Concurrent analysis of genome and transcriptome in one single cell.

Thus far, multiple techniques for single cell analysis have been developed, yet we lack a relatively simple tool to assess DNA and RNA from the same cell at whole-transcriptome and whole-genome depths. Here we present an updated method for physical separation of cytoplasmic RNA from the nuclei, which allows for simultaneous studies of DNA and RNA from the same single cell. The method consists of three steps-(1) immobilization of a single cell on solid substrate, (2) hypotonic lysis of immobilized single cell, and (3) separation of cytosol containing aqueous phase and immobilized nucleus. We found that DNA and RNA extracted from single cell using our approach is suitable for downstream sequencing-based applications. We demonstrated that the coverage of transcriptome and genome sequencing data obtained after DNA/RNA separation is similar to that observed without separation. We also showed that the separation procedure does not create any noticeable bias in observed mutational load or mutation spectra. Thus, our method can serve as a tool for simultaneous complex analysis of the genome and transcriptome, providing necessary information on the relationship between somatic mutations and the regulation of gene expression.

Clinical and Neuropathological Correlates of Substance Use in American Football Players.

Background: Chronic traumatic encephalopathy (CTE) is a neurodegenerative tauopathy more frequently found in deceased former football players. CTE has heterogeneous clinical presentations with multifactorial causes. Previous literature has shown substance use (alcohol/drug) can contribute to Alzheimer's disease and related tauopathies pathologically and clinically. Objective: To examine the association between substance use and clinical and neuropathological endpoints of CTE. Methods: Our sample included 429 deceased male football players. CTE was neuropathologically diagnosed. Informant interviews assessed features of substance use and history of treatment for substance use to define indicators: history of substance use treatment (yes vs no, primary variable), alcohol severity, and drug severity. Outcomes included scales that were completed by informants to assess cognition (Cognitive Difficulties Scale, BRIEF-A Metacognition Index), mood (Geriatric Depression Scale-15), behavioral regulation (BRIEF-A Behavioral Regulation Index, Barratt Impulsiveness Scale-11), functional ability (Functional Activities Questionnaire), as well as CTE status and cumulative p-tau burden. Regression models tested associations between substance use indicators and outcomes. Results: Of the 429 football players (mean age = 62.07), 313 (73%) had autopsy confirmed CTE and 100 (23%) had substance use treatment history. Substance use treatment and alcohol/drug severity were associated with measures of behavioral regulation (FDR-p-values<0.05, ΔR2 = 0.04-0.18) and depression (FDR-p-values<0.05, ΔR2 = 0.02-0.05). Substance use indicators had minimal associations with cognitive scales, whereas p-tau burden was associated with all cognitive scales (p-values <0.05). Substance use treatment had no associations with neuropathological endpoints (FDR-p-values>0.05). Conclusions: Among deceased football players, substance use was common and associated with clinical symptoms.

Precursor central memory versus effector cell fate and naïve CD4+ T cell heterogeneity.

Upon antigenic stimulation, naïve CD4+ T cells can give rise to phenotypically distinct effector T helper cells and long-lived memory T cells. We computationally reconstructed the in vivo trajectory of CD4+ T cell differentiation during a type I inflammatory immune response and identified two distinct differentiation paths for effector and precursor central memory T cells arising directly from naïve CD4+ T cells. Unexpectedly, our studies revealed heterogeneity among naïve CD4+ T cells, which are typically considered homogeneous save for their diverse T cell receptor usage. Specifically, a previously unappreciated population of naïve CD4+ T cells sensing environmental type I IFN exhibited distinct activation thresholds, suggesting that naïve CD4+ T cell differentiation potential may be influenced by environmental cues. This population was expanded in human viral infection and type I IFN response-lined autoimmunity. Understanding the relevance of naïve T cell heterogeneity to beneficial and maladaptive T cell responses may have therapeutic implications for adoptive T cell therapies in cancer immunotherapy and vaccination.

Lower Trapezius Tendon Transfer for Restoration of External Rotation in Brachial Plexus Birth Injury.

OBJECTIVE: Patients with brachial plexus birth injuries (BPBIs) are at risk for limitations in shoulder external rotation. The role of lower trapezius tendon transfer to restore shoulder external rotation in this population has not been well characterized. This study aimed to evaluate the utility of lower trapezius tendon transfer for restoration of external rotation in a subset of pediatric patients. METHODS: Seventeen pediatric patients with BPBI were treated with lower trapezius tendon transfer to restore external rotation of the shoulder. Mean age at surgery was 8 years, and 11 were female. Six patients had prior shoulder surgery to restore external rotation, while 1 had prior nerve surgery to restore shoulder function. Range of motion before lower trapezius transfer and at latest follow-up was obtained. Mean follow-up was 36 months. RESULTS: Active forward flexion did not significantly change from preoperative to final follow-up (mean, 147° and 141°; P = 0.46). External rotation in adduction significantly changed from preoperative to final follow-up (mean, 4° and 26°; P < 0.001). External rotation in abduction significantly changed from preoperative to final follow-up (mean, 75° and 84°; P = 0.048). Six patients (35%) had subsequent surgeries at average 17 months from this procedure. Significant univariate associations with subsequent surgery included certain intraoperative concomitant procedures-coracoid osteotomy/excision (P = 0.02) and biceps tenodesis (P = 0.04)-while bony glenoid augmentation/reconstruction trended toward significant association (P = 0.05). CONCLUSIONS: Lower trapezius tendon transfer for BPBI showed a statistically significant but unlikely clinically meaningful improvement in external rotation with a high rate of reoperation.

Biomarker discovery in progressive supranuclear palsy from human cerebrospinal fluid.

BACKGROUND: Progressive supranuclear palsy (PSP) is a neurodegenerative disorder often misdiagnosed as Parkinson's Disease (PD) due to shared symptoms. PSP is characterized by the accumulation of tau protein in specific brain regions, leading to loss of balance, gaze impairment, and dementia. Diagnosing PSP is challenging, and there is a significant demand for reliable biomarkers. Existing biomarkers, including tau protein and neurofilament light chain (NfL) levels in cerebrospinal fluid (CSF), show inconsistencies in distinguishing PSP from other neurodegenerative disorders. Therefore, the development of new biomarkers for PSP is imperative. METHODS: We conducted an extensive proteome analysis of CSF samples from 40 PSP patients, 40 PD patients, and 40 healthy controls (HC) using tandem mass tag-based quantification. Mass spectrometry analysis of 120 CSF samples was performed across 13 batches of 11-plex TMT experiments, with data normalization to reduce batch effects. Pathway, interactome, cell-type-specific enrichment, and bootstrap receiver operating characteristic analyses were performed to identify key candidate biomarkers. RESULTS: We identified a total of 3,653 unique proteins. Our analysis revealed 190, 152, and 247 differentially expressed proteins in comparisons of PSP vs. HC, PSP vs. PD, and PSP vs. both PD and HC, respectively. Gene set enrichment and interactome analysis of the differentially expressed proteins in PSP CSF showed their involvement in cell adhesion, cholesterol metabolism, and glycan biosynthesis. Cell-type enrichment analysis indicated a predominance of neuronally-derived proteins among the differentially expressed proteins. The potential biomarker classification performance demonstrated that ATP6AP2 (reduced in PSP) had the highest AUC (0.922), followed by NEFM, EFEMP2, LAMP2, CHST12, FAT2, B4GALT1, LCAT, CBLN3, FSTL5, ATP6AP1, and GGH. CONCLUSION: Biomarker candidate proteins ATP6AP2, NEFM, and CHI3L1 were identified as key differentiators of PSP from the other groups. This study represents the first large-scale use of mass spectrometry-based proteome analysis to identify cerebrospinal fluid (CSF) biomarkers specific to progressive supranuclear palsy (PSP) that can differentiate it from Parkinson's disease (PD) and healthy controls. Our findings lay a crucial foundation for the development and validation of reliable biomarkers, which will enhance diagnostic accuracy and facilitate early detection of PSP.

Development of pharmacy-based best practices to support safer use and management of prescription opioids based on an e-Delphi methodology.

BACKGROUND: Opioid utilization and related harm have increased in recent decades, notably in Australia, the United States, Canada, and some European countries. For people who are prescribed opioids, pharmacies offer an accessible, regular point-of-contact, providing a unique opportunity to address opioid prescription drugs risks. OBJECTIVE: This project aimed to develop consensus-based, best practice statements for improving the safer use of prescription opioids through community pharmacy settings. METHODS: The e-Delphi technique is used to obtain consensus from experts about issues where conclusive evidence is lacking, using multiple rounds of online participation. The investigator group identified an international group of potential participants with relevant expertise who were invited to the study, and asked to identify other experts for invitation. The e-Delphi process comprised three online rounds, involving (1) statement idea generation, (2) developing statement consensus, and (3) confirming and ranking statements. RESULTS: A diverse group of 42 experts (76 % female, 6 countries) participated, comprising pharmacists (n = 24, 57 %), medical doctors of differing specialties (n = 12, 29 %), and/or researchers (n = 28, 67 %), with a mean of 15 years' professional experience (SD = 8.08). Eighty-five statements were initially developed in Round 1, and 78 were supported with amendments, with suggestions to merge and remove items in Round 2, resulting in 72 final statements which were all endorsed in Round 3. Items spanned seven themes: education, monitoring outcomes and risk, deprescribing and pain management, overdose education and naloxone, opioid agonist treatment, staff education, and overarching practices. Preferred terminology was determined in Round 2 and confirmed in Round 3. CONCLUSIONS: Community pharmacies offer a unique opportunity to support the safer use of prescription opioids. These 72 best practice statements provide practical guidance on specific practices that pharmacists can undertake to support patients' safer use of prescription opioids and prevent or reduce harms from prescribed opioid use.

Quantitative label-free digital holographic imaging of cardiomyocyte optical volume, nucleation, and cell division.

Cardiac regeneration in newborn rodents depends on the ability of pre-existing cardiomyocytes to proliferate and divide. This capacity is lost within the first week of postnatal development when these cells rapidly switch from hyperplasia to hypertrophy, withdraw from the cell cycle, become binucleated, and increase in size. How these dynamic changes in cell size and nucleation impact cardiomyocyte proliferative potential is not well understood. In this study, we innovate the application of a commercially available digital holographic imaging microscope, the Holomonitor M4, to evaluate the proliferative responses of mononucleated and binucleated cardiomyocytes after CHIR99021 treatment, a model proliferative stimulus. This system enables long-term label-free quantitative tracking of primary cardiomyocyte dynamics in real-time with single-cell resolution. Our results confirm that chemical inhibition of glycogen synthase kinase 3 with CHIR99021 promotes complete cell division of both mononucleated and binucleated cardiomyocytes with high frequency. Quantitative tracking of cardiomyocyte volume dynamics during these proliferative events revealed that both mononucleated and binucleated cardiomyocytes reach a similar size-increase threshold prior to attempted cell division. Binucleated cardiomyocytes attempt to divide with lower frequency than mononucleated cardiomyocytes, which may be associated with inadequate increases in cell size. By defining the interrelationship between cardiomyocyte size, nucleation, and cell cycle control, we may better understand the cellular mechanisms that drive the loss of mammalian cardiac regenerative capacity after birth.

Design of a long-lived Mo2C-MoO2@GC-N electrocatalyst by the ambient DC arc plasma for the hydrogen evolution reaction.

A crucial challenge in hydrogen production through electrolysis is developing inexpensive, earth-abundant, and highly efficient Pt-free electrocatalysts for the hydrogen evolution reaction (HER). Molybdenum carbide is ideal for this application because of its special electrical structure, low cost, and advantageous characteristics. Herein, the long-lived electrocatalysts for HER have been synthesized via the direct current (DC) arc discharge plasma method under ambient air conditions, and the relationship between the properties of materials and catalytic characteristics has been established. The samples differed in the ratio of molybdenum, graphite, and melamine. The sample with the highest proportion of melamine in the initial mixture has Mo2C-MoO2 heterointerfaces, which demonstrates the highest and most stable electrocatalytic activity with the overpotential of 148 mV at 10 mA·cm-2 and Tafel slope of 63 mV·dec-1 in alkaline electrolyte. Meanwhile, the electrodes demonstrated long-lived electrochemical durability for two weeks and investigated the features of forming a stable system for HER.

A call for compassionate opioid overdose response.

High dose and long-acting opioid overdose reversal drugs can precipitate withdrawal in people who are opioid dependent. Products recently brought to market for community use in the United States (US) have drawn international concern because of their increased risk of withdrawal. At the March 18-19, 2024, Compassionate Overdose Response Summit & Naloxone Dosing Meeting, a panel of harm reduction experts issued the following call to action: 1) people who use drugs should be directly involved in decisions regarding the research, development, selection, and distribution of opioid overdose reversal products; 2) regulatory agencies and pharmaceutical manufacturers should carefully consider and communicate the risk and duration of withdrawal associated with higher dose and longer-acting opioid antagonists; 3) take-home naloxone kits should include at least two doses of an intramuscular (IM) product containing 0.4 mg or an intranasal (IN) product containing ≤4 mg; 4) At this time, high dose and long-acting opioid antagonists have no use in acute opioid overdose response; and, 5) overdose response educational materials, instructions on overdose response, and training should emphasize the restoration of breathing, avoiding withdrawal, and compassionate post-overdose support and care. High dose and long-acting opioid overdose reversal drugs were approved without testing for withdrawal and are often aggressively marketed despite decades of evidence from naloxone distribution programs worldwide that the ideal dose of naloxone is one that restores breathing without inducing withdrawal. Government agencies should direct resources to harm reduction programs to make standard dose take-home naloxone products widely available among people who use drugs. Lay bystanders, people who use drugs, their families, and professional first responders can learn and apply a compassionate approach to opioid overdose response.

Metroticket approach in a retrospective cohort study to predict overall survival after surgical resection for intermediate stage hepatocellular carcinoma.

BACKGROUND: Surgical resection is a curative therapy for early-stage hepatocellular carcinoma (HCC) patients meeting the Milan criteria as well as a widely used therapy in intermediate-stage HCC. However, intermediate-stage HCC encompasses a wide spectrum of disease and there is a lack of good predictive models for the long-term clinical outcome of HCC patients currently. Here, we adopt Mazzaferro's Metroticket 2.0 to create a robust survival prediction model for intermediate-stage HCC patients undergoing surgical resection. Our algorithm considers age, AFP levels, ALBI score, and nodule size/number to generate survival estimates in an accessible graph format. Importantly, our model surpasses the American Joint Committee on Cancer staging model and was validated with independent US patient data. METHODS: We conducted a retrospective analysis of OS and RFS in early- and intermediate-stage HCC patients treated with liver resection, including a training cohort in Singapore and a validation cohort in North Carolina, USA. RESULTS: We recorded 278 deaths (35.0%) and 428 patients (53.9%) in the first 5-years after surgical resection; higher ALBI score, higher lnAFP, more advanced age and higher tumour burden index were identified as significant parameters. The overall predictive capability of our model, with the inclusion of AFP, is reflected with a UNO's C-statistic of 0.655, which is 1.11 times better than the 0.5895 C-statistic of the 8th AJCC TNM Staging model. CONCLUSIONS: Our modified Metroticket model allows for more granular and better-informed prognostication. This will help surgeons and patients make accurate comparisons between the clinical outcomes of surgical resection and other non-surgical treatments.

Regulatory T cells in the context: deciphering the dynamic interplay with the tissue environment.

The delicate balance between protective immunity against pathogens and the prevention of autoimmunity requires finely tuned generation and function of regulatory CD4+ T (Treg) cells. Here, we review recent progress in the understanding of a complex set of cues, which converge on Treg cells in lymphoid and nonlymphoid organs and in tumors and how these cues modulate Treg functions. We highlight the versatility of Treg cells underlying their ability to dynamically adapt to local microenvironments and perform a wide range of functions that extend beyond the archetypal role of Treg cells in moderating adverse effects of immune response-associated inflammation and in suppressing autoimmunity.

Development of non-sedating benzodiazepines with in vivo antischistosomal activity.

The neglected tropical disease schistosomiasis infects over 200 million people worldwide and is treated with just one broad-spectrum antiparasitic drug (praziquantel). Alternative drugs are needed in the event of emerging praziquantel resistance or treatment failure. One promising lead that has shown efficacy in animal models and a human clinical trial is the benzodiazepine meclonazepam, discovered by Roche in the 1970s. Meclonazepam was not brought to market because of dose-limiting sedative side effects. However, the human target of meclonazepam that causes sedation (GABAARs) is not orthologous to the parasite targets that cause worm death. Therefore, we were interested in whether the structure of meclonazepam could be modified to produce antiparasitic benzodiazepines that do not cause host sedation. We synthesized 18 meclonazepam derivatives with modifications at different positions on the benzodiazepine ring system and tested them for in vitro antiparasitic activity. This identified five compounds that progressed to in vivo screening in a murine model, two of which cured parasite infections with comparable potency to meclonazepam. When these two compounds were administered to mice that were run on the rotarod test, both were less sedating than meclonazepam. These findings demonstrate the proof of concept that meclonazepam analogs can be designed with an improved therapeutic index and point to the C3 position of the benzodiazepine ring system as a logical site for further structure-activity exploration to further optimize this chemical series.

Broad-spectrum antibiotics disrupt homeostatic efferocytosis.

The clearance of apoptotic cells, termed efferocytosis, is essential for tissue homeostasis and prevention of autoimmunity1. Although past studies have elucidated local molecular signals that regulate homeostatic efferocytosis in a tissue2,3, whether signals arising distally also regulate homeostatic efferocytosis remains elusive. Here, we show that large peritoneal macrophage (LPM) display impairs efferocytosis in broad-spectrum antibiotics (ABX)-treated, vancomycin-treated and germ-free mice in vivo, all of which have a depleted gut microbiota. Mechanistically, the microbiota-derived short-chain fatty acid butyrate directly boosts efferocytosis efficiency and capacity in mouse and human macrophages, and rescues ABX-induced LPM efferocytosis defects in vivo. Bulk messenger RNA sequencing of butyrate-treated macrophages in vitro and single-cell messenger RNA sequencing of LPMs isolated from ABX-treated and butyrate-rescued mice reveals regulation of efferocytosis-supportive transcriptional programmes. Specifically, we find that the efferocytosis receptor T cell immunoglobulin and mucin domain containing 4 (TIM-4, Timd4) is downregulated in LPMs of ABX-treated mice but rescued by oral butyrate. We show that TIM-4 is required for the butyrate-induced enhancement of LPM efferocytosis capacity and that LPM efferocytosis is impaired beyond withdrawal of ABX. ABX-treated mice exhibit significantly worse disease in a mouse model of lupus. Our results demonstrate that homeostatic efferocytosis relies on distal metabolic signals and suggest that defective homeostatic efferocytosis may explain the link between ABX use and inflammatory disease4-7.

Targeting multiple hallmarks of mammalian aging with combinations of interventions.

Aging is currently viewed as a result of multiple biological processes that manifest themselves independently, reinforce each other and in their totality lead to the aged phenotype. Genetic and pharmaceutical approaches targeting specific underlying causes of aging have been used to extend the lifespan and healthspan of model organisms ranging from yeast to mammals. However, most interventions display only a modest benefit. This outcome is to be expected if we consider that even if one aging process is successfully treated, other aging pathways may remain intact. Hence solving the problem of aging may require targeting not one but many of its underlying causes at once. Here we review the challenges and successes of combination therapies aimed at increasing the lifespan of mammals and propose novel directions for their development. We conclude that both additive and synergistic effects on mammalian lifespan can be achieved by combining interventions that target the same or different hallmarks of aging. However, the number of studies in which multiple hallmarks were targeted simultaneously is surprisingly limited. We argue that this approach is as promising as it is understudied.

The use of acupuncture for addressing neurological and neuropsychiatric symptoms in patients with long COVID: a systematic review and meta-analysis.

Importance: Acupuncture has been used to treat neurological and neuropsychiatric symptoms in China and other parts of the world. These symptoms, such as fatigue, headache, cognitive impairment, anxiety, depression, and insomnia, are common in people experiencing long COVID. Objective: This study aims to explore the feasibility of acupuncture in the treatment of neurological and neuropsychiatric symptoms in long COVID patients. Data Sources: A systematic search was conducted in four English and four Chinese databases from inception to 23 June 2023. Literature selection and data extraction were conducted by two pairs of independent reviewers. Study Selection: Randomized controlled trials (RCTs) that explored the effect of acupuncture on fatigue, depression, anxiety, cognitive abnormalities, headache, and insomnia were included. Data Extraction and Synthesis: RCTs that explored the effect of acupuncture on fatigue, depression, anxiety, cognitive abnormalities, headache, and insomnia were included. A meta-analysis was performed using R software. Heterogeneity was measured using I2. Subgroup analyses were performed focusing on the duration of treatment and acupuncture modalities. The systematic review protocol was registered on PROSPERO (registration number: CRD42022354940). Main outcomes and measures: Widely adopted clinical outcome scales included the Fatigue Scale for assessing fatigue, the Hamilton Depression Rating Scale for evaluating depression, the Mini-Mental State Examination for assessing cognitive impairment, the Visual Analog Scale for headache severity, and the Pittsburgh Sleep Quality Index for measuring insomnia. Results: A total of 110 RCTs were included in the systematic review and meta-analysis. Overall, acupuncture was found to improve the scores of the Fatigue Scale (vs. medication: mean differences (MD): -2.27, P < 0.01; vs. sham acupuncture: MD: -3.36, P < 0.01), the Hamilton Depression Rating Scale (vs. medication: MD: -1.62, 95%, P < 0.01; vs. sham acupuncture: MD: -9.47, P < 0.01), the Mini-Mental State Examination (vs. medication: MD: 1.15, P < 0.01; vs. sham acupuncture: MD: 1.20, P < 0.01), the Visual Analog Scale (vs. medication: MD: -1.05, P < 0.01; vs. waitlist: MD: -0.48, P=0.04), and the Pittsburgh Sleep Quality Index (vs. medication: MD: -2.33, P < 0.01; vs. sham acupuncture: MD: -4.19, P < 0.01). Conclusion and relevance: This systematic review suggested acupuncture as a potentially beneficial approach for the treatment of neurological and neuropsychiatric symptoms, as assessed using clinical scales, and it may have applicability in long COVID patients. Further well-designed clinical studies specifically targeting long COVID patients are needed to validate the role of acupuncture in alleviating long COVID symptoms. Systematic Review Registration: PROSPERO, identifier [CRD42022354940].

A potent, broadly neutralizing human monoclonal antibody that efficiently protects hACE2-transgenic mice from infection with the Wuhan, BA.5, and XBB.1.5 SARS-CoV-2 variants.

The COVID-19 pandemic has uncovered the high genetic variability of the SARS-CoV-2 virus and its ability to evade the immune responses that were induced by earlier viral variants. Only a few monoclonal antibodies that have been reported to date are capable of neutralizing a broad spectrum of SARS-CoV-2 variants. Here, we report the isolation of a new broadly neutralizing human monoclonal antibody, iC1. The antibody was identified through sorting the SARS-CoV-1 RBD-stained individual B cells that were isolated from the blood of a vaccinated donor following a breakthrough infection. In vitro, iC1 potently neutralizes pseudoviruses expressing a wide range of SARS-CoV-2 Spike variants, including those of the XBB sublineage. In an hACE2-transgenic mouse model, iC1 provided effective protection against the Wuhan strain of the virus as well as the BA.5 and XBB.1.5 variants. Therefore, iC1 can be considered as a potential component of the broadly neutralizing antibody cocktails resisting the SARS-CoV-2 mutation escape.

Hirayama Disease: Surgical Restoration of Hand Function.

PURPOSE: Hirayama disease (HD) is a rare, nonfamilial, self-limiting, progressive lower cervical myelopathy, resulting in debilitating distal upper-extremity motor deficits, mimicking high ulnar neuropathy, lower trunk brachial plexopathy, or C8-T1 radiculopathy. Although most literature focuses on pathophysiology and prevention of disease progression, there remains limited discussion regarding treatment to improve upper-extremity function in patients with stable disease. The upper-extremity manifestations of HD are reviewed along with surgical options for restoring hand function. METHODS: A retrospective review of patients with HD who underwent reconstruction to improve hand function was undertaken. Demographic data, preoperative electrodiagnostic and electromyographic, and physical examination findings were collected. Outcome data involved postoperative grip, pinch, and functional assessment documented on clinical visits. Qualitative descriptions of the surgical techniques are described. RESULTS: Among six patients identified, four met the inclusion criteria and underwent tendon transfers and selected joint arthrodeses. All patients were diagnosed as teenagers, were right hand-dominant, and three were male. Unilateral symptoms were present in one patient and were bilateral in the rest. All patients were treated with tendon transfers for thumb opposition, grasp, anticlaw, and thumb interphalangeal joint arthrodesis. All patients had postoperative grip strength improvement. The average follow-up was 3.2 years. CONCLUSIONS: Hirayama disease is a rare disease often managed by spine surgeons and neurologists who may be unaware of options for restoring hand function deficits. Technical strategies and outcomes of improving hand function in HD have not been adequately described. Surgical options to improve hand function are tailored to the deficits and include tendon transfers, select joint arthrodeses, and/or tenodeses. Risk of disease progression and expectations following hand reconstruction must be managed carefully. TYPE OF STUDY LEVEL OF EVIDENCE: Therapeutic V.

Preoperative Evaluation for Free Functional Muscle Transfer in Upper Extremity Amyoplasia: A Multicenter Report of 3 Cases.

CASE: A multicenter series of 3 patients with amyoplasia of the upper extremity were indicated for gracilis free functional muscle transfer (FFMT) to restore elbow flexion and found to have an absent gracilis. A final case is discussed detailing standardized evaluation with ultrasound to confirm gracilis before surgical intervention. CONCLUSION: In amyoplasia, the gracilis muscle may be absent or have fatty infiltration, making this donor muscle inadequate. Preoperative ultrasound to determine the presence of the gracilis is noninvasive and recommended in patients with amyoplasia of the upper extremity being considered for FFMT.

A novel kinetic model to demonstrate the independent effects of ATP and ADP/Pi concentrations on sarcomere function.

Understanding muscle contraction mechanisms is a standing challenge, and one of the approaches has been to create models of the sarcomere-the basic contractile unit of striated muscle. While these models have been successful in elucidating many aspects of muscle contraction, they fall short in explaining the energetics of functional phenomena, such as rigor, and in particular, their dependence on the concentrations of the biomolecules involved in the cross-bridge cycle. Our hypothesis posits that the stochastic time delay between ATP adsorption and ADP/Pi release in the cross-bridge cycle necessitates a modeling approach where the rates of these two reaction steps are controlled by two independent parts of the total free energy change of the hydrolysis reaction. To test this hypothesis, we built a two-filament, stochastic-mechanical half-sarcomere model that separates the energetic roles of ATP and ADP/Pi in the cross-bridge cycle's free energy landscape. Our results clearly demonstrate that there is a nontrivial dependence of the cross-bridge cycle's kinetics on the independent concentrations of ATP, ADP, and Pi. The simplicity of the proposed model allows for analytical solutions of the more basic systems, which provide novel insight into the dominant mechanisms driving some of the experimentally observed contractile phenomena.

Design and Development of a Powered Myoelectric Elbow Orthosis for Neuromuscular Injuries.

INTRODUCTION: Recovering from neuromuscular injuries or conditions can be a challenging journey that involves complex surgeries and extensive physical rehabilitation. During this process, individuals often rely on orthotic devices to support and enable movement of the affected limb. However, users have criticized current commercially available powered orthotic devices for their bulky and heavy design. To address these limitations, we developed a novel powered myoelectric elbow orthosis. MATERIALS AND METHODS: The orthosis incorporates 3 mechanisms: a solenoid brake, a Bowden cable-powered constant torque elbow mechanism, and an extension limiter. The device controller and battery are in a backpack to reduce the weight on the affected arm. We performed extensive calculations and testing to ensure that the orthosis could withstand at least 15 Nm of elbow torque. We developed a custom software effectively control the orthosis, enhancing its usability and functionality. A certified orthotist fitted a subject who had undergone a gracilis free functioning muscle transfer surgery with the device. We studied the subject under Mayo clinic IRB no. 20-006849 and obtained objective measurements to assess the orthosis's impact on upper extremity functionality during daily activities. RESULTS: The results are promising since the orthosis significantly improved elbow flexion range of motion by 40° and reduced compensatory movements at the shoulder (humerothoracic joint) by 50°. Additionally, the subject was able to perform tasks which were not possible before, such as carrying a basket with weights, highlighting the enhanced functionality provided by the orthosis. CONCLUSION: In brief, by addressing the limitations of existing devices, this novel powered myoelectric elbow orthosis offers individuals with neuromuscular injuries/conditions improved quality of life. Further research will expand the patient population and control mechanisms.