Testosterone Assays.

Challenges to the accurate and precise measurement of testosterone include deficiencies in standardization, variable reference ranges, expenses related to gold standard equipment, and other challenges. Total testosterone remains the most accessible for standard laboratories, while free testosterone and bioavailable testosterone may be useful adjuncts, particularly in men with low borderline testosterone values. Mass spectrometry is the gold standard measurement modality for total testosterone, while equilibrium dialysis followed by direct assessment with a trusted method is the gold standard technique for measuring free testosterone. Although reference ranges may vary, efforts to adapt reference ranges to different populations include age-adjusted values.

Hematospermia Etiology, Diagnosis, Treatment, and Sexual Ramifications: A Narrative Review.

INTRODUCTION: Hematospermia (HS) is the presence of blood in ejaculatory fluid. It is a rare condition that is historically idiopathic or associated with sexual behavior. Technological advances have identified many of the etiologies behind HS, improving treatment. Though often benign, HS remains a source of considerable sexual anxiety for patients. Few papers have outlined a diagnostic and therapeutic approach to HS, and none have explicitly addressed its sexual consequences. OBJECTIVES: To provide a comprehensive overview of HS, emphasizing its sexual ramifications. METHODS: A PubMed literature search was performed through May 2021 to identify all relevant publications related to etiology, diagnosis, treatment, and sexual effects of HS. Original research and reviews were analyzed, and pertinent studies were included in this review. RESULTS: Iatrogenic interventions (eg, transrectal ultrasound-guided prostate biopsies) are the most common cause of HS. Infection and/or nonspecific inflammation is the most common non-iatrogenic etiology. Malignancies, including prostate, testicular, and other genitourinary cancers, are rarely the cause of HS. Diagnostic approaches to HS can be organized according to patient age (less than or greater than 40 years old), persistence of bleeding, and the presence/absence of concerning symptoms. Though HS often spontaneously resolves, treatment may require various medications (eg, antibiotics, anti-inflammatories) or surgical interventions. HS has several sexual ramifications, including libido-affecting anxiety, social repercussions from sexual partners and non-sexual affiliates, increased risk of erectile dysfunction or transmission of sexual infections, and compromised fertility, especially when cryopreservation is utilized. CONCLUSION: HS may significantly affect sexual health through several mechanisms, though there is a paucity of formal data on this subject. Further research is needed to fully understand the severity and extent of HS's effect on sexual well-being, especially in those with refractory bleeding. Drury RH, King B, Herzog B, et al. Hematospermia Etiology, Diagnosis, Treatment, and Sexual Ramifications: A Narrative Review. Sex Med Rev. 2022;10:669-680.

Hematospermia Etiology, Diagnosis, Treatment, and Sexual Ramifications: A Narrative Review.

INTRODUCTION: Hematospermia (HS) is the presence of blood in ejaculatory fluid. It is a rare condition that is historically idiopathic or associated with sexual behavior. Technological advances have identified many of the etiologies behind HS, improving treatment. Though often benign, HS remains a source of considerable sexual anxiety for patients. Few papers have outlined a diagnostic and therapeutic approach to HS, and none have explicitly addressed its sexual consequences. OBJECTIVES: To provide a comprehensive overview of HS, emphasizing its sexual ramifications. METHODS: A PubMed literature search was performed through May 2021 to identify all relevant publications related to etiology, diagnosis, treatment, and sexual effects of HS. Original research and reviews were analyzed, and pertinent studies were included in this review. RESULTS: Iatrogenic interventions (eg, transrectal ultrasound-guided prostate biopsies) are the most common cause of HS. Infection and/or nonspecific inflammation is the most common non-iatrogenic etiology. Malignancies, including prostate, testicular, and other genitourinary cancers, are rarely the cause of HS. Diagnostic approaches to HS can be organized according to patient age (less than or greater than 40 years old), persistence of bleeding, and the presence/absence of concerning symptoms. Though HS often spontaneously resolves, treatment may require various medications (eg, antibiotics, anti-inflammatories) or surgical interventions. HS has several sexual ramifications, including libido-affecting anxiety, social repercussions from sexual partners and non-sexual affiliates, increased risk of erectile dysfunction or transmission of sexual infections, and compromised fertility, especially when cryopreservation is utilized. CONCLUSION: HS may significantly affect sexual health through several mechanisms, though there is a paucity of formal data on this subject. Further research is needed to fully understand the severity and extent of HS's effect on sexual well-being, especially in those with refractory bleeding.

Corrigendum: The Phosphorylation Profile of Myosin Binding Protein-C Slow is Dynamically Regulated in Slow-Twitch Muscles in Health and Disease.

This corrects the article DOI: 10.1038/srep12637.

ProbAnnoWeb and ProbAnnoPy: probabilistic annotation and gap-filling of metabolic reconstructions.

Summary: Gap-filling is a necessary step to produce quality genome-scale metabolic reconstructions capable of flux-balance simulation. Most available gap-filling tools use an organism-agnostic approach, where reactions are selected from a database to fill gaps without consideration of the target organism. Conversely, our likelihood based gap-filling with probabilistic annotations selects candidate reactions based on a likelihood score derived specifically from the target organism's genome. Here, we present two new implementations of probabilistic annotation and likelihood based gap-filling: a web service called ProbAnnoWeb, and a standalone python package called ProbAnnoPy. Availability and implementation: Our tools are available as a web service with no installation needed (ProbAnnoWeb) at probannoweb.systemsbiology.net, and as a local python package implementation (ProbAnnoPy) at github.com/PriceLab/probannopy. Contact: evangelos.simeonidis@systemsbiology.org or nathan.price@systemsbiology.org. Supplementary information: Supplementary data are available at Bioinformatics online.

Novel obscurins mediate cardiomyocyte adhesion and size via the PI3K/AKT/mTOR signaling pathway.

The intercalated disc of cardiac muscle embodies a highly-ordered, multifunctional network, essential for the synchronous contraction of the heart. Over 200 known proteins localize to the intercalated disc. The challenge now lies in their characterization as it relates to the coupling of neighboring cells and whole heart function. Using molecular, biochemical and imaging techniques, we characterized for the first time two small obscurin isoforms, obscurin-40 and obscurin-80, which are enriched at distinct locations of the intercalated disc. Both proteins bind specifically and directly to select phospholipids via their pleckstrin homology (PH) domain. Overexpression of either isoform or the PH-domain in cardiomyocytes results in decreased cell adhesion and size via reduced activation of the PI3K/AKT/mTOR pathway that is intimately linked to cardiac hypertrophy. In addition, obscurin-80 and obscurin-40 are significantly reduced in acute (myocardial infarction) and chronic (pressure overload) murine cardiac-stress models underscoring their key role in maintaining cardiac homeostasis. Our novel findings implicate small obscurins in the maintenance of cardiomyocyte size and coupling, and the development of heart failure by antagonizing the PI3K/AKT/mTOR pathway.

Deregulated Ca2+ cycling underlies the development of arrhythmia and heart disease due to mutant obscurin.

Obscurins are cytoskeletal proteins with structural and regulatory roles encoded by OBSCN. Mutations in OBSCN are associated with the development of hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). Specifically, the R4344Q mutation present in immunoglobulin domain 58 (Ig58) was the first to be linked with the development of HCM. To assess the effects of R4344Q in vivo, we generated the respective knock-in mouse model. Mutant obscurins are expressed and incorporated normally into sarcomeres. The expression patterns of sarcomeric and Ca2+-cycling proteins are unaltered in sedentary 1-year-old knock-in myocardia, with the exception of sarco/endoplasmic reticulum Ca2+ adenosine triphosphatase 2 (SERCA2) and pentameric phospholamban whose levels are significantly increased and decreased, respectively. Isolated cardiomyocytes from 1-year-old knock-in hearts exhibit increased Ca2+-transients and Ca2+-load in the sarcoplasmic reticulum and faster contractility kinetics. Moreover, sedentary 1-year-old knock-in animals develop tachycardia accompanied by premature ventricular contractions, whereas 2-month-old knock-in animals subjected to pressure overload develop a DCM-like phenotype. Structural analysis revealed that the R4344Q mutation alters the distribution of electrostatic charges over the Ig58 surface, thus interfering with its binding capabilities. Consistent with this, wild-type Ig58 interacts with phospholamban modestly, and this interaction is markedly enhanced in the presence of R4344Q. Together, our studies demonstrate that under sedentary conditions, the R4344Q mutation results in Ca2+ deregulation and spontaneous arrhythmia, whereas in the presence of chronic, pathological stress, it leads to cardiac remodeling and dilation. We postulate that enhanced binding between mutant obscurins and phospholamban leads to SERCA2 disinhibition, which may underlie the observed pathological alterations.

The Phosphorylation Profile of Myosin Binding Protein-C Slow is Dynamically Regulated in Slow-Twitch Muscles in Health and Disease.

Myosin Binding Protein-C slow (sMyBP-C) is expressed in skeletal muscles where it plays structural and regulatory roles. The functions of sMyBP-C are modulated through alternative splicing and phosphorylation. Herein, we examined the phosphorylation profile of sMyBP-C in mouse slow-twitch soleus muscle isolated from fatigued or non-fatigued young (2-4-months old) and old (~14-months old) wild type and mdx mice. Our findings are two-fold. First, we identified the phosphorylation events present in individual sMyBP-C variants at different states. Secondly, we quantified the relative abundance of each phosphorylation event, and of sMyBP-C phospho-species as a function of age and dystrophy, in the presence or absence of fatigue. Our results revealed both constitutive and differential phosphorylation of sMyBP-C. Moreover, we noted a 10-40% and a 25-35% reduction in the phosphorylation levels of select sites in old wild type and young or old mdx soleus muscles, respectively. On the contrary, we observed a 5-10% and a 20-25% increase in the phosphorylation levels of specific sites in young fatigued wild type and mdx soleus muscles, respectively. Overall, our studies showed that the phosphorylation pattern of sMyBP-C is differentially regulated following reversible (i.e. fatigue) and non-reversible (i.e. age and disease) (patho)physiological stressors.