Ameliorative effect of different mesoporous bioactive glass materials in experimental tibial defects in rats.

Background: Enhancing the bone healing procedure would resultantly improve the post-recovery life quality, as well as the speed with which the patient returns to their former life quality. Porous structures can provide a large surface area and abundant channels to facilitate mass transfer. Objective: To evaluate the application of mesoporous materials in the bone healing of surgically created defects on the tibiae of male adult Wistar rats. Methods: The defect areas were evaluated after implantation of 4 types of bioactive glass histopathologically and immunohistochemically. Fifty adult rats were divided into 5 groups including a control group without material. The used products were mesoporous bioactive glass (MBG), Cu-MBG, Zn-MBG, and Cu-Zn-MBG. Unicortical bone defects with a 3 mm diameter were performed in both tibiae of the animals and filled with 4 types of glass particles. The rats were then euthanized at 15 d and 30 d. Tibial samples were collected and the tissues forwarded for histological processing, and examined using light microscopy. Additionally, bone healing was evaluated by assessing the levels of bone morphogenetic protein BMP2, collagen 1, osteocalcin (OST), and vascular endothelial growth factor (VEGF) using immunohistochemical methods. Results: Within the 15th day, all groups presented connective tissue septa; at the 30th day, the new bone formation was more intense in the Cu-Zn-MBG group. Additionally, BMP2, collagen 1, OST, and VEGF immune expression were more prominent in the Cu-Zn-MBG group. Conclusions: The study results indicated that MBG may be used for the repairing of bone defects. Cu-Zn-MBG may be the best choice for this purpose.

Investigation of the preventive effect of proanthocyanidin in ischemia-reperfusion injury in lung transplantation: An experimental study.

BACKGROUND: This study aims to investigate the preventive effect of proanthocyanidin against ischemia-reperfusion injury after lung transplantation. METHODS: The study included 12 swines (weighing 35±5 kg) and separated into four groups. Groups 1 and 3 were identified as control groups and left upper lobectomy was performed. Groups 2 and 4 were identified as transplantation groups and left lower lobectomy and heterotransplantation were performed. Proanthocyanidin was only given to groups 3 and 4. Tissue samples were analyzed under light microscope and histopathological findings were recorded. RESULTS: There was no statistically significant difference between control groups in terms of the numerical values of histopathological findings that include congestion (p=0.565), alveolar edema (p=0.197) and peribronchial inflammation (p=0.444). However, numerical values of acute cellular rejection were statistically significantly different between transplantation groups (p=0.048). Mean oxidative stress enzyme levels were higher in group 2 compared to group 4; however, the difference was not statistically significant (p>0.05). CONCLUSION: According to the findings of our experimental study, proanthocyanidin can be safely used in lung transplantation based on its preventive effect in ischemia-reperfusion injury that may lead to morbidity and mortality.

The aromatase inhibitor letrozole reduces adhesion formation after intraperitoneal surgery in a rat uterine horn model.

OBJECTIVE: To investigate, in an experimental animal study, the effects of letrozole and tamoxifen in the reduction of adhesion formation following abdominopelvic surgery. STUDY DESIGN: Thirty female Wistar albino rats were included and divided into three groups. One group received 500 µg/d tamoxifen and a second group received 1 mg/kg/d letrozole through an enteric tube. A third group did not receive any drugs and served as the control group. On the fifth day, a laparotomy was performed and the right uterine horn was injured by monopolar cautery. The left uterine horn was incised with a scalpel and sutured. The preventive therapy protocols were continued for 7 days after surgery. On the 14th day after first surgery the animals were sacrificed, and the intraperitoneal macroscopic adhesion formation and microscopic adhesion features were evaluated. The Kruskal-Wallis test was used to compare the scores of the macroscopic adhesion scores and histologic features among the three groups, followed by a post hoc Mann-Whitney test. The total histological score was analyzed with a one-way ANOVA, followed by post hoc Bonferroni correction tests. p values ≤0.05 were considered statistically significant. The level of significance was set at p≤0.016 for the post hoc tests. RESULTS: The letrozole and tamoxifen groups had significantly lower adhesion scores for the right uterine horn than the control group (p=0.005 and p=0.013, respectively). For the left horn, however, only the letrozole group had a lower macroscopic adhesion score than the controls (p=0.011). The total histological score was significantly lower in the letrozole group than in the control group (p=0.014), but no differences were found between the tamoxifen group and the control group (p=0.954). Inflammation, fibroblastic activity, collagen formation and vascular proliferation were significantly lower in the letrozole group compared with the control group (p<0.05). The foreign body reactions were similar among the three groups (p>0.05). Tamoxifen administration did not result in any significant effects on the histological scores (p>0.05). CONCLUSION: Letrozole resulted in a significant decrease in postoperative macroscopic adhesion formation and the total histological scores, but tamoxifen did not demonstrate a similar effect on the histological scores.

The efficiency of proanthocyanidin in an experimental pulmonary fibrosis model: comparison with taurine.

Pulmonary fibrosis (PF) is a progressive fatal disorder. Bleomycin (BLM) is a widely used chemotherapeutic agent causing PF. Numerous agents have been investigated to prevent the progression of PF so far, but there is still a need to find more efficacious agents. Proanthocyanidin (PA) is a strong antioxidant, the main ingredient of grape seed extract. Since PA is ready for use in practice, we aimed to compare the preventive effect of PA in comparison with taurine (Tau) in BLM-induced PF. Forty Wistar male albino rats were used in the study and were divided into four groups: group 1, control; group 2, BLM-induced PF group; group 3, BLM-induced PF and treated with PA group; and group 4, BLM-induced PF and treated with Tau group. Treatments were begun 10 days before and continued 21 days after BLM injection. PA and Tau effectively inhibited inflammation, edema, severity of fibrosis, fibrosis extension, inflammatory cell accumulation, iNOS staining, and hydroxyproline level as well (p < 0.05). Total histological scores of the PA group were similar to the control group; Tau was significantly higher than the control group but lower than the BLM group (p < 0.05). We believe that PA could be a new treatment choice for PF, but further studies need to be conducted to verify the findings of the current study.

Passive smoke exposure of female rats caused aortic atherosclerotic precursor lesions in their offspring.

The aim of this study was to evaluate the presence and degree of preclinical atherosclerosis in pups of pregnant rats exposed to cigarette smoke. Abdominal aorta examined for atherosclerotic lesions and intimal medial thickness of the abdominal aorta was measured by image analysis. The study groups showed endothelial cellular losses, marked intimal injuries, elastic fiber damages, mononuclear cellular infiltration, and irregularities in internal elastic membrane, with pronounced damages as integrity losses and local fragmentations. The results provide evidence for development of an atherosclerotic process in the neonatal period, even in prenatal stage, long before the formation of smoke-related cardiovascular diseases.

Effects of carbamazepine on spinal cord ischemia.

BACKGROUND: Prophylactic treatment with carbamazepine has been shown to reduce the cerebral damage and neurologic deficit in ischemic conditions. A randomized controlled study based on a rabbit model was designed to study the effect of carbamazepine on a spinal cord ischemic reperfusion injury. METHODS: Thirty New Zealand rabbits were randomly assigned to 1 of the 2 groups (n = 15 per group): group I (control group) and group II (carbamazepine group). Spinal cord ischemia was induced by infrarenal aortic crossclamp for 25 minutes in both groups. Functional evaluation with the Tarlov score during a 2-day observation period and histopathologic assessment of the lumbar spinal cord were performed. Changes in spinal cord morphology were observed with hematoxylin-eosin staining and electron microscopy. Gray matter damage was assessed on the basis of the number of normal neurons in the ventral horn. RESULTS: Diffuse destruction of gray matter with moderate to severe vacuolization and essentially no normal ganglion cells was observed in the spinal cord of rabbits in the control group, whereas specimens of rabbits assigned to the carbamazepine group showed ganglion cells with normal nuclei and cytoplasm (P < .0001). Neurologic impairment was significantly attenuated in the carbamazepine group compared with the Tarlov scores of the control group (P < .0001 at day 2). CONCLUSION: Carbamazepine may protect the spinal cord from ischemic reperfusion injury that is associated with ameliorated neurologic and histopathologic results.