Hepatotoxic effects caused by simultaneous exposure to noise and toluene in New Zealand white rabbits: a biochemical and histopathological study

The aim of this experimental study was to investigate hepatotoxicity effects of noise and toluene, and in particular, to study hepatotoxicity effects of simultaneous exposure to noise and toluene by histopathological and biochemical experiments. To experiment hepatotoxicity effects of noise and toluene, 100 dB white noise and 1000 ppm toluene vapors were generated during two consecutive weeks in healthy male New Zealand White rabbits. Non-simultaneous exposure to noise and toluene increased liver enzymes and the serum levels of superoxide dismutase, malondialdehyde, and total antioxidant capacity, and also decreased serum level of glutathione peroxidase. Alanine transaminase, aspartate transaminase, gamma-glutamyl transferase, malondialdehyde, total antioxidant capacity, and superoxide dismutase levels increased by simultaneous exposure to noise and toluene. Furthermore, catalase and alkaline phosphatase level decreased by simultaneous exposure to noise and toluene. The hematoxylin and eosin stain (H&E) experiments indicated significant swelling, lipidosis, eosinophilic cytoplasm, pyknosis, karyorrhexis, and disruption of the cytoplasmic membrane in the liver tissue due to exposure to noise, toluene and simultaneous exposure to them.

     

Protective effect of ghrelin on testicular damages caused by chronic hypoxia in rats: A histopathological study

Hypoxia can lead to changes in the blood flow, nutrition and oxygenation of male germ cells and results in fertility reduction through the increase in oxidative stress. This study aims to evaluate the effect of ghrelin on testicular damage induced by hypoxia in rats. In this experimental study, 24 male rats were randomly divided into four groups: control, hypoxia, hypoxia + ghrelin and ghrelin. Animals in the control and ghrelin groups were kept in room air with 21% oxygen. The animals in the groups of hypoxia and hypoxia + ghrelin were subjected to 11% oxygen for 14 consecutive days in the hypoxia chamber. At the end of the study, the testes were removed and histological changes, as well as the apoptotic index, were investigated. Morphometrical analysis showed that hypoxia caused a significant decrease in the seminiferous tubules diameter, the germinal epithelium thickness and main Johnson's score compared to the control group (p < .05). In addition, statistical comparisons revealed a significant increase in the apoptotic index in the hypoxia group (p < .05). Administration of ghrelin + hypoxia improved the parameters mentioned above (p < .05). The results of this study indicated that ghrelin decreases the testicular damages caused by hypoxia in the rats by antioxidative activity.     

The Effect of Quince Leaf (Cydonia Oblonga Miller) Decoction on Testes in Hypercholesterolemic Rabbits: A Pilot Study

Current medical literature lacks any evidence of the protective effects of quince leaf on testes. Therefore, the aim of the present study was to assess the effect of quince (Cydonia oblonga Miller) leaf decoction on testicular injury and impaired spermatogenesis induced by hypercholesterolemia in rabbits. Eleven mature New Zealand white male rabbits were randomly divided into three groups: group 1 (hypercholesterolemia, n=3), group 2 (hypercholesterolemia plus quince treatment, n=6), and group 3 (control, n=2). Groups 1 and 2 received a cholesterol-enriched diet for six weeks. Group 2 received C. oblonga leaf decoction as drinking supplement as well. After six weeks, a normal diet was substituted in groups 1 and 2 for another six weeks. Group 3 (control group) was maintained throughout the study on a regular diet. At the end of the 12^th week, the left testes of the animals were resected for light microscopic study with particular attention to the maturity of germ cells in seminiferous tubules using Johnsen''s score. Increase in intertubular connective tissue and diameter of vessels, abundant spermatogonia and primary spermatocytes along the reduced germinal epithelium were noted in all rabbits of the group 1. The remaining animals in groups 2 and 3 had no significant changes in their testicular sections. The mean Johnsen''s score of group 1 (4.20±1.92) was significantly lower than that of group 2 (7.33±0.52) and group 3 (7.05±0.07). (P=0.01). In conclusion, quince leaf decoction (C. oblonga Miller) protected rabbit testes and spermatogenesis from damage induced by hypercholesterolemia.     

Fumaria parviflora regulates oxidative stress and apoptosis gene expression in the rat model of varicocele induction

Varicocele is one of the leading causes of male infertility in which oxidative stress induces DNA damages in spermatozoa of patients with varicocele. Recent studies indicated that the treatment with antioxidant agents has protective effects against the formation of reactive oxygen species (ROS). Our research aimed to evaluate the impact of Fumaria Parviflora (FP) on the varicocele-induced testicular injury. For this purpose, 32 adult male Wistar rats (n = 8 per group) were randomly assigned to four groups as follows: sham group, varicocele group, varicocele treatment group and the control treatment group. The experimental groups daily received FP (250 mg/kg) for 8 weeks. The induction of varicocele was conducted by partial occlusion on the left renal vein. The diameter of seminiferous tubules, Johnsen's score and the epithelium thickness improved in the treated-varicocele group as compared to the varicocele group. FP extract could increase the biochemical parameters including superoxide dismutase and glutathione peroxidase, and also decrease malondialdehyde level in the varicocele group. Furthermore, varicocele markedly increased both mRNA and intensity of Bax, while treatment with FP could alleviate them. We concluded that FP could alleviate varicocele, possibly by lowering oxidative stress and testicular damage.     

Fluid–Structure Interactions Analysis of Shear‐Induced Modulation of a Mesenchymal Stem Cell: An Image‐Based Study

Although effects of biochemical modulation of stem cells have been widely investigated, only recent advances have been made in the identification of mechanical conditioning on cell signaling pathways. Experimental investigations quantifying the micromechanical environment of mesenchymal stem cells (MSCs) are challenging while computational approaches can predict their behavior due to in vitro stimulations. This study introduces a 3D cell‐specific finite element model simulating large deformations of MSCs. Here emphasizing cell mechanical modulation which represents the most challenging multiphysics phenomena in sub‐cellular level, we focused on an approach attempting to elicit unique responses of a cell under fluid flow. Fluorescent staining of MSCs was performed in order to visualize the MSC morphology and develop a geometrically accurate model of it based on a confocal 3D image. We developed a 3D model of a cell fixed in a microchannel under fluid flow and then solved the numerical model by fluid–structure interactions method. By imposing flow characteristics representative of vigorous in vitro conditions, the model predicts that the employed external flow induces significant localized effective stress in the nucleo‐cytoplasmic interface and average cell deformation of about 40%. Moreover, it can be concluded that a lower strain level is made in the cell by the oscillatory flow as compared with steady flow, while same ranges of effective stress are recorded inside the cell in both conditions. The deeper understanding provided by this study is beneficial for better design of single cell in vitro studies.     

Marginal Gap,Internal Fit,and Fracture Load of Leucite‐Reinforced Ceramic Inlays Fabricated by CEREC inLab and Hot‐Pressed Techniques

Purpose: This in vitro study was designed to evaluate and compare the marginal gap, internal fit, and fracture load of resin‐bonded, leucite‐reinforced glass ceramic mesio‐occlusal‐distal (MOD) inlays fabricated by computer‐aided design/manufacturing (CAD/CAM) or hot pressing. Materials and Methods: Fifty caries‐free extracted human molars were prepared for standardized MOD inlays. Impressions of each specimen were made and poured using type IV dental stone. Dies were randomly divided into two equal groups. Twenty‐five ceramic inlays were fabricated by the hot‐pressed technique using IPS Empress leucite‐reinforced glass ceramics, and the other 25 ceramic inlays were produced by CAD/CAM technology using ProCAD leucite‐reinforced ceramic blocks and CEREC inLab facilities. Inlays were bonded to the teeth using a dual‐cured resin cement. The specimens were stored in distilled water at 37°C for 24 hours and then thermocycled for 5000 cycles. The marginal gap measurements were taken with a stereomicroscope. Specimens in each group of inlay systems were randomly divided into two subgroups of 10 and 15 specimens each. Ten specimens in each subgroup were sectioned mesiodistally for evaluation of the internal fit. The fracture load of specimens in the second subgroup (n = 15) of the two inlay systems was determined under compressive load in a universal testing machine. Data were analyzed using Student's t‐test at a significance level of p < 0.05. Results: The mean marginal and internal gap size in both IPS Empress and ProCAD inlays were less than 100 μm; however, the marginal gap for the IPS Empress restorations was significantly higher than that of ProCAD restorations (p < 0.05). There was no significant difference in the mean internal fit or the fracture load between the two glass ceramic inlays (p > 0.05). Conclusions: The leucite‐reinforced glass ceramic inlay restorations fabricated by CEREC inLab (CAD/CAM) and the hot‐pressed technique provided clinically acceptable marginal and internal fit with comparable fracture loads after luting.     

How do red and infrared low-level lasers affect folliculogenesis cycle in rat’s ovary tissue in comparison with clomiphene under in vivo condition

Folliculogenesis is a cycle that produces the majority of oocyte. Any disruption to this cycle leads to ovulation diseases, like polycystic ovarian syndrome (PCOS). Treatments include drugs and surgery; lasers have also been used complementarily. Meanwhile, still there is no definite treatment for PCOS. This study investigated the photo-bio stimulation effect of near-infrared and red low-level laser on producing follicles and compared the result with result of using common drug, clomiphene. Therefore, the aim of this study was to propose the use of lasers autonomously treatment. So, there was one question: how do lasers affect folliculogenesis cycle in rat’s ovary tissue? In this study, 28 rats were assigned to four groups as follows: control (CT), clomiphene drug (D), red laser (RL), and near-infrared laser (NIRL). Afterwards, 14 rats of RL and NIRL groups received laser on the first 2 days of estrous cycle, each 6 days, for 48 days. During treatment period, each rat received energy density of 5 J/cm². Seven rats in D group received clomiphene. After the experiment, lasers’ effects at two wavelengths of 630 and 810 nm groups have been investigated and compared with clomiphene and CT groups. Producing different follicles to complement folliculogenesis cycle increased in NIRL and RL groups, but this increase was significant only in the NIRL group. This indicates that NIRL increases ovarian activity to produce oocyte that certainly can be used in future studies for finding a cure to ovarian negligence to produce more oocyte and treat diseases caused by it like PCOS.     

Troxerutin Preconditioning and Ischemic Postconditioning Modulate Inflammatory Response after Myocardial Ischemia/Reperfusion Injury in Rat Model

Protective effects of ischemic postconditioning in myocardial ischemia/reperfusion (I/R) injury have been ever demonstrated, but the exact mechanisms remain unclear. Because of their multiplex activities, using natural pharmaceuticals seems to be clinically interesting. The aim of present study was to investigate the effects of troxerutin preconditioning and ischemic postconditioning on inflammatory responses after myocardial I/R injury in a rat model. Twenty-four Wistar rats were divided into four groups as the control, troxerutin receiving (TXR), postconditioning receiving (PostC), and combined therapy (TXR + PostC). Rats’ isolated hearts underwent 30-min LAD regional ischemia followed by 45-min reperfusion. Troxerutin was orally administered for a month before I/R. Ischemic PostC was applied by alternative three cycles of 30-s R/I at the onset of reperfusion. The coronary effluent and ischemic left ventricular samples were used to determine the activities of creatine kinase (CK), intercellular adhesion molecule-1 (ICAM-1), interlukin-1beta (IL-1β), tumor-necrosis factor (TNF-α), and also histopathological studies. Pretreatment of rats with troxerutin significantly reduced myocardial inflammatory cytokines TNF-α and IL-1β levels and ICAM-1 activity after I/R insult compared to those of control I/R hearts (P?<?0.05). Application of PostC showed similar impacts on those parameters. In fact, anti-inflammatory mechanisms of both treatments were associated with their protective effects against myocardial damages causing from I/R injury. Pretreatment with troxerutin as well as postconditioning can induce cardioprotection through prevention of the cell-cell interaction and release of inflammatory mediators, minimizing I/R pathological changes in myocardial cells. These two treatments may share same mechanisms in their actions since they showed no significant additive effects.