First, we construct a bounded surgery theory and bounded Whitehead torsion for foliations, which correspond to the Connes' foliation algebra in the K-theory of operator algebras, in the sense that there is an analogy between surgery theory and index theory, and a Novikov Conjecture for bounded surgery on foliations in analogy with the foliated Novikov conjecture of P.Baum and A.Connes in operator theory. This surgery theory classifies the leaves topologically. Secondly, we construct a bounded geometry surgery for foliations, which is a generalization of blocked surgery, and a bounded geometry Whitehead torsion. The classifications in this surgery theory include the specification of the Riemannian metrics of the leaves up to quasi=isometry. We state Borel conjectures for foliations, which solves a problem posed by S.Weinberger \cite{Wein}, and verify these in some cases of geometrical interest.

John Etnyre, Marc Kegel, Sinem Onaran

It is known that any contact 3-manifold can be obtained by rational contact Dehn surgery along a Legendrian link L in the standard tight contact 3-sphere. We define and study various versions of contact surgery numbers, the minimal number of components of a surgery link L describing a given contact 3-manifold under consideration. In the first part of the paper, we relate contact surgery numbers to other invariants in terms of various inequalities. In particular, we show that the contact surgery number of a contact manifold is bounded from above by the topological surgery number of the underlying topological manifold plus three. In the second part, we compute contact surgery numbers of all contact structures on the 3-sphere. Moreover, we completely classify the contact structures with contact surgery number one on $S^1\times S^2$, the Poincaré homology sphere, and the Brieskorn sphere $Σ(2,3,7)$. We conclude that there exist infinitely many non-isotopic contact structures on each of the above manifolds which cannot be obtained by a single rational contact surgery from the standard tight contact $3$-sphere. We further obtain results for the 3-torus and lens spaces. As one ingredient of the proofs of the above results we generalize computations of the homotopical invariants of contact structures to contact surgeries with more general surgery coefficients which might be of independent interest.

Tatsumasa Suzuki, Motoo Tange

Iwase and Matsumoto defined `pochette surgery' as a cut-and-paste on 4-manifolds along a 4-manifold homotopy equivalent to $S^2\vee S^1$. The first author in [10] studied infinitely many homotopy 4-spheres obtained by pochette surgery. In this paper we compute the homology of pochette surgery of any homology 4-sphere by using `linking number' of a pochette embedding. We prove that pochette surgery with the trivial cord does not change the diffeomorphism type or gives a Gluck surgery. We also show that there exist pochette surgeries on the 4-sphere with a non-trivial core sphere and a non-trivial cord such that the surgeries give the 4-sphere.

Mateusz Kudelko, Peikai Chen, Vivian Tam et al.

Mice are commonly used to study intervertebral disc (IVD) biology and related diseases such as IVD degeneration. Discs from both the lumbar and tail regions are used. However, little is known about compartmental characteristics in the different regions, nor their relevance to the human setting, where a functional IVD unit depends on a homeostatic proteome. Here, we address these major gaps through comprehensive proteomic profiling and in-depth analyses of 8-week-old healthy murine discs, followed by comparisons with human. Leveraging on a dataset of over 2,700 proteins from 31 proteomic profiles, we identified key molecular and cellular differences between disc compartments and spine levels, but not gender. The nucleus pulposus (NP) and annulus fibrosus (AF) compartments differ the most, both in matrisome and cellularity contents. Differences in the matrisome are consistent with the fibrous nature required for tensile strength in the AF and hydration property in the NP. Novel findings for the NP cells included an enrichment in cell junction proteins for cell–cell communication (Cdh2, Dsp and Gja1) and osmoregulation (Slc12a2 and Wnk1). In NP cells, we detected heterogeneity of vacuolar organelles; where about half have potential lysosomal function (Vamp3, Copb2, Lamp1/2, Lamtor1), some contain lipid droplets and others with undefined contents. The AF is enriched in proteins for the oxidative stress responses (Sod3 and Clu). Interestingly, mitochondrial proteins are elevated in the lumbar than tail IVDs that may reflect differences in metabolic requirement. Relative to the human, cellular and structural information are conserved for the AF. Even though the NP is more divergent between mouse and human, there are similarities at the level of cell biology. Further, common cross-species markers were identified for both NP (KRT8/19, CD109) and AF (COL12A1). Overall, mouse is a relevant model to study IVD biology, and an understanding of the limitation will facilitate research planning and data interpretation, maximizing the translation of research findings to human IVDs.

Sathish Kumar Chidire, Sairani karanam, Anees fatima

Background: Paediatric cataract though being an avoidable cause of blindness, if not intervened timely, presents an enormous problem in terms of human morbidity, economic loss and social burden. Aims and objective: The objective of this study was to observe the visual outcome after developmental cataract surgery. Materials and Methods: A prospective study was conducted in department of pediatric ophthalmology at sankara eye care hospital. The study was conducted for nine months period from february 2019 to september 2019. All the patients of developmental cataract up to age of 15 years were included in the study. The patients underwent either a) lens aspiration + PCIOL implantation b) lens aspiration + PPC+Anterior Vitrectomy+PCIOL implantation depending upon age of patient. Post surgery patients were examined on day 1, 1 week and 1 month period. Glass prescription was done at the end of 1 month post operative period. Results: A total of 50 eyes of 31 children were included in the study. The mean age was 7.83 ± 4.07 years. Male participants were 24 (77%) and 7 (23%) were female participants. post-operative BCVA of 6/6 - 6/18 was seen in 27 (54%) eyes, 6/60 < 6/18 was seen in 9 (18%) of eyes and < 6/60 in 1(2%) eye. In 13 (26%) of eyes, fixation and follow up of light was seen. There was a statistically significant improvement in post surgical BCVA (p value<0.001). Conclusion: Our study demonstrates that good visual outcome following pediatric cataract surgery can be achieved by early diagnosis, timely intervention, skill of the surgeon and regular followup in the post-operative period. The tendency to develop posterior capsular opacification in the post-operative period is less likely to occur with lens aspiration +PPC+ Anterior Vitrectomy+PCIOL implantation when compared to lens aspiration+ PCIOL implantation.

Zhen Li, Yannik Gehlen, Yannik Gehlen et al.

Discogenic low back pain (LBP) is a main cause of disability and inflammation is presumed to be a major driver of symptomatic intervertebral disc degeneration (IDD). Anti-inflammatory agents are currently under investigation as they demonstrated to alleviate symptoms in patients having IDD. However, their underlying anti-inflammatory and regenerative activity is poorly explored. The present study sought to investigate the potential of Etanercept and Tofacitinib for maintaining disc homeostasis in a preclinical intervertebral disc (IVD) organ culture model within IVD bioreactors allowing for dynamic loading and nutrient exchange. Bovine caudal IVDs were cultured in a bioreactor system for 4 days to simulate physiological or degenerative conditions: (1) Phy—physiological loading (0.02–0.2 MPa; 0.2 Hz; 2 h/day) and high glucose DMEM medium (4.5 g/L); (2) Deg+Tumor necrosis factor α (TNF-α)—degenerative loading (0.32–0.5 MPa; 5 Hz; 2 h/day) and low glucose DMEM medium (2 g/L), with TNF-α injection. Etanercept was injected intradiscally while Tofacitinib was supplemented into the culture medium. Gene expression in the IVD tissue was measured by RT-qPCR. Release of nitric oxide (NO), interleukin 8 (IL-8) and glycosaminoglycan (GAG) into the IVD conditioned medium were analyzed. Cell viability in the IVD was assessed using lactate dehydrogenase and ethidium homodimer-1 staining. Immunohistochemistry was performed to assess protein expression of IL-1β, IL-6, IL-8, and collagen type II in the IVD tissue. Etanercept and Tofacitinib downregulated the expression of IL-1β, IL-6, IL-8, Matrix metalloproteinase 1 (MMP1), and MMP3 in the nucleus pulposus (NP) tissue and IL-1β, MMP3, Cyclooxygenase-2 (COX2), and Nerve growth factor (NGF) in the annulus fibrosus (AF) tissue. Furthermore, Etanercept significantly reduced the IL-1β positively stained cells in the outer AF and NP regions. Tofacitinib significantly reduced IL-1β and IL-8 positively stained cells in the inner AF region. Both, Etanercept and Tofacitinib reduced the GAG loss to the level under physiological culture condition. Etanercept and Tofacitinib are able to neutralize the proinflammatory and catabolic environment in the IDD organ culture model. However, combined anti-inflammatory and anabolic treatment may be required to constrain accelerated IDD and relieving inflammation-induced back pain.

Rafael García Capurro

Presentado en la Sesión del 27 de Abril de 1949.