The role of autophagy in odontogenesis, dental implant surgery, periapical and periodontal diseases.

Autophagy is a cellular process that is evolutionarily conserved, involving the sequestration of damaged organelles and proteins into autophagic vesicles, which subsequently fuse with lysosomes for degradation. Autophagy controls the development of many diseases by influencing apoptosis, inflammation, the immune response and different cellular processes. Autophagy plays a significant role in the aetiology of disorders associated with dentistry. Autophagy controls odontogenesis. Furthermore, it is implicated in the pathophysiology of pulpitis and periapical disorders. It enhances the survival, penetration and colonization of periodontal pathogenic bacteria into the host periodontal tissues and facilitates their escape from host defences. Autophagy plays a crucial role in mitigating exaggerated inflammatory reactions within the host's system during instances of infection and inflammation. Autophagy also plays a role in the relationship between periodontal disease and systemic diseases. Autophagy promotes wound healing and may enhance implant osseointegration. This study reviews autophagy's dento-alveolar effects, focusing on its role in odontogenesis, periapical diseases, periodontal diseases and dental implant surgery, providing valuable insights for dentists on tooth development and dental applications. A thorough examination of autophagy has the potential to discover novel and efficacious treatment targets within the field of dentistry.

Influence of omega-3 fatty acid on orthodontic tooth movement in rats: A biochemical, histological, immunohistochemical and gene expression study.

OBJECTIVE: The aim of this study was to investigate the effects of omega-3 fatty acids on orthodontic tooth movement. SETTING AND SAMPLE POPULATION: For this study, 56 12-week-old adult male Wistar albino rats from the Animal Laboratory at Adnan Menderes University, Faculty of Medicine, were used. MATERIAL AND METHODS: Rats were randomly divided into seven groups (n = 8 each): control group (without any treatment), tooth movement groups (three groups of animals with only tooth movement) and omega groups (three groups of animals with tooth movement and omega-3 administration). Omega-3 fatty acids were administered to the rats systemically during the tooth movement period. On the 3rd, 7th and 14th days after the orthodontic tooth movement, the rats were sacrificed and biochemical, histological, immunohistochemical andgene expression examinations were performed. RESULTS: On the 14th experimental day, the amount of tooth movement in the omega groups was significantly lower than the tooth movement groups (P = 0.012). Biochemical experimentsshowed that the omega groups had significantly lower total oxidant levels and higher total antioxidant levels compared to the tooth movement group on the 14th experimental day (P = 0.001). The levels of RANKL, IL-6 and IL-1ß in the omega groups were significantly lower than the tooth movement groups on all experimental days (P < 0.05). CONCLUSION: Systemic administration of omega-3 fatty acids showed antioxidant and antiinflammatory effects and decelerate the orthodontic tooth movement.

JAK/STAT pathway interacts with intercellular cell adhesion molecule (ICAM) and vascular cell adhesion molecule (VCAM) while prostate cancer stem cells form tumor spheroids.

PURPOSE: JAK/STAT is an evolutionarily conserved pathway and very important for second messenger system. This pathway is important in malignant transformation and accumulated evidence indicates that this pathway is involved in tumorigenesis and progression of several cancers. It was possible to assume that activation of JAK/STAT pathway is associated with increase in the expressions of ICAM/1 and VCAM-1. In this study we hypothesized that when cells were maintained as spheroids or monolayers, the structure of cancer stem cells (CSCs) could show differentiation when compared with non-CSCs. METHODS: DU-145 human prostate cancer cells were cultured using the Ege University molecular embryology laboratory medium supplemented with 10% fetal bovine serum. Clusters of differentiation 133 (CD133)(+high)/CD44(+high) prostate CSCs were isolated from the DU145 cell line by using BD FACSAria. CD133//CD44+ CSCs were cultured until confluent with 3% noble agar. The expression of these proteins in CSCs and non-CSCs was analyzed by immunohistochemistry. RESULTS: Different expression profiles were observed in the conventional two-dimensional (2D) and three-dimensional (3D) experimental model system when CSCs and non-CSCs were compared. Human prostate CSCs exhibited intense ICAM-1 and VCAM-1 immunoreaction when compared with non-CSCs. These findings were supported by the fact that VCAM-1 on the surface of cancer cells binds to its counterreceptor, the α4ß1 integrin (also known as very-late antigen, VLA-4), on metastasis-associated macrophages, triggering VCAM-1-mediated activation of the phosphoinositide 3-kinase growth and survival pathway in cancer cells. CONCLUSIONS: The results of this study showed that changes in JAK/STAT pathway are related with adhesion molecules and could affect cancer progression.

Effects of oral intake of cetirizine HCl and desloratadine molecules on the middle ear mucosa: an experimental animal study.

We have planned to demonstrate histopathologic effects of mid- or long-term oral use of desloratadine and cetirizine HCl molecules on middle ear mucosa of rats. Thirty-six rats were randomized equally into six groups. Desloratadine groups received once daily doses of 1 mg/ml desloratadine for 30 (D30 Group) or 60 (D60 Group) days. The Cetirizine study groups were given once daily doses of 1 mg/ml cetirizine for 30 (S30 Group) or 60 (S60 Group) days. Control groups were given 2 cc physiologic saline using orogastric gavage method through a 12 G gavage catheter for 30 (K30 Group) or 60 (K60) days. At the end of 30 days, D30, S30 and K30 Groups were sacrificed. Tissue samples harvested from groups were evaluated between 1 and 4 Grades for histological characteristics of middle ear canal, eardrum, middle ear epithelium and connective tissue, edema, vascular congestion and inflammatory cells. In the control group no pathological finding was encountered in rats sacrificed on 30 and 60 days. No statistical difference was observed when groups were compared on external ear epithelial tissue, external ear sebaceous gland, middle ear inflammation, and middle ear capillary dilatation both on 30 and 60 days. Tympanic membrane collagen was more evident in D30 and D60 groups when compared with C30 and C60 groups. Comparison of histopathological grading results between 30 and 60 days revealed no significant changes. In conclusion, oral intake of cetirizine and desloratadine preparations has effects of tympanic membrane collagen, degrees of edema and vascular congestion being more prominent with desloratadine molecule.

Cancer stem cell and embryonic development-associated molecules contribute to prognostic significance in ovarian cancer.

OBJECTIVES: Embryonic molecules and cancer stem cell signaling resemble each other, and they organize cancer modality. We hypothesized that similar immunohistochemical expressions between tumor spheroids and patients' samples compared with clinical relevance would give an important clue in patients' prognosis. METHODS: Immunohistochemical expression of c-kit, Notch1, Jagged1, and Delta1 in 50 cases of primary ovarian tumors (10 endometrioid, 10 serous, 10 mucinous adenocarcinoma, 10 borderline serous, and 10 borderline mucinous tumors) and MDAH-2774 spheroids were investigated. Results were compared in both spheroids and tumor samples with morphologic parameters (histological grade) and clinical data (age, stage, tumor size, and metastasis). RESULTS: High c-kit and Notch1 immunoreactivity was shown in spheroids, but interestingly immunoreactivity of these molecules in tumor samples was different from patients' clinicopathological characteristics. In serous carcinoma, metastasis correlated with Notch1 immunoexpression; in mucinous carcinoma, Jagged1 immunohistochemistry correlated with grade, stage, and metastasis of tumor; in borderline serous and mucinous tumors, Jagged1 correlated with high grade. Moreover, Jagged1 correlated with stage and Notch1 with size in borderline mucinous tumor. Endometrioid carcinoma statistics showed that there was a correlation between age and Notch1 expression. CONCLUSION: Notch1, Jagged1, and Delta1 expressions might be useful markers for clinical prognosis of ovarian carcinomas; and Notch pathway, one of the most intensively studied putative therapeutic targets, may be a useful marker for cancer. Consequently, Jagged1 could be a marker for tumor grades and Notch1 as a marker for metastases.

Comparison of the effects of Contractubex® gel in an experimental model of scar formation in rats: an immunohistochemical and ultrastructural study.

BACKGROUND: Contractubex® gel, a commercial treatment for scars, consists of a mixture of onion extract (cepea extract), heparin sodium, and allantoin. It exerts a softening and smoothing effect on indurated, hypertrophic, painful, and cosmetically-disfiguring scar tissue. AIM: To compare and discuss the immunohistochemical and ultrastructural effects of treatment of an experimental scar in a rat model with Contractubex gel. METHODS: Thirty-two Sprague-Dawley rats were divided into four groups. Skin biopsies were taken to develop full thickness wounds. After 10 days, Contractubex gel, heparin, and allantoin were topically applied daily to groups 2, 3, and 4, respectively. Group 1 was the control group. On the 30th day, scar tissues were excised to investigate the immunohistochemical and ultrastructural effects of these agents. For this purpose we used TGF-beta, laminin, and fibronectin primary antibodies. RESULTS: Increased immunoreactivities of laminin, fibronectin, and TGF-beta in control group, moderate immunoreactivities in heparin and allantoin groups, and mild immunoreactivities in the Contractubex gel group were observed. In semi-thin sections, Group 2 showed the thinnest epidermis of the four groups. In electron micrographs of Group 2, completely keratinized and normally appearing cells could be seen. CONCLUSIONS: Immunohistochemical and ultrastructural observations demonstrated that the Contractubex gel significantly improved the quality of wound healing and reduction of scar formation. Also, it was a more appropriate treatment choice than heparin monotherapy and allantoin monotherapy in keloidal and hypertrophic scars.

Metrical and histological investigation of the effects of low-level laser therapy on orthodontic tooth movement.

The aim of this study was to evaluate the effects of 820-nm diode laser on osteoclastic and osteoblastic cell proliferation-activity and RANKL/OPG release during orthodontic tooth movement. Thirty-eight albino Wistar rats were used for this experiment. Maxillary incisors of the subjects were moved orthodontically by a helical spring with force of 20 g. An 820-nm Ga-Al-As diode laser with an output power of 100 mW and a fiber probe with spot size of 2 mm in diameter were used for laser treatment and irradiations were performed on 5 points at the distal side of the tooth root on the first, second, and 3rd days of the experiment. Total laser energy of 54 J (100 mW, 3.18 W/cm(2), 1717.2 J/cm(2)) was applied to group II and a total of 15 J (100 mW, 3.18 W/cm(2), 477 J/cm(2)) to group III. The experiment lasted for 8 days. The number of osteoclasts, osteoblasts, inflammatory cells and capillaries, and new bone formation were evaluated histologically. Besides immunohistochemical staining of PCNA, RANKL and OPG were also performed. No statistical difference was found for the amount of tooth movement in between the control and study groups (p > 0.05). The number of osteoclasts, osteoblasts, inflammatory cells, capillary vascularization, and new bone formation were found to be increased significantly in group II (p < 0.05). Immunohistochemical staining findings showed that RANKL immunoreactivity was stronger in group II than in the other groups. As to OPG immunoreactivity, no difference was found between the groups. Immunohistochemical parameters were higher in group III than in group I, while both were lower than group II. On the basis of these findings, low-level laser irradiation accelerates the bone remodeling process by stimulating osteoblastic and osteoclastic cell proliferation and function during orthodontic tooth movement.

Repeated acetaminophen administration damaged hippocampal tissue but did not affect prefrontal cortex or anxiety behaviors.

Acetaminophen is one of the most widely used over­the­counter drugs worldwide for the treatment of pain and fever. Although acetaminophen use is known to impair hippocampus­related learning and memory, its effect on anxiety is not clear. Insulin­like growth factor­1 (IGF­1) and matrix metalloproteinase­2 (MMP2) are important for cellular survival, maintenance and tissue integrity. The aim of this study was to investigate the dose­dependent effects of acetaminophen on anxiety levels as well as on hippocampus, prefrontal cortex and liver tissue. Doses of 100, 200 and 400 mg/kg acetaminophen were administered to male Sprague Dawley rats for 11 days and anxiety tests were conducted on the last day. Twenty­four hours after the last acetaminophen administration, all animals were sacrificed and hippocampus, prefrontal cortex and liver tissues were removed for analyses. Hippocampal IGF­1 and MMP2 levels were shown to decrease only at the highest dose of acetaminophen, which was accompanied by pathological changes in histology. The prefrontal cortex was not affected. Behavioral analyses also did not indicate changes in anxiety levels in the rats. Liver IGF­1 and MMP2 levels decreased in all experimental groups. Serum alanine aminotransferase and aspartate aminotransferase levels increased in the 200 mg/kg and 400 mg/kg acetaminophen groups. Our findings showed that varying doses of acetaminophen did not affect the prefrontal cortex or anxiety levels. Further research is needed to elucidate the hippocampal and hepatic protective roles of IGF­1 and MMP2 in acetaminophen toxicity and their potential use in therapeutic approaches.

Acute spiral ganglion cell degeneration following acoustic overstimulation: an experimental study.

BACKGROUND: To evaluate acoustic overstimulation-induced spiral ganglion cell (SGC) degeneration, and determine the relationship between the duration of acoustic overstimulation and rate of SGC degeneration. METHODS: Fifteen guinea pigs were randomized equally to 4 experimental groups, which were exposed to different durations (7.5, 15, 30 and 60 min) of acoustic overstimulation (120 dB at 4 kHz), and a control group. Every bulla was examined histopathologically and immunohistochemically. A quantitative and statistical analysis of acidophilic and TUNEL-positive SGCs was performed. RESULTS: In the control group, 2.1% of SGCs were acidophilic and no TUNEL-positive SGC was detected. In contrast, a statistically significant number of acidophilic (p = 0.000) and TUNEL-positive SGCs (p = 0.002) was determined in the experimental groups. Moreover, a positive correlation between the duration of acoustic overstimulation and acidophilic SGCs (p = 0.000), and a statistically significant relationship between the duration of acoustic overstimulation and TUNEL-positive SGCs (p = 0.000) were demonstrated. CONCLUSION: Acoustic overstimulation may induce acute SGC degeneration. A positive correlation was determined between the duration of acoustic overstimulation and rate of degenerated SGCs.

Effects of bisphosphonates on sutural bone formation and relapse: A histologic and immunohistochemical study.

INTRODUCTION: The aim of this experimental study was to evaluate the effects of systemically applied zoledronic acid on bone regeneration in response to expansion of the sagittal suture and relapse in rats. METHODS: Thirty-six male Wistar rats were divided into 3 groups. In the first and second groups, saline solution was given subcutaneously after expansion, and the retention periods lasted 14 and 7 days, respectively. In the third group, 0.1 mg of zoledronic acid was diluted with saline solution and given subcutaneously after expansion; the retention period lasted for 7 days. Expansion and relapse amounts were measured by using computed tomography. After the retention period, 6 rats from each group were killed for histologic and immunohistochemical assessments. The other 6 rats from each group were used for observation of the relapse. RESULTS: The histologic evaluation showed that, in groups 1 and 2, the numbers of osteoblasts were less than observed in group 3. When scores of staining intensity were compared, immunoreactivities were statistically significantly increased in group 3 compared with groups 2 and 1. Statistically significant differences were found when the relapse percentages were compared between the groups (P <0.05). The smallest relapse occurred in group 3. CONCLUSIONS: Zoledronic acid has positive effects on bone formation in the sagittal suture in response to expansion and decreases the relapse ratio after expansion in rats.

Do Wortmannin and Thalidomide induce apoptosis by autophagy inhibition in 4T1 breast cancer cells in vitro and in vivo?

The aim of this study was to show the effects of autophagy inhibitor Wortmannin and antiangiogenic-proapoptotic Thalidomide on autophagy and apoptosis markers in 4T1 breast cancer cells in vitro and in vivo. The half-maximal inhibitory concentration (IC50) values of 4T1 cells for Wortmannin and Thalidomide were evaluated by Methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay. After cancer formation in 28 BALB/C female mice, drugs were administered for seven days. Cells and tissue sections were evaluated for anti-phosphoinositide 3-kinase (PI3K), anti- the microtubule-associated protein 1 light chain3 (MAPLC3ß), anti-caspase 8, anti-caspase 9, and anti-caspase 3 immunoreactivities by immunohistochemical staining and apoptosis by Terminal Transferase dUTP Nick End Labeling (TUNEL) assay. Both PI3K and MAPLC3ß immunoreactivities decreased in all treatments when compared to control group except Thalidomide treatment in primary cancer tissue. The caspase 3, 8, and 9 immunoreactivities were increased in all treatment groups and TUNEL positive cells were the highest in the Wortmannin and Thalidomide group. Our findings suggest that autophagy is an important mechanism for 4T1 cells and both Wortmannin and Thalidomide treatments inhibit autophagy and induce apoptosis. In primary cancer tissues, autophagy was not effective as in vitro. The treatment of Wortmannin and Thalidomide increased the apoptotic cells in vivo independent from autophagy inhibition. Different results may be because of microenvironment. Further studies must be done to elucidate the effect of microenvironment.

Anti-VEGF treatment suppresses remodeling factors and restores epithelial barrier function through the E-cadherin/ß-catenin signaling axis in experimental asthma models.

Besides maintaining a physical barrier with adherens junctional (AJ) and tight junctional proteins, airway epithelial cells have important roles in modulating the inflammatory processes of allergic asthma. E-cadherin and ß-catenin are the key AJ proteins that are involved in airway remodeling. Various mediators such as transforming growth factor-ß (TGF-ß), epidermal growth factor (EGF), fibroblast growth factor (FGF), platelet derived growth factor (PDGF), insulin-like growth factor (IGF), tumor necrosis factor-α (TNF-α) and angiogenic factors, such as vascular endothelial growth factor (VEGF), are released by the airway epithelium in allergic asthma. The signaling pathways activated by these growth factors trigger epithelial-mesenchymal transition (EMT), which contributes to fibrosis and subsequent downregulation of E-cadherin. The present study used a mouse asthma model to investigate the effects of anti-VEGF, anti-TNF and corticosteroid therapies on growth factor and E-cadherin/ß-catenin expression. The study used 38 male BALB/c mice, divided into 5 groups. A chronic mouse asthma model was created by treating 4 of the groups with inhaled and intraperitoneal ovalbumin (n= 8 per group). Saline, anti-TNF-α (etanercept), anti-VEGF (bevacizumab) or a corticosteroid (dexamethasone) were applied to each group by intraperitoneal injection. No medication was administered to the control group (n=6). Immunohistochemistry for E-cadherin, ß-catenin and growth factors was performed on lung tissues and protein expression levels assessed using H-scores. Statistically significant differences were observed in E-cadherin, ß-catenin, EGF, FG, and PFGF (P<0.001 for all) as well as the IGF H-scores between the five groups (P<0.005). Only anti-VEGF treatment caused E-cadherin and ß-catenin levels to increase to the level of non-asthmatic control groups (P>0.005). All treatment groups had reduced TGF-ß, PDGF and FGF H-scores in comparison with the untreated asthma group (P=0.001). The EGF and IGF levels were not significantly different between the untreated asthmatic and non-asthmatic controls. The results suggested that anti-VEGF and TNF-α inhibition treatments are effective in decreasing growth factors, in a similar manner to conventional corticosteroid treatments. Anti-VEGF and TNF inhibition therapy may be an effective treatment for remodeling in asthma while offering an alternative therapeutic option to steroid protective agents. The data suggested that anti-VEGF treatment offered greater restoration of the epithelial barrier than both anti-TNF-α and corticosteroid treatment.

Immunohistochemical determination of mTOR pathway molecules in ovaries and uterus in rat estrous cycle stages.

mTOR is a member of the PI3K/Akt/mTOR signaling pathway that participates in cell growth, proliferation, protein synthesis, transcription, angiogenesis, apoptosis and autophagy. mTOR and MAPK pahways are two important key signal pathways which are related to each other. We investigated the role of mTOR and other signaling molecules in rat ovaries and uteruses in stages of the estrous cycle. Young adult female rats were divided into four groups as proestrous, estrous, metestrous and diestrous according to vaginal smears. Immunohistochemical staining of mTORC1, IGF1, PI3K, pAKT1/2/3, ERK1 and pERK1/2 was performed and pAKT1/2/3 and ERK1 were also analyzed using western blotting on ovarian and uterine tissue samples. According to our results, PI3K/Akt/mTOR and ERK/pERK showed an increase in the rat ovulation period. When all the groups were evaluated the immunoreactivities for all of the antibodies were detected in the oocytes, granulosa and theca cells, corpus luteum and stroma of ovary and lamina propria, surface and glandular epithelium of uterus with the strongest observed with anti-ERK1 antibody and then with a decreasing trend with anti-mTORC1, anti-pAkt1/2/3, anti-IGF1, anti-PI3K and anti-pERK1/2 antibodies in the proestrus and estrus stages. Differently from other parts of the ovary, highest antibody expression in the corpus luteum was observed in the metestrous stage. Moreover, the existence of pAKT1/2/3 and ERK1 proteins was confirmed with the Western blotting technique. We suggest that mTOR and mTOR-related ERK signaling molecules may participate in the rat ovulation process.

Adjuvant effects of chemotherapeutics and Metformin on MFE-319 endometrial carcinoma cell line.

We aimed to investigate the cytotoxicity of Metformin, Cisplatin, and Paclitaxel on MFE-319 endometrial carcinoma cell line using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and immunocytochemistry assays. Half maximal inhibitory concentration (IC50) doses of three drugs alone and in the dual combinations were applied to the cells. Immunocytochemical method was performed for the cell survival and for phosphatidylinositol 3-kinase (PI3K), phosphorylated extracellular regulated kinases (pErk)-1∕2, Akt-1, phosphorylated Akt (pAkt)-1∕2∕3 cell growth markers and angiogenic vascular endothelial growth factor (VEGF). Immunoreactivities were evaluated using H-score and analyzed using the one-way analysis of variance (ANOVA) test for statistics. It was found that these drugs caused a decrease in the immunoreactivities of these markers. Particularly, dual combination of Paclitaxel and Cisplatin decreased the immunoreactivities of PI3K, pErk-1∕2, Akt-1, and pAkt-1∕2∕3. Cisplatin and Paclitaxel were more effective than Metformin; on the other hand, Metformin has been shown to enhance the efficacy of these two drugs. In vitro or in vivo further studies are needed to investigate the efficacy of these three drugs via PI3K∕Akt signal pathway.

Significant Changes in Trans-Epithelial Barrier Proteins of Adenoid Tissue with Atopic Status in Children.

OBJECTIVES: Adenoid tissue is important in local immune response and epithelial barrier dysfunction of this tissue may contribute to allergies. The aim of this study was to evaluate the relationship between the status of cross-epithelial barrier elements in adenoid tissue lymphoepithelium and inhalant allergen sensitization. MATERIALS AND METHODS: Children aged 5-15 years, who underwent adenotonsillectomy, participated in this study. All subjects underwent skin prick testing with environmental inhalant allergens. Occludin, ZO1, e-cadherin, ß-catenin, desmoglein, desmoplakin, and connexon-43 were stained immunohistochemically in the adenoid tissues obtained and scored by H-score. RESULTS: We enrolled 76 children, 14 among whom were sensitized to environmental allergens. Among the zonula occludens proteins, median H-scores for occludin, claudin, and ZO-1 were significantly lower in the atopic compared to the nonatopic group respectively (p<0.001). Similarly, median H-scores for e-cadherin and ß catenin proteins of the zonula adherens were significantly lower in the atopic group (p<0.001). Both desmoglein and desmoplakin H-scores were significantly lower in the atopic group [60 (50-100) vs 280 (260-300), p<0.001 and 105 (87.5-120) vs 280 (67.25-300), p<0.001 respectively]. Moreover, connexin-43 protein of the gap junction was significantly lower in the atopic group (p<0.001). CONCLUSION: Adenoid tissue, which is the initial point of contact of inhalant allergens demonstrates epithelial barrier junctional protein, changes in children with inhalant allergen sensitization without clinical allergic disease symptoms. Therefore, it may be concluded that epithelial barrier function plays an important role in the development of allergen sensitization versus tolerance.

Defining the macroscopic and microscopic findings of experimental focal brain ischemia in rats from a forensic scientist's point of view.

Approximately 10% of all deaths in the world occur as a result of stroke. Determination of the time schedule of the pathologic events in a stroke patient is invaluable for a forensic specialist. The aim of this study was to define the schedule of the macroscopic and microscopic changes that occurred in a rat model of permanent focal ischemia for providing useful clues for the evaluation of stroke patients. Male Wistar rats weighing 250 to 350 g were used in this study. Permanent focal brain ischemia was applied by the suture occlusion method. The animals were divided into 7 experimental groups (n = 6) with time schedules including 1.5, 3, 6, 12, 24, 72 hours, and the sham. Brains were harvested at the end of the determined time schedule. Lesions in the frontoparietal cortex were evaluated macroscopically first and later hematoxylin eosin stained sections from the infarct core were investigated microscopically. Macroscopically, enlargement of the ipsilateral hemisphere was mild at 6 hour, apparent at 12 and 24 hours, and mild again at 72 hours. Microscopically, ischemic changes were apparent even at 1.5 hour. Red neurons and infiltration of the parenchyma with neutrophil leukocytes were observed at 12 hours. Pannecrosis and massive leukocyte infiltration were observed at 72 hours. Macroscopic and microscopic findings obtained from a rat model may provide clues for determination of the time-dependent changes due to brain ischemia in human subjects. Finally, the benefits of determination of time course of pathologic changes in the brain for forensic scientists were discussed.

Cell Signaling Pathways Related to Epithelial Mesenchymal Transition in Cancer Metastasis.

The epithelial mesenchymal transition (EMT) is a highly complex and dynamic morphogenetic process in which epithelial cells change their cellular characteristics and transform to mesenchymal cells. It plays a key role in tissue remodeling, not only during embryonic development and stem cell biology but also during wound healing, fibrosis, and cancer progression. In EMT, under different extracellular cell signals and stimuli, epithelial cells undergo an orchestrated series of morphological, cellular, biochemical, and molecular changes. The mechanism of cancer cell metastasis is similar to embryonic development, like epithelial cells migrating and differentiating into all tissues of the embryo. In this period, epithelial cells differentiate into mesenchymal cells, migrate, and return to the epithelial cells when necessary. The important cell signaling pathways in embryonic development, such as growth factor receptor tyrosine kinases (FGF, HGF, TGF-α), TGF-ß, Wnt, NOTCH, MAPK, JAK/STAT and inflammatory cytokines such as NF-κB, TNF-α, IL6, cathepsin and HIF-1α. All play crucial roles in EMT during cancer cell invasion and metastasis. In cancer progression, similar cell signaling pathways and molecular activation occur in embryonic development; therefore, it is important to understand the molecular mechanisms of cell signaling pathways related to cancer metastasis and improve new diagnostic and therapeutic approaches for resistance to drugs.

Auditory and Histopathological Effects of Topical Mercurochrome Treatment in Rats with Tympanic Membrane Perforation.

OBJECTIVES: Topical treatment is first choice in the treatment of uncomplicated chronic otitis media. It was intended to assess auditory and histopathological safety of ototopical use of mercurochrome solution in rats with induced tympanic membrane perforation. MATERIALS AND METHODS: The study was conducted on 21 female Wistar-Albino rats which were randomly assigned into 3 groups. In all rats, perforation was performed at right tympanic membrane. Distortion product otoacoustic emissions (DPOAEs) measurements were performed at frequencies of 2000, 3000 and 4000 Hz (with L1/L2: 70 /70 dB at 2f1-f2 frequency; f2/f1 ratio: 1:22) before recovery from anesthesia and signal-to-noise ratio (SNR) were recorded. Normal saline, 2% mercurochrome and gentamicin were given to group 1, 2 and 3 twice daily over a week, respectively. Rats were sacrificed after DPOAE measurements on day 14. Right temporal bone specimens were examined under light microscope after processing. RESULTS: Based on DPOAE results, there was no significant difference among groups before treatment. On day 14, significant differences were found in DPOAE measurements at 3000 and 4000 Hz, and in mean SNR values in 2% mercurochrome and gentamicin groups when compared to normal saline group while no significant difference was detected at 2000 Hz among groups. In addition, significant degeneration was detected in Corti organs, spiral ganglions and stria vascularis in groups 2 and 3. CONCLUSION: In this study, it was observed that mercurochrome use in external otitis and otitis media with tympanic membrane perforation could cause ototoxicity and concluded that the solution should be used cautiously.

Comparison of the effects of collagenase and extract of Centella asiatica in an experimental model of wound healing: an immunohistochemical and histopathological study.

In this study, we compared the effects of collagenase and Centella asiatica in the rat model. Twenty-seven female rats were divided into three groups, and two full-thickness wounds were made for each animal. Collagenase ointment was applied topically to Group I and C. asiatica ointment to Group II rats. In Group III, no treatment was applied. On the third day of treatment, wounds on the left side of three animals of each group were excised. On the fifth and eighth day of the treatments, the same procedure was performed for the remaining animals. Indirect immunohistochemical examination was performed to detect transforming growth factor beta (TGF)-beta, endothelial and inducible nitric oxide synthase (eNOS and iNOS), vascular endothelial growth factor, TGF-alpha, laminin, fibronectin, collagen I, and interleukin-1beta. According to the measurements of the wound areas and wound healing periodo, collagenase was superior to the control group. Immunohistochemical examinations showed strong (+++) iNOS and TGF-beta immunoreactivities in C. asiatica group. eNOS immunoreactivity was moderate (++) in this group. For the collagenase group, iNOS, eNOS, and TGF-beta immunoreactivities were moderate (++). In the collagenase group, while TGF-beta and iNOS immunoreactivities were weaker, laminin and fibronectin reactivities were stronger than in C. asiatica and control groups. Collagenase was superior to C. asiatica according to the immunohistochemical findings. Collagenase ointment significantly improves the quality of wound healing and scar formation and is a more appropriate treatment choice than extract of C. asiatica in the early stages of the wound healing process.

Immunolocalization of VEGF, VEGFR-1 and VEGFR-2 in lung tissues after acute hemorrhage in rats.

In treatment of hypovolemia it is important to reestablish normal tissue hemodynamics after fluid resuscitation. Vascular endothelial growth factor (VEGF) and VEGF receptors (VEGFR) have been identified as important in many physiological and pathological processes. In this study, we aimed to investigate the histo-physiological effects of VEGF, VEGFR-1 (flt-1) and VEGFR-2 (KDR/flk-1) in resuscitation with different plasma substitutes on lung tissues after acute hemorrhage in rats. Male Sprague-Dawley rats (n=25) were used in this study. The left femoral vein and artery were cannulated for the administration of volume expanders and for direct measurement of mean arterial blood pressure (MAP) (Power-Lab) and heart rate (HR). Fifteen rats were bled (5 ml/10 min) and infused (5 ml/5 min) with one of three randomly selected fluids: (a) dextran-70 (Macrodex); (b) gelatin (Gelofusine); or (c) physiological saline (PS, 0.9% isotonic saline) solutions. Five rats were bled and none were infused (hypovolemia group) and five rats were untreated as the control group. At the end of the experiment, rats were sacrificed and lung tissues were removed for routine processing and paraffin wax embedding. Sections of tissue were stained with hematoxylin and eosin (H&E) and selected blocks were then prepared for indirect immunohistochemical labeling for anti-VEGF, anti-VEGFR-1 and anti-VEGFR-2 primary antibodies. It was observed that both MAP and HR decreased parallel to blood withdrawn in this time interval. The MAP and HR were restored in the following periods. In the control rats, positive immunoreactivity of VEGF and its receptors (VEGFR-1 and VEGFR-2) were detected in respiratory epithelial cells, respiratory and vascular smooth muscle cells, alveolar cells and endothelial cells. While strong immunoreactivities of VEGF and VEGFR-1 were observed in the hypovolemia group, only moderate immunoreactivity of VEGFR-2 was seen in this group. Moderately strong immunolabeling of VEGF and VEGFR-1 were observed in the dextran-70, gelatin and PS resuscitated groups, whereas only weak immunolabeling of VEGFR-2 was observed in these groups. In summary, the vascular protecting effects of these factors were observed with fluid resuscitation, contributing to the pathophysiological changes seen in hypovolemia.