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Background and purpose: During present research the effects of low power helium-neon laser rediation on rabbit’s tibia after partial ostetomy were studied by quantitively histological methods.
Materials and Methods: The type of the research was experimental. 42 male adult rabbits randomly divided into experimental (ex) and control (co) groups. Ëach group divided into 3 equall sub groups. Ünder general anesthesia and sterile conditions one incision were made on the soft tissue of medial aspects of the left tibia and then one small circular defect was made in the shaft of the tibia (partial osteotomy). The depth of defect was reached the central the chanal of bone. The day of surgery was day zero and next day was day one and etc ... . Ïn the ex group from day zero until 14th day at subgroup one and until 21th day at subgroup two and unril 28th day at subgroup three low power helium neon laser was irradiated on the defect by Grid technique. Ënergy density of the laser was 1.2. Ât the end of the above mentioned periods, rabbits were killed by ether and one sample were obtained from obtained from the defect. The samle fixed and decalcified and processed and embedded in parafin and sections were obtained from the block. Sections were stained by Hematoxyline and Ëosin method and masson’s trichrome method. Sections were studied histologically by 2 following mthods: 1- Graded descriptively evaluation method. 2- Quantitative method. When sections were studied by the first method , according to the quality of maturation of the callus , they were graded from zero until 8. When section by the second method the depth of newly periosteum and callus were calculated by a special eyepiece. Tow groups were compared with each other by ann Whitney Ü test method.
Results: Results of graded descriptively evaluation method of ex. group were lower than co. group at 14th day and were equall at 21 th day and were higher at 28th day but non of this differences weren’t significant. Results of quantitative method of ex. Group were better than co. group and differences of increased depth of newly formed periosteum at 21th day were significant (P<0.05).
Çonclusion: Low power helium-neon laser radiation on partial osteotomy of rabbit’s tibia were increased significantly the depth of newly formed periosteum and total depth of newly formed periosteum and callus at 21th day and results of graded descriptively evaluation method at 28th day were higher than control group.

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Background and purpose: Auto-transplantation is the best bone graft substitute, but there are some limitations. Therefore, other methods using synthetic or natural materials are recommended. Propolis is a resinous natural product derived from plant exudates collected by honeybees. It has been extensively used in folk medicine because of its biological and pharmacological activities. The present study was carried out to evaluate the osteogenic properties of propolis on healing of diaphyseal defects in rabbit ulna. Materials and methods: In this study ten healthy adult male white New Zealand rabbits were used. The animals were randomly divided into control and treatment groups (n=5 per group). Three millimeters defects were created in right diaphysis of ulna in all animals and intramedullary pins were used for bone fixation. In treatment group the defects were filled with propolis but in control group the defects were left unfilled. Results: Radiological study showed that propolis as a scaffold could somewhat guide the bone growth. Histological section showed moderately differentiated lamellar bone in the cortical part with presence of haversian canal at peripheral cortex, whereas fibrocollagenous tissue and good amount of bone marrow tissue, fat cells and bone vessels were observed in control group. The results showed no significant difference in bone healing between the two groups. Conclusion: Propolis have biological materials, minerals and amino and organic acid properties, therefore, further studies are required to clarify the efficacy of propolis on bone healing.

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Background and purpose: Cyclophosphamide (Cyclo) is a common chemotherapy medicine that reduces male fertility. Various antioxidant agents have been used to reduce the side effects of chemotherapy medicines. Zinc oxide nano particles (nZno) have been introduced as a potent antioxidant. This study aimed at investigating the protective effects of nZno on testis tissue structure in Cyclo treated mice.

Materials and methods: We conducted an experimental study in which 15 adult male mice were divided into three groups (n=5 per group) and treated for 4 weeks as: 1) control: normal saline (0.1 cc daily), 2) treatment I: Cyclo (15 mg/kg, once a week) and 3) treatment II: Cylo (15 mg/kg kg, once a week) + nZno (5mg/kg, daily) intraperitoneally. Twenty four hr after the last administration of drugs, the animals were euthanized and right testes were isolated and fixed. Five-micrometer testicular tissue sections were prepared according to routine histotechnique process and were studied by light microscope.

Results: Compared with the control group, cyclophosphamide reduced the diameter and septal epithelium thickness of the seminiferous tubuli, primary spermatocyte, spermatid, and spermatozoid (P≤0.05) while co administration of nZno with cyclophosphamide prevented these changes (P≤0.05). nZno also prevented the luminal extension and epithelial disorganization of seminiferous tubuli induced by cyclophosphamide.

Conclusion: nZno could prevent testicular tissue changes and reduction of spermatogenic cell counts induced by cyclophosphamide.