Vieira JC, Dominguez A, Richards F, Cupp EW, Mendez-Galvan J, Sauerbrey M, Cupp MS, Eversole RR, Castro J, Guzman JR, Duke BO, Mackenzie CD
[
Am J Trop Med Hyg,
2004]
The objective of this study was to examine nodules from Mexico, Guatemala, and Ecuador collected over a one-year period (2001) to determine the effects of semi-annual ivermectin treatments on Onchocerca volvulus macrofilarial populations. Nodules were sectioned, stained with hematoxylin and eosin, and histologic findings were compared between countries and with historical data prior to the introduction of ivermectin into the region. Nodules from Ecuador had 10 times more dead or moribund worms than the historical control (66.6% versus 6.5%); nodules from patients from Mexico and Guatemala did not differ from the control. More than 80% of the female worms in each country were uninseminated and producing unfertilized oocytes. Nodules containing males differed in each country from the historical control (P < 0.0001), with presence of males ranging from 19.7% in Mexico to 13.6% in Ecuador versus 73% in the control. Nodules with females producing active microfilariae ranged from 7.8% (Mexico) to 2.7% (Ecuador) versus 60% in the historical control (P < 0.0001). Nodules from Ecuador and Mexico were significantly smaller in size than those from Guatemala or historical controls (P < 0.0005). These results depict a deteriorating condition of adult O. volvulus populations in Mexico, Guatemala and Ecuador, indicating that semi-annual ivermectin treatment of >/=6 years has had a profound effect on survival and reproduction of this species.
[
Genetics,
2020]
Environmental toxicants are chemicals that negatively affect human health. Although there are numerous ways to limit exposure, the ubiquitous nature of certain environmental toxicants makes it impossible to avoid them entirely. Consequently, scientists are continuously working toward developing strategies for combating their harmful effects. Using the nematode <i>Caenorhabditis elegans</i>, a model with many genetic and physiological similarities to humans, researchers in the Colaiacovo laboratory have identified several molecular mechanisms by which the toxic agent bisphenol A (BPA) interferes with reproduction. Here, we address their recent discovery that a widely available compound, Coenzyme Q10 (CoQ10), can rescue BPA-induced damage. This work is significant in that it poses a low-cost method for improving reproductive success in humans. The goal of this primer is to assist educators and students with navigating the paper entitled "Antioxidant CoQ10 Restores Fertility by Rescuing Bisphenol A-Induced Oxidative DNA Damage in the <i>Caenorhabditis elegans</i> Germline." It is ideally suited for integration into an upper-level undergraduate course such as Genetics, Cell and Molecular Biology, Developmental Biology, or Toxicology. The primer provides background information on the history of BPA, the utility of the <i>C. elegans</i> germ line as a model for studying reproductive toxicity, and research methods including assessment of programmed cell death, fluorescent microscopy applications, and assays to quantify gene expression. Questions for deeper exploration in-class or online are provided.<b>Related article in <i>GENETICS</i>:</b> Hornos Carneiro MF, Shin N, Karthikraj R, Barbosa F Jr, Kannan K, Colaiacovo MP. Antioxidant CoQ10 restores fertility by rescuing bisphenol A-induced oxidative DNA damage in the <i>Caenorhabditis elegans</i> Germline. Genetics 214:381-395.