Evaluation of possible cytotoxic, genotoxic and epigenotoxic effects of titanium dioxide nanoparticles and possible protective effect of melatonin.

Nanoparticles (NPs) are particles of matter that are between 1 to 100 nm in diameter. They are suggested to cause toxic effects in both humans and environment thorough different mechanisms. However, their toxicity profile may be different from the parent material. Titanium dioxide (TiO2) NPs are widely used in cosmetic, pharmaceutical and food industries. As a white pigment, the use of TiO2 is used in food coloring, industrial paints, clothing and UV filters has increased tremendously in recent years. Melatonin, on the other hand, is a well-known antioxidant and may prevent oxidative stress caused by a variety of different substances, including NPs. In the current study, we aimed to comparatively investigate the effects of normal-sized TiO2 (220 nm) and nano-sized TiO2 (21 nm) on cytopathology, cytotoxicity, oxidative damage (lipid peroxidation, protein oxidation and glutathione), genotoxicity (8-hydroxydeoxyguanosine), apoptosis (caspase 3, 8 and 9) and epigenetic alterations (global DNA methylation, H3 acetylation) on 3T3 fibroblast cells. In addition, the possible protective effects of melatonin, which is known to have strong antioxidant effects, against the toxicity of TiO2 were also evaluated. Study groups were: a. the control group; b. melatonin group; c. TiO2 group; d. nano-sized TiO2 group; e. TiO2 + melatonin group and f. nano-sized TiO2 + melatonin group. We observed that both normal-sized and nano-sized TiO2 NPs showed significant toxic effects. However, TiO2 NPs caused higher DNA damage and global DNA methylation compared to normal-sized TiO2 whereas normal-sized TiO2 led to lower H3 acetylation vs. TiO2 NPs. Melatonin showed partial protective effect against the toxicity caused by TiO2 NPs.

Evaluation of oxidative stress cycle in healthy and inflamed dental pulp tissue: a laboratory investigation.

OBJECTIVES: The purpose of this study was to investigate the oxidative stress cycle consisting of reactive oxygen molecules (ROS), glutathione (GSH) and glutathione S-transferase (GST) in caries-related pulp inflammation. METHODOLOGY: Fifty-four pulp tissue samples were collected from healthy donors with the diagnosis of reversible pulpitis, symptomatic irreversible pulpitis, and healthy pulp. Twelve pulp samples from each group were homogenized and total protein, ROS, GSH, and GST were measured by spectrophotometer. The remaining 6 samples from each group were prepared for paraffin block and used for the histopathologic and immunohistochemical evaluation of oxidative stress parameters and TUNEL labeling. Data were analyzed statistically. RESULTS: The results revealed that total protein levels significantly decreased; however, ROS levels increased in both reversible and irreversible pulpitis compared to the healthy pulp (p < 0.01). Also, as inflammation increases, GST enzyme levels decrease while GSH levels increase significantly (p < 0.05). It was found that the number of TUNEL (+) cells was increased in irreversible pulpitis samples compared to healthy and reversible pulpitis groups (p < 0.05). GSTP1 and GSH immunoreactivity were also observed in irreversible pulpitis samples. CONCLUSIONS: It has been revealed that caries-related inflammation alters the oxidative stress cycle in dental pulp tissue. The increase in GSH levels in the inflamed dental pulp due to the increase in ROS levels may improve the defensive ability of the dental pulp. CLINICAL RELEVANCE: There is a relationship between oxidative stress and inflammation. Control of excessive oxidative stress in pulpitis can stimulate reparative and regenerative processes. The present findings may provide an overview of the management of oxidative stress in cases with pulpitis during regenerative treatments.

Prophylactic Ozone Administration Reduces Intestinal Mucosa Injury Induced by Intestinal Ischemia-Reperfusion in the Rat.

OBJECTIVES: Intestinal ischemia-reperfusion injury is associated with mucosal damage and has a high rate of mortality. Various beneficial effects of ozone have been shown. The aim of the present study was to show the effects of ozone in ischemia reperfusion model in intestine. MATERIAL AND METHOD: Twenty eight Wistar rats were randomized into four groups with seven rats in each group. Control group was administered serum physiologic (SF) intraperitoneally (ip) for five days. Ozone group was administered 1 mg/kg ozone ip for five days. Ischemia Reperfusion (IR) group underwent superior mesenteric artery occlusion for one hour and then reperfusion for two hours. Ozone + IR group was administered 1 mg/kg ozone ip for five days and at sixth day IR model was applied. Rats were anesthetized with ketamine∖xyzlazine and their intracardiac blood was drawn completely and they were sacrificed. Intestinal tissue samples were examined under light microscope. Levels of superoxide dismutase (SOD), catalase (CAT), glutathioneperoxidase (GSH-Px), malondyaldehide (MDA), and protein carbonyl (PCO) were analyzed in tissue samples. Total oxidant status (TOS), and total antioxidant capacity (TAC) were analyzed in blood samples. Data were evaluated statistically by Kruskal Wallis test. RESULTS: In the ozone administered group, degree of intestinal injury was not different from the control group. IR caused an increase in intestinal injury score. The intestinal epithelium maintained its integrity and decrease in intestinal injury score was detected in Ozone + IR group. SOD, GSH-Px, and CAT values were high in ozone group and low in IR. TOS parameter was highest in the IR group and the TAC parameter was highest in the ozone group and lowest in the IR group. CONCLUSION: In the present study, IR model caused an increase in intestinal injury.In the present study, ozone administration had an effect improving IR associated tissue injury. In the present study, ozone therapy prevented intestine from ischemia reperfusion injury. It is thought that the therapeutic effect of ozone is associated with increase in antioxidant enzymes and protection of cells from oxidation and inflammation.

In vitro effects of phenytoin and DAPT on MDA-MB-231 breast cancer cells.

Voltage-gated sodium channel (VGSC) activity enhances cell behaviors related to metastasis, such as motility, invasion, and oncogene expression. Neonatal alternative splice form of Nav1.5 isoform is expressed in metastatic breast cancers. Furthermore, aberrant Notch signaling pathway can induce oncogenesis and may promote the progression of breast cancers. In this study, we aimed to analyze the effect of the nNav1.5 inhibitor phenytoin and Notch signal inhibitor N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine-t-butyl ester (DAPT) on triple negative breast cancer cell line (MDA-MB-231) via inhibition of nNav1.5 VGSC activity and Notch signaling, respectively. In order to determine the individual and combined effects of these inhibitors, the 4-[3-(4-iyodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate (WST-1) test, wound healing assay, and zymography were performed to detect the proliferation, lateral motility, and matrix metalloproteinase-9 (MMP9) activity, respectively. The expressions of nNav1.5, Notch4, MMP9, and tissue inhibitor of metalloproteinases-1 (TIMP1) were also detected by quantitative real-time reverse transcriptase-polymerase chain reaction. DAPT caused an antiproliferative effect when the doses were higher than 10 µM, whereas phenytoin showed no inhibitory action either alone or in combination with DAPT on the MDA-MB-231 cells. Furthermore, it was found that the lateral motility was inhibited by both inhibitors; however, this inhibitory effect was partially rescued when they were used in combination. Meanwhile, the results showed that the MMP9 activity and the ratio of MMP9 mRNA to TIMP1 mRNA were only decreased by DAPT. Thus, we conclude that the combined effect of DAPT and phenytoin is not as beneficial as using DAPT alone on MDA-MB-231 breast cancer cells.

Effect of coenzyme Q10 on organ damage in sepsis.

OBJECTIVE: Investigating the effects of coenzyme Q10 on organ damage and survival on mice in cecal ligation perforation (CLP) model in sepsis. BACKGROUND: Coenzyme Q10 is an antioxidant molecule playing an important role in mitochondria. Mitochondrial dysfunction is an important mechanism in sepsis pathophysiology. METHODS: Nintyfour Swiss Albino male mice were divided into 8 groups. CLP was performed in Group I. Coenzyme Q10, 100 mg/kg subcutaneously, was given 5 hours after CLP to Group II and 20 hours after CLP to Group III. Sham operation was performed in Group IV, 100 mg/kg coenzyme Q10 subcutaneously was given 5 hours after sham operation to Group V and 20 hours after sham operation to Group VI. No operation was performed in Group VII; coenzyme Q10, 100 mg/kg subcutaneously, was given to Group VIII. Antibiotics and fluid replacement were applied for 3 days. The mice still living were sacrificed at 576th hour. The organ damages were scored under light microscopy. RESULTS: The survival of Group I and Group II was lower than that of the control groups, but the survival in the Group III was similar to control groups. It was established that spleen, kidney, heart damage and total organ damage were decreased when compared to CLP group. CONCLUSIONS: Coenzyme Q10 is effective in decreasing histological organ damage in sepsis (Tab. 3. Fig. 1, Ref. 30).

The effects of di(2-ethylhexyl)phthalate exposure and selenium nutrition on sertoli cell vimentin structure and germ-cell apoptosis in rat testis.

This study aimed to investigate the effects of di(2-ethylhexyl)phthalate (DEHP) on Sertoli-cell vimentin filaments and germ-cell apoptosis in testes of pubertal rats at different selenium (Se) status. Se deficiency was produced in 3-weeks old Sprague-Dawley rats by feeding them ≤ 0.05 Se mg/kg diet for 5 weeks, Se supplementation group was on 1 mg Se/kg diet, and DEHP was applied at 1000 mg/kg dose by gavage during the last 10 days of the feeding period. The diet with excess Se did not cause any appreciable alteration in vimentin staining and apoptosis of germ cells, but Se deficiency caused a mild decrease in the intensity of vimentin immunoreactivity and enhanced germ-cell apoptosis significantly (approximately 3-fold, p <0.0033). DEHP exposure caused disruption and collapse of vimentin filaments and significantly induced apoptotic death of germ cells (approximately 8-fold, p <0.0033). In DEHP-exposed Se-deficient animals, compared with the control, collapse of vimentin filaments was more prominent; there was serious damage to the seminiferous epithelium; and a high increment (approximately 25-fold, p <0.0033) in apoptotic germ cells was observed. Thus, Se deficiency exacerbated the toxicity of DEHP on Sertoli cells and spermatogenesis, whereas Se supplementation provided protection. These results put forward the critical role of Se in the modulation of redox status of testicular cells and emphasize the importance of Se status for reproductive health.

Effect of intra-articular injection of levobupivacaine on articular cartilage and synovium in rats.

OBJECTIVE: Intra-articular local anesthetics are often used for prevention of pain after arthroscopic knee surgery. However, the effect of local anesthetics other than bupivacaine on articular cartilage and synovium has not been studied. Also, complications associated with the injection of intra-articular bupivacaine have appeared in the literature. The aim of this study was to evaluate the effects of levobupivacaine on the articular cartilage and the synovium in rats. METHODS: Under aseptic conditions 0.25 ml (5 mg/ml) of levobupivacaine was injected into the right knee joint while 0.25 ml of saline was simultaneously injected into the left knee joint of 20 adult Sprague-Dawley rats. The purpose of saline injections was to serve as a control group. Groups of five rats were killed on days 1, 7, 14 and 21 after administration of injections. The knee joint samples were evaluated for the presence of inflammation in the articular and periarticular tissues and the synovium. RESULTS: There were no significant differences between the levobupivacaine and control groups with respect to inflammation in the articular and periarticular tissues and the synovium. CONCLUSIONS: Although more studies are needed before final recommendations can be made, by evaluating the results obtained from this study, the clinical use of intra-articular levobupivacaine can be recommended for arthroscopic knee surgery.

Reproductive toxicity of di(2-ethylhexyl) phthalate in selenium-supplemented and selenium-deficient rats.

Phthalates are abundantly produced plasticizers, and di(ethylhexyl) phthalate (DEHP) is the most widely used derivative in various consumer products and medical devices. Animal studies show that DEHP and various other phthalates cause reproductive and developmental toxicity. Although the evidences are limited, it seems reasonable that DEHP may have a potential for similar adverse effects in humans. Such concerns are increasing, particularly for the developing reproductive system of male infants and children. By taking into account the essentiality of selenium (Se) in testicular structure and functions and the high prevalence of inadequate Se intake in various part of the world, this study was designed to investigate the testicular toxicity of DEHP in Se-deficient male rats and to examine the possible preventive effects of Se supplementation on phthalate toxicity. Se deficiency was generated by feeding 3-week-old Sprague-Dawley rats with a ≤0.05 Se mg/kg diet for 5 weeks. Supplementation groups were on a 1 mg Se/kg diet, and DEHP-treated groups received a 1,000 mg/kg dose by gavage during the last 10 days of the feeding period. Testicular histopathology, sperm count and motility, and sperm morphology were examined, and plasma levels of sex hormones were measured. Toxicity and antiandrogenic effects of DEHP were evidenced by disturbed testicular histology and spermatogenesis, diminished testosterone, leutinizing hormone (LH) and follicle stimulating hormone (FSH) levels, and sperm motility. The effects of DEHP were much more pronounced in Se-deficient rats, whereas Se supplementation was found to be protective, reflecting its regulating role in cellular redox equilibrium.

The effect of melatonin on Hippo signaling pathway in dental pulp stem cells.

Dental pulp stem cells (DPSCs) have a high capacity to differentiate into the neuronal cell lineage. Meanwhile, both Hippo signaling and melatonin are key regulators in neuronal differentiation of neuronal progenitor cells. Recently emerging evidences suggest the possible interaction between melatonin and Hippo signaling in different cell lines. But underlying mechanisms involved in the initiation or progression of neurogenic differentiation in DPSCs through this connection need to be explored. Therefore, the scope of this study is to investigate the effect of melatonin on Hippo signaling pathway through the expression of its downstream effector (YAP/p-YAPY357) after the neuronal differentiation of DPSCs. In regard with this, DPSCs were incubated with growth and dopaminergic neuronal differentiation medium with or without melatonin (10 µM) for 21 days. The morphological changes were followed by phase contrast microscopy and differentiation of DPSCs was evaluated by immunofluorescence labelling with NeuN, GFAP, and tyrosine hydroxylase. Furthermore, we evaluated the presence of neural progenitor cells by nestin immunoreactivity. Hippo signaling pathway was investigated by evaluating the immunoreactivity of YAP and p-YAPY357. Our results were also supported by western-blot analysis and SOX2, PCNA and caspase-3 were also evaluated. The positive immunoreactivity for NeuN, tyrosine hydroxylase and negative immunoreactivity for GFAP showed the successful differentiation of DPSCs to neurons, not glial cells. Melatonin addition to dopaminergic media induced tyrosine hydroxylase and decreased significantly nestin expression. The expressions of PCNA and caspase-3 were also decreased significantly with melatonin addition into growth media. Melatonin treatment induced phosphorylation of YAPY357 and reduced YAP expression. In conclusion, melatonin has potential to induce neuronal differentiation and reduce the proliferation of DPSCs by increasing phosphorylation of YAPY357 and eliminating the activity of YAP, which indicates the active state of Hippo signaling pathway.

Tumor apelin immunoreactivity is correlated with body mass index in ovarian high grade serous carcinoma.

Ovarian cancer has a high mortality rate. Serous carcinoma is the most common subtype and can be detected by distant or lymph node metastasis in advanced stages. Apelin, an adipokine associated with obesity, and its receptor, APJ, participate in lymphatic invasion. Angiogenesis also can affect lymph node involvement in serous ovarian carcinomas. We investigated apelin/APJ receptor immunoreactivity in stages III and IV ovarian cancer with or without lymph node involvement and correlated the results with body mass index (BMI) to determine whether the potential relation of the two affects the outcome of the cancer. We investigated 30 patients diagnosed between 2014 and 2016 with high grade serous ovarian cancer. Tumor:stroma ratio, indirect immunoperoxidase method, H-score and MATLAB analysis were performed. In obese and pre-obese patients, tumor apelin immunoreactivity was stronger than for patients with normal BMI. Tumor:stroma ratio was correlated with survival and lymph node involvement. Strong apelin and moderate APJ immunoreactivity was detected in both lymph node negative and positive patients. BMI was related to both survival outcome and apelin immunoreactivity. BMI, adipokines such as apelin, and the stromal compartment play critical roles in advanced stage serous carcinomas.

Immunohistochemical analysis of small plaque parapsoriasis: involvement of dendritic cells.

Small plaque parapsoriasis (SPP) is one of the cutaneous T-cell lymphoproliferative disorders. The aim of the present study was to show the antigenic profile of a subset of dendritic cells and lymphocytes in SPP in comparison with normal cells to provide data on the role of these two cell types in the pathogenesis of SPP. Skin biopsy specimens of lesions were obtained from 8 patients with SPP. Biopsies of the healthy skin from 9 control individuals were also analyzed. Immunohistochemistry was performed on the frozen tissue sections to reveal binding of anti-HLA Class II, anti-CD1a, anti-CD4, anti-CD8, anti-CD44, anti-CD45, and anti-CD68 monoclonal antibodies. There was a statistically significant increase in the number of CD1a(+), Langerhans cells (LCs), HLA-DR-immunoreactive and, CD1a-positive dermal dendritic cells and CD68(+) macrophages in the SPP group (p=0.008, 0.008, 0.002 and <0.0009, respectively). The number of lymphocytes positive for CD4, CD8 and CD45 was significantly higher than normal in the SPP group (p=0.015, <0.0009 and <0.0009, respectively). Our study demonstrates that both peptide- and lipid-based antigens are involved in the persistent antigenic exposure in SPP. Dendritic cells play a pivotal role in SPP by presenting antigens by both LC and dermal dendritic cells via MHC Class II and CD1a molecules. The CD68(+) macrophages are thought to be involved in the immune response in this pathology as an antigen-presenting cell.

Butyrylcholinesterase expression is regulated by fatty acids in HepG2 cells.

Butyrylcholinesterase (BChE) is mostly associated with the detoxification of xenobiotics. In this study to analyze the involvement of BChE in lipid metabolism, linoleic acid (LA) and α-linolenic acid (ALA) were applied to HepG2 cells along with expression of wild type human BChE. After 48 h of these treatments WST-1 cell proliferation assay, FACS analysis, RT-PCR, Oil Red O staining and activity assays were performed. Application of high concentrations of LA to HepG2 cells without BChE transfection lead to detachment of the cells. The IC50 value LA was found as 149.3 µM whereas the IC50 value for ALA could not be calculated. Hence, in order to display minimal effects on cell viability, 5 µM was chosen as appropriate concentration for LA and ALA application to HepG2 cells. Transfection of wild-type BChE plasmid to HepG2 cells yielded increased BChE expression. Application of 5 µM ALA after BChE transfection to HepG2 cells resulted in increased expression of BChE. Although with this low concentration the number of apoptotic cells was decreased with ALA treatments, LA application did not cause a similar result with the same dose. Moreover ghost cell like property was observed in LA-treated cells. Application of ALA, on the other hand, led to an overall increase in cell numbers, BChE expression and activity. Our results indicate that BChE expression might be regulated by ALA in HepG2 cells.

Diagnostic features and treatment modalities in solitary rectal ulcer syndrome.

Solitary rectal ulcer syndrome (SRUS) is a traumatic lesion of the anterior or circular rectal wall caused by straining due to functional disorders of defecation. Defecography, transrectal ultrasonography or anorectal manometry are suitable procedures that may be used to detect the causative disorder and should, therefore, be performed in patients with solitary rectal ulcer syndrome. Histopathological features of SRUS are characteristic and pathognomonic, nevertheless the endoscopic and clinical presentations may be confusing. The lesions may mimic other rectal pathologies and lead to wrong diagnosis. We retrospectively evaluated 34 patients with SRUS who had various treatments. Rectosigmoidoscopy, defecography, transrectal ultrasonography and anorectal manometry were performed for evaluation of cases. The operative management was rectopexy in 26 patients, rectal mucosectomy in 4 patients, segmental colonic resection in 2 patients, local excision in 1 patient and colostomy in 1 patient. Total regression and healing of the ulcer occurred in 32 of 34 patients. Partial regression of symptoms in 2 patients, who underwent rectopexy and rectal mucosectomy, occurred, but we could not get complete healing.

Augmentation of mucosal adaptation following small-bowel resection by electromagnetic field stimulation in rats.

Survival following massive resection of the small intestine is often possible due to substantial hyperplasia of the mucosal surface in the remaining small intestine. While nutrients provide the major stimulus for hyperplasia in the clinical setting, the availability of drugs to augment this process would have obvious therapeutic implications. Electromagnetic field stimulation (EMF) of connective tissue and skin increased the DNA and messenger RNA and protein synthesis in experimental studies. We evaluated the ability of electromagnetic field stimulation to augment mucosal hyperplasia following massive small bowel resection in the rat. Two groups of 10 Wistar rats, 250 gr body weight, were subjected to 70% jejunoileal resection. The first group received EMF stimulation for ten days at a dosage of 43.20 gauss, the second group did not receive any stimulation. After fourteen days, segmental evaluation of mucosal mass in the remaining small intestine was determined by measuring mucosal protein, and disaccharidase levels, as well as intestinal length and circumference. EMF stimulation appears to augment mucosal adaptation following massive small bowel resection in rat, in the proximal and distal small intestine.

Protective effect of lycopene against ochratoxin A induced renal oxidative stress and apoptosis in rats.

This study was designed to investigate the possible protective effect of lycopene against the renal toxic effects of OTA. Male Sprague-Dawley rats (<200 g, n=6) were treated with OTA (0.5 mg/kg/day) and/or lycopene (5 mg/kg/day) by gavage for 14 days. Histopathological examinations were performed and apoptotic cell death in both cortex and medulla was evaluated by TUNEL assay. Besides, biochemical parameters and activities of renal antioxidant selenoenzymes [glutathione peroxidase 1 (GPx1), thioredoxin reductase (TrxR)], catalase (CAT), superoxide dismutase (SOD); concentrations of total glutathione (GSH), and malondialdehyde (MDA) levels were measured. OTA treatment was found to induce oxidative stress in rat kidney, as evidenced by marked decreases in CAT (35%) activity and GSH levels (44%) as well as increase in SOD activity (22%) vs control group. Furthermore, TUNEL analysis revealed a significant increase in the number of TUNEL-positive cells in cortex (49%) and medulla (75%) in OTA administrated group compared to control (p<0.05). Lycopene supplementation with OTA increased GPx1 activity and GSH levels, and decreased apoptotic cell death in both cortex and medulla vs. control. The results of this study showed that at least one of the mechanisms underlying the renal toxicity of OTA is oxidative stress and apoptosis is the major form of cell death caused by OTA. Besides, our data indicate that the natural antioxidant lycopene might be partially protective against OTA-induced nephrotoxicity and oxidative stress in rat.

Rosuvastatin induces apoptosis in cultured human papillary thyroid cancer cells.

Statins show antiproliferative activity in various cancer cells. The aim of this study was to evaluate the effects of rosuvastatin treatment on papillary thyroid carcinoma. The papillary thyroid carcinoma (B-CPAP) and normal (Nthy-ori 3-1) thyroid cell lines were treated with rosuvastatin at 12.5, 18.5, 25, 50, 100, and 200 µM concentrations. After 48 and 72 h of rosuvastatin treatment, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, Ki-67 immunolabeling, FACS analysis, electron microscopy, caspase-3, and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) analysis were performed. Decreased cell viability and G1 phase arrest were detected in papillary thyroid cell line treated with rosuvastatin. Positive immunoreactivity of Ki-67 and dose-dependent increase in S phase on Nthy-ori 3-1 cells were also detected. B-CPAP cells showed intense vacuolisation and autophagosomes with low concentrations and 48 h incubations, while Nthy-ori 3-1 cells showed these changes at higher concentrations. A decrease in the percentage of cells showing autophagy was determined with increasing concentrations of rosuvastatin in B-CPAP cells. Rosuvastatin treatment also caused a dose- and time-dependent increase in caspase-3 activity and apoptotic index by TUNEL assay in B-CPAP cells compared with the Nthy-ori 3-1 cells. Apoptotic cells with nuclear condensation and fragmentation were observed in B-CPAP cell line. Rosuvastatin induced autophagic changes in B-CPAP papillary thyroid cancer cells in lower doses and caused a shift from autophagy to apoptosis. Rosuvastatin may be an alternative treatment for refractory papillary thyroid cancer. Further in vivo studies are necessary to clarify the effects of rosuvastatin in papillary thyroid carcinoma and the clinical implications of rosuvastatin treatment.

Growth inhibition of SK-MEL-30 human melanoma cells by antisense c-myc oligonucleotides delivered by poly(N-isopropylacrylamide)/ poly(ethyleneimine) copolymer.

The c-myc oncogene has been shown to be overexpressed in a number of malignancies and plays a key role in the abnormal growth regulation of melanoma cells. This study aimed to provide an efficient system for the in vitro manipulation of c-myc expression by antisense oligonucleotides. Therefore, we used poly(NIPA)/PEI2B copolymer as vector in order to improve the intracellular availability and stability of AS ODNs. We targeted oligonucleotide sequences within the human c-myc mRNA as free AS ODNs or conjugated with a thermosensitive copolymer, in an effort to inhibit the growth of human melanoma cells. The conjugates adopted more positive charge and smaller size at 37 degrees C and they had no toxic effects on human fibroblast cells. The conjugated AS ODNs showed increased antiproliferative effect on melanoma cells as compared to free AS ODNs. At a concentration of 100 ng, AS ODNs inhibited SK-MEL 30 human melanoma cell line proliferation maximally by 18.6%, whereas the same amount of conjugated AS ODN provided 52% inhibition. The greatest inhibition was obtained by conjugates having a polymer:AS ODN ratio of 9. Greatest inhibition was detected at 48 h and decreased after 96 h, which may be due to the depletion of AS ODNs. The results confirm the enhanced antiproliferative effects of poly(NIPA)/PEI2B-conjugated AS ODNs, which may provide improved intracellular availability for c-myc-directed antisense strategies.

The effect of subcutaneously injected nicotine on achilles tendon healing in rabbits.

The objective of this study was to evaluate the effect of subcutaneously injected nicotine on transversely transected and sutured achilles tendon healing in an experimental rabbit model. Adult New Zealand rabbits (n=22) weighting 3,000-3,500 g were used in this experimental study. Rabbits were randomly divided into two groups. Achilles tendon was transversely incised and repaired in all animals. In the experiment group subcutaneous injection of Nicotine tartrate 3 mg/kg/day was done. In the control group Serum physiologic injection was done at the same dosage. The injections were made three times a day in equal dosages. Nicotine and SF injections were made until the end of the 8-week, and then all animals were euthanized. Both light microscopic and electron microscopic evaluations were made on 14 animals. In N group light microscopic evaluation showed a visible gap in repair site. The total tendon score represented in N group was less than in SF group. The statistical analysis of the groups was significantly different for total tendon scores (P=0.002). Beside this electron microscopic examination showed inactive and degenerated fibroblasts and irregular collagen fibrils around them as well as collagen synthesis interruption in N group. Biomechanical evaluation was made on eight animals. The average tensile strength values in Group N (139.47+/-44.55 N) were significantly lower than those in Group SF (265.9+/-39.01 N) (z=2.309, P=0.029). Nicotine is the major chemical component common to all cigarettes and previously has been shown to affect wound and fracture healing adversely. The results of this study show that nicotine impairs achilles tendon healing after a surgical repair.

[Gastrointestinal hemorrhage due to traumatic superior mesenteric artery aneurysm (case report)]. / Travmatik süperior mezenterik arter anevrizmasina bagli gastrointestinal kanama (olgu sunumu).

We report the case of a 21-year-old male patient with superior mesenteric artery aneurysm due to missed arterial injuries, its complications of enteric fistula and results of surgical treatment. The aneurysm was excised, enteric fistula was closed and aorta-mesenteric bypass using saphenous vein graft was performed. The hemorrhage became masked because of the tamponade in the mesentery during penetrating abdominal injury and initial surgery, and the late complication of false aneurysm came on the scene in follow up. Aorta-mesenteric bypass by a transmesenteric approach provides successful result in surgical treatment of superior mesenteric artery aneurysm.