Citations

The proportion of the different types of fibers in a given skeletal muscle contributes to its overall metabolic and functional characteristics. Greater proportion of type I muscle fibers is associated with favorable oxidative metabolism and function of the muscle. Humans with obesity have a lower proportion of type I muscle fibers. We discuss how lower proportion of type I fibers in skeletal muscle of humans with obesity may explain metabolic and functional abnormalities reported in these individuals. These include lower muscle glucose disposal rate, mitochondrial content, protein synthesis, and quality/contractile function, as well as increased risk for heart disease, lower levels of physical activity, and propensity for weight gain/resistance to weight loss. We delineate future research directions and the need to examine hybrid muscle fiber populations, which are indicative of a transitory state of fiber phenotype within skeletal muscle. We also describe methodologies for precisely characterizing muscle fibers and gene expression at the single muscle fiber level to enhance our understanding of the regulation of muscle fiber phenotype in obesity. By contextualizing research in the field of muscle fiber type in obesity, we lay a foundation for future advancements and pave the way for translation of this knowledge to address impaired metabolism and function in obesity.

AbstractThis report highlights information and outcomes from the November 2022 ASC/IAC joint Cytology Education Symposium, an annual conference organized by the Cytology Programs Review Committee. The manuscript provides information on shared educational opportunities and practices for cytology students and other learners in anatomic pathology, discusses recruitment strategies for schools of cytology, conveys teaching resources, introduces perspectives on virtual microscopy and online learning, and transmits information about wellness of students in schools of cytology.

AbstractBackgroundUsing the pencil beam raster scanning method employed at most carbon beam treatment facilities, spots can be moved without interrupting the beam, allowing for the delivery of a dose between spots (move dose). This technique is also known as Dose‐Driven‐Continuous‐Scanning (DDCS). To minimize its impact on HIMAK patient dosimetry, there's an upper limit to the move dose. Spots within a layer are grouped into sets, or “break points,” allowing continuous irradiation. The beam is turned off when transitioning between sets or at the end of a treatment layer or spill. The control system beam‐off is accomplished by turning off the RF Knockout (RFKO) extraction and after a brief delay the High Speed Steering Magnet (HSST) redirects the beam transport away from isocenter to a beam dump.PurposeThe influence of the move dose and beam on/off control on the dose distribution and irradiation time was evaluated by measurements never before reported and modelled for Hitachi Carbon DDCS.MethodWe conducted fixed‐point and scanning irradiation experiments at three different energies, both with and without breakpoints. For fixed‐point irradiation, we utilized a 2D array detector and an oscilloscope to measure beam intensity over time. The oscilloscope data enabled us to confirm beam‐off and beam‐on timing due to breakpoints, as well as the relative timing of the RFKO signal, HSST signal, and dose monitor (DM) signals. From these measurements, we analyzed and modelled the temporal characteristics of the beam intensity. We also developed a model for the spot shape and amplitude at isocenter occurring after the beam‐off signal which we called flap dose and its dependence on beam intensity. In the case of scanning irradiation, we measured move doses using the 2D array detector and compared these measurements with our model.ResultWe observed that the most dominant time variation of the beam intensity was at 1 kHz and its harmonic frequencies. Our findings revealed that the derived beam intensity cannot reach the preset beam intensity when each spot belongs to different breakpoints. The beam‐off time due to breakpoints was approximately 100 ms, while the beam rise time and fall time (tdecay) were remarkably fast, about 10 ms and 0.2 ms, respectively. Moreover, we measured the time lag (tdelay) of approximately 0.2 ms between the RFKO and HSST signals. Since tdelay ≈ tdecay at HIMAK then the HSST is activated after the residual beam intensity, resulting in essentially zero flap dose at isocenter from the HSST. Our measurements of the move dose demonstrated excellent agreement with the modelled move dose.ConclusionWe conducted the first move dose measurement for a Hitachi Carbon synchrotron, and our findings, considering beam on/off control details, indicate that Hitachi's carbon synchrotron provides a stable beam at HIMAK. Our work suggests that measuring both move dose and flap dose should be part of the commissioning process and possibly using our model in the Treatment Planning System (TPS) for new facilities with treatment delivery control systems with higher beam intensities and faster beam‐off control.

AbstractBackgroundRecent therapeutic advances and screening technologies have improved survival among patients with lung cancer, who are now at high risk of developing second primary lung cancer (SPLC). Recently, an SPLC risk‐prediction model (called SPLC‐RAT) was developed and validated using data from population‐based epidemiological cohorts and clinical trials, but real‐world validation has been lacking. The predictive performance of SPLC‐RAT was evaluated in a hospital‐based cohort of lung cancer survivors.MethodsThe authors analyzed data from 8448 ever‐smoking patients diagnosed with initial primary lung cancer (IPLC) in 1997–2006 at Mayo Clinic, with each patient followed for SPLC through 2018. The predictive performance of SPLC‐RAT and further explored the potential of improving SPLC detection through risk model‐based surveillance using SPLC‐RAT versus existing clinical surveillance guidelines.ResultsOf 8448 IPLC patients, 483 (5.7%) developed SPLC over 26,470 person‐years. The application of SPLC‐RAT showed high discrimination area under the receiver operating characteristics curve: 0.81). When the cohort was stratified by a 10‐year risk threshold of ≥5.6% (i.e., 80th percentile from the SPLC‐RAT development cohort), the observed SPLC incidence was significantly elevated in the high‐risk versus low‐risk subgroup (13.1% vs. 1.1%, p < 1 × 10–6). The risk‐based surveillance through SPLC‐RAT (≥5.6% threshold) outperformed the National Comprehensive Cancer Network guidelines with higher sensitivity (86.4% vs. 79.4%) and specificity (38.9% vs. 30.4%) and required 20% fewer computed tomography follow‐ups needed to detect one SPLC (162 vs. 202).ConclusionIn a large, hospital‐based cohort, the authors validated the predictive performance of SPLC‐RAT in identifying high‐risk survivors of SPLC and showed its potential to improve SPLC detection through risk‐based surveillance.Plain Language Summary Lung cancer survivors have a high risk of developing second primary lung cancer (SPLC). However, no evidence‐based guidelines for SPLC surveillance are available for lung cancer survivors. Recently, an SPLC risk‐prediction model was developed and validated using data from population‐based epidemiological cohorts and clinical trials, but real‐world validation has been lacking. Using a large, real‐world cohort of lung cancer survivors, we showed the high predictive accuracy and risk‐stratification ability of the SPLC risk‐prediction model. Furthermore, we demonstrated the potential to enhance efficiency in detecting SPLC using risk model‐based surveillance strategies compared to the existing consensus‐based clinical guidelines, including the National Comprehensive Cancer Network.

We characterized three phases of neuromotor control—motor unit recruitment, sustained activity, and derecruitment—based on statistical assessments of stationarity of the diaphragm muscle (DIAm) EMG activity in awake rats. Our findings may allow indirect estimates of the contribution of motor unit recruitment and frequency coding toward generating force and provide novel insights about the temporal aspects of DIAm neuromotor control and descending respiratory drive in unanesthetized animals.

Stroke is one of the leading causes of disability worldwide despite recent advances in hyperacute interventions to lessen the initial impact of stroke. Stroke recovery therapies are crucial in reducing the long-term disability burden after stroke. Stroke recovery treatment options have rapidly expanded within the last decade, and we are in the dawn of an exciting era of multimodal therapeutic approaches to improve post-stroke recovery. In this narrative review, we highlighted various promising advances in treatment and technologies targeting stroke rehabilitation, including activity-based therapies, non-invasive and minimally invasive brain stimulation techniques, robotics-assisted therapies, brain–computer interfaces, pharmacological treatments, and cognitive therapies. These new therapies are targeted to enhance neural plasticity as well as provide an adequate dose of rehabilitation and improve adherence and participation. Novel activity-based therapies and telerehabilitation are promising tools to improve accessibility and provide adequate dosing. Multidisciplinary treatment models are crucial for post-stroke neurorehabilitation, and further adjuvant treatments with brain stimulation techniques and pharmacological agents should be considered to maximize the recovery. Among many challenges in the field, the heterogeneity of patients included in the study and the mixed methodologies and results across small-scale studies are the cardinal ones. Biomarker-driven individualized approaches will move the field forward, and so will large-scale clinical trials with a well-targeted patient population.

AbstractPeripheral T‐cell lymphoma (PTCL) is a clinically heterogeneous group that represents 10%–15% of all lymphomas. Despite improved genetic and molecular understanding, treatment outcomes for PTCL have not shown significant improvement. Although Janus kinase‐2 (JAK2) plays an important role in myeloproliferative neoplasms, the critical role of JAK isoforms in mediating prosurvival signaling in PTCL cells is not well defined. Immunohistochemical analysis of PTCL tumors (n = 96) revealed high levels of constitutively active JAK3 (pJAK3) that significantly (p < 0.04) correlated with the activation state of its canonical substrate STAT3. Furthermore, constitutive activation of JAK3 and STAT3 positively correlated, at least in part, with an oncogenic tyrosine phosphatase PTPN11. Pharmacological inhibition of JAK3 but not JAK1/JAK2 significantly (p < 0.001) decreased PTCL proliferation, survival and STAT3 activation. A sharp contrast was observed in the pJAK3 positivity between ALK+ (85.7%) versus ALK‐negative (10.0%) in human PTCL tumors and PTCL cell lines. Moreover, JAK3 and ALK reciprocally interacted in PTCL cells, forming a complex to possibly regulate STAT3 signaling. Finally, combined inhibition of JAK3 (by WHI‐P154) and ALK (by crizotinib or alectinib) significantly (p < 0.01) decreased the survival of PTCL cells as compared to either agent alone by inhibiting STAT3 downstream signaling. Collectively, our findings establish that JAK3 is a therapeutic target for a subset of PTCL, and provide rationale for the clinical evaluation of JAK3 inhibitors combined with ALK‐targeted therapy in PTCL.