Browsing by Author "Johnston, Nancy A."

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    Effectiveness of the Glass Bead Sterilizer for Sterilizing Surgical Instruments
    (American Association for Laboratory Animal Science, 2022) Skiles, Beth; Johnston, Nancy A.; Hendrix, G. Kenitra; Hickman, Debra L.; Laboratory Animal Resource Center, School of Medicine
    Survival rodent surgery requires the use of sterile instruments for each animal, which can be challenging when performing multiple surgeries on batches of animals. Glass bead sterilizers (GBS) are widely considered to facilitate this practice by sterilizing the tips of the instruments between animals. However, other disciplines have raised questions about the efficacy of the GBS, especially when used with surgical tools that have grooves or ridges that may contain organic debris. In this study, we evaluated the efficacy of the GBS to sterilize instruments commonly used in rodent surgery by intentionally contaminating a selection of instruments with a standardized bacterial broth inoculated with Staphylococcus aureus and Escherichia coli. As expected, a simple ethanol wipe was ineffective in sterilizing instruments in all treatment groups. An ethanol wipe followed by GBS was effective in sterilizing 82.5% (99 of 120) of the instruments. Our study suggests that the GBS may not be effective for consistent sterilization of surgical instruments.
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    Osteoclast-mediated bone loss observed in a COVID-19 mouse model
    (2021-10-02) Awosanya, Olatundun D.; Dalloul, Christopher E.; Blosser, Rachel J.; Dadwal, Ushashi C.; Carozza, Mariel; Boschen, Karen; Klemsz, Michael J.; Johnston, Nancy A.; Bruzzaniti, Angela; Robinson, Christopher M.; Srour, Edward F.; Kacena, Melissa A.
    The consequences of SARS-CoV-2 infection on the musculoskeletal system represent a dangerous knowledge gap. Aging patients are at added risk for SARS-CoV-2 infection; therefore, a greater understanding of the resulting musculoskeletal sequelae of SARS-CoV-2 infection may help guide clinical strategies. This study examined fundamental bone parameters among mice treated with escalating viral loads. Male C57BL/6J (WT, n = 17) and B6.Cg-Tg(K18-ACE2)2Prlmn/J mice (K18-hACE2 transgenic mice, n = 21) expressing human ACE2 (TG) were divided into eight groups (n = 4-6/group) and subjected to intranasal dosing of 0, 1 × 103, 1 × 104, and 1 × 105 PFU (plaque forming units) of human SARS-CoV-2. Animal health was assessed daily by veterinary staff using established and validated scoring criteria (activity, posture, body condition scores and body weight). We report here that mock and WT infected mice were healthy and completed the study, surviving until 12-14 days post infection (dpi). In contrast, the TG mice infected with 1 × 105 PFU all experienced severe health declines that necessitated early euthanasia (6-7 dpi). For TG mice infected with 1 × 104 PFU, 2 mice were also euthanized after 7 dpi, while 3 mice showed signs of moderate disease at day 6 dpi, but recovered fully by day 11 dpi. Four of the 5 TG mice that were infected with 1 × 103 PFU remained healthy throughout the study. This suggests that our study mimics what is seen during human disease, where some patients develop severe disease resulting in death, while others have moderate to severe disease but recover, and others are asymptomatic. At necropsy, femurs were extracted and analyzed by μCT. No difference was found in μCT determined bone parameters among the WT groups. There was, however, a significant 24.4% decrease in trabecular bone volume fraction (p = 0.0009), 19.0% decrease in trabecular number (p = 0.004), 6.2% decrease in trabecular thickness (p = 0.04), and a 9.8% increase in trabecular separation (p = 0.04) among surviving TG mice receiving any viral load compared to non-infected controls. No differences in cortical bone parameters were detected. TRAP staining revealed surviving infected mice had a significant 64% increase in osteoclast number, a 27% increase in osteoclast surface, and a 38% increase in osteoclasts per bone surface. While more studies are needed to investigate the long-term consequences of SARS-CoV-2 infection on skeletal health, this study demonstrates a significant reduction in several bone parameters and corresponding robust increases in osteoclast number observed within 2 weeks post-infection in surviving asymptomatic and moderately affected mice.
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    Osteoclast-mediated bone loss observed in a COVID-19 mouse model
    (Elsevier, 2022-01) Awosanya, Olatundun D.; Dalloul, Christopher E.; Blosser, Rachel J.; Dadwal, Ushashi C.; Carozza, Mariel; Boschen, Karen; Klemsz, Michael J.; Johnston, Nancy A.; Bruzzaniti, Angela; Robinson, Christopher M.; Srour, Edward F.; Kacena, Melissa A.; Orthopaedic Surgery, School of Medicine
    The consequences of SARS-CoV-2 infection on the musculoskeletal system represent a dangerous knowledge gap. Aging patients are at added risk for SARS-CoV-2 infection; therefore, a greater understanding of the resulting musculoskeletal sequelae of SARS-CoV-2 infection may help guide clinical strategies. This study examined fundamental bone parameters among mice treated with escalating viral loads. Male C57BL/6J (WT, n = 17) and B6.Cg-Tg(K18-ACE2)2Prlmn/J mice (K18-hACE2 transgenic mice, n = 21) expressing human ACE2 (TG) were divided into eight groups (n = 4-6/group) and subjected to intranasal dosing of 0, 1 × 103, 1 × 104, and 1 × 105 PFU (plaque forming units) of human SARS-CoV-2. Animal health was assessed daily by veterinary staff using established and validated scoring criteria (activity, posture, body condition scores and body weight). We report here that mock and WT infected mice were healthy and completed the study, surviving until 12-14 days post infection (dpi). In contrast, the TG mice infected with 1 × 105 PFU all experienced severe health declines that necessitated early euthanasia (6-7 dpi). For TG mice infected with 1 × 104 PFU, 2 mice were also euthanized after 7 dpi, while 3 mice showed signs of moderate disease at day 6 dpi, but recovered fully by day 11 dpi. Four of the 5 TG mice that were infected with 1 × 103 PFU remained healthy throughout the study. This suggests that our study mimics what is seen during human disease, where some patients develop severe disease resulting in death, while others have moderate to severe disease but recover, and others are asymptomatic. At necropsy, femurs were extracted and analyzed by μCT. No difference was found in μCT determined bone parameters among the WT groups. There was, however, a significant 24.4% decrease in trabecular bone volume fraction (p = 0.0009), 19.0% decrease in trabecular number (p = 0.004), 6.2% decrease in trabecular thickness (p = 0.04), and a 9.8% increase in trabecular separation (p = 0.04) among surviving TG mice receiving any viral load compared to non-infected controls. No differences in cortical bone parameters were detected. TRAP staining revealed surviving infected mice had a significant 64% increase in osteoclast number, a 27% increase in osteoclast surface, and a 38% increase in osteoclasts per bone surface. While more studies are needed to investigate the long-term consequences of SARS-CoV-2 infection on skeletal health, this study demonstrates a significant reduction in several bone parameters and corresponding robust increases in osteoclast number observed within 2 weeks post-infection in surviving asymptomatic and moderately affected mice.
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    Peripheral blood-derived mesenchymal stem cells demonstrate immunomodulatory potential for therapeutic use in horses
    (PLOS, 2019-03-14) Longhini, Ana Leda F.; Salazar, Tatiana E.; Vieira, Cristiano; Trinh, Thao; Duan, Yaqian; Pay, Louise M.; Li Calzi, Sergio; Losh, Megan; Johnston, Nancy A.; Xie, Huisheng; Kim, Minsu; Hunt, Robert J.; Yoder, Mervin C.; Santoro, Domenico; McCarrel, Taralyn M.; Grant, Maria B.; Ophthalmology, School of Medicine
    Previously, we showed that mesenchymal stem cells (MSC) can be mobilized into peripheral blood using electroacupuncture (EA) at acupoints, LI-4, LI-11, GV-14, and GV-20. The purpose of this study was to determine whether EA-mobilized MSC could be harvested and expanded in vitro to be used as an autologous cell therapy in horses. Peripheral blood mononuclear cells (PBMC) isolated from young and aged lame horses (n = 29) showed a marked enrichment for MSCs. MSC were expanded in vitro (n = 25) and administered intravenously at a dose of 50 x 106 (n = 24). Treatment resulted in significant improvement in lameness as assessed by the American Association of Equine Practitioners (AAEP) lameness scale (n = 23). MSCs exhibited immunomodulatory function by inhibition of lymphocyte proliferation and induction of IL-10. Intradermal testing showed no immediate or delayed immune reactions to MSC (1 x 106 to 1 x 104). In this study, we demonstrated an efficient, safe and reproducible method to mobilize and expand, in vitro, MSCs in sufficiently high concentrations for therapeutic administration. We confirm the immunomodulatory function of these cells in vitro. This non-pharmacological and non-surgical strategy for stem cell harvest has a broad range of biomedical applications and represents an improved clinically translatable and economical cell source for humans.