Phosphoglucomutase 1 contributes to optimal cyst development in Toxoplasma gondii.

OBJECTIVE: Toxoplasma gondii is a ubiquitous parasite of medical and veterinary importance; however, there exists no cure for chronic toxoplasmosis. Metabolic enzymes required for the production and maintenance of tissue cysts represent promising targets for novel therapies. Here, we use reverse genetics to investigate the role of Toxoplasma phosphoglucomutase 1, PGM1, in Toxoplasma growth and cystogenesis. RESULTS: We found that disruption of pgm1 did not significantly affect Toxoplasma intracellular growth and the lytic cycle. pgm1-defective parasites could differentiate into bradyzoites and produced cysts containing amylopectin in vitro. However, cysts produced in the absence of pgm1 were significantly smaller than wildtype. Together, our findings suggest that PGM1 is dispensable for in vitro growth but contributes to optimal Toxoplasma cyst development in vitro, thereby necessitating further investigation into the function of this enzyme in Toxoplasma persistence in its host.

Identifying and Addressing Health Disparities among African American Men with Prostate Cancer: a Systematic Literature Review.

OBJECTIVE: To answer the research question inquiring which determinants lead to health disparities among African American Men with Prostate Cancer and what factors influence clinical decision making by oncologists when delivering prostate cancer interventions in order to improve morbidity and mortality. METHODS: Primary and secondary sources were extracted from articles located using Google Scholar and PubMed databases. Terms included in the literature search were "African American men," "prostate cancer," "determinants," "disparities," and "interventions." Focusing on these specific terms helped narrow the scope of this systematic review by indicating which studies met the inclusion criteria. Only 20 articles were included in this systematic review. Specific inclusion criteria for this review were: 1) a publication date between 2013 and the current year; 2) a focus on African American men diagnosed with prostate cancer; 3), randomized or quasi-randomized controlled trials (RCTs), and; 4) evidence-based interventions used by oncologists. RESULTS: The articles included when this systematic review provide evidence that oncologists will need to play more central roles in preventing premature death when African American men who present a higher risk of prostate cancer compared to their White and Hispanic/Latino counterparts. Shared decision-making in screening and diagnosis is also essential to close health disparities as well as improve population-level health outcomes. CONCLUSION: The systematic review argues that oncologists will need to integrate population-based interventions capable of presenting strong empirical evidence about which determinants contribute to health disparities among African American men diagnosed with prostate cancer.

Nitrogen form, concentration, and micronutrient availability affect microcystin production in cyanobacterial blooms.

Harmful algal blooms (HABs) are increasing in magnitude, frequency, and duration caused by anthropogenic factors such as eutrophication and altered climatic regimes. While the concentrations and ratios of nitrogen (N) and phosphorus are correlated with bloom biomass and cyanotoxin production, there is less known about how N forms and micronutrients (MN) interact to regulate HABs and cyanotoxin production. Here, we used two separate approaches to examine how N and MN supply affects cyanobacteria biomass and cyanotoxin production. First, we used a Microcystis laboratory culture to examine how N and MN concentration and N form affected the biomass, particulate N, and microcystin-LR concentration and cell quotas. Then, we monitored the N, iron, molybdenum, and total microcystin concentrations from a hypereutrophic reservoir. From this hypereutrophic reservoir, we performed a community HAB bioassay to examine how N and MN addition affected the biomass, particulate N, and microcystin concentration. Microcystis laboratory cultures grown in high urea and MN conditions produced more biomass, particulate N, and had similar C:N stoichiometry, but lower microcystin-LR concentrations and cell quotas when compared to high nitrate and MN conditions. Our community HAB bioassay revealed no interactions between N concentration and MN addition caused by non-limiting MN background concentrations. Biomass, particulate N, and microcystin concentration increased with N addition. The community HAB amended with MN resulted in greater microcystin-LA concentration compared to non-MN amended community HABs. Our results highlight the complexity of how abiotic variables control biomass and cyanotoxin production in both laboratory cultures of Microcystis and community HABs.