Publications by authors named "Ralph Meyer"

Reproductive toxicology testing is essential to safeguard public health of current and future generations. Traditional toxicological testing of male reproduction has focused on evaluating substances for acute toxicity to the reproductive system, with fertility assessment as a main endpoint and infertility a main adverse outcome. Newer studies in the last few decades have significantly widened our understanding of what represents an adverse event in reproductive toxicology, and thus changed our perspective of what constitutes a reproductive toxicant, such as endocrine disrupting chemicals that affect fertility and offspring health in an intergenerational manner.

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  • This study investigates the psychological impacts of the COVID-19 pandemic on Canadian cancer patients, focusing on levels of distress and post-traumatic growth (PTG).
  • A survey conducted from February to December 2021 revealed that significant portions of patients reported severe depression, anxiety, and emotional distress, while 43% experienced high PTG.
  • Factors such as social difficulties, gender, education level, and safety behaviors influenced levels of distress and PTG, highlighting the need for tailored post-pandemic care strategies for cancer patients.
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Tumor-infiltrating regulatory T cells (TI-Tregs) elicit immunosuppressive effects in the tumor microenvironment (TME) leading to accelerated tumor growth and resistance to immunotherapies against solid tumors. Here, we demonstrate that poly-(ADP-ribose)-polymerase-11 (PARP11) is an essential regulator of immunosuppressive activities of TI-Tregs. Expression of PARP11 correlates with TI-Treg cell numbers and poor responses to immune checkpoint blockade (ICB) in human patients with cancer.

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The prevalence of frailty in clinical trials of lymphoma is unknown. We conducted a secondary analysis of the phase III LY.12 trial in which patients with relapsed aggressive non-Hodgkin lymphoma were randomized to different salvage regimens before autologous stem cell transplant.

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Early integrated palliative care (EIPC) for patients with advanced cancers requires the involvement of family doctors (FDs) and oncologists. We compared attitudes between patients and their providers regarding the delivery of EIPC. Patients with newly diagnosed incurable gastrointestinal (GI) cancer at a tertiary cancer centre in Ontario, Canada, were surveyed using a study-specific instrument regarding the importance of and preferences for accessing support across eight domains of palliative care.

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Background: Cancer in a loved one can have negative effects on child health and development. Child Life Specialists (CLSs) specialize in assisting children understand and cope with difficult medical scenarios but are generally not available in adult care facilities to support the needs of patient-families with minor children. We conducted a mixed-methods study of the implementation of a pilot CLS program at a tertiary oncology centre.

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In Brief: In light of the increasing age of first-time fathers, this article summarizes the current scientific knowledge base on reproductive aging in the male, including sperm quality and health impacts for the offspring. The emerging role of NAD decline in reproductive aging is highlighted.

Abstract: Over the past decades, the age of first-time fathers has been steadily increasing due to socio-economic pressures.

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Early-stage Hodgkin lymphoma has become one of the most curable hematologic malignancies. Depending upon the disease location, possible toxicities, and patient preference, chemotherapy alone with ABVD remains an accepted treatment modality for this disease. There remains a paucity of data regarding the longitudinal trajectory of health-related quality of life (HRQoL) in patients treated for HL.

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Research into the functions of nicotinamide adenine dinucleotide (NAD) has intensified in recent years due to the insight that abnormally low levels of NAD are involved in many human pathologies including metabolic disorders, neurodegeneration, reproductive dysfunction, cancer, and aging. Consequently, the development and validation of novel NAD-boosting strategies has been of central interest, along with the development of models that accurately represent the complexity of human NAD dynamics and deficiency levels. In this review, we discuss pioneering research and show how modern researchers have long since moved past believing that pellagra is the overt and most dramatic clinical presentation of NAD deficiency.

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In mammals, nicotinamide (NAM) is the primary NAD precursor available in circulation, a signaling molecule, and a precursor for methyl-nicotinamide (M-NAM) synthesis. However, our knowledge about how the body regulates tissue NAM levels is still limited. Here we demonstrate that dietary vitamin B partially regulates plasma NAM and NAM-derived metabolites, but not their tissue levels.

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  • Evasion of tumor immunity and resistance to treatments in solid tumors is supported by an immunosuppressive tumor microenvironment (TME), characterized by factors like regulatory T cells and adenosine.
  • The study identified that these TME factors downregulate the IFNAR1 receptor on CD8 cytotoxic T lymphocytes (CTLs) through the action of PARP11, which is increased in CTLs within tumors.
  • Inhibition of PARP11 not only maintains IFNAR1 levels but also boosts CTL activity against tumors, enhancing the effectiveness of chimeric antigen receptor (CAR) T cell therapies.
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Advanced paternal age has increasingly been recognized as a risk factor for male fertility and progeny health. While underlying causes are not well understood, aging is associated with a continuous decline of blood and tissue NAD levels, as well as a decline of testicular functions. The important basic question to what extent ageing-related NAD decline is functionally linked to decreased male fertility has been difficult to address due to the pleiotropic effects of aging, and the lack of a suitable animal model in which NAD levels can be lowered experimentally in chronologically young adult males.

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  • The study aimed to compare the effectiveness of virtual care with remote automated monitoring (RAM) versus standard care in increasing the number of days adults were able to stay at home after non-elective surgery during the COVID-19 pandemic.
  • Conducted as a multicenter randomized controlled trial in eight Canadian hospitals, 905 adults were divided into two groups: one receiving virtual care with daily monitoring and the other receiving standard post-operative care.
  • The results showed a slight advantage for the virtual care group in terms of days alive at home (29.7 vs. 29.5 days), but the difference was minimal and not statistically significant, indicating no major benefit from the virtual care approach.
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We conducted an analysis of indirect costs alongside the LY.12 randomized trial in patients with relapsed or refractory (R/R) aggressive non-Hodgkin lymphoma (NHL). Lost productivity data for Canadian patients and caregivers in the trial were collected at baseline and with each chemotherapy cycle pre-transplant, using an adapted Lost Productivity questionnaire.

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In a prospective study, we sought to determine acceptability of linkage of administrative and clinical trial data among Canadian patients and Research Ethics Boards (REBs). The goal is to develop a more harmonized approach to data, with potential to improve clinical trial conduct through enhanced data quality collected at reduced cost and inconvenience for patients. On completion of the original LY.

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  • The PVC-RAM trial aims to assess whether virtual care with remote automated monitoring (RAM) improves post-discharge outcomes for patients who have undergone nonelective surgeries during the COVID-19 pandemic.
  • The study involves 900 adults from 8 Canadian hospitals, who are randomly assigned to receive either RAM or standard care, with daily monitoring of vital signs and interaction with nurses over a 30-day period.
  • Results from this trial will help shape better post-surgical care strategies and will be shared through various platforms for broader impact, both during and after the pandemic.
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Similar to female reproductive health, male reproductive health declines with increasing age, albeit in a more gradual way. In the US, the average age of first-time fathers has been steadily increasing since 1980. This is concerning because increasing paternal age is positively correlated with reduced sperm chromatin quality and higher numbers of DNA strand breaks (DNA sb), which negatively affects pregnancy outcome and child development.

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The conditional survival of patients after frontline therapy for diffuse large B-cell lymphoma (DLBCL) approaches that of the general population once patients have survived disease free for 2 years. We sought to determine the conditional survival of patients among patients with relapsed de novo DLBCL successfully undergoing an autologous stem-cell transplant (ASCT) after first relapse. A total of 478 patients with de novo DLBCL, relapsed after 1 treatment from the Collaborative Trial in Relapsed Aggressive Lymphoma (CORAL) and LY.

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Objective: To evaluate effects of poly(ADP-ribose) polymerase-1 (PARP1) inhibitors on the production of tumor necrosis factor-α (TNF-α) by interferon-γ (IFN-γ)- and lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMCs) of horses as an in vitro model of inflammation in horses.

Sample: 1,440 samples of PBMCs from 6 healthy research horses.

Procedures: From heparinized whole blood samples, PBMC cultures were obtained.

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Maraviroc (MVC, a CCR5 antagonist) is only fully active against CCR5 tropic [R5] HIV-1, and tropism testing is required prior to initiating treatment. The MODERN study prospectively compared genotypic (GTT) and phenotypic (Trofile®) tropism testing with treatment-naive HIV-1-infected participants randomized 1:1 to either GTT or Trofile tropism assessments. Participants with R5 virus were randomized 1:1 to receive darunavir/ritonavir (DRV/r) with either MVC or tenofovir/emtricitabine.

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NAD is essential for redox reactions in energy metabolism and necessary for DNA repair and epigenetic modification. Humans require sufficient amounts of dietary niacin (nicotinic acid, nicotinamide, and nicotinamide riboside) for adequate NAD synthesis. In contrast, mice easily generate sufficient NAD solely from tryptophan through the kynurenine pathway.

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Poly(ADP-ribosyl)ation (PAR) is a post-translational protein modification catalysed by enzyme member of the poly(ADP-ribose) polymerases (PARPs) family. The activation of several PARPs is triggered by DNA strand breakage and the main PARP enzyme involved in this process is PARP1. Besides its involvement in DNA repair, PARP1 is involved in several cellular processes including transcription, epigenetics, chromatin re-modelling as well as in the maintenance of genomic stability.

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We developed a novel simulation model integrating multiple data sets to project long-term outcomes with contemporary therapy for early-stage Hodgkin lymphoma (ESHL), namely combined modality therapy (CMT) versus chemotherapy alone (CA) via F-fluorodeoxyglucose positron emission tomography response-adaption. The model incorporated 3-year progression-free survival (PFS), probability of cure with/without relapse, frequency of severe late effects (LEs), and 35-year probability of LEs. Furthermore, we generated estimates for quality-adjusted life years (QALYs) and unadjusted survival (life years, LY) and used model projections to compare outcomes for CMTversusCA for two index patients.

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Due to gravity the venous vasculature in the lower extremities is exposed to elevated pressure levels which may be amplified by obesity or pregnancy. As a consequence, venules dilate and may be slowly transformed into varicose or spider veins. In fact, chronically elevated venous pressure was sufficient to cause the corkscrew-like enlargement of superficial veins in mice.

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