In this study, the vertical and transverse diameters of the spinal cord segments and ependymal canal and the ratio between gray matter and white matter in various segments (C1, C4, C8, T4, T7, T13, L4, L7, S2, Co1) of mid-stage fetus, late stage fetus, newborn, 6month old and adult (each on male cat) were measured by standard micrometric method using 5mm thick sections in light microscope.In fetal stage towards adult age, the ratio of gray matter to white matter and the vertical dimeter of ependymal canal were reduced but other measured diameters were increased. Statistically, there were significant differences between parameters, which were measured.

Pregnancy make demands upon maternal calcium homeostasis and the extent to which ‎the maternal bone mass is effected remains uncertain. Recently changes in the bone ‎mass during human pregnancy have been associated also with the transformation of ‎the cancellous architecture and the bone surface available for exchange. These ‎jistomorphometrical structural changes were examined further in an animal, model. ‎Using uniparous laboratory rats fed libitum, the histomorphometry of cancellous bone ‎was compared in undecalcified of caudal vertebrae. Between 3 and 6 sections (8 pm) ‎were analyzed by an automated trabecular analysis system (TAS) which measures a ‎comprehensive range of structural variables including the trabecular separation, ‎number, connectivity and width. There was an early stimulation of bone formation ‎that was indicated by generation of thicker and interconnected trabecular. However in ‎caudal vertebrae, there were architectural changes in cancellous bone commencing ‎with a significant increase in the trabecular separation. It was concluded that ‎strengthens the cancellous component of the maternal skeleton possibly to counter ‎increased load and to facilitate mineral mobilization in maternal/neonate exchange ‎during the subsequent lactation period‏.‏

Statement of Problem: The goal of bone regenerative therapy is to reconstruct the damaged tissues to initial condition, which seems so important in periodontology and implantology. In such therapies, different biomaterials, with some advantages and disadvantages, may by use.Purpose: The aim of this research was to evaluate the quality, bone trabecular density and thickness of newly forming bone as well as foreign body reaction against Biostite®, in comparison with the control group.Material and Methods: In this experimental study the total number of 5 sheep was operated with general anesthesia. At first 10 standard defects were created in 5x5x5 mm on the left and right edentulous mandibular ridge. Five defects were randomly treated by Biostite®, the remaining five were considered as controls. After six months, the sheep were sacrificed and the separated defect areas with intact margin were placed in 10% formalin and prepared for histologic and histomorphometric study. To analyze the data, Mann- Whitney U test was used.Results: The mean percentage of new bone formation in Biostite®group was statistically more han the control group (P<0.05). Newly formed bone was vital in both groups which was a combination of lamellar and woven types, however, the thickness and density of new bone in biostite® group was more than the controls. Foreign body reaction was observed in Biostite® group. Conclusion: It is suggested that Biostite® synthetic material can be useful in bone regenerative therapies.

In this study wound healing process in soft and hard tissues of the gingival area and ‎the Mandibular bone of rats whose ovary glands were removed bilaterally (as samples ‎which are similar to menopause period in human) was assessed histologically and ‎hisomorphoemtrically and results write compared with those of control group. For ‎performing this study, 20 rats were chosen and divided into two groups with ten rats ‎in each group. In one group of rats bilateral ovariectomy was applied and in another ‎group, simi operation was done except for ovariectomy (Sham operation). 5 months ‎after ovariectomy, a defect was created (Sham operation), 5 months after ‎ovariectomy, a defect was created in gingival area and mandibular bone of lower right ‎central incisor in 5 mm lower than gingival margin which was 5 mm deep with a ‎‎1.3mm diameter. In 1, 4, 7, 21 and 42 days after creation of the defect, biopsies were ‎taken from the defect area and histologic and histomorphometic studies were done. ‎Histological assessment sections consisted of clotting formation, degree and kind of ‎inflammation and granulation tissue and degree and nature of bone formation.Results ‎demonstrated that during the first days, the inflammation was more severe in the ‎control group rather than the study group, but gradually the inflammation process ‎became similar in both groups. The produced fibrous tissue in control group was also ‎more than the study group on the 7th day samples, producing of new bone was ‎obvious in the bone defect margins in both groups. On the 21st day, formation of ‎woven bone was observed in both groups. On the 42nd day, the produced bone in ‎both groups was lamellar, but histomorphometic studies showed that bone formation ‎in the control group was greater than the study group. Few studies through histologic ‎evaluation of wound healing process in soft and hard (bone) tissues after ovariectomy ‎operation have been done. In this study wound healing process in soft tissue in ‎ovariectomized rats has been decelerated and the amount of new bone formation is ‎decreased‏.‏

Objective: Quantitative comparison between different layer of aorta in three age groups: neonate, young adult and old ag of female guinea pig.Design: Histomorphometric study of 7 segments of the aorta by light microscope.Animals: A total of 15 female guinea pig (5 neonate, 5 young adult and 5 old age).Procedure: Immediately following euthinization of anima: the whole aorta was collected and separated into the ascending, aortae, aortic arch, cranial and caudal thoracic aortae, crania. middle and caudal abdominal aortae segments. After fixation in 10% buffered formalin solution, the aortic segments were embedded in paraffin, and histological sections were mad from each segment. The sections were stained with H&E an masson trichrome.Statistical analysis: One way analysis and Duncan tests b using of SPSS program.Results: It was observed that the greatest external and interne diameters and the thickest wall of the aorta occur in the ascending aorta. The percentage of the tunica internal an external, as compared with the total wall thickness was increased gradually from the ascending aorta to the caudal abdominal aorta, whereas the tunica media was decreased.Clinical implication: External and internal diameters, was thickness and the thickness of tunica internal and media were decreased from the ascending aorta to the caudal abdomen aorta, on the other hand the thickness of the tunica external was increased.

Objective: To study microscopic structure of renal artery and measurement of histomorphometrical parameters before birth.Design: Observational study.Animals: Twelve embryonic artery of both sexes at 3 and 4 months age.Procedure: Samples of arteries were taken and fixed in 10% formalin. The process was done in autotechnicon. Sections of 6 micron were stained by H&E and green mason trichrom and studied under light microscope.Statistical analysis: Descriptive statistics.Results: All 3 layers of the wall of vessels were well developed in both sexes and ages of renal artery. In both ages, histomorphometrical studies showed that total diameter of renal artery in males was lesser than the females. Increase in age increased thickness of wall and diameter of lumen. While there were not significant difference between sexes, the measured parameters of renal artery showed significant difference between age groups.Conclusion: Histomorphological structures of embryonic renal artery in sheep showed 3 vascular layers. Internal elastic membrane was clearly and external elastic membrane was poorly observed and in some regions was interrupted. The recent layer will completely develop after birth by development of blood circulation. Increase in the age increase percentage of tunica media. On the other hand, percentage of other layers showed partially decrease.

Developmental changes of pancreas were studied in different age groups of female sheep by calculation of frequency and percentage of parenchymal and stromal structures of the gland, and measuring diameter of islets of langerhans. In this study, glands were selected from four different age groups included, fetus(2.5-3 months), newborn(1 week old), Sexually mature(6-7 months), and old (upper 3 years old). The results of histomorphometrical analysis showed that frequency and percentage of parenchymal and stromal structures in fetal stage were: exocrine secretory units 11.84±0.63 (%35.61), secretory ducts 3.72±0.37 (%11.19), blood vessels 1.66±0.89 (%4.99), islet of langerhans 2.26±0.13(%6.79) and stromal connective tissue 13.76±0.33 (%41.39); these findings showed that the minimum percentage belong to blood vessels (%4.99) and the maximum to stromal connective tissue (%41.39). Diameter of islet of langerhans in fetus was measured 43.59:1:21.9flm.In newborn stage exocrine secretory units were calculated 19.15±0.21(%65.85), secretory ducts 2.43±0.29 (%8.35), blood vessels 0.88±0.07(%3.02),islet of langerhans 2.29±0.08 (%7.87) and stromal connective tissue 4.33±0.21(%14.86); that the minimum percentage belong to blood vessels (%3.02) and the maximum to exocrine secretory units (%65.85). Diameter of islet of langerhans in newborn was measured, 52.75±1.35 mm. In sexually mature stage exocrine secretory units were calculated 18.85±0.15 (%63.66), secretory ducts 1.99±0.18 (%6.72), blood vessels 1.86±0.27(%6.28), islet of langerhans 1.74±0.06 (%5.87) and stromal connective tissue 5.17±0.39 (%17.46) that the minimum percentage belong to islet of langerhans (%5.87) and the maximum to exocrine secretory units (%63.66). Diameter of islet of Langerhans in sexually mature stage was ascertainmented 51.56±1.20mm. In old stage exocrine secretory units were calculated 19.37±0.36 (%64.07), secretory ducts 1.9±0.21 (%6.28), blood vessels 2.29±0.37(%7.57), isletof Langerhans 1.69±0.09 (%5.59) and stromal connective tissue 4.98±0.18 (%16.47) that the minimum percent belong to islet of langerhans (%5.59) and the maximum to exocrine secretory units (%64.07). Diameter of islet of Langerhans in old stage was measured 46.2±1.81mm. In comparison between different age groups, the frequency of exocrine secretory units showed a significant increase from fetal stage to newborn, sexually mature and old stages. On the other hand, there was a significant decrease in frequency of secretory ducts from fetal stage to newborn, sexually mature and old stages and there was also a significant decrease in frequency of blood vessels from fetal to newborn stage. Significant decrease was observed in frequency of islet of Langerhans from fetal and new-born stages to sexually mature and old stage (P<0.05). In comparison between groups there was a significant decrease in diameter of islet of Langerhans from fetal to new-born and sexually mature stage and from newborn and sexually mature stage to old stage (p<0.05) and there was no significant difference between the other structures. Our study revealed that, there was no significant difference in parenchymal and stromal structures and diameter of islets of Langerhans between different lobes of the gland in each age group. However, the above mentioned parameters often showed significant difference between different age groups. These differences were more prominent between fetal stage compare to the other age groups. Therefore, it can be concluded that structural changes of parenchyma and stroma of pancreas gland begin from prenatal period and will relatively continue in the period of postnatal development.