[ comparative study of an experimental model of tendon healing process between healthy rats and streptozotocin induced-diabetic rats by a biomechanical evaluating method]

The aim of the present investigation was to compare the healing process of repaired Achilles tendons of healthy rats and streptozotocin induced diabetic [STZ-D] rats by evaluating strength and toughness of repaired tendons via tensiometrical test. 14 healthy male adult rat were divided into control [n=6] and experimental rats [n=8]. Type 1 diabetes was induced in experimental rats by an injection of 55 mg/kg STZ intraperitoneally. Control rats were received distilled water. Blood Sugar of all rats was recorded after seven days. Animals of experimental group that failed to develop average blood glucose concentration greater than 250mg/dc were excluded from the study. Right Achilles tendon of all rats was transected completely 30 days after STZ injection. Repairing Achilles tendons were extracted and were submitted to a tensiometerical examination10 days after surgery. Data were compared by student t test. Independent sample t test analysis showed that Young's modulus of elasticity [18.5 +/- 12.1MPa/mm] and stress high load [3.04 +/- 1.38, MPa/mm] of control group were significantly higher than those of experimental group [2.5 +/- 2 and 0.975 +/- 0.269 respectively], [p=0.003 and p=0.004 respectively]. It is concluded that induction of type one diabetes by STZ in rats after 30 days reduced significantly tensiometrical parameters of repairing Achilles tendon in comparison with control rats

[Effect of low - level He - Ne laser irradiation on biomechanical property of wound healing process in healthy and streptozotocin induced diabetic rats]

The aim of present investigation was to determine the effects of low-level He-Ne laser therapy on biomechanical property of skin wound of healthy and streptozotocin induced diabetic [STZ-D] rats. The study was performed by experimental method. 36 male adult Wistar rats weighing above 250 gr. were used. Rats were divided equally into control and experimental groups, each group [n=18] were equally divided into 3 subgroups in order to radiate 3 different energy densities of laser. Weight of healthy and diabetic rats were recorded in the beginning and at the end of study. Blood glucose of rats in the beginning of study was recorded and rats with more than 120 mg/dl were excluded from study. Diabetes was induced by one time intra peritoneal injection of 55 mg/kg STZ. After one month, hyperglycemia was established in experimental group. Two 15-mm, vertical incision wounds were made on the dorsum of rats. Three groups of healthy and diabetic rats were received 22.4J/cm[2], 1.2J/cm[2] and 4J/cm[2] energy densities He-Ne laser for two weeks. At the end of study, rats were killed and skin sample were extracted and were submitted to a biomechanical evaluation [maximum force] examination. Data was analyzed by paired student t test methods. Mean value of blood glucose of diabetic rats was 518.37 +/- 23.3. Laser-treated healthy rats with 1.2J/cm[2] energy density showed significant increase of maximum force [p=0.05]. Laser-treated diabetic rats with 4J/cm[2] energy density showed significant increase of maximum force [p=0.05]. It seems ideal parameters for effectiveness of Low- Level He-Ne laser in healthy and diabetic rats are different. Wounds of diabetic rats should be radiated with more energy density of low- level laser for accelerating wound healing process in comparison with healthy rats

[ rare case report of musculocutaneous nerve]

Knowing the variations of the brachial plexus is of high importance during the surgery of axilla for surgeons. A rare case was observed in the left upper limb of a 55- year old female's cadaver, during the routine dissection in Gilan Medical University. In this case the musculocutaneous nerve that normally arises from the lateral cord of brachial plexus, originated from median nerve, without perforating coracobrachialis muscle, and was located between biceps brachii and brachialis muscles and innervated them. Then, it pierces the deep fascia just below the elbow and extends as lateral cutaneous nerve of forearm. The nerve of coracobrachialis muscle is a branch directly isolated from lateral cord and enters into the muscle