Using the Microbiome as a Regenerative Medicine Strategy for Autoimmune Diseases.

Autoimmune (AI) diseases, which present in a multitude of systemic manifestations, have been connected to many underlying factors. These factors include the environment, genetics, individual microbiomes, and diet. An individual's gut microbiota is an integral aspect of human functioning, as it is intimately integrated into the metabolic, mechanical, immunological, and neurologic pathways of the body. The microbiota dynamically changes throughout our lifetimes and is individually unique. While the gut microbiome is ever-adaptive, gut dysbiosis can exert a significant influence on physical and mental health. Gut dysbiosis is a common factor in various AI, and diets with elevated fat and sugar content have been linked to gut microbiome alterations, contributing to increased systemic inflammation. Additionally, multiple AI's have increased levels of certain inflammatory markers such as TNF-a, IL-6, and IL-17 that have been shown to contribute to arthropathy and are also linked to increased levels of gut dysbiosis. While chronic inflammation has been shown to affect many physiologic systems, this review explores the connection between gut microbiota, bone metabolism, and the skeletal and joint destruction associated with various AI, including psoriatic arthritis, systemic lupus erythematosus, irritable bowel disease, and rheumatoid arthritis. This review aims to define the mechanisms of microbiome crosstalk between the cells of bone and cartilage, as well as to investigate the potential bidirectional connections between AI, bony and cartilaginous tissue, and the gut microbiome. By doing this, the review also introduces the concept of altering an individual's specific gut microbiota as a form of regenerative medicine and potential tailored therapy for joint destruction seen in AI. We hope to show multiple, specific ways to target the microbiome through diet changes, rebalancing microbial diversity, or decreasing specific microbes associated with increased gut permeability, leading to reduced systemic inflammation contributing to joint pathology. Additionally, we plan to show that diet alterations can promote beneficial changes in the gut microbiota, supporting the body's own endogenous processes to decrease inflammation and increase healing. This concept of microbial alteration falls under the definition of regenerative medicine and should be included accordingly. By implementing microbial alterations in regenerative medicine, this current study could lend increasing support to the current research on the associations of the gut microbiota, bone metabolism, and AI-related musculoskeletal pathology.

Poor Outcomes of Patients From Delayed Care After Ground Level Falls.

BACKGROUND: Ground level falls are a common cause of morbidity and mortality in trauma patients. Delayed presentation in many conditions has been proven to lead to worsened outcomes. Currently, there are limited data on outcomes of those who have a delayed presentation after a ground level fall. MATERIALS AND METHODS: This study was a retrospective analysis of the Trauma Registry at our center. Any adult patient who presented after a ground level fall was grouped based on their time to presentation post-injury: less than or greater than 24 h. Age, gender, hospital length of stay (LOS), intensive care unit (ICU) LOS, mechanical ventilation days, Injury Severity Score, and mortality were patient characteristics gathered. A Student's t-test and Chi-squared testing were utilized to determine the presence of significant differences between the groups. Significance was set at P < .05. RESULTS: Two hundred of 4018 patients had delayed presentation. Those with delayed presentation were more likely to be male (P = .028), younger in age (71 vs 74 years old, P < .01), had greater hospital LOS (6 vs. 5, P < .01), ICU LOS (5 vs. 3, P < .01), and mechanical ventilation days (13 vs. 5 days, P < .01). They also had higher ISS (8 vs. 7, P < .01), and mortality was significantly higher in those who presented after 24 h (P = .034). CONCLUSION: Patients with delayed presentation after a ground level fall have worsened Injury Severity Scores and outcomes to include hospital and ICU LOS, ventilator days, and overall mortality.

Optical Imaging of Isolated Murine Ventricular Myocytes.

The ability to isolate adult cardiac myocytes has permitted researchers to study a variety of cardiac pathologies at the single cell level. While advances in calcium sensitive dyes have permitted the robust optical recording of single cell calcium dynamics, recording of robust transmembrane optical voltage signals has remained difficult. Arguably, this is because of the low single to noise ratio, phototoxicity, and photobleaching of traditional potentiometric dyes. Therefore, single cell voltage measurements have long been confined to the patch clamp technique which while the gold standard, is technically demanding and low throughput. However, with the development of novel potentiometric dyes, large, fast optical responses to changes in voltage can be obtained with little to no phototoxicity and photobleaching. This protocol describes in detail how to isolate adult murine myocytes which can be used for cellular shortening, calcium, and optical voltage measurements. Specifically, the protocol describes how to use a ratiometric calcium dye, a single-excitation calcium dye, and a single excitation voltage dye. This approach can be used to assess the cardiotoxicity and arrhythmogenicity of various chemical agents. While phototoxicity is still an issue at the single cell level, methodology is discussed on how to reduce it.

The effects of the ketone body ß-hydroxybutyrate on isolated rat ventricular myocyte excitation-contraction coupling.

ß-hydroxybutyrate is the primary ketone body produced by the body during ketosis and is used to meet its metabolic demands. The healthy adult heart derives most of its energy from fatty acid oxidation. However, in certain diseases, the heart alters its substrate preference and increases its ketone body metabolism. Little is known about the effects of ßOHB on ventricular myocyte excitation-contraction coupling. Therefore, we examined the effects of ketone body metabolism on single cell excitation-contraction coupling during normoxic and hypoxic conditions. Myocytes were isolated from adult rats, cultured for 18 h in RPMI 1640, RPMI 1640 no glucose, and M199, HEPES with/without various amount of ßOHB added. To simulate hypoxia, myocytes were incubated at 1%O2, 5% CO2 for 1 h followed by incubation at atmospheric oxygen (21%O2,5% CO2) for 30 min before recordings. Recordings were obtained using an IonOptix system at 36±1ᵒ C. Myocytes were paced at 0.5, 1, 2, 3, and 4 Hz. We found that exposure to ßOHB had no effect on excitation-contraction coupling. However, culturing cells with ßOHB results in a significant increase in both contraction and calcium in RPMI 1640 media. Dose response experiments demonstrated 0.5 mM ßOHB is enough to increase myocyte contraction in the absence of glucose. However, ßOHB has no measurable effects on myocytes cultured in a nutrient rich media, M199, HEPES. Therefore, ßOHB improves single cell excitation-contraction coupling, is protective against hypoxia, and may be a beneficial adaptation for the heart during periods of nutrient scarcity and or metabolic dysregulation.