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.

toxic effect of prolonged ultram administration on cerebral cortex of albino rats. Toxicological and histological study

Ultram [Tramadol] is a widely used opioid analgesic effective in treating both acute and chronic pains and has acceptable adverse effects. The aim of the present study was to evaluate the cerebrocortical toxicity resulting from one month and two month Ultram administration in to albino rats using biochemical and histological parameters. The study was carried out on 25 adult male albino rats divided into: control group received 0.5 ml /day saline orally by orogastric tube for two months, a short-term Ultram-treated group that received a dose of 30 mg/kg/day [1/10 LD50] for one month orally and a long-term Ultram-treated group that received the same dose for two months. The study revealed that Ultram administration caused a significant elevation of serotonin level in the cerebral cortical tissues of rats which was directly proportional to the duration of Ultram admistration. Histologically, there were many changes in the organization and ultrastructure of neurons in the different layers of cerebral cortex associated with an increased response of the supporting neuroglial cells. Intense neurological tissue lesions were more evident with the two months Ultram dosing than with one month. The correlation between the biochemical results and the histological findings proved that Ultram induced neuronal lesions could be mediated by the elevated cerebrocortical serotonin level which gives serious alarms for reconsidering the rush towards the excessive use of ultram