Comparing the Organs and Vasculature of the Head and Neck in Five Murine Species.

BACKGROUND/AIM: The purpose of the present study was to delineate the cervical and facial vascular and associated anatomy in five murine species, and compare them for optimal use in research studies focused on understanding the pathology and treatment of diseases in humans. MATERIALS AND METHODS: The specific adult male animals examined were mice (C57BL/6J), rats (F344), mongolian gerbils (Merionesunguiculatus), hamsters (Syrian), and guinea pigs (Hartley). To stain the vasculature and organs, of the face and neck, each animal was systemically perfused using the vital stain, Trypan Blue. Following this step, the detailed anatomy of the head and neck could be easily visualized in all species. RESULTS: Unique morphological characteristics were demonstrated by comparing the five species, including symmetry of the common carotid origin bilaterally in the Mongolian Gerbil, a large submandibular gland in the hamster and an enlarged buccal branch in the Guinea Pig. In reviewing the anatomical details, this staining technique proves superior for direct surgical visualization and identification. CONCLUSION: The anatomical details provided through these five species atlas will help experimental researchers in the future to select the most appropriate animal model for specific laboratory studies aimed to improve our understanding and treatment of diseases in patients.

p21WAF/CIP1/SDI1 is upregulated due to increased mRNA stability during hydroxyurea-induced senescence of human fibroblasts.

Hydoxyurea induces senescence-like growth arrest in normal human fibroblasts. p21(WAF/CIP1/SDI1), a cyclin dependent kinase inhibitor, was found to be upregulated during this growth arrest. Levels of p21(WAF/CIP1/SDI1) protein and mRNA were increased nine-fold by hydroxyurea in these cells. In order to determine whether p21(WAF/CIP1/SDI1) mRNA is increased by hydroxyurea at the transcriptional level, human fibroblast cells were transfected with reporter constructs containing a p21(WAF/CIP1/SDI1) promoter fragment and then treated with hydroxyurea. The luciferase activities in the reporter-transfected fibroblast cells were not increased by hydroxyurea, indicating that p21(WAF/CIP1/SDI1) transcription was not elevated by hydroxyurea. The half-life of the p21(WAF/CIP1/SDI1) mRNA was increased by 2.5-fold but that of p21(WAF/CIP1/SDI1) protein was not. Our results suggest that increased mRNA stability is the major mechanism of p21(WAF/CIP1/SDI1) elevation in the hydroxyurea-induced growth arrest of human fibroblasts.