ABSTRACT
A conducted electrical device (CED), usually Taser®, is commonly used by law enforcement officers to aid in the incapacitation of subjects. While CEDs are considered "safe" for use on subjects, adverse events may rarely occur. We report a case of a 23-year-old male presenting with severe back pain following deployment of a CED with resulting acute compression fractures of the thoracic sixth, seventh, and eighth vertebral bodies. To the best of our knowledge, this represents the third case of traumatic injury from CED discharge to be reported in the literature since 1995.
ABSTRACT
More than 29 million adults in the United States have been diagnosed with hearing loss. Interestingly, elevated homocysteine (Hcy) levels, known as hyperhomocysteinemia (HHcy), are also associated with impaired hearing. However, the associated mechanism remains obscure. The collagen receptor such as discoidin domain receptor 1 and matrix metalloproteinase (MMP) play a significant role in inner ear structure and function. We hypothesize that HHcy increases hearing thresholds by compromise in inner ear vasculature resulted from impaired Hcy metabolism, increased oxidative stress, collagen IVa and collagen Ia turnover. The treatment with folic acid (FA) protects elevated hearing thresholds and prevents reduction in vessel density by lowering abundant collagen deposition and oxidative stress in inner ear. To test this hypothesis we employed 8 weeks old male wild type (WT), cystathionine-beta-synthase heterozygote knockout (CBS+/-) mice, WT + FA (0.0057 µg/g/day, equivalent to a 400 µg/70 kg/day human dose in drinking water); and CBS(+/-) +FA. The mice were treated for four weeks. The hearing thresholds were determined by recording the auditory brainstem responses. Integrity of vessels was analyzed by perfusion of horseradish peroxidase (HRP) tracer. Endothelial permeability was assessed, which indicated restoration of HRP leakage by FA treatment. A total Hcy level was increased in stria vascularis (SV) and spiral ligament (SL) of CBS+/- mice which was lowered by FA. Interestingly, FA treatment lowered Col IVa Immunostaining by affecting its turnover. The levels of MMP-2, -9, methylenetetrahydrofolate reductase (MTHFR) and cystathione gamma lyase (CSE) were measured by Western blot analysis. The oxidative stress was high in SV and SL of CBS+/- compared to WT however the treatment with FA lowered oxidative stress in CBS+/- mice. These data suggested that hearing loss in CBS+/- mice was primarily due to leakage in inner ear circulation, also partly by induced collagen imbalance, increase in Hcy and oxidative stress in inner ear.
Subject(s)
Ear, Inner/blood supply , Ear, Inner/drug effects , Folic Acid/pharmacology , Hyperhomocysteinemia/drug therapy , Hyperhomocysteinemia/physiopathology , Adult , Animals , Auditory Threshold/drug effects , Auditory Threshold/physiology , Cochlea/blood supply , Cochlea/drug effects , Cochlea/physiopathology , Collagen Type IV/genetics , Collagen Type IV/metabolism , Cystathionine beta-Synthase/genetics , Cystathionine beta-Synthase/metabolism , Ear, Inner/physiopathology , Evoked Potentials, Auditory, Brain Stem/drug effects , Hearing Loss/etiology , Hearing Loss/genetics , Hearing Loss/physiopathology , Heterozygote , Humans , Hyperhomocysteinemia/complications , Hyperhomocysteinemia/genetics , Male , Matrix Metalloproteinase 9/genetics , Matrix Metalloproteinase 9/metabolism , Metabolic Networks and Pathways , Methylenetetrahydrofolate Reductase (NADPH2)/genetics , Methylenetetrahydrofolate Reductase (NADPH2)/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Models, Biological , Oxidative Stress/drug effects , RNA, Messenger/genetics , RNA, Messenger/metabolismABSTRACT
MicroRNAs ( miRNAs) are highly conserved, 19-23 nucleotide long, non-coding, endogenous RNA, which are transcribed from either intergenic, intronic or polycistronic regions and modulate gene expression through mRNA degradation or translational repression. They are fine tuners of biological processes and have recently emerged as biomarkers and therapeutic targets of cardiovascular diseases. Several miRNAs regulate stem cell for differentiation, proliferation and degeneration. Stem cells are pluripotent, self-renewing and clonogenic cells having tremendous potential for regenerative therapy. The current therapeutic approach is unable to cope up with rapidly increasing rates of diabetes and cardiovascular diseases. The empirical and clinical evidences revealed that transplantation of exogenous stem cells can regenerate beta cells in diabetic patients and myocardium in patients with myocardial infarction. Nevertheless, the major limitation of stem cell therapy is unpredictable behavior of exogenous stem cells that incur few reports of teratoma and cancer after transplantation. Therefore, understanding the regulation of newly transplanted stem cells into the foreign body is a major challenge to translational research / clinical trail. Since miRNA plays pivotal role in the fine regulation of proliferation and differentiation of stem cells, investigations on the regulation of miRNA in transplanted stem cells in a specific micro-environment that houses the stem cell is indispensable. Additionally, the inhibition or over expression of specific miRNAs in the niche surrounding the stem cell will be crucial for maintaining the specific lineage of exogenous stem cells. This review embodies major advancement in the field of miRNA biogenesis and its regulatory mechanisms, role of different miRNAs and stem cells as a therapeutic target for diabetes and cardiovascular diseases. It also provides insights into the novel future therapy, where synergistic approach for manipulating miRNAs and stem cells will emerged as a potential treatment for diabetes and cardiovascular diseases.
