Arthroscopic Lateral Retinacular-Lengthening Procedure.

Anterior knee pain is a common musculoskeletal complaint that is often due to an excessively tight lateral retinaculum, which normally plays a role in patellar tracking and stabilization. Several etiologies underlie lateral soft-tissue tightness in the knee, including lateral patellar compression syndrome, patellofemoral arthritis, patellofemoral instability, and patellofemoral pain syndrome. Stretching the lateral retinaculum through conservative treatment may be helpful, but lateral retinacular lengthening may be indicated. Since this surgical procedure has classically been performed in an open fashion, the purpose of this Technical Note is to describe an arthroscopic technique designed to limit complications, improve patient outcomes, and reduce operative and recovery times.

Toward Intraoperative Visual Intelligence: Real-Time Surgical Instrument Segmentation for Enhanced Surgical Monitoring.

BACKGROUND: Open surgery relies heavily on the surgeon's visual acuity and spatial awareness to track instruments within a dynamic and often cluttered surgical field. METHODS: This system utilizes a head-mounted depth camera to monitor surgical scenes, providing both image data and depth information. The video captured from this camera is scaled down, compressed using MPEG, and transmitted to a high-performance workstation via the RTSP (Real-Time Streaming Protocol), a reliable protocol designed for real-time media transmission. To segment surgical instruments, we utilize the enhanced U-Net with GridMask (EUGNet) for its proven effectiveness in surgical tool segmentation. RESULTS: For rigorous validation, the system's performance reliability and accuracy are evaluated using prerecorded RGB-D surgical videos. This work demonstrates the potential of this system to improve situational awareness, surgical efficiency, and generate data-driven insights within the operating room. In a simulated surgical environment, the system achieves a high accuracy of 85.5% in identifying and segmenting surgical instruments. Furthermore, the wireless video transmission proves reliable with a latency of 200 ms, suitable for real-time processing. CONCLUSIONS: These findings represent a promising step towards the development of assistive technologies with the potential to significantly enhance surgical practice.

Does Prior Breast Irradiation Increase Complications of Subsequent Reduction Surgery in Breast Cancer Patients? A systematic Review and Meta-Analysis.

BACKGROUND: Reduction mammoplasty and mastopexy are potentially complicated by prior breast irradiation as part of breast conserving therapy. Associated tissue changes with therapeutic irradiation have led to surgeons deciding the risks may outweigh potential benefit for those patients. A systematic review of the existing literature was performed to explore surgical outcomes of patients undergoing delayed bilateral reduction mammoplasty or mastopexy following unilateral breast irradiation as part of breast conserving therapy. METHODS: Medline, PubMed and EMBASE were searched from 1990 to 2023 according to PRISMA guidelines. Studies were combined by the generic inverse variance method on the natural logarithms of rate ratios (RR) using a random effect model in Review manager 5.4.1. RESULTS: Fifteen studies reported outcomes in 188 patients who underwent breast reduction (BR) following unilateral breast conserving surgery and radiotherapy. The median age at BR was 51.5 years (range 39-60), and median time since radiotherapy was 48 months (range 11.7-86). We compared outcomes for irradiated breast (IB) versus non-irradiated breast (NIB). Pooled results showed higher rate of major complications in the IB (RR 2.52, 95%CI 0.96-6.63, p=0.06), but not statistically significant. However, rate of minor complications was significantly higher in the IB (RR 3.97 95%CI 1.86-8.50, p<0.0004). Incidence of fat necrosis as a discrete complication was 2× higher in IB (RR 2.14 95%CI 0.85-5.35, p-value 0.10) compared to the NIB, but not significant. CONCLUSION: We found breast reduction to be safe with acceptable risk of major complications. However, the overall complication rate remains higher in IB compared to NIB. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of contents or the online Instructions to Authors www.springer.com/00266 .

Macroscopic resting-state brain dynamics are best described by linear models.

It is typically assumed that large networks of neurons exhibit a large repertoire of nonlinear behaviours. Here we challenge this assumption by leveraging mathematical models derived from measurements of local field potentials via intracranial electroencephalography and of whole-brain blood-oxygen-level-dependent brain activity via functional magnetic resonance imaging. We used state-of-the-art linear and nonlinear families of models to describe spontaneous resting-state activity of 700 participants in the Human Connectome Project and 122 participants in the Restoring Active Memory project. We found that linear autoregressive models provide the best fit across both data types and three performance metrics: predictive power, computational complexity and the extent of the residual dynamics unexplained by the model. To explain this observation, we show that microscopic nonlinear dynamics can be counteracted or masked by four factors associated with macroscopic dynamics: averaging over space and over time, which are inherent to aggregated macroscopic brain activity, and observation noise and limited data samples, which stem from technological limitations. We therefore argue that easier-to-interpret linear models can faithfully describe macroscopic brain dynamics during resting-state conditions.

NAD+ regulates nucleotide metabolism and genomic DNA replication.

The intricate orchestration of enzymatic activities involving nicotinamide adenine dinucleotide (NAD+) is essential for maintaining metabolic homeostasis and preserving genomic integrity. As a co-enzyme, NAD+ plays a key role in regulating metabolic pathways, such as glycolysis and Kreb's cycle. ADP-ribosyltransferases (PARPs) and sirtuins rely on NAD+ to mediate post-translational modifications of target proteins. The activation of PARP1 in response to DNA breaks leads to rapid depletion of cellular NAD+ compromising cell viability. Therefore, the levels of NAD+ must be tightly regulated. Here we show that exogenous NAD+, but not its precursors, has a direct effect on mitochondrial activity. Short-term incubation with NAD+ boosts Kreb's cycle and the electron transport chain and enhances pyrimidine biosynthesis. Extended incubation with NAD+ results in depletion of pyrimidines, accumulation of purines, activation of the replication stress response and cell cycle arrest. Moreover, a combination of NAD+ and 5-fluorouridine selectively kills cancer cells that rely on de novo pyrimidine synthesis. We propose an integrated model of how NAD+ regulates nucleotide metabolism, with relevance to healthspan, ageing and cancer therapy.

Diagnostic Radiology Fellowship Applicant Selection Criteria: A Survey of Program Directors.

Introduction In this study, we aimed to investigate the importance of various characteristics used by diagnostic radiology subspecialty fellowship programs when selecting candidates for their fellowship programs. Methods An online survey was sent to program directors from multiple radiology fellowship programs in the United States. Multiple questions were asked, including applicant gender, personal statement, interview performance, research experience, United States Medical Licensing Exam (USMLE) performance, and residency program attended. Survey recipients were asked to rank these characteristics from least to most important.  Results A total of 119 responses were collected (response rate of 26.2%), with a relatively balanced representation of the different subspecialties. An aggregate analysis of all the subspecialties showed interview performance, letters of recommendation, and residency program attended as the three most important factors considered by the program directors when selecting a candidate for their fellowship program. In contrast, the three least important factors were gender, prior subspecialty training, and minority status. The applicant's visa status, personal statement, and USMLE Step 3 performance were the only statistically significant (p<0.05) differences between the subspecialties. The women's and body imaging subspecialties rated the personal statement more important than musculoskeletal imaging and neuroradiology. Cardiothoracic and musculoskeletal imaging rated the applicant's visa status more important than neuroradiology. Women's and cardiothoracic imaging rated USMLE Step 3 performance as more important than musculoskeletal imaging. Conclusion Selecting the ideal candidate for a fellowship in radiology can be difficult. Our findings outline which applicant characteristics program directors believe are the most and least important when selecting an ideal candidate. For instance, personal characteristics such as interview performance and letters of recommendation are more valued than extracurricular activities such as research experience. Identifying these characteristics provides a better understanding of the fellowship application process and may guide future applicants.

MDC1 maintains active elongation complexes of RNA polymerase II.

The role of MDC1 in the DNA damage response has been extensively studied; however, its impact on other cellular processes is not well understood. Here, we describe the role of MDC1 in transcription as a regulator of RNA polymerase II (RNAPII). Depletion of MDC1 causes a genome-wide reduction in the abundance of actively engaged RNAPII elongation complexes throughout the gene body of protein-encoding genes under unperturbed conditions. Decreased engaged RNAPII subsequently alters the assembly of the spliceosome complex on chromatin, leading to changes in pre-mRNA splicing. Mechanistically, the S/TQ domain of MDC1 modulates RNAPII-mediated transcription. Upon genotoxic stress, MDC1 promotes the abundance of engaged RNAPII complexes at DNA breaks, thereby stimulating nascent transcription at the damaged sites. Of clinical relevance, cancer cells lacking MDC1 display hypersensitivity to RNAPII inhibitors. Overall, we unveil a role of MDC1 in RNAPII-mediated transcription with potential implications for cancer treatment.

CtIP-dependent nascent RNA expression flanking DNA breaks guides the choice of DNA repair pathway.

The RNA world is changing our views about sensing and resolution of DNA damage. Here, we develop single-molecule DNA/RNA analysis approaches to visualize how nascent RNA facilitates the repair of DNA double-strand breaks (DSBs). RNA polymerase II (RNAPII) is crucial for DSB resolution in human cells. DSB-flanking, RNAPII-generated nascent RNA forms RNA:DNA hybrids, guiding the upstream DNA repair steps towards favouring the error-free Homologous Recombination (HR) pathway over Non-Homologous End Joining. Specific RNAPII inhibitor, THZ1, impairs recruitment of essential HR proteins to DSBs, implicating nascent RNA in DNA end resection, initiation and execution of HR repair. We further propose that resection factor CtIP interacts with and helps re-activate RNAPII when paused by the RNA:DNA hybrids, collectively promoting faithful repair of chromosome breaks to maintain genomic integrity.

Cancer cells use self-inflicted DNA breaks to evade growth limits imposed by genotoxic stress.

Genotoxic therapy such as radiation serves as a frontline cancer treatment, yet acquired resistance that leads to tumor reoccurrence is frequent. We found that cancer cells maintain viability during irradiation by reversibly increasing genome-wide DNA breaks, thereby limiting premature mitotic progression. We identify caspase-activated DNase (CAD) as the nuclease inflicting these de novo DNA lesions at defined loci, which are in proximity to chromatin-modifying CCCTC-binding factor (CTCF) sites. CAD nuclease activity is governed through phosphorylation by DNA damage response kinases, independent of caspase activity. In turn, loss of CAD activity impairs cell fate decisions, rendering cancer cells vulnerable to radiation-induced DNA double-strand breaks. Our observations highlight a cancer-selective survival adaptation, whereby tumor cells deploy regulated DNA breaks to delimit the detrimental effects of therapy-evoked DNA damage.

Reinfection with SARS-CoV-2 and Waning Humoral Immunity: A Case Report.

Recovery from COVID-19 is associated with production of anti-SARS-CoV-2 antibodies, but it is uncertain whether these confer immunity. We describe viral RNA shedding duration in hospitalized patients and identify patients with recurrent shedding. We sequenced viruses from two distinct episodes of symptomatic COVID-19 separated by 144 days in a single patient, to conclusively describe reinfection with a different strain harboring the spike variant D614G. This case of reinfection was one of the first cases of reinfection reported in 2020. With antibody, B cell and T cell analytics, we show correlates of adaptive immunity at reinfection, including a differential response in neutralizing antibodies to a D614G pseudovirus. Finally, we discuss implications for vaccine programs and begin to define benchmarks for protection against reinfection from SARS-CoV-2.

Post-colonoscopy appendicitis: a case report.

Appendicitis after colonoscopy is rare, with an estimated incidence of 3.8 cases per 10 000 colonoscopies. Herein, we report a 56-year-old female who visited the emergency department with a history of diffuse abdominal pain and nausea 8 h after a screening colonoscopy. Abdominal examination disclosed deep tenderness at Mc Burney point and positive Rovsign's sign. Laboratory studies revealed elevated white blood cells and neutrophils (WBC 15.37 K/Ul and NEUT 86.5%) with normal C-reactive protein (5 mg/l). The initial diagnosis was acute appendicitis, which was confirmed by the ultrasonographic findings. The patient was admitted to the surgical department, and a laparoscopic appendectomy was performed. Post-colonoscopy appendicitis is increasingly recognized as a complication after colonoscopy in the last decade. Early recognition is vital in preventing morbidity and mortality. It may also be worthwhile to include appendicitis after colonoscopy as a possible complication during the consent before the procedure.

Small bowel obstruction due to a congenital adhesion: a rare case report.

The exact incidence of small bowel obstruction (SBO) due to congenital adhesions remains unclear. Herein, we report a 59-year-old male who appeared in the emergency department with diffuse abdominal pain associated with vomiting. The patient reported no previous medical or surgical history. Clinical examination revealed a soft, distended abdomen and diffuse tenderness. Computed tomography indicated a close loop obstruction. A congenital band extending from mesentery to ileum and causing an internal hernia was identified via a midline incision. The band was ligated and divided. There is no difference in the clinical presentation, and the initial work-up of SBO on account of congenital adhesions was compared to other bowel obstruction causes. Surgical exploration is crucial for the diagnosis and treatment of congenital adhesions. Although laparotomy is considered the cornerstone of surgical management, laparoscopy has emerged as a feasible and safe alternative for the diagnosis and treatment of these congenital bands.

An Innovatory Surgical Technique for Submacular Hemorrhage Displacement by Means of a Bioengineering Perspective.

The purpose of this case report is to present a new surgical technique for the treatment of large Subretinal Hemorrhage (SRH) secondary to Age-related Macular Degeneration (AMD). Considering the biomechanics of foam evolution theory, bubble coarsening effect, and gas-liquid biphasic absorption, an SRH due to an AMD case was treated with vitrectomy. The treatment was implemented by subretinal injection of air bubbles combined with rtPA followed by air fluid exchange. The air bubbles helped mess up and remove the blood from the macula area, and no complications occurred. Two weeks postoperatively, there was no sign of hemorrhage and the Central Macular Thickness (CMT) was sharply decreased from 443 µm to 317 µm. At the five-month follow-up, the CMT remained at 267 µm and the patient's visual acuity improved from light perception to 20/70 according to the Snellen chart. The combination of injecting multiple air bubbles and submacular rtPA, followed by air fluid exchange, was able to displace more than (90%) of the subretinal blood just two weeks postoperatively. Our technique is a promising alternative surgical approach for the displacement of SMH due to AMD, with a clear visual and anatomical benefit seen in the early follow-up period.

Abdominal wall endometriosis: a case report.

Abdominal wall endometriosis has an incidence of 0.3-1% of extrapelvic disease. Α 48-year-old female appeared in the emergency department with cellulitis in a lower midline incision. She had an endometrioma of the anterior abdominal wall removed 2 years ago. After 5 months, she underwent an open repair of an incisional hernia with a propylene mesh, which was unfortunately infected and removed 1 month later. Finally, in July 2019, she had her incisional hernia repaired with a biological mesh. Imaging modalities revealed a large mass below the umbilicus. Mass was punctured under ultrasound guidance. Cytology reported the recurrence of endometriosis. Pain and abdominal mass associating with menses were the two most typical symptoms. Wide local excision of the mass with at least 1 cm negative margins is the preferred treatment. Surgeons should maintain a high suspicion of the disease in reproductive women with circular pain, palpable abdominal mass and history of uterine-relating surgery.

Models of communication and control for brain networks: distinctions, convergence, and future outlook.

Recent advances in computational models of signal propagation and routing in the human brain have underscored the critical role of white-matter structure. A complementary approach has utilized the framework of network control theory to better understand how white matter constrains the manner in which a region or set of regions can direct or control the activity of other regions. Despite the potential for both of these approaches to enhance our understanding of the role of network structure in brain function, little work has sought to understand the relations between them. Here, we seek to explicitly bridge computational models of communication and principles of network control in a conceptual review of the current literature. By drawing comparisons between communication and control models in terms of the level of abstraction, the dynamical complexity, the dependence on network attributes, and the interplay of multiple spatiotemporal scales, we highlight the convergence of and distinctions between the two frameworks. Based on the understanding of the intertwined nature of communication and control in human brain networks, this work provides an integrative perspective for the field and outlines exciting directions for future work.

Hybrid Porous Microparticles Based on a Single Organosilica Cyclophosphazene Precursor.

Porous organosilica microparticles consisting of silane-derived cyclophosphazene bridges were synthesized by a surfactant-mediated sol-gel process. Starting from the substitution of hexachlorocyclotriphosphazene with allylamine, two different precursors were obtained by anchoring three or six alkoxysilane units, via a thiol-ene photoaddition reaction. In both cases, spherical, microparticles (size average of ca. 1000 nm) with large pores were obtained, confirmed by both, scanning and transmission electron microscopy. Particles synthesized using the partially functionalized precursor containing free vinyl groups were further functionalized with a thiol-containing molecule. While most other reported mesoporous organosilica particles are essentially hybrids with tetraethyl orthosilicate (TEOS), a unique feature of these particles is that structural control is achieved by exclusively using organosilane precursors. This allows an increase in the proportion of the co-components and could springboard these novel phosphorus-containing organosilica microparticles for different areas of technology.

Individualized Ophthalmic Exoplants by Means of Reverse Engineering and 3D Printing Technologies for Treating High Myopia Complications with Macular Buckles.

Myopic macular foveoschisis maculopathy is an eye disease that is treated, in most cases, with surgical intervention, in which a macular buckle is applied to restore eye anatomy and functionality. A macular buckle is a type of exoplant that comes in various designs and sizes. Often, they are difficult to apply or they do not fit properly in the eye geometry since they have a generic form. In this work, the effort to develop the most suitable tailor-made macular buckle for each individual patient for treating myopic traction maculopathy is studied. Pattern recognition techniques are applied to the patient's Computed Tomography (CT) data to develop the exact 3D geometry of the eye. Using this 3D geometry, the trajectory of the buckle is fitted and the buckle is formed, which is then 3D-printed with biocompatible polymer materials. It is expected that the power of technology will be used to activate the most precise approach for each individual patient. Considering the possible complications and technical difficulties of other surgical methods, the customized macular buckle is an appropriate, easy-to-use, and most precise piece of medical equipment for the treatment of myopic traction maculopathy.

Reinfection with SARS-CoV-2 and Failure of Humoral Immunity: a case report.

Recovery from COVID-19 is associated with production of anti-SARS-CoV-2 antibodies, but it is uncertain whether these confer immunity. We describe viral RNA shedding duration in hospitalized patients and identify patients with recurrent shedding. We sequenced viruses from two distinct episodes of symptomatic COVID-19 separated by 144 days in a single patient, to conclusively describe reinfection with a new strain harboring the spike variant D614G. With antibody and B cell analytics, we show correlates of adaptive immunity, including a differential response to D614G. Finally, we discuss implications for vaccine programs and begin to define benchmarks for protection against reinfection from SARS-CoV-2.

Outcomes of Arthroscopic All-Inside Repair Versus Observation in Older Patients With Meniscus Root Tears.

BACKGROUND: Meniscus root tears lead to de-tensioning of the meniscus, increased contact forces, and cartilage damage. Management of older patients with root tears is controversial and the efficacy of different treatment options is unclear. PURPOSE: To compare the clinical outcomes of patients with moderate knee osteoarthritis who underwent an all-inside meniscus root repair technique versus nonoperative management for either medial or lateral meniscus root tears. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Patients with a diagnosed posterior meniscus root tear who underwent arthroscopic repair (AR: 30 knees) or nonoperative treatment with observation (O: 18 knees) were followed for a minimum of 2 years (mean follow-up, 4.4 years). The arthroscopic repair included all-inside sutures to reduce the root back to its remnant (reduction sutures), thereby re-tensioning the meniscus, and 1 mattress suture to strengthen the repair by reapproximating the construct to the posterior capsule. The data collected included the Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm, Tegner, and Veterans RAND 12-Item Health Survey (VR-12) Physical Component Summary (PCS) and Mental Component Summary (MCS) scores and conversion to total knee arthroplasty (TKA). RESULTS: Medial meniscus root tears comprised 80.0% of the AR group and 77.8% of the O group. The average Kellgren-Lawrence grade was 2 in both groups. The baseline scores for the KOOS Symptoms subscale were lower for AR (50.2 ± 19.3) than for O (66.5 ± 16.1) (P = .003), as were the KOOS Knee-Related Quality of Life scores (AR, 26.7 ± 16.1; O, 39.6 ± 22.1) (P = .046). No differences were found between groups for the absolute values at follow-up except that follow-up Tegner scores were lower in the O group than in the AR group (P = .004). Significant improvements were seen in the AR group from baseline to ultimate follow-up in average KOOS subscale scores (P < .001), Lysholm scores (P < .001), Tegner scores (P = .0002), and VR-12 PCS scores (P < .001), whereas the O group had a significant improvement only in average KOOS Pain (P = .003), KOOS Function in Daily Living (P = .006), and VR-12 PCS (P = .038) scores. Compared with the O group, the AR group had a significantly larger improvement from baseline to follow-up in average KOOS Pain (P = .009), KOOS Symptoms (P = .029), and Lysholm scores (P = .016). During follow-up, 3.3% of the AR group underwent a TKA compared with 33.3% of the O group (P = .008). The hazard ratio of TKA conversion was 93.2% lower for the AR group compared with the O group (P = .013). CONCLUSION: All-inside medial or lateral meniscus root repair showed improved functional outcomes and decreased TKA conversion rates compared with nonoperative treatment and may be considered as a treatment option for the management of meniscus root tears in older patients with moderate osteoarthritis.