Role of Endogenous Bone Marrow Stem Cells Mobilization in Repair of Damaged Inner Ear in Rats

BACKGROUND AND OBJECTIVES: The utilization of the stem cells is widely used in the last few years in different fields of medicine, either by external transplantation or endogenous mobilization, most of these studies still experimental on animals; few were tried on human as in the spinal cord injury or myocardial infarction. As regard its use in the inner ear, stem cell transplantation was examined in many previous studies, while the mobilization idea is a new method to be experimented in inner ear hair cell regeneration. The present work assessed the possibility of mobilizing endogenous bone marrow derived stem cells (SCs) in rats using granulocyte colony stimulating factor (G-CSF) to induce regeneration and repair to experimentally damaged inner ear hair cells by Amikacin injection. METHODS: The study included thirty adult Sprague Dawley male rats. Experimental induction of inner ear damage was done by repeated intratympanic injection of amikacin sulfate. Mobilization of bone marrow SCs was provoked by subcutaneous injection of GCSF. Cochlear integrity, induction of hearing loss and functional recovery of sensory hearing loss were assessed using Distortion Product Otoacoustic Emission (DPOAEs). The morphological alteration and recovery of the organ of Corti was assessed histologically using the light and scanning electron microscopes. RESULTS: After six month duration, there was improvement in 50% of the sensorineural DPOAE results. Functional recovery coincided with the repair of structural components of organ of Corti. CONCLUSIONS: SCs mobilization by G-CSF is a promising alternative method for replacement therapy in sensorineural hearing loss.

S100-beta and cytokines as early markers to predict outcome after moderate head injury

The aim of this study was to evaluate the potential role of S-100[beta] protein, 1L-1[beta], IL-6 and TNF-alpha as early predictive markers of the severity and outcome after moderate head injury. Twenty-four patients with moderate head injury with Glasgow Coma Scale score "GCS score" [9-12], who, required admission to the intensive care Unit[ICU] were included in this study. Routine ICU monitoring was applied e. g. heart rate, mean blood pressure, continuous ECG, capnography, SaO[2], and CVP. Parameters assessed included GCS at admission, 30 minutes, 60 minutes, 4 hours and then every 12 hours till the end of the study. Ten ml of blood was taken from the internal jugular cannula and another ten mil from the radial artery cannula at admission then at 24, 48, 72 hours for analysis of S-100[beta] protein and interleukin-1 beta;, interteukin-6 and tumour necrosis factor-alpha. A single venous blood sample was taken from 24 healthy volunteers to be considered as a control for the laboratory work. The serum concentrations of S-100[beta] protein, IL-1[beta] IL-6 and TNF-alpha were found to be significantly increased in the arterial and the venous samples at admission, then gradually declines over the next three days with management suggesting that there is a significant brain release of S-100[beta], IL-1[beta], IL-6 and TNF alpha with head injury. The jugular venous concentrations were significantly higher than the arterial concentration all over the time of the study. There were significant inverse correlations between GCS score and both arterial and venous concentrations of S-100[beta] and IL-6 throughout the study period. Also, there were significant inverse correlations between aterial venous concentrations of interleukin-1 beta, TNf -alpha and GCS score at admission and at 24 hours and this correlations became insignificant thereafter. The present study has demonstratred that S-100[beta], interleukin-1 [beta], and tumor- necrosis factor-alpha were increased after head injury. However, S-100 [beta] and interleukin-6 appeared to be the most sensitive predictors and their significant correlations with GCS score make them helpful as prognostic tools in assessing the severity and predicting the outcome after moderate head trauma