Iontophoresis Corneal Cross-linking With Oxygen Supplementation in Ovine Eyes.

PURPOSE: To evaluate the biomechanical changes and advanced oxidation protein products (AOPP) production after different corneal cross-linking (CXL) protocols with or without oxygen supplementation. METHODS: Ovine eyes in the study were equally distributed to five groups as control, standard Dresden protocol, diluted alcohol- and iontophoresis-assisted CXL (DAI-CXL), and 0.1% and 0.2% riboflavin-mediated iontophoresis-assisted CXL with oxygen supplementation (I-CXL). Corneas that received CXL were divided into two equal parts, one part was used for uniaxial tensiometry and one part was used for AOPP measurement. RESULTS: All treatment groups showed higher Young's modulus and stiffness compared to the control group (P < .05). Both oxygen-assisted I-CXL groups with 0.1% and 0.2% riboflavin concentrations had higher corneal Young's modulus (P = .009 and .006, respectively) and stiffness (P = .009) values, whereas the DAI-CXL group had lesser Young's modulus and stiffness values (P = .032) compared to the Dresden protocol group. All treatment groups showed higher AOPP concentrations compared to the control group (P < .05). DAI-CXL and I-CXL groups showed similar AOPP formation compared to the Dresden protocol (P = .673). CONCLUSIONS: When the epithelium is intact, the desired increase in corneal stiffness might not be achieved. However, increasing the oxygen in the environment might provide a sufficient increase in stiffness in cases undergoing epitheliumon I-CXL, which might be promising in terms of shortening the CXL therapy and decreasing the complications. [J Refract Surg. 2022;38(10):674-681.].

Singlet oxygen formation during accelerated and hyperaccelerated corneal cross-linking: in vitro study.

BACKGROUND: To evaluate the singlet oxygen (1O2) production of oxygen assisted %0.1 riboflavin and ultraviolet-A (UVA) crosslinking therapy (with and without oxygen assistance), in combination with standard, accelerated and hyper-accelerated procedures via an important quantitive marker of 1O2 which is the photo-oxidation of 1,3 diphenylisobenzofuran (DPBF). METHODS: %0.1 riboflavin-containing wells were irradiated with UVA light (365-nm wavelength) with or without 2-4-6-8 L/min oxygen flow assistance. Measurements of decrease in absorbance of DPBF were made in 30 mW (hyper-accelerated), 9 mW (accelerated), and 3 mW UV-A (standard) applications, and with additional 2-4-6-8 L/min oxygen flow in 30 mW and 2 L/min oxygen flow in 9 mW. A total of 8 different UV-A irradiance with and without oxygen supplementation groups were formed. RESULTS: 2 L/min oxygen assisted accelerated UV-A irradiance group has shown a greater decrease in DPBF absorbance compared to Dresden protocol. (p = 0.014) Also, Dresden protocol has shown a greater decrease in DPBF compared to all groups except accelerated crosslinking with 2 L/min oxygen. (p < 0.001) Oxygen assisted hyper-accelerated crosslinking groups were showed greater reduction in DPBF absorbance compared to standard crosslinking without oxygen groups. (p < 0.001). CONCLUSION: Oxygen supplementation may increase the singlet oxygen generation to the similar levels of Dresden Protocol's in accelerated group. Also, more singlet oxygen generation with oxygen supplementation compared to standard UV-A application might be considered to be promising in terms of shortening the crosslinking therapy.

The Effect of Sildenafil on Selenite-Induced Cataract in Rats.

PURPOSE: To investigate the effect of sildenafil on an experimental sodium selenite-induced cataract model in rats. MATERIALS AND METHODS: Twenty-six young Wistar rats were separated into four groups. On postpartum day 10, six rats received only selenite (group 1, selenite-induced cataract), seven rats received selenite and high dose oral sildenafil (group 2, high-dose sildenafil-treated), seven rats received selenite and low dose oral sildenafil (group 3, low-dose sildenafil-treated), and six rats received only saline (group 4, controls). On postpartum day 30, cataract formation was graded and recorded using an operating microscope. The rats were sacrificed, lens tissues were isolated, and serum samples were collected. Nitrite oxide metabolites (NOx), advanced oxidative protein products (AOPP), and total sulfhydryl (TSH) levels were assessed in both serum and lenticular samples. RESULTS: The rats treated with low-dose sildenafil showed lower levels of AOPP and NOx, and the higher levels of TSH than the rats in other experimental groups. Otherwise, the rats treated with high-dose sildenafil, similar to the selenite-induced cataract group, showed higher levels of AOPP and serum NOx than rats in the low-dose sildenafil-treated group. The rats treated with low-dose sildenafil also showed less cataract development than rats in the other experimental groups. CONCLUSION: Low doses (0.7 mg/kg) of oral sildenafil might show a protective effect on cataract development by lowering oxidative stress.

Angiopoietin-like protein 2 and angiopoietin-like protein 6 levels in patients with nonalcoholic fatty liver disease.

INTRODUCTION: The aim of the current study was to examine the difference between patients detected with nonalcoholic fatty liver disease (NAFLD) and healthy subjects in terms of serum angiopoietin-like protein (ANGPTL) 2 and ANGPTL6 levels and to evaluate the correlation between ANGPTL2 and ANGPTL6 levels and liver enzyme levels, fasting glucose, lipid levels, and steatosis degree on ultrasonography (USG). MATERIAL AND METHODS: A total of 159 participants were included in the study. The participants were divided into 3 groups depending on the steatosis degree on USG and serum alanine aminotransferase (ALT) levels: the NAFLD group with increased ALT, the NAFLD group with normal ALT, and the healthy control group. The groups were compared in terms of biochemical and ultrasonographic findings, insulin resistance, metabolic syndrome (MetS), and anthropometric parameters. RESULTS: There was no significant difference between NAFLD patients and healthy subjects with respect to serum ANGPTL2 and ANGPTL6 levels (p > 0.05). ANGPTL2 levels did not correlate with serum, biochemical, or ultrasonographic findings, or anthropometric parameters (p > 0.05). A positive correlation was found between serum ANGPTL6 levels and fasting blood glucose, ALT, alkaline phosphatase, γ-glutamyl transpeptidase, fasting insulin, and HOMA-IR levels. CONCLUSIONS: While our findings suggest no relationship between serum ANGPTL2 and ANGPTL6 levels and NAFLD, ANGPTL6 levels may be related to metabolic and biochemical parameters. The effects of ANGPTL2 and ANGPTL6 in the pathogenesis of NAFLD should be investigated further.

Serum and Aqueous Humor Levels of Fetuin-A in Pseudoexfoliation Syndrome.

PURPOSE: To evaluate serum and aqueous humor levels of fetuin-A in patients with pseudoexfoliation syndrome (PEXS) in comparison with those of age- and sex-matched healthy subjects. MATERIALS AND METHODS: This prospective study included 25 patients with PEXS and 25 control subjects who were undergoing cataract surgery without any systemic or ocular disease. Aqueous humor and serum fetuin-A levels were measured with enzyme-linked immunosorbent assay method. RESULTS: The mean age of the PEXS group (14 males, 11 females, n = 25) was 57.7 ± 6.9 years, and the control group (13 males, 12 females, n = 25) was 58.1 ± 5.7 years. There was no difference between the groups in terms of age (p = 0.77) and sex (p = 0.83). The mean serum fetuin-A level of the PEXS group did not differ from that of the control group (p = 0.53). The mean aqueous humor level of the PEXS group was significantly higher than that of the control group (p = 0.032). There were no significant correlations between aqueous humor and serum fetuin-A levels among patients with PEXS and control group (p > 0.05). CONCLUSIONS: Increased levels of fetuin-A in aqueous humor of patients with PEXS may show the local effect of fetuin-A on the anterior segment. With considering the wide range of possible biological functions of fetuin-A in the pathogenesis of PEXS, further studies are needed to clarify the clinical relevance of these findings.

Advanced oxidation protein products and malondialdehyde - the new biological markers of oxidative stress - are elevated in postmenopausal women.

OBJECTIVES: The aim of the study was to measure advanced oxidation protein products (AOPPs) as markers for oxidative stress to evaluate cardiovascular risk in pre- and postmenopausal women and to compare the results with malondialde-hyde (MDA) levels. MATERIAL AND METHODS: Twenty premenopausal women and 84 naturally postmenopausal patients were enrolled in the study. AOPP and MDA plasma levels were measured. The postmenopausal group was further subdivided into two groups: postmenopausal age of 40-49 and of 50-59 years. AOPP and MDA levels were compared between premenopausal, 40-49 and 50-59 year old menopausal women. RESULTS: Plasma AOPP and MDA levels in postmenopausal women were increased when compared with their premeno-pausal peers (123.83 ± 55.51 µmol/L vs. 61.59 ± 16.42 µmol/L and 6.50 ± 1.05 µmol/L vs. 5.98 ± 0.77 µmol/L; respectively). Mean plasma AOPP levels in the two menopausal age groups were both significantly higher from the premenopausal group (118.64 ± 59.1 µmol/L vs. 61.59 ± 16.42 µmol/L and 132.31 ± 48.97 µmol/L vs. 61.59 ± 16.42 µmol/L; respectively). No significant difference was found in mean AOPP levels between postmenopausal subjects of 40-49 and 50-59 years age (118.64 ± 59.12 µmol/L vs. 132.31 ± 48.97 µmol/L). Mean plasma MDA levels of each of two postmenopausal age groups were both significantly higher from the premenopausal group (6.50 ± 1.04 µmol/L vs. 5.98 ± 0.77 µmol/L and 6.50 ± 1.10 µmol/L vs. 5.98 ± 0.77 µmol/L; respectively). However, no statistically significant difference between the two postmenopausal age groups (6.50 ± 1.04 µmol/L vs. 6.50 ± 1.10 µmol/L) was found. CONCLUSIONS: AOPP and MDA levels are elevated in postmenopausal women as compared to their premenopausal peers, suggesting they can be used as markers for cardiovascular risk in postmenopausal women.

Comparison of Aqueous Humor Nitric Oxide Levels After Different Corneal Collagen Cross-Linking Methods.

PURPOSE: Nitric oxide production can cause either apoptotic or necrotic cell death through oxidative stress. We aimed to investigate the nitrite oxide metabolites (NOx) and nitrite levels in the aqueous humor of rabbit eyes after different methods of corneal collagen cross-linking (CXL). MATERIALS AND METHODS: Twenty-four eyes of 12 adult New Zealand rabbits were used. They were assigned into four groups, each including six eyes. Group 1 (control) consisted of eyes with no treatment. Group 2 received UV-A power setting at 3 mW/cm2 for 30 minutes of continuous exposure and named as standard CXL group. Group 3 received UV-A power setting at 30 mW/cm2 for 3 minutes of continuous exposure and named as accelerated CXL (A-CXL) group. Group 4 received UV-A power setting at 30 mW/cm2 for 6 minutes of pulsed exposure (1 sec on, 1 sec off) and named as pulse-light accelerated CXL (PLA-CXL). Aqueous humors were aspirated from anterior chamber with a 27G needle after 1 hour UV-A exposure. NOx and nitrite levels were measured Results: The nitrite levels in aqueous humor were significantly increased in Group 2 and Group 3 when compared with Group 1 (p = 0.000, p = 0.036, respectively). When treatment modalities were compared with each other, high nitrite level in Group 2 was statistically significant when compared with Group 4 (p = 0.019). NOx levels were higher in Group 2 when compared with Group 1 (p = 0.006). CONCLUSIONS: Numerous studies investigated the physiological and pathophysiological roles of NO. NO is considered one of the most important molecule for ocular health. According to NOx level in aqueous humor, it seems that PLA-CXL is the safest method due to the similar results with control group.

Protein Oxidation Levels After Different Corneal Collagen Cross-Linking Methods.

PURPOSE: To evaluate advanced oxidation protein products (AOPP) levels, superoxide dismutase (SOD) enzyme activity, and total sulfhydryl (TSH) levels in rabbit corneas after different corneal collagen cross-linking (CXL) methods. METHODS: Eighteen eyes of 9 adult New Zealand rabbits were divided into 3 groups of 6 eyes. The standard CXL group was continuously exposed to UV-A at a power setting of 3 mW/cm for 30 minutes. The accelerated CXL (A-CXL) group was continuously exposed to UV-A at a power setting of 30 mW/cm for 3 minutes. The pulse light-accelerated CXL (PLA-CXL) group received UV-A at a power setting of 30 mW/cm for 6 minutes of pulsed exposure (1 second on, 1 second off). Corneas were obtained after 1 hour of UV-A exposure, and 360-degree keratotomy was performed. SOD enzyme activity, AOPP, and TSH levels were measured in the corneal tissues. RESULTS: Compared with the standard CXL and A-CXL groups (133.2 ± 8.5 and 140.2 ± 6.2 µmol/mg, respectively), AOPP levels were found to be significantly increased in the PLA-CXL group (230.7 ± 30.2 µmol/mg) (P = 0.005 and 0.009, respectively). SOD enzyme activities and TSH levels did not differ between the groups (P = 0.167 and 0.187, respectively). CONCLUSIONS: CXL creates covalent bonds between collagen fibers because of reactive oxygen species. This means that more oxygen concentration during the CXL method will produce more reactive oxygen species and, thereby, AOPP. This means that in which CXL method occurs in more oxygen concentration that will produce more reactive oxygen species and thereby AOPP. This study demonstrated that PLA-CXL results in more AOPP formation than did standard CXL and A-CXL.

Effect of intraoperative PEEP application on colonic anastomoses healing: An experimental animal study.

PURPOSE: This study aimed to assess the effect of intraoperative PEEP intervention on the healing of colonic anastomoses in rabbits. MATERIALS AND METHODS: Thirty-two New Zealand type male rabbits were divided into two groups of sixteen animals each. Following ventilation with tracheostomy, colonic resection and anastomosis were performed in both groups. While 10 cm H2O PEEP level was applied in Group I (PEEP), Group II (ZEEP) was ventilated without PEEP throughout the surgery. Half of the both PEEP and ZEEP group animals were killed on the third postoperative day, while the remaining half on the seventh. Anastomotic bursting pressures, the tissue concentrations in hydroxyproline, and histological assessments were performed. Besides, intraoperative oxygen saturation and postoperative arterial blood gas parameters were also compared. RESULTS: On the first postoperative day, both arterial oxygen tension (PO2) and oxygen saturation (SO2) in the PEEP group were significantly higher than in the ZEEP group. On the seventh postoperative day, the bursting pressures of the anastomoses were significantly higher in the PEEP group, however the hydroxyproline content was significantly lower in the PEEP group than that in the ZEEP group. At day 7, PEEP group was significantly associated with increased neoangiogenesis compared with the ZEEP group. CONCLUSION: The anastomotic healing process is positively influenced by the intraoperative PEEP application.

Can Riboflavin Penetrate Stroma Without Disrupting Integrity of Corneal Epithelium in Rabbits? Iontophoresis and Ultraperformance Liquid Chromatography With Electrospray Ionization Tandem Mass Spectrometry.

PURPOSE: To examine riboflavin concentrations in corneas and aqueous humor from rabbits with standard and transepithelial methods and iontophoresis without disrupting the integrity of the corneal epithelium before corneal collagen cross-linking. METHODS: Twenty-four eyes of 12 adult New Zealand rabbits were used. They were assigned to 4 groups, each including 6 eyes. Group 1 was exposed to the standard method and given riboflavin 0.1% after epithelial debridement. Group 2 was exposed to the transepithelial method and given benzalkonium chloride (BAC), ethylenediaminetetraacetic acid (EDTA), trometamol (TRIS), hydroxypropylmethylcellulose (HPMC), and riboflavin 0.2% 3 times at 1.5-minute intervals followed by riboflavin 0.2%. Group 3 was given riboflavin 0.1% by using 1-mA electric current for 10 minutes with the help of iontophoresis without using substances disrupting the integrity of the corneal epithelium. Group 4 received the same treatment as did group 3, except that it was given riboflavin 0.2%. Following these treatments, riboflavin concentrations in aqueous humor and corneas were measured with ultraperformance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS). RESULTS: Riboflavin concentrations in the cornea and aqueous humor were higher in group 1 (42.4 ± 5.4 µg/g) than in the other groups. They were significantly higher in group 4 (34.2 ± 6.6 µg/g) than in group 2 (24.4 ± 1.2 µg/g) (P = 0.009) and group 3 (23.6 ± 6.1 µg/g) (P = 0.026). There was not a significant difference in corneal riboflavin concentrations between group 2 and group 3 (P = 0.937). CONCLUSIONS: Intrastromal and aqueous riboflavin concentrations after administration of riboflavin 0.2% through iontophoresis without disrupting the integrity of the corneal epithelium were lower than those after the standard method, but higher than those after the transepithelial method. In this study, in which riboflavin concentrations were measured with a very sensitive method, iontophoresis was observed to increase the transmission of riboflavin molecules into the cornea without using substances disrupting epithelial integrity.

Increased collagen maturity with sildenafil citrate: experimental high risk colonic anastomosis model.

BACKGROUND: Inadequate healing and high anastomosis leak rates at rectal anastomosis may be due to lack of supportive serosal layer and technical difficulty of low anterior resections. Positive effects of sildenafil on wound healing were observed. The aim of this study was to simulate rectal anastomosis as a technical insufficient anastomosis and investigate the effects of sildenafil on anastomosis healing. METHODS: Colonic anastomoses were carried out in 64 rats and randomized into four groups, CA-S, complete anastomoses without sildenafil (10 mg/kg for 5 days); CA+S, complete anastomoses with sildenafil; IA-S, incomplete anastomoses without sildenafil; IA+S, incomplete anastomoses with sildenafil. Half of the rats in every group were sacrificed on post-operative day (POD) 3, half of them sacrificed on POD 7. Tissues from the anastomoses were used for functional, histochemical, biochemical investigations. RESULTS: Sildenafil treatment resulted in increased bursting pressures in IA+S on POD 7 (p=0.010). Collagen maturity was higher in IA+S on POD 3 and POD 7, CA+S on POD 7 (p=0.010; p=0.010; p<0.007). Collagen content was higher in IA+S on POD 7 (p<0.001). Glutathione, hydroxyproline levels were similar. Malondialdehyde levels were lower in IA+S on POD 3 (p<0.001). Epithelization score was higher in IA+S on POD 7 (p=0.007). Inflammation score was higher in CA-S group on POD 3 and POD 7 (p<0.001; p<0.001). Neutrophil score was lower in CA+S on POD 3 (p=0.005). CONCLUSION: An increase in collagen content, maturity, and epithelization, a decrease in neutrophil infiltration, oxidative stress and better mechanical strength were observed with the administration of sildenafil.

The relationship between advanced oxidation protein products (AOPP) and biochemical and histopathological findings in patients with nonalcoholic steatohepatitis.

OBJECTIVE: To investigate the correlation between advanced oxidation protein products (AOPP) levels and biochemical and histopathological findings in patients with nonalcoholic steatohepatitis (NASH). METHODS: Sixty biopsy-proven NASH patients and 60 individuals with ultrasonographically healthy liver (the control group) were included in the study. AOPP levels were determined in all the participants and liver histopathological examination based on liver biopsy was performed in NASH patients. The NASH activity score (NAS), hepatosteatosis, liver inflammation and fibrosis were evaluated. RESULTS: Serum AOPP level was significantly higher in the NASH group than that in the control group (461.8 ± 201.9 µmol/L vs 191.7 ± 152.5 µmol/L, P < 0.001). The receiver operating characteristic (ROC) curve revealed a sensitivity of 73.3% and a specificity of 88.3% for the diagnosis of NASH with an AOPP cut-off value of 332 µmol/L (the area under ROC curve 0.88, 95% confidence interval 0.82-0.94, P < 0.01). AOPP levels were positively correlated with NAS (r = 0.27, P = 0.035), fibrosis (r = 0.27, P = 0.037) and inflammation (r = 0.34, P = 0.008), but not the grade of steatosis (r = 0.02, P = 0.83) or ballooning (r = 0.02, P = 0.55). CONCLUSIONS: AOPP levels are significantly higher in patients with NASH than in those with ultrasonographically healthy liver. AOPP levels are positively correlated with biochemical and histopathological findings (NAS, liver inflammation and fibrosis), indicating that AOPP may play a role in the development of liver fibrosis and inflammation and may predict liver histopathology in NASH.

Comparison of acute effect of systemic versus intravitreal infliximab treatment in an experimental model of endotoxin-induced uveitis.

PURPOSE: In this study, we investigated the efficacy of systemic and intravitreal (IV) infliximab treatments and compared these 2 different treatment modalities in an experimental model of endotoxin-induced uveitis (EIU). METHODS: Twenty-four white New Zealand rabbits were equally divided into 4 groups. Group 1 received IV injection of lipopolysaccharide (LPS), group 2 received IV injections of LPS and saline, group 3 received IV LPS and IV 2 mg/0.1 cc infliximab, and group 4 received IV LPS and 5 mg/kg intravenous infliximab. Inflammation was determined with objective and subjective tests. The subjective test was clinical determination of uveitis, the objective tests were determination of protein concentrations and tumor necrosis factor alpha (TNF-α) levels and histopathology. RESULTS: Clinical examination score was lower in group 3 and group 4 (4±0.6 and 3.5±1.6, respectively) when compared with group 1 (P=0.02; P=0.04, respectively) and group 2. In group 3 and 4, the aqueous and vitreous protein and TNF-α concentration measured significantly lower than group 1 and 2. In histopathologic examination, there was no statistically significant difference between group 1, 2, and 3 (3.5±0.5, 3.6±0.5, 3.6±0.5, respectively). However, the lowest histopathologic inflammation was determined in group 4 (2.5±0.5) (compared with group 1 and group 3, respectively; P=0.03; P=0.014). CONCLUSION: In a rabbit model of experimental EIU, intravenous administration of infliximab was more effective than IV route in an acute period.

Effects of ß-glucan on colon anastomotic healing in rats given preoperative irradiation.

BACKGROUND: Radiation therapy is an essential therapeutic modality in the management of a wide variety of tumors. We aimed to investigate the short-term effects of pelvic irradiation on the healing of colon anastomoses and to determine the potential protective effects of ß-glucan in this situation. MATERIAL AND METHODS: Sixty Wistar albino rats were randomized into three experimental groups: a control group (n = 20), an irradiation (IR) group (n = 20), and an irradiation+ß-glucan (IR+ß-glucan) group (n = 20). Only segmental colonic resection and anastomosis were performed on the control group. The IR group underwent the same surgical procedure as the control group 5 days after pelvic irradiation. In the IR+ß-glucan group, the same procedure was applied as in the IR group after ß-glucan administration. The groups were subdivided into subgroups according to the date of euthanasia (third [n = 10] or seventh [n = 10] postoperative [PO] day), and anastomotic colonic segments were resected to evaluate bursting pressures and biochemical and histopathological parameters. RESULTS: Bursting pressure values were significantly lower in the IR group (p < .001). Malondialdehyde (MDA) levels were significantly higher in the IR group, whereas ß-glucan significantly decreased MDA levels on the third PO day (p < .001). Granulation tissue formation scores were significantly lower in the IR+ß-glucan group compared with the control group and the IR group (p < .001). CONCLUSIONS: The results of this study indicate that irradiation has negative effects on the early healing of colon anastomoses. The administration of ß-glucan ameliorates these unfavorable effects by altering bursting pressures and biochemical parameters.

The effects of Pycnogenol(®) on colon anastomotic healing in rats given preoperative irradiation.

Pycnogenol(®) has excellent radical scavenging properties and enhances the production of antioxidative enzymes which contributes to the anti-inflammatory effect of the extract. Irradiation delivered to the abdominal region, typically results in severe damage to the intestinal mucosa. The effects of ionizing radiation are mediated by the formation of free radicals through radiolysis. Irradiation has local effects on tissues. These local effects of irradiation on the bowel are believed to involve a two-stage process which includes both short and long term components. In our study we aimed to investigate the short term effects of Pycnogenol(®) on the healing of colon anastomoses in irradiated bowel. Sixty male Wistar-Albino rats were used in this study. There were three groups: Group I, control group (n = 20); group II which received preoperative irradiation (n = 20); group III which received per oral Pycnogenol(®) before irradiation (n = 20). Only segmeter colonic resection and anastomosis was performed to the control group (Group I). The other groups (Group II, III) underwent surgery on the 5th day after pelvic irradiation. On postoperative days 3 and 7, half of the rats in each group were sacrificed and then relaparotomy was performed. There was no statistical difference between groups with respect to biochemical parameters. Bursting pressure was significantly higher in the Control and Group III compared with the Group II. In conclusion, the present study showed that preoperative irradiation effect negatively on colonic anastomoses in rats by means of mechanical parameters and administration of Pycnogenol(®) preoperatively ameliorates this unfavorable effect.

Effects of dexamethasone and pheniramine hydrogen maleate on stress response in patients undergoing elective laparoscopic cholecystectomy.

BACKGROUND: Laparoscopic cholecystectomy (LC) still leads to significant postoperative nausea and vomiting (PONV) and pain. Our aim was to evaluate the efficacy of dexamethasone or pheniramine hydrogen maleate, either alone or combined, in reducing the stress response and symptoms after LC. METHODS: Patients were randomly assigned to 1 of 4 groups, each consisting of 20 patients: control, dexamethasone (8 mg/2 mL), pheniramine hydrogen maleate (45.5 mg/2 mL), and the combined group. The drugs were given before anesthesia induction. RESULTS: C-reactive protein levels (CRP) and visual analog scale (VAS) scores were significantly less in the dexamethasone (P = .003) and combined groups (P < .001). Both dexamethasone (P < .001) and pheniramine hydrogen maleate (P = .005) significantly reduced PONV. CONCLUSIONS: Dexamethasone significantly reduced postoperative pain and the systemic acute-phase response, whereas these effects were only partially attained with pheniramine hydrogen maleate. Both dexamethasone and pheniramine hydrogen maleate significantly reduced PONV. An additive effect seemed to occur if these drugs were used in combination.

Increased plasma levels of advanced oxidation protein products (AOPP) as a marker for oxidative stress in patients with active ulcerative colitis.

BACKGROUND AND AIMS: After NADPH oxidase mediated radical formation, hypochloric acid (HOCl) is formed when Cl is used as a substrate by the myeloperoxidase enzyme. Myeloperoxidase is secreted from H2O2 activated leukocytes with polymorphic nuclei. The generation of HOCl also causes the formation of advanced oxidation protein products (AOPP) through damage to normal tissue and protein oxidation. AOPP has been identified as a marker of inflammation in many diseases. However, AOPP has not been investigated in ulcerative colitis. As a result of mucosal inflammation in ulcerative colitis, oxidative stress can occur. We aimed to determine whether plasma AOPP and oxidative stress markers are detectable in active ulcerative colitis. METHODS: The patient group consisted of 59 patients who were diagnosed with ulcerative colitis in the clinic by histology and endoscopy. The patients were hospitalised and treated in the Gastroenterology Department of Gazi University Medical Facility. The 59 patients were separated into active and inactive groups according to the endoscopic activation index (EAI). Group I consisted of 33 active ulcerative colitis patients, Group II consisted of 26 inactive ulcerative colitis patients and Group III consisted of healthy control subjects. The disease activity of these patients were measured using the Rachmilewitz EAI based on rectosigmoidoscopic or colonoscopic findings. Patients with EAI scores greater than 4 were scored as having active disease (Group I). Patients with EAI<4 were scored as being in disease remission (Group II). The control subjects (Group III) were 51 healthy individuals. The plasma AOPP levels were measured using a spectrophotometric method. RESULTS: There were no statistically significant differences in gender (P<0.22) and age (P<0.11) between the groups examined. The plasma AOPP level in Group I was 148.72±9.08µmol/L. The plasma AOPP level in Group II was 74.48±7.06µmol/L, and the plasma AOPP level in Group III was 64.93±2.55µmol/L. The AOPP levels in Group I were statistically different than in Group II and III (P<0.05). The AOPP levels were similar between Group II and Group III (P>0.05). The EAI value was 8.84±0.31 in Group I and 2.76±0.08 in Group II. There were statistically significant differences for EAI between groups (P<0.05). The correlation between AOPP and EAI in all patients with ulcerative colitis were statistically significant (P<0.05, r=0.61). The regression model in this correlation was statistically significant (y=49.68+10.75x, P<0.05). DISCUSSION: Based on our results, we suggest that AOPP could be used as a non invasive activation marker for ulcerative colitis patients.

Effects of thyroid hormone supplementation on anastomotic healing after segmental colonic resection.

BACKGROUND: Alterations of thyroid hormones in colorectal surgery were previously studied. The aim of the present study was to determine the effects of triiodothyronine (T3) supplementation on anastomotic healing after segmental colectomy. MATERIAL AND METHODS: Thirty male Wistar albino rats were divided into sham (n = 6), control (n = 12), and experimental (n = 12) groups. Sham group rats were immediately sacrificed after segmental colonic resection. Control and experimental group rats underwent resection and anastomosis. Experimental group rats received a single dose of T3 (400 µg/100 g) in postoperative day 1. Half of both control and experimental group rats were sacrificed on postoperative d 3 and the remaining half were sacrificed on postoperative d 7. Hydroxiproline (HP), myeloperoxidase (MPO), thyroid stimulating hormone (TSH), free T3 (FT3), and free thyroxine (FT4) levels, bursting pressure, and histologic analyses of the anastomotic segments were compared. RESULTS: FT3 levels significantly decreased in control groups rats compared with the sham group (P < 0.01). However, T3 hormone given rats had no decline in FT3 levels. Anastomotic bursting pressure was significantly higher in the experimental group rats on postoperative d 7 (P = 0.015). Histopathologic analyses of the anastomotic segments determined significantly more severe edema and necrosis in control group rats (P < 0.05). Collagen deposition in the anastomotic tissue was significantly higher in experimental group rats on postoperative d 7 (P = 0.015). CONCLUSION: Anastomosis after colon resection is associated with decreased FT3 level. T3 supplementation ameliorates the reduction in FT3 and seems to provide constructive therapeutic effects on anastomotic healing.

Serum levels of advanced oxidation protein products, malonyldialdehyde, and total radical trapping antioxidant parameter in patients with chronic hepatitis C.

BACKGROUND/AIMS: Oxidative stress increases in chronic hepatitis C, and antioxidant defense mechanisms are impaired. The aims of this study were to compare chronic hepatitis C patients and healthy subjects according to oxidative stress and antioxidant system markers, and to determine the relationship between oxidative stress and hepatosteatosis. METHODS: This is an observational study in a tertiary center. Twenty-nine biopsy-proven chronic hepatitis C patients, with no prior anti-viral treatment and persistently elevated serum transaminase levels for 6 months, were included. The control group included 46 healthy subjects. Advanced oxidation protein products and malonyldialdehyde levels were measured. Total radical-trapping antioxidant parameter was calculated. RESULTS: Baseline characteristics were similar in the patient and control groups. In chronic hepatitis C patients, serum levels of advanced oxidation protein products were significantly higher than in the control group (235.0±142.8 vs 116.7±79.5, p<0.001). Serum levels of malonyldialdehyde were also significantly higher than in the control group (9.3±2.1 vs 6.5±1.1, p<0.001). However, there was no significant difference in total radical-trapping antioxidant parameter. The total radical-trapping antioxidant parameter/advanced oxidation protein products index was significantly lower in chronic hepatitis C patients than in healthy controls (p<0.05). There was no significant correlation between advanced oxidation protein products and malonyldialdehyde and hepatosteatosis. CONCLUSIONS: We conclude that oxidative stress occurs in chronic hepatitis C, and antioxidant defense mechanisms are inadequate. Serum levels of advanced oxidation protein products and malonyldialdehyde are higher in chronic hepatitis C patients when compared to healthy individuals, and may be useful markers in chronic hepatitis C.

Cardiovascular risk assessment with oxidised LDL measurement in postmenopausal women receiving intranasal estrogen replacement therapy.

OBJECTIVE: To investigate the effect of intranasal estrogen replacement therapy administered to postmenopausal women alone or in combination with progesterone on markers of cardiovascular risk. METHODS: The study was conducted with 44 voluntary postmenopausal women. In group I (n = 15), the patients were treated with only intranasal estradiol (300 µg/day estradiol hemihydrate). In group II (n = 11), the patients received cyclic progesterone (200 mg/day micronized progesterone) for 12 days in each cycle in addition to continuous intranasal estradiol. Group III (n = 18) was the controls. Serum lipid profiles, oxidised low-density lipoprotein (LDL) and other markers of cardiovascular risk were assessed at baseline and at the 3rd month of the treatment. RESULTS: Lipid profile, LDL apolipoprotein B, lipoprotein a, homocysteine, oxidised LDL values and oxidised LDL/LDL cholesterol ratio were not observed to change after 3 months compared to baseline values within each group (p > 0.016). In comparison to changes between the groups after the treatment, only oxidised LDL levels and oxidised LDL/LDL cholesterol ratios of group II were increased compared to control group (p < 0.05). CONCLUSIONS: Intranasal estradiol alone did not appear to have an effect on markers of cardiovascular risk in healthy postmenopausal women. However, the addition of cyclic oral micronized progesterone to intranasal estradiol influenced the markers of cardiovascular risk negatively in comparison to non-users in healthy postmenopausal women.