Basic Science Research Research Articles

Long QT syndrome-associated calmodulin mutations and their interactions with the Kv7.1 voltage-gated potassium channel

Abstract Introduction Calmodulin (CaM) is a highly conserved mediator of calcium (Ca2+) dependent signalling. Its flexible structure allows CaM to bind and modulate many targets, including cardiac ion channels. Genotyping has revealed several CaM mutations associated with congenital disorders of heart rhythm, known as long QT-syndrome (LQTS). LQTS patients suffer from prolonged ventricular recovery times (QT-interval) which increases their risk of significant cardiac events. Loss of function KV7.1 mutations are the largest cause of LQTS, accounting for >50% of cases. CaM facilitates Ca2+-sensitivity to KV7.1 in producing IKs, Kv7.1 mutations which reduce CaM binding promote LQTS pathology. However, the effects of LQTS-associated CaM mutations on Kv7.1 function remain unknown. Purpose To determine the biophysical consequences of congenital LQTS-associated CaM mutations and how they alter modulation of Kv7.1 in producing the ventricular repolarising IKs current. Methods WT and mutant CaM proteins were recombinantly expressed and purified for biophysical characterisation. Using circular dichroism, secondary structures and thermostability of proteins were quantified. Isothermal titration calorimetry was used to quantitatively measure interactions between CaM proteins and binding sites of KV7.1 (Helix B). NMR was employed to study the conformations of target-bound WT and mutant proteins. Whole cell currents were determined using voltage clamp electrophysiology in HEK cells. Results Mutations significantly changed the thermostability and secondary structure distributions of CaM, and also caused site-dependent increases in susceptibility to protease digestion. CaM interacted with Helix B (KV7.1) via both Ca2+-dependent and independent mechanisms. Ca2+ dependent binding to Helix B was much higher affinity than Ca2+-independent binding, with >2000-fold reduction in dissociation constant measured. LQTS-CaM variants reduced Helix B affinity with the largest reductions found in EF-hand IV mutants. These mutants also adopted most distinct conformations when Helix B-bound. Calmodulation of the KV7.1 channel produced larger (IKs) currents without altering channel activation kinetics. IKs exhibited Ca2+-sensitivity, in response to increased cytosolic Ca2+, larger currents were generated. Modulation by CaM mutants reduced current density at systolic Ca2+-concentrations (1000 nM), within physiological time periods (0.35 s), revealing a direct QT-prolonging modulatory effect. Conclusions Provided here are mechanistic insights as to how LQTS-associated CaM variants contribute to electrical disease of the heart. Mutations in the highly conserved structure of CaM disrupt protein conformation and perturb complex formation with KV7.1. This results in aberrant Ca2+-sensitivity of Kv7.1, reducing IKs generation. This ultimately decreases the repolarisation capacity of cells and would extend the QT interval of myocytes. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): British Heart Foundation Intermediate Basic Science Research Fellowship

Disease-associated calmodulin mutations disrupt L-type Ca2+ channel (Cav1.2) activity and CaMKIIdelta phosphorylation in long QT syndrome

Abstract Introduction Long QT Syndrome (LQTS) is a major inherited arrhythmia syndrome that can cause sudden cardiac death. Using genome sequencing in human patients, mutations in the ubiquitous calcium (Ca2+) sensor protein calmodulin (CaM) have been associated to LQTS. CaM is an ion channel regulator and can modulate the activity of the voltage-gated calcium channel (Cav1.2) and Ca2+/CaM-dependent protein kinase II (CaMKIIδ), involved in cardiac muscle contraction. However the molecular mechanism by which CaM mutations contribute to irregular heartbeats remains unclear. Methods Interaction of CaM proteins with Cav1.2 and CaMKIId synthetic peptides (Cav1.2-NSCaTE51–68, Cav1.2-IQ1665–1685, Cav1.2-C1627–1652, CaMKIIδ294–315,) was investigated using Isothermal Titration Calorimetry (ITC) and X-ray crystallography. Whole-cell patch clamp electrophysiology was used to determine the effect of CaM mutations on L-type Ca2+ currents and Ca2+-dependent inactivation (CDI). CaMKIIδ phosphorylation activity was determined by western blot and fluorescence kinase assay. Results Binding affinity of CaMKIId and Cav1.2 peptides to the LQTS-associated CaM variants was significantly reduced, up to 7-fold. Interestingly, the Cav1.2-IQ1665–1685 peptide showed a stronger binding, up to 2-fold, towards LQTS-CaM mutants. Crystal structures of Ca2+-CaM:CaMKIId294–315 showed structural alterations induced by LQTS associated mutations. In addition, we demonstrated that CaMKIIδ autophosphorylation and kinase activity can be significantly reduced by LQTS-associated CaM mutants. Electrophysiological examination of Cav1.2 function revealed that CaM mutations significantly impaired channel CDI, without affecting the voltage dependence of activation and inactivation. Conclusions These data demonstrate a strong correlation between LQTS-associated CaM mutations and Cav1.2 activity. We provide molecular insights into the diverse factors contributing to CaM-mediated arrhythmias. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): British Heart Foundation Intermediate Basic Science Research Fellowship

Inclusion of Social and Structural Determinants of Health to Advance Understanding of their Influence on the Biology of Chronic Disease.

Social Determinants of Health (SDOH) consider social, political, and economic factors that contribute to health disparities in patients and populations. The most common health-related SDOH exposures are food and housing insecurity, financial instability, transportation needs, low levels of education, and psychosocial stress. These domains describe risks that can impact health outcomes more than health care. Epidemiologic and translational research demonstrates that SDOH factors represent exposures that predict harm and impact the health of individuals. International and national guidelines urge health professionals to address SDOH in clinical practice and public health. The further implementation of these recommendations into basic and translational research, however, is lagging. Herein, we consider a precision health framework to describe how SDOH contributes to the exposome and exacerbates physiologic pathways that lead to chronic disease. SDOH factors are associated with various forms of stressors that impact physiological processes through epigenetic, inflammatory, and redox regulation. Many SDOH exposures may add to or potentiate the pathologic effects of additional environmental exposures. This overview aims to inform basic life science and translational researchers about SDOH exposures that can confound associations between classic biomedical determinants of disease and health outcomes. To advance the study of toxicology through either qualitative or quantitative assessment of exposures to chemical and biological substances, a more complete environmental evaluation should include SDOH exposures. We discuss common approaches to measure SDOH factors at individual and population levels and review the associations between SDOH risk factors and physiologic mechanisms that influence chronic disease. We provide clinical and policy-based motivation to encourage researchers to consider the impact of SDOH exposures on study results and data interpretation. With valid measures of SDOH factors incorporated into study design and analyses, future toxicological research may contribute to an evidence base that can better inform prevention and treatment options, to improve equitable clinical care and population health. © 2022 Wiley Periodicals LLC.

The gripping story of integrins.

The foundational research recognized by this year's Lasker Basic Science Research Award "for discoveries concerning the integrins-key mediators of cell-matrix and cell-cell adhesion in physiology and disease" reaches back to the 1970s.

Interphase mechanical behaviors of nickel/yttria-stabilized zirconia cermets: A study by nanoindentation and molecular dynamics simulations

The metal/ceramic interface is of great importance in a variety of basic science research and technological applications. In this paper, the interphase mechanical behaviors of the nickel/yttria-stabilized zirconia (Ni/YSZ) system serving as an anode material in solid oxide fuel cells are investigated by nanoindentation experiments and molecular dynamics (MD) simulations. The experimental results indicate that the interface effect can greatly enhance the Young's modulus and hardness of Ni near Ni/YSZ interface, while a reduction is observed in the aforementioned mechanical properties of YSZ near the interface. In addition, the change in the mechanical properties and the affected region of the YSZ component due to the interface effect are both much larger than those of its Ni counterpart. Our MD simulation results reveal that the different effects of Ni/YSZ interface on the mechanical properties of Ni and YSZ near the interface can be ascribed to different transport capabilities of deformations generated in these two components across the interface. Based on MD simulation results, an interface barrier model and a model considering the structural compliance are proposed here for theoretically predicting the interphase hardness and Young's modulus of the Ni/YSZ system.

Applications and challenges of rhodopsin-based optogenetics in biomedicine.

Optogenetics is an emerging bioengineering technology that has been rapidly developed in recent years by cross-integrating optics, genetic engineering, electrophysiology, software control, and other disciplines. Since the first demonstration of the millisecond neuromodulation ability of the channelrhodopsin-2 (ChR2), the application of optogenetic technology in basic life science research has been rapidly progressed, especially in neurobiology, which has driven the development of the discipline. As the optogenetic tool protein, microbial rhodopsins have been continuously explored, modified, and optimized, with many variants becoming available, with structural characteristics and functions that are highly diversified. Their applicability has been broadened, encouraging more researchers and clinicians to utilize optogenetics technology in research. In this review, we summarize the species and variant types of the most important class of tool proteins in optogenetic techniques, the microbial rhodopsins, and review the current applications of optogenetics based on rhodopsin qualitative light in biology and other fields. We also review the challenges facing this technology, to ultimately provide an in-depth technical reference to support the application of optogenetics in translational and clinical research.

Health Risk Assessment for Pest Control Workers Using Biocidal Products after COVID-19 Outbreak: A Comparison of EU and US

After the COVID-19 outbreak, the workloads of disinfection have remarkably increased. As disinfectants are harmful to human, health risk assessment of disinfection workers is needed to ensure their safety. However, the acceptable operator exposure level (AOEL) for most disinfectants are not established. Moreover, the method of calculating the AOEL varies across the countries. This study aims to identify the health risks of disinfection workers based on two different risk assessment methods of EU and US after the COVID-19 outbreak. We surveyed 533 disinfection workers to identify exposure patterns of disinfectants. The inhalation and dermal exposure were calculated based on different work types. The AOEL was calculated and compared using the EU and US methods. The health risks of workers are determined by hazard index based on whether the exposure exceeds AOEL. Workers used 53 chemicals from 175 biocidal products, and only 34 chemicals (65%) had AOEL. 17 Chemicals with absorption factors for each route or AOEL were selected for risk assessment. When compared the estimated AOEL was calusing EU and US methods, only 2 (4%) were the same. The result of health risk assessment showed 10 (19%) were exceed 1 (acceptable level) using EU method, while 9 (17%) were exceed 1 using US method. This study performed the health risk assessment of disinfection workers based on EU and US methods after the COVID-19 outbreak. Only 65% had an AOEL, and health risks of workers were differd according to risk calculation methods of EU and US. Given the increasing use of biocides after the COVID-19 outbreak, AOEL need to be established for health risk assessment of workers. Biocides, Risk assessment, Reference dose, AOEL, COVID-19, pest control worker This study was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2021R1F1A1063967).

Speculations on the W-mass measurement at CDF* *J.G. is supported by the National Natural Science Foundation of China (NNSFC) ( 12035008). Z.L. is supported in part by the U.S. Department of Energy (DOE) (DE-SC0022345). T.M. is supported by "Study in Israel" Fellowship for Outstanding Post-Doctoral Researchers from China, by PBC of CHE from India, and also partially supported by grants

The W mass determination at the Tevatron CDF experiment reported a deviation from the SM expectation at the 7σ level. We discuss a few possible interpretations and their collider implications. We perform electroweak global fits under various frameworks and assumptions. We consider three types of electroweak global fits in the effective-field-theory framework: the S-T, S-T-, and eight-parameter flavor-universal one. We discuss the amounts of tensions between different measurements reflected in these fits and the corresponding shifts in central values of these parameters. With these electroweak fit pictures in hand, we present a few different classes of models and discuss their compatibility with these results. We find that while explaining the discrepancy, the single gauge boson extensions face strong LHC direct search constraints unless the is fermiophobic (leptophobic), which can be realized if extra vector fermions (leptons) mix with the SM fermions (leptons). Vector-like top partners can partially generate the needed shift to the electroweak observables. The compatibility with the top squark is also studied in detail. We find that the non-degenerate top squark soft masses enhance the needed operator coefficients, enabling an allowed explanation compatible with current LHC measurements. Overall, more theoretical and experimental developments are highly in demand to reveal the physics behind this discrepancy.

“They were already inside my head to begin with”: Trust, Translational Misconception, and Intraoperative Brain Research

Background: Patients undergoing invasive neurosurgical procedures offer researchers unique opportunities to study the brain. Deep brain stimulation patients, for example, may participate in research during the surgical implantation of the stimulator device. Although this research raises many ethical concerns, little attention has been paid to basic studies, which offer no therapeutic benefits, and the value of patient-participant perspectives. Methods: Semi-structured interviews were conducted with fourteen individuals across two studies who participated in basic intraoperative research during their deep brain stimulator surgery. Interviews explored interpretations of risks and benefits, enrollment motivations, and experiences of participating in awake brain research. Reflexive thematic analysis was conducted. Results: Seven themes were identified from participant narratives, including robust attitudes of trust, high valuations of basic science research, impacts of the surgical context, and mixed experiences of participation. Conclusion: We argue that these narratives raise the potential for a translational misconception and motivate intraoperative re-consent procedures.

The melanin-concentrating hormone system as a target for the treatment of sleep disorders.

Given the widespread prevalence of sleep disorders and their impacts on health, it is critical that researchers continue to identify and evaluate novel avenues of treatment. Recently the melanin-concentrating hormone (MCH) system has attracted commercial and scientific interest as a potential target of pharmacotherapy for sleep disorders. This interest emerges from basic scientific research demonstrating a role for MCH in regulating sleep, and particularly REM sleep. In addition to this role in sleep regulation, the MCH system and the MCH receptor 1 (MCHR1) have been implicated in a wide variety of other physiological functions and behaviors, including feeding/metabolism, reward, anxiety, depression, and learning. The basic research literature on sleep and the MCH system, and the history of MCH drug development, provide cause for both skepticism and cautious optimism about the prospects of MCH-targeting drugs in sleep disorders. Extensive efforts have focused on developing MCHR1 antagonists for use in obesity, however, few of these drugs have advanced to clinical trials, and none have gained regulatory approval. Additional basic research will be needed to fully characterize the MCH system’s role in sleep regulation, for example, to fully differentiate between MCH-neuron and peptide/receptor-mediated functions. Additionally, a number of issues relating to drug design will continue to pose a practical challenge for novel pharmacotherapies targeting the MCH system.

Integrated system of traditional THz time-domain spectroscopy and asynchronous optical sampling

Terahertz time-domain spectroscopy (THz-TDS) system, as a new means of spectral analysis and detection, plays an increasingly pivotal role in basic scientific research. However, owing to the long scanning time of the traditional THz-TDS system and the complex control of the asynchronous optical scanning (ASOPS) system, which requires frequent calibration, we combine traditional THz-TDS and ASOPS systems to form a composite system and propose an all-fiber trigger signal generation method based on the time overlapping interference signal generated by the collinear motion of two laser pulses. Finally, the time-domain and frequency-domain spectra are obtained by using two independent systems in the integrated systems. It is found that the full width at half maximum (FWHM) of the time-domain spectra and the spectral width of the frequency-domain spectra are almost the same, but the sampling speed of the ASOPS system is significantly faster than that of the traditional THz-TDS system, which conduces to the study of the transient characteristics of substances.

ACL Research Retreat IX Summary Statement: The Pediatric Athlete, March 17-19, 2022; High Point, North Carolina.

ACL Research Retreat IX Summary Statement: The Pediatric Athlete, March 17-19, 2022; High Point, North Carolina.

Effects Of Probiotics Supplementation On Aerobic Capacity And Inflammatory Markers In Male Soccer University Student-athletes

PURPOSE: The aims of the study was to determine the effect of 6 weeks probiotic supplementation on the aerobic capacity and inflammatory markers of athletes after strenuous exercise. METHODS: 30 male soccer university student-athletes from Beijing Sport University were recruited and randomly assigned into the prebiotic group (CG) and probiotic group (PG) (n = 15 per group). CG group supplemented daily with prebiotics (including galactose oligosaccharide, inulin, and maltitol), PG group supplemented with a multi-species probiotic (8 × 109 CFU), including Lactobacillus casei Zhang, Lactobacillus Plantarum P-8, and Bifidobacterium animalis subsp lactis V9. The height and weight were measured before and after supplementation. Maximal oxygen uptake (VO2max) test and 12-minute running test were used to assess aerobic capacity. Venous blood samples were collected before and immediately after VO2max test. Serum inflammatory markers and salivary immunoglobulin A (SIgA) were detected by ELISA. During the 6 weeks, subjects were requested to completed a upper respiratory tract infections (URTI) questionnaire. RESULTS: The time to exhaustion was prolonged by 8.68% and the distance of 12-minute running was increased from 3101.33 ± 35.05 m to 3190.67 ± 28.00 m (P < 0.01) in PG group, while no obvious change in CG group. The incidence and duration of URTI during training significantly decreased by 56.10% (P < 0.01) and 33.26% (P < 0.05) in PG group vs. CG Group, respectively. In the basal state, the level of SIgA in PG group was significantly increased (from 7.63 ± 0.29 pg/mL to 8.72 ± 0.34 pg/mL, P < 0.05), while the level of C-reactive protein and interleukin-8 (IL-8) in CG group was markedly decreased by 37.90% and 23.40% (P < 0.05), respectively. Immediately after VO2max test, IL-4 increased by 58.60% in the PG group (P < 0.05), IL-10 increased from 152.10 ± 29.64 pg/mL to 219.28 ± 55.44 pg/mL (P < 0.05), and IL-6 decreased by 11.67% in the CG group (P < 0.05). CONCLUSIONS: Probiotics supplementation showed improved aerobic capacity. Both prebiotics and probiotics supplementation had inhibitory effects on inflammation. Prebiotics have a better effect on the basal state, while probiotics is more capable immediately after VO2max test. Supported by the Special Funds for Basic Scientific Research Fees of Central Universities (2021TD002).

Advances in Optical Coherence Tomography Imaging Technology and Techniques for Choroidal and Retinal Disorders.

Optical coherence tomography (OCT) imaging has played a pivotal role in the field of retina. This light-based, non-invasive imaging modality provides high-quality, cross-sectional analysis of the retina and has revolutionized the diagnosis and management of retinal and choroidal diseases. Since its introduction in the early 1990s, OCT technology has continued to advance to provide quicker acquisition times and higher resolution. In this manuscript, we discuss some of the most recent advances in OCT technology and techniques for choroidal and retinal diseases. The emerging innovations discussed include wide-field OCT, adaptive optics OCT, polarization sensitive OCT, full-field OCT, hand-held OCT, intraoperative OCT, at-home OCT, and more. The applications of these rising OCT systems and techniques will allow for a closer monitoring of chorioretinal diseases and treatment response, more robust analysis in basic science research, and further insights into surgical management. In addition, these innovations to optimize visualization of the choroid and retina offer a promising future for advancing our understanding of the pathophysiology of chorioretinal diseases.

Recent advances in understanding and treating priapism.

Priapism is a rare condition that can lead to long-term erectile dysfunction if left untreated. It is one of the few urological emergencies that require prompt medical intervention. Priapism refers to a penile erection that lasts for more than 4 hours and is unrelated to sexual stimulation or orgasm. The aims of immediate intervention for ischaemic priapism are to resolve the painful erection and preserve the cavernosal smooth muscle function. The aim of this review is to evaluate the latest advances in the management of priapism. Despite the continuous challenge in providing an optimal treatment for this rare urological condition, our understanding and management of it have been advanced by decades of clinical and basic science research. Proximal shunts (Quackels or Grayhack) are no longer routinely performed. Distal shunt procedures are currently the most commonly used techniques. A novel penoscrotal decompression technique has recently been described. Ischaemic priapism can be managed conservatively in most cases with the preservation of erectile function. In cases where ischaemic priapism has persisted for more than 36 hours, the majority will develop erectile dysfunction. Early penile prosthesis with thorough patient counselling should be considered in such cases. In some cases of long-standing non-ischaemic priapism, patients can develop fibrosis within the distal corpora, and, therefore, early treatment with super-selective embolisation is required to prevent this.

RETRACTED: The Top 50 Articles on Knee Posterolateral Corner Injuries

PurposeTo identify and characterize the most cited publications in orthopaedic research related to posterolateral corner (PLC) injuries of the knee.MethodsThe Science Citation Index Expanded was queried for PLC injury articles. The 50 most-cited studies from 1976 to 2021 were selected. Article characteristics, including number of citations, citation density, year of publication, source journal, country of origin, article type, article subtype, and level of evidence, were analyzed.ResultsThe number of citations for individual articles ranged from 47 to 205. The 50 most cited articles were published in 16 journals. Eleven of the 50 articles (22%) were published in Arthroscopy—The Journal of Arthroscopic and Related Surgery. The largest proportion of the articles (n = 22, 44%) were classified as clinical, with the rest classified as reviews (n = 15, 30%), and basic science research (n = 13, 26%). The most common level of evidence for clinical articles was IV (14/22, 63.6%). Nine countries contributed to the top 50 articles, with the majority published in the United States (n = 35, 70%).ConclusionsIn the last 20 years, papers published on the diagnosis and surgical management of PLC injuries have a high citation frequency. Future high-quality research is needed to establish best-practice guidelines for the management of PLC injuries due to the low overall level of evidence of existing clinical studies.Clinical RelevanceThis research provides a comprehensive list for practitioners and may help educators identify articles to include in the curriculum for residents and fellows.

Recent progresses in novel in vitro models of primary neurons: A biomaterial perspective.

Central nervous system (CNS) diseases have been a growing threat to the health of humanity, emphasizing the urgent need of exploring the pathogenesis and therapeutic approaches of various CNS diseases. Primary neurons are directly obtained from animals or humans, which have wide applications including disease modeling, mechanism exploration and drug development. However, traditional two-dimensional (2D) monoculture cannot resemble the native microenvironment of CNS. With the increasing understanding of the complexity of the CNS and the remarkable development of novel biomaterials, in vitro models have experienced great innovation from 2D monoculture toward three-dimensional (3D) multicellular culture. The scope of this review includes the progress of various in vitro models of primary neurons in recent years to provide a holistic view of the modalities and applications of primary neuron models and how they have been connected with the revolution of biofabrication techniques. Special attention has been paid to the interaction between primary neurons and biomaterials. First, a brief introduction on the history of CNS modeling and primary neuron culture was conducted. Next, detailed progress in novel in vitro models were discussed ranging from 2D culture, ex vivo model, spheroid, scaffold-based model, 3D bioprinting model, and microfluidic chip. Modalities, applications, advantages, and limitations of the aforementioned models were described separately. Finally, we explored future prospects, providing new insights into how basic science research methodologies have advanced our understanding of the CNS, and highlighted some future directions of primary neuron culture in the next few decades.

NIR-II bioimaging of small molecule fluorophores: From basic research to clinical applications

Due to the low autofluorescence and deep-photo penetration, the second near-infrared region fluorescence imaging technology (NIR-II, 1000–2000 nm) has been widely utilized in basic scientific research and preclinical practice throughout the past decade. The most attractive candidates for clinical translation are organic NIR-II fluorophores with a small-molecule framework, owing to their low toxicity, high synthetic repeatability, and simplicity of chemical modification. In order to enhance the translation of small molecule applications in NIR-II bioimaging, NIR-II fluorescence imaging technology has evolved from its usage in cells to the diagnosis of diseases in large animals and even humans. Although several examples of NIR-II fluorescence imaging have been used in preclinical studies, there are still many challenges that need to be addressed before they can finally be used in clinical settings. In this paper, we reviewed the evolution of the chemical structures and photophysical properties of small-molecule fluorophores, with an emphasis on their biomedical applications ranging from small animals to humans. We also explored the potential of small-molecule fluorophores.

New advances in medical imaging technology for the evaluation of anthracycline-induced cardiotoxicity.

New advances in medical imaging technology for the evaluation of anthracycline-induced cardiotoxicity.

The role of testosterone in men's health: is it time for a new approach?

Because of many unanswered questions regarding men's health, a literature review was performed to better understand the role of testosterone and testosterone replacement therapy (TRT) in the management of hypogonadism and aging related prostate gland diseases (ARPGD) including prostate cancer (PCa) and benign prostatic hyperplasia (BPH) with lower urinary tract symptoms (LUTS). The PubMed database was screened for pertinent peer reviewed articles published during the last four decades that culminated in the positions and recommendations in this paper. Hypogonadism seriously impacts men's health, and the diagnosis remains controversial. The incidence of ARPGD is projected to increase worldwide and treatment still has significant limitations. There is compelling evidence that lower, not higher, testosterone levels trigger the development of PCa and BPH through androgen receptor over-expression. TRT was found to be safe and effective in treating hypogonadism including in PCa survivors and those harboring PCa. There is also evidence that TRT might reduce the incidence and prevalence of ARPGD. This review synthesizes a wide-ranging compendium of basic science and clinical research that strongly encourages altering the present approach to diagnosing and treating men with hypogonadism and ARPGD. These findings underscore the importance of avoiding significant testosterone decline and support the use of TRT. Ten recommendations are offered as a framework for the way forward. It is now time for clinicians, payers, researchers, funding agencies, professional associations, and patient advocacy groups to embrace this new paradigm to increase longevity and improve the quality of life.