Per capita sperm metabolism is density dependent.

From bacteria to metazoans, higher density populations have lower per capita metabolic rates than lower density populations. The negative covariance between population density and metabolic rate is thought to represent a form of adaptive metabolic plasticity. A relationship between density and metabolism was actually first noted 100 years ago, and was focused on spermatozoa; even then, it was postulated that adaptive plasticity drove this pattern. Since then, contemporary studies of sperm metabolism specifically assume that sperm concentration has no effect on metabolism and that sperm metabolic rates show no adaptive plasticity. We did a systematic review to estimate the relationship between sperm aerobic metabolism and sperm concentration, for 198 estimates spanning 49 species, from protostomes to humans from 88 studies. We found strong evidence that per capita metabolic rates are concentration dependent: both within and among species, sperm have lower metabolisms in dense ejaculates, but increase their metabolism when diluted. On average, a 10-fold decrease in sperm concentration increased per capita metabolic rate by 35%. Metabolic plasticity in sperm appears to be an adaptive response, whereby sperm maximize their chances of encountering eggs.

Real-World Outcomes With Lurbinectedin in Second-Line Setting and Beyond for Extensive Stage Small Cell Lung Cancer.

BACKGROUND: Lurbinectedin has emerged as a potential treatment option for relapsed small cell lung cancer (SCLC). While clinical trials have demonstrated its efficacy and safety, real-world data are limited. This study aimed to evaluate the safety and efficacy of lurbinectedin in a real-world setting, focusing on its use as a second-line agent and beyond in SCLC patients. METHODS: A retrospective analysis was conducted on 90 patients who received lurbinectedin between June 2020 and June 2022 within the Mayo Clinic Health System. Of these, 50 patients received lurbinectedin as a second-line agent, and 14 patients received it as a third-line or later agent. The primary outcomes assessed were overall survival (OS), progression-free survival (PFS), and treatment-related adverse events. RESULTS: Lurbinectedin was generally well tolerated in this real-world cohort, with a median OS of 5.1 months in the second-line cohort and 5.6 months in the third-line or later cohort. Median PFS was 2.1 months in the second-line cohort and 3.4 months in the third-line or later cohort. Adverse events were manageable, with the most common being neutropenia, anemia, fatigue, and febrile neutropenia. No treatment-related deaths or grade 5 toxicities were reported. CONCLUSION: This real-world study provides valuable insights into the safety and efficacy of lurbinectedin in relapsed SCLC. Lurbinectedin demonstrated modest efficacy and a comparable safety profile to that observed in clinical trials. However, outcomes for relapsed SCLC remain suboptimal, particularly for patients with a shorter chemotherapy-free interval and central nervous system metastases.

Time from immune checkpoint inhibitor to sotorasib use correlates with risk of hepatotoxicity in non-small cell lung cancer: A brief report.

INTRODUCTION: We evaluated the risk factors and outcomes for patients who experienced hepatotoxicity after use of sotorasib in KRAS G12C mutated NSCLC. METHODS: Retrospective review of medical records of patients with KRAS G12C mutated NSCLC who received sotorasib between May 28th, 2021, and December 31st, 2021 across all Mayo Clinic sites, with follow up until December 31st, 2022. RESULTS: Thirty-one patients received sotorasib as standard of care treatment. Grade 3 or higher hepatoxicity was seen in 32% (10/31) patients presenting at a median of 51 days (range, 27-123) of sotorasib initiation. Baseline demographics were comparable between patients with and without ≥grade 3 hepatotoxicity, except for presence of CNS metastases and time from prior immune checkpoint inhibitor (ICI) treatment. Improvement in liver tests was observed in all patients after stopping sotorasib, and it was restarted at a lower dose in 8 patients. Despite dose reduction, hepatotoxicity requiring sotorasib discontinuation occurred in 2 patients. Twenty-eight of 31 patients had received prior ICI. Median time from prior ICI therapy was 69 days (range, 4-542). Rates of ≥grade 3 hepatoxicity were 75% (3/4), 64% (7/11) and 0% (0/13) for patients who received ICI within 30 days, 31-90 days and >90 days. None of the 3 patients without prior ICI exposure developed hepatoxicity. The median PFS and OS were 3.9 months and 9.9 months respectively. CONCLUSION: One-third of patients developed grade 3 or higher sotorasib induced hepatotoxicity. Risk of hepatotoxicity was higher in patients who received sotorasib within 90 days of ICI treatment.

Dosimetric predictors of pneumonitis in locally advanced non-small cell lung cancer patients treated with chemoradiation followed by durvalumab.

OBJECTIVES: The incidence and predictors of pneumonitis for patients with unresectable, locally advanced non-small cell lung cancer (NSCLC) in the era of consolidation durvalumab have yet to be fully elucidated. In this large single institution analysis, we report the incidence of and factors associated with grade 2 + pneumonitis in NSCLC patients treated with the PACIFIC regimen. MATERIALS AND METHODS: We identified all patients treated at our institution with definitive CRT followed by durvalumab from 2018 to 2021. Clinical documentation and imaging studies were reviewed to determine grade 2 + pneumonitis events, which required the following: 1) pulmonary symptoms warranting prolonged steroid taper, oxygen dependence, and/or hospital admission and 2) radiographic findings consistent with pneumonitis. RESULTS: One-hundred ninety patients were included. The majority received 60 Gray (Gy) in 30 fractions with concurrent carboplatin and paclitaxel. Median number of durvalumab cycles received was 12 (IQR: 4-22). At a median follow-up of 14.8 months, 50 (26.3%) patients experienced grade 2 + pneumonitis with a 1-year cumulative incidence of 27.8% (95% CI: 21.9-35.4). Seventeen (8.9%) patients experienced grade 3 + pneumonitis and 4 grade 5 (2.1%). Dosimetric predictors of pneumonitis included ipsilateral and total lung volume receiving 5 Gy or greater (V5Gy), V10Gy, V20Gy, V40Gy, and mean dose and contralateral V40Gy. Heart V5Gy, V10Gy, and mean dose were also significant variables. Overall survival estimates at 1 and 3 years were 87.4% (95% CI: 82.4-92.8) and 60.3% (95% CI: 47.9-74.4), respectively. CONCLUSION: We report a risk of pneumonitis higher than that seen on RTOG 0617 and comparable to the PACIFIC study. Multiple lung and heart dosimetric factors were predictive of pneumonitis.

Home-Based Hematopoietic Cell Transplantation in the United States.

Patients undergoing allogeneic (allo) and autologous (auto) hematopoietic cell transplantation (HCT) require extensive hospitalizations or daily clinic visits for the duration of their transplantation. Home HCT, wherein patients live at home and providers make daily trips to the patient's residence to perform assessments and deliver any necessary interventions, may enhance patient quality of life and improve outcomes. We conducted the first study of home HCT in the United States to evaluate this model in the US healthcare setting and to determine the effect on clinical outcomes and quality of life. This case-control study evaluated patients who received home HCT at Duke University in Durham, North Carolina, from November 2012 to March 2018. Each home HCT patient was matched with 2 controls from the same institution who had received standard treatment based on age, disease, and type of transplant for outcomes comparison. Clinical outcomes were abstracted from electronic health records, and quality of life was assessed via Functional Assessment of Cancer Therapy-Bone Marrow Transplant. Clinical outcomes were compared with Student's t-test or Fisher's exact test (continuous variables) or chi-square test (categorical variables). Quality of life scores were compared using the Student t-test. All analyses used a significance threshold of 0.05. Twenty-five patients received home HCT, including 8 allos and 17 autos. Clinical outcomes were not significantly different between the home HCT patients and their matched controls; home HCT patients had decreased incidence of relapse within 1 year of transplantation. Pre-HCT quality of life was well preserved for autologous home HCT patients. This Phase I study demonstrated that home HCT can be successfully implemented in the United States. There was no evidence that home HCT outcomes were inferior to standard-of-care treatment, and patients undergoing autologous home HCT were able to maintain their quality of life. A Phase II randomized trial of home versus standard HCT is currently underway to better compare outcomes and costs.

Engrafting Horse Immune Cells into Mouse Hosts for the Study of the Acute Equine Immune Responses.

Immunological studies in the horse are frequently hampered by lack of environmental control, complicated study design, and ethical concerns when performing high risk studies. The purpose of the current study was to investigate the utility of a xenograft model for studying acute equine immune responses. Immunocompromised non obese diabetic (NOD). sudden combined immunodeficiency (scid).gamma-/- (NSG) mice were engrafted with either equine peripheral blood lymphocytes (PBLs) or equine bone marrow to determine an optimal protocol for equine lymphocyte engraftment. We found that both PBL and bone marrow grafts populated the host mice successfully. Bone marrow transplants were technically more challenging and required further processing to retard graft versus host disease. Graft vs host disease was apparent at 28 days post-PBL transfer and 56 days post-bone marrow transfer. The results of these studies support the use of mouse hosts to study acute equine immune responses and that different engraftment techniques can be used depending on the experimental design.

Interferon gamma protective against Sarcocystis neurona encephalitis in susceptible murine model.

Sarcocystis neurona is the predominant etiological agent of the infectious equine neurologic disease, equine protozoal myeloencephalitis (EPM), which is prevalent in the United States. A wealth of knowledge about S. neurona biology and its life cycle has accumulated over the last several decades. However, much remains unknown about the aberrant equine host's immune response to S. neurona and the relatively high prevalence of exposure to the protozoa but relatively infrequent occurrence of clinical neurologic disease. Mouse models simulating EPM are commonly used to study the disease due to numerous challenges associated with studying the disease in horses. The critical role of the cytokine, interferon gamma (IFNγ), in protection against S. neurona encephalitis has been well established as Ifnγ-/- mice are highly susceptible to S. neurona encephalitis. However, there are discrepancies in the literature regarding S. neurona disease susceptibility in lymphocyte deficient mice, lacking T-lymphocytes and their associated Ifnγ production. In the current study, we investigated S. neurona encephalitis susceptibility in 2 genetically different strains of lymphocyte null mice, C57Bl/6 (B6).scid and Balb/c.scid. The B6.scid mouse was determined to be susceptible to S. neurona encephalitis as 100 % of infected mice developed neurologic disease within 60 days post infection (DPI). The Balb/c.scid mouse was nearly disease resistant as only 10 % of mice developed neurologic disease 60 DPI. Encephalitis was histologically demonstrable and S. neurona was identified in cerebellar samples collected from B6.scid but absent in Balb/c.scid mice. To further investigate the importance of T-lymphocyte derived Ifnγ, T- lymphocytes were adoptively transferred into B6.scid mice. The adoptive transfer of Ifnγ competent T- lymphocytes offered complete protection against S. neurona encephalitis but transfer of Ifnγ deficient T- lymphocytes did not with 100 % of these recipient mice succumbing to S. neruona encephalitis. Histological analysis of collected cerebellar samples confirmed the presences of S. neurona and encephalitis in recipient mice that developed neurologic disease. These studies show that the background strain is critical in studying SCID susceptibility to S. neurona disease and suggest a protective role of Ifnγ producing T- lymphocytes in S. neurona encephalitis susceptible mice.

Can targeting women with behavioural science 'nudges' help black men to find out more about their high risk of contracting prostate cancer?

OBJECTIVE: Prostate cancer is now deadlier than breast cancer in the UK, with more than 12,000 men dying from it in the country in 2018. Black men are nearly three times more likely to suffer prostate cancer, with one in four contracting the disease in their lifetime. Despite being a high risk group very few black men aged 45 and over visit their GP to discuss the pros and cons of screening. This is a problem as early onset of the disease presents no symptoms and when symptoms do appear, such as urinary problems, and men do visit a doctor it is often too late to reverse the cancer's spread. This study investigates using the strong social norm of wives and girlfriends being the guardian of black men's health as a way of influencing their behaviour. METHODS: Using a historically controlled study via email we tested the social norm nudge in the field with 13 Afro-Caribbean organisations across the UK. RESULTS: The trial found the social norm nudge produced a 15.5 per cent click-through rate, which was significantly higher than the historical controls. Meanwhile, the messenger effect saw a click-through rate of 38.5 per cent on men. CONCLUSION: At a national level the social norm nudge would equate to 37,315 black women taking positive action to find out more information about their husband or boyfriend's high risk of contracting prostate cancer. PRACTICE IMPLICATIONS: Use clinicians as messengers in correspondence to promote engagement with information about prostate cancer screening.

Incidence, clinical presentation, and outcomes of Pneumocystis pneumonia when utilizing Polymerase Chain Reaction-based diagnosis in patients with Hodgkin lymphoma.

A Polymerase Chain Reaction-based diagnosis of Pneumocystis Pneumonia (PCP) and the need for anti-Pneumocystis prophylaxis in Hodgkin lymphoma patients receiving chemotherapy requires further investigation. This retrospective, single-center, study evaluated 506 consecutive adult patients diagnosed with Hodgkin lymphoma receiving chemotherapy between January 2006 and August 2018. The cumulative incidence of PCP 1 year after start of chemotherapy was 6.2% (95% CI 3.8-8.5%). Mortality 30 days from PCP diagnosis was 8% (n = 2) with one death attributable to PCP. Bleomycin-containing combination chemotherapy regimen was not significantly associated with a higher risk for PCP when compared to other regimens (HR = 1.59, 95% CI 0.55-4.62 p = 0.40). Anti-Pneumocystis prophylaxis was not significantly associated with a decreased incidence of PCP (HR = 0.51, 95% CI 0.15-1.71, p = 0.28). As the overall incidence is above the commonly accepted 3.5% threshold, clinicians should consider the potential value of prophylaxis. The utility of universal vs. targeted anti-Pneumocystis prophylaxis requires prospective, randomized investigation.

Abrogated AID Function Prolongs Survival and Diminishes Renal Pathology in the BXSB Mouse Model of Systemic Lupus Erythematosus.

Almost a decade has passed since the approval of belimumab, an mAb directed against B lymphocyte stimulation and the first targeted therapy approved for systemic lupus erythematous (SLE) in over 50 y. Although well tolerated, the efficacy of belimumab remains limited and is not labeled for patients suffering from nephritis, the leading cause of patient mortality. We sought to explore alternative targets of autoreactive B lymphocytes through manipulation of affinity maturation. The BXSB/MpJ mouse, a well-established model of human SLE, develops elevated antinuclear Abs and immune complex-mediated nephritis along with other manifestations of SLE-like disease. To limit interfering with critical background genetics, we used CRISPR-Cas9 to disrupt activation-induced cytidine deaminase (AID; Aicda) directly in BXSB zygotes. Homozygous null mice demonstrated significantly prolonged survival compared with wild-type. Although mice continued to develop plasma cells, splenic follicular structure was restored, and renal pathology was reduced. Mice developed expanded germinal center B lymphocyte populations as in other models of AID deficiency as well as increased populations of CD73+ B lymphocytes. Treatment with the small molecule inhibitor of RAD51, 4,4'-diisothiocyano-2,2'-stilbenedisulfonic acid, resulted in minimal changes in disease markers in BXSB mice. The prolonged survival in AID-deficient BXSB mice appears attributed primarily to the reduced renal pathology, warranting further exploration, as current therapeutics targeting lupus nephritis are limited and, thus, in great demand.

Tbo-filgrastim versus filgrastim for stem cell mobilization and engraftment in autologous hematopoietic stem cell transplant patients: A retrospective review.

INTRODUCTION: Filgrastim, a granulocyte colony-stimulating factor, is commonly used in autologous hematopoietic stem cell transplants (HSCTs) to assist with peripheral blood progenitor cell (PBPC) collection and to support stem cell engraftment. In the United States, tbo-filgrastim is approved under its own Biologic License Application and is limited to a single indication excluding the HSCT population. METHODS: Approximately one year after a system-wide formulary change to tbo-filgrastim for all on- and off-label indications, our institution conducted an IRB-approved retrospective comparison of tbo-filgrastim to filgrastim in the autologous HSCT setting. The study included 71 patients who received an autologous HSCT from 1 January 2013 to 31 December 2016 with a documented administration of tbo-filgrastim or filgrastim. RESULTS: There were no statistically significant differences noted on CD34 + counts during stem cell mobilization, neutrophil engraftment, infection rates during the engraftment phase, nor duration of hospitalization during the engraftment phase. More patients in the tbo-filgrastim group received plerixafor per protocol resulting in more patients meeting their PBPC collection goal in one day with fewer collection days overall, a result potentially confounded by institutional protocol changes. Utilizing tbo-filgrastim offered an average cost savings per patient of $2664.26 ($1907.33 for PBPC mobilization and $756.93 for stem cell engraftment) when comparing dollars spent on granulocyte colony-stimulating factor products only. CONCLUSION: Tbo-filgrastim demonstrates comparable efficacy with a cost savings benefit compared to filgrastim for autologous PBPC mobilization and stem cell engraftment.

RAPID COMMUNICATION: TLR4 expressed but with reduced functionality on equine B lymphocytes.

Varying susceptibility exists among mammalian species to the development of potentially fatal endotoxemia due to gram-negative bacteria molecular component, lipopolysaccharide (LPS). Toll-like receptor 4 (TLR4) is responsible for LPS-associated immune response and is expressed on numerous immune cells including B lymphocytes. TLR4 is expressed in a functional form on mouse B lymphocytes, a species much less susceptible to endotoxemia compared with humans who are highly sensitive to endotoxin. Humans possess B lymphocytes that are not responsive to LPS. Likewise, horses are highly susceptible to endotoxemia but the expression and function of TLR4 on horse B lymphocytes is not known. Colic, the major cause of mortality in horses, is often complicated by resultant endotoxemia. The objective of this study was to determine the expression and function of TLR4 on equine B lymphocytes. Lymphocytes were isolated from peripheral blood mononuclear cells that were collected from six horses, and the expression and function of TLR4 was analyzed for each horse. Flow cytometry results indicate TLR4 is expressed on horse B lymphocytes but stimulation with LPS did not alter this expression (P = 0.99) compared with unstimulated B lymphocytes after 24 h. After 72 h of in vitro LPS stimulation, analysis of cell proliferation dye by flow cytometry demonstrated that equine B lymphocytes did not proliferate, while mouse B lymphocytes predictably did. Furthermore, the total number of LPS stimulated equine B lymphocytes did not significantly differ from unstimulated cells after 72 h of culture (P = 0.92). Horse lymphocytes exhibited no significant differences in the measured TLR4 signaling pathway genes (TLR4, IL-10, IL-6, IFNß, and TNFα) when expression was compared with LPS stimulated vs. unstimulated cells. In conclusion, while TLR4 is expressed on horse B lymphocytes, it appears minimally responsive to LPS in vitro, similar to results seen in human B lymphocytes. While further studies are still needed, our work reveals a potential link between B lymphocyte TLR4 expression and endotoxin sensitivity.

Evaluation of a dithiocarbamate derivative as a model of thiol oxidative stress in H9c2 rat cardiomyocytes.

Thiol redox state (TRS) refers to the balance between reduced thiols and their corresponding disulfides and is mainly reflected by the ratio of reduced and oxidized glutathione (GSH/GSSG). A decrease in GSH/GSSG, which reflects a state of thiol oxidative stress, as well as thiol modifications such as S-glutathionylation, has been shown to have important implications in a variety of cardiovascular diseases. Therefore, research models for inducing thiol oxidative stress are important tools for studying the pathophysiology of these disease states as well as examining the impact of pharmacological interventions on thiol pathways. The purpose of this study was to evaluate the use of a dithiocarbamate derivative, 2-acetylamino-3-[4-(2-acetylamino-2-carboxyethylsulfanylthiocarbonylamino)phenylthiocarbamoylsulfanyl]propionic acid (2-AAPA), as a pharmacological model of thiol oxidative stress by examining the extent of thiol modifications induced in H9c2 rat cardiomyocytes and its impact on cellular functions. The extent of thiol oxidative stress produced by 2-AAPA was also compared to other models of oxidative stress including hydrogen peroxide (H2O2), diamide, buthionine sulfoximine, and N,N׳-bis(2-chloroethyl)-N-nitroso-urea. Results indicated that 2-AAPA effectively inhibited glutathione reductase and thioredoxin reductase activities and decreased the GSH/GSSG ratio by causing a significant accumulation of GSSG. 2-AAPA also increased the formation of protein disulfides as well as S-glutathionylation. The alteration in TRS led to a loss of mitochondrial membrane potential, release of cytochrome c, and increase in reactive oxygen species production. Compared to other models, 2-AAPA is more potent at creating a state of thiol oxidative stress with lower cytotoxicity, higher specificity, and more pharmacological relevance, and could be utilized as a research tool to study TRS-related normal and abnormal biochemical processes in cardiovascular diseases.