In vitro cell-based assays are an essential and universally used step in elucidation of biological processes as well as in drug development. However, results obtained depend on the validity of protocols used. This statement certainly pertains to in vitro assays of oxidative stress. The holy grail of in vitro models is reliability and predictability of outcomes that relate to a single variable like addition of hydrogen peroxide or xanthine oxidase. Without such validated outcomes, comparison of results among different laboratories is not possible. Achieving this goal requires a thorough understanding of the complex interplay between the cells, their environment, and the experimental assays. Furthermore, as this knowledge is attained, it must be disseminated and used to update and standardize existing protocols. Here, we confirm and extend the effect of pyruvate and cell density on in vitro oxidative stress assays. Cell viability was assessed using a colorimetric assay measuring the reduction of a tetrazolium salt (XTT) into a colored formazan dye. Extracellular hydrogen peroxide concentrations were measured using the foxp3 assay. We confirmed a previously reported finding that pyruvate, a common ingredient in cell culture media, acts as an extracellular scavenger of reactive oxygen species. We also demonstrated that cell density directly correlates with resistance to oxidative stress in tissue culture. It is theorized that the protective effect due to cell density predominantly relates to intracellular factors such as reduced glutathione and extracellular factors such as catalase.
Cervical spine injuries are challenging to diagnose based on clinical assessment alone for even the most seasoned pediatric emergency medicine physician. Traumatic cervical spine injuries in the pediatric population are quite rare; however, when present they have the potential for devastating neurological outcomes. Unlike adults, no well validated clinical assessment tool exists for pediatric patients. When imaging is obtained, what may appear as pathologic to the unseasoned eye may in reality be a normal variant, non-pathological, or normal growth pattern. On the other hand, detection of cervical spine injuries may be very subtle, and in some cases can only be identified on MRI. Any child presenting with abnormal vital signs, altered mental status, or an abnormal neurological exam should be assumed to have a cervical spine injury. Maintaining cervical spine precautions and obtaining prompt imaging and specialist evaluation are indicated when stable and in the appropriate clinical setting.
Hirschsprung’s disease and Hirschsprung-associated enterocolitis are functional disorders of the enteric nervous system leading to a functional bowel obstruction. Patients will often present in the first few days of life with delayed passage of meconium, abdominal distention, and poor feeding. Hirschsprung-associated enterocolitis is associated with increased morbidity and mortality and will present with signs and symptoms consistent with bowel obstruction, frankly bloody diarrhea, lethargy, fever, and, in severe cases, septic shock. Suspected cases should receive aggressive fluid resuscitation and broad-spectrum antibiotics. The gold standard for diagnosis is rectal biopsy and definitive management is surgical. Though many patients report some degree of bowel dysfunction later in life, a great number of patients do well.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.