High cholesterol diet leads to oxidant load and peroxidation in the rabbit kidney tissue.

OBJECTIVES: The aim of this study was to investigate possible effects of high cholesterol diet on oxidant/antioxidant status in rabbit kidney tissues. BACKGROUND: Although a number of experimental animal models have suggested that hyperlipidemia is associated with progressive kidney failure data remain sparse on the role of dietary cholesterol intake on kidney disease. METHODS: Twelve male New Zealand albino rabbits were randomly divided into two groups (control and cholesterol). Both groups were fed on a standard laboratory diet. Animals in the cholesterol group additionally received cholesterol (1 g/kg/day), orally. The study period was 12 weeks. Activities of catalase (CAT), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), nitric oxide synthase (NOS), xanthine oxidase (XO), paraoxonase (PON), adenosine deaminase (ADA) enzymes and levels of malondialdehyde (MDA) and nitric oxide (NO) were measured in kidney tissue samples. Histological examination of the kidney tissue samples was also done. RESULTS: SOD, GSH-Px and XO enzyme activities were found to be decreased and NOS and PON activities increased significantly in cholesterol group compared to controls. As an indication of oxidation, MDA levels were found to be increased in cholesterol group. Histological examination revealed some derangements in the kidney tissue. CONCLUSION: High cholesterol diet creates oxidant load and causes peroxidation, which in turn, leads derangements in the rabbit kidney tissue (Tab. 2, Fig. 2, Ref. 69).

Effects of aqueous soybean, mistletoe and red clover extracts on activities of adenosine deaminase and xanthine oxidase enzyme.

Soybean (Glycine max), mistletoe (Viscum album) and red clover (Trifolium pratence) have been argued to have anti-cancer effects. In the present study it was aimed to investigate possible effects of these plant extracts on the activities of DNA turn-over enzymes, namely adenosine deaminase (ADA) and xanthine oxidase (XO) in cancerous and non-cancerous gastric and colon tissues. For this aim, 6 cancerous and 6 non-cancerous adjacent human gastric tissues, and 7 cancerous and 7 non-cancerous adjacent colon tissues were obtained by surgical operations. Our results suggest that aqueous soybean, mistletoe and red clover extracts may exhibit anti-tumoral activity by depleting hypoxanthine concentration in the cancer cells through XO activation, which may lead to lowered salvage pathway activity necessary for the cancer cells to proliferate in the cancerous colon tissue. Some foods like soybean, mistletoe and red clover may provide nutritional support to medical cancer therapy through inhibiting and/or activating key enzymes in cancer metabolism (Tab. 4, Ref. 33).

Antibiotic Fermentation Broth Treatment by a pilot upflow anaerobic sludge bed reactor and kinetic modeling.

In this study, an upflow anaerobic sludge blanket (UASB) mesophilic reactor was used to remove antibiotic fermentation broth wastewater. The hydraulic retention time was held constant at 13.3 days. The volumetric organic loading value increased from 0.33 to 7.43 kg(COD)m(-3)d(-1) using antibiotic fermentation broth wastewater gradually diluted with various ratios of domestic wastewater. A COD removal efficiency of 95.7% was obtained with a maximum yield of 3,700 L d(-1) methane gas production. The results of the study were interpreted using the modified Stover-Kincannon, first-order, substrate mass balance and Van der Meer and Heertjes kinetic models. The obtained kinetic coefficients showed that antibiotic fermentation broth wastewater can be successfully treated using a UASB reactor while taking COD removal and methane production into account.

The effects of dexamethasone on oxidant/antioxidant status in kidneys of rats administered mercuric chloride.

The study was aimed to evaluate the possible effects of dexamethasone on oxidant/antioxidant status in kidney tissues of rats administered mercuric chloride (HgCl2). Thirty male Wistar-albino rats were enrolled in this study. Rats were divided into 4 groups: G1 (n=7) underwent no therapy (control group), G2 (n=8) received HgCl2 + physiological saline, G3 (n=7) dexamethasone (DM) + physiological saline and G4 (n=8) received HgCl2 + DM. HgCl2 was injected subcutaneously into rats in the G2 and G4 on the first day of the study. Dexamethasone was injected intraperitoneally into rats in the G3 and G4 for 3 days. Malondialdehyde (MDA) levels, catalase (CAT), glutathione peroxidase (GSH-Px), xanthine oxidase (XO) and superoxide dismutase (SOD) activities were evaluated in the kidney tissues. Serum creatinine levels were also measured. Xanthine oxidase activity was increased in the G2 compared to the control group. Catalase activity in the control group was significantly higher compared to the other groups. In the histopathological examination of kidneys, there was a tubular degeneration in G2 and G4. It was concluded that HgCl2 administration may cause oxidative stress through increasing XO and decreasing CAT activities. Dexamethasone injection may partially protect the rat kidneys against oxidative reactions by preventing the increase in XO activity (Tab. 1, Ref. 33).

Nitric oxide metabolism in cancerous and non-cancerous oral gingivomucosal tissues: possible implications of nitric oxide in cancer process.

PURPOSE: Nitric oxide (NO) is a molecule that plays various roles in the body tissues. NO plays important roles in vasodilatation, platelet aggregation, cytokine stimulation, neurotransmission, immune function, etc. NO also exerts dual functions as an oxidant and antioxidant substance depending on its concentrations and environmental conditions. In this study, we aimed to examine possible correlation between NO levels and NO synthase (NOS) activity in the patients with oral cancer. MATERIALS AND METHODS: The study included 19 tissues from human subjects (11 malign and eight benign lesions). RESULTS: NO level and NOS activity were found decreased in the malign lesions compared with those of the benign ones. CONCLUSIONS: In conclusion, two suggestions can be made; first, decreased NO synthesis may be an attempt to suppress angiogenesis, which is known to provide more essential nutrients to malign lesions and/or second, malign lesions may suppress NO production to be capable of creating more rapid proliferation as it has been known that NO is also a powerful free radical inducing apoptosis.

Effect of propolis on oxidative stress and histomorphology of liver tissue in experimental obstructive jaundice.

BACKGROUND: Propolis is a natural product collected by honey bees from various plant sources. We aimed to determine the possible effects of propolis on oxidative stress and hepatocyte apoptosis in experimental obstructive jaundice. METHODS: Thirty rats were divided into three groups: group I, sham-operated; group II, ligation and division of the common bile duct (BDL); group III, BDL followed by oral supplementation of propolis in a daily dose of 100 mg/kg. Liver samples were examined under the light microscope and transmission electron microscope. Hepatocyte apoptosis was quantitated using the transferase-mediated uridine nick end labeling (TUNEL) assay. Plasma and liver malondialdehyde (MDA) levels and glutathione peroxidase (GSH-Px) activities were measured. RESULTS: The plasma and liver levels of MDA were significantly lower in the propolis group than in the BDL group (p < 0.05 and 0.014, respectively). Although liver GSH-Px activities were significantly higher in the propolis group than in the BDL group (p < 0.001), there was no significant difference between the plasma GSH-Px activities of these groups (p > 0.05). In the propolis group, the enlargement of hepatocytes, dilatation of canaliculi and the edema regressed. The regenerating and normal hepatocytes were demonstrated. In the TUNEL assay, propolis administration reduced hepatocyte apoptosis. CONCLUSION: Propolis showed a significant hepatoprotective effect in this experimental obstructive jaundice model.

Phacoemulsification and intraocular lens implantation in eyes with long axial length.

We evaluated the results of phacoemulsification and intraocular lens implantation in 414 eyes with long axial length and classified them according to axial length (AL): Group A: AL: 25-28 mm, Group B: AL >28 mm. Intraoperative maneuvers, pre- and postoperative photocoagulation for predisposing retinal lesions and retinal detachment rates were significantly higher in Group B than Group A. Eyes with an axial length over 28 mm are prone to more problems when compared to those with an axial length between 25 and 28 mm.

Oxidant status in maternal and cord plasma and placental tissue in gestational diabetes.

The aim of this study was to measure oxidant/antioxidant status in maternal and cord plasma and in placental tissue in gestational diabetes and to correlate the results with the quality of glycemic control of the mother. To achieve this, blood and placental tissue samples have been obtained from pregnant women with gestational diabetes mellitus (GDM) and from the umbilical cord of their fetuses. The same samples have been collected from pregnant women without GDM. In all the samples, oxidant and antioxidant parameters have been studied. It has been observed that the antioxidant defense system was impaired; xanthine oxidase, which is the main free radical-producing enzyme (XO) in the living cells, was activated; and oxidation reactions were accelerated in the samples obtained from patients with GDM. Results suggest presence of oxidant stress in the gestational diabetes, the reason probably being impaired antioxidant defense mechanism and increased free radical production through XO activation.

Adenosine deaminase and 5'-nucleotidase activities in saliva from patients with oral and laryngeal cancer.

OBJECTIVE: The aim of this study was to evaluate saliva's activities of adenosine deaminase (ADA) and 5'-nucleotidase (5'-NT) enzymes and their utility as diagnostic and therapeutic markers in oral and laryngeal cancer. MATERIALS AND METHODS: Pre- and post-operative saliva's activities of ADA and 5'-NT enzymes were measured in patients with squamous cell oral (n = 10) and laryngeal cancer (n = 17) and compared with control saliva samples (n = 19). RESULTS: The ADA was found to be lower in saliva of the patients with oral cancer compared with the laryngeal cancer and controls. However, no significant differences were found between pre- and post-operative values for both enzymes in the patient groups. We also could not find statistically significant differences between saliva's activities of 5'-NT in patients and control subjects. CONCLUSIONS: Low activity of ADA observed in saliva of the patients with oral cancer has been suggested as a compensatory mechanism against rapid purine and DNA metabolism in cancer cells. The current study does not support the hypothesis that saliva's activities of these enzymes may be used as additional diagnostic and prognostic cancer markers.

A potential role for nitric oxide pathway in tuberculous pleural effusion.

SETTING: Tuberculous pleural effusion leads to an immune response involving mainly immune and mesothelial cells. Nitric oxide (NO) produced by these cells may have antimycobacterial effects against Mycobacterium tuberculosis. OBJECTIVE: To investigate the possible role of NO in connection with the arginase enzyme, which controls the synthesis of NO through arginine depletion. DESIGN: Pleural fluid samples from 20 patients with tuberculous pleural effusion were used for arginase activity and NO level determination. Results were compared with those from 12 lung cancer, 12 pneumonia and 12 congestive heart failure (CHF) patients. RESULTS: Pleural arginase activity in tuberculosis patients was found to be significantly decreased compared to lung cancer and pneumonia groups, while the NO level was higher in tuberculosis patients. All groups except the CHF group had significant correlations between NO level and white blood cell count. Arginase activity and red blood cell count correlated significantly in lung cancer and CHF groups. CONCLUSION: The arginine-NO pathway seems to be involved in the pathogenesis of tuberculous pleural effusion. Decreased arginase activity may cause arginine accumulation, which may then lead to increased NO synthesis by immune and mesothelial cells, reflecting a host defence mechanism.

Effects of cholesterol supplementation on antioxidant enzyme activities in rat hepatic tissues: possible implications of hepatic paraoxonase in atherogenesis.

BACKGROUND AND AIM: The effects of cholesterol supplementation on antioxidant enzyme activities were investigated hepatic tissue taken from Sprague Dawley rats. METHODS AND REULTS: The study involved 14 male Sprague Dawley rats: seven fed a normal laboratory diet and seven a normal diet plus cholesterol (3.6 g/kg/day) for three months, during which blood samples were obtained to measure serum cholesterol levels. At the end of the 3-month period, the livers were surgically removed in order to measure antioxidant enzyme activities (superoxide dismutase, catalase, glutathione peroxidase and paraoxonase-1). At the end of the study period, serum total cholesterol and HDL-cholesterol levels were significantly higher in the cholesterol-fed group than the control group. There were no significant between-group differences in hepatic superoxide dismutase, catalase and glutathione peroxidase activities, but there was a significant decrease in hepatic paraoxonase-1 activity in the cholesterol-fed group. CONCLUSIONS: Cholesterol supplementation significantly decreases paraoxonase-1 activity in rat liver tissue without changing the activities of other antioxidant enzymes. These results suggest that cholesterol significantly suppresses hepatic paraoxonase-1 synthesis. It seems that the decreased paraoxinase-1 activity in the plasma HDL-fraction of atherosclerotic patients is associated with suppressed liver synthesis. A reduction in paraoxonase-1 activity may therefore lead to the more intensive exposure of LDL to oxidant attacks.

Staining of intraocular lenses with various dyes: a study of digital image analysis.

PURPOSE: To evaluate the interaction of various intraocular lens (IOL) materials with commonly used dyes. MATERIALS AND METHODS: One IOL of each of the five groups (polymethylmethacrylate, silicone, three-piece hydrophobic acrylic, single-piece hydrophobic acrylic and single-piece hydrophilic acrylic) was bathed in trypan blue 0.1%, fluorescein sodium 2% and indocyanine green (ICG) 0.5% for 15 min. Digital photographs of the IOLs were obtained prior to bathing and after the 15-min bath in each dye. The same IOLs were immersed in the same dye for another 15 min and digital images were reobtained to depict the 30-min dye uptake. New IOLs from the group that exhibited visible colour change after the 15-min bath were then bathed in twofold dilution and if there was still visible dye uptake, fourfold dilution was performed, repeating the 15-min bath and digital photography. The images were then processed using Adobe Photoshop 5.1 to get mean luminosity and red-green-blue values. These values were compared between the groups and the undyed control. Also, dye washout was observed in serum-containing vials. RESULTS: None of the polymethylmethacrylate, silicone and hydrophobic acrylic IOLs were stained with the dyes used. The only IOL material that changed colour was hydrophilic acrylic and did so with all dyes. The most marked colour change was with fluorescein sodium 2%, the least was with trypan blue 0.05%. Twofold dilution of trypan blue and fourfold dilutions of fluorescein sodium and ICG still stained the hydrophilic acrylic IOL; however, fourfold dilution of trypan blue did not cause a significant colour change. Trypan blue washed out within 6 h, while the IOL stained with ICG remained stained for longer than 24 h. COMMENT: Hydrophilic acrylic IOLs should be used with caution together with dyes since this material demonstrates marked dye uptake and washout may also take some time.

Comparison of sedation requirements for cataract surgery under topical anesthesia or retrobulbar block.

PURPOSE: Topical anesthesia is increasingly being used for cataract surgery. However, it is believed that topical anesthesia causes an increased risk of intraoperative complications from unrestricted eye movement and insufficient pain control and more need for sedation. It is difficult to compare pain and anxiety experienced by individual patients; therefore, the authors used the method of patient-controlled sedation to determine whether there is a difference in sedation requirements under topical or retrobulbar anesthesia. METHODS: In this prospective study, patients received either topical anesthesia (n=87) or retrobulbar block (n=104) and self-administered a mixture of midazolam (0.5 mg) and fentanyl (25 g) in increments using a patient controlled analgesia infuser to achieve sedation. At the end of surgery, patients rated their pain on a 10-point numerical rating scale and their comfort on a 5-point scale. The number of demands and deliveries were noted from the patient controlled analgesia infuser display. RESULTS: Pain scores were between 0 and 2 in 95.4% in the topical and in 94.2% in the retrobulbar group (p>0.05). Patient comfort was equal in both groups with 2.94 0.92 in the topical group and 2.92 0.99 in the retrobulbar group (p>0.05). Mean sedation requirements were similar in both groups: 26.4% of patients in the topical group and 19.2% in the retrobulbar group did not request any sedation (not significant, p>0.05). CONCLUSIONS: Sedation requirements were similar for cataract surgery under topical and retrobulbar anesthesia. (Eur J Ophthalmol 2004; 14: #-7).

Comparison of sedation requirements for cataract surgery under topical anesthesia or retrobulbar block.

PURPOSE: Topical anesthesia is increasingly being used for cataract surgery. However, it is believed that topical anesthesia causes an increased risk of intraoperative complications from unrestricted eye movement and insufficient pain control and more need for sedation. It is difficult to compare pain and anxiety experienced by individual patients; therefore, the authors used the method of patient-controlled sedation to determine whether there is a difference in sedation requirements under topical or retrobulbar anesthesia. METHODS: In this prospective study, patients received either topical anesthesia (n=87) or retrobulbar block (n=104) and self-administered a mixture of midazolam (0.5 mg) and fentanyl (25 microg) in increments using a patient controlled analgesia infuser to achieve sedation. At the end of surgery, patients rated their pain on a 10-point numerical rating scale and their comfort on a 5-point scale. The number of demands and deliveries were noted from the patient controlled analgesia infuser display. RESULTS: Pain scores were between 0 and 2 in 95.4% in the topical and in 94.2% in the retrobulbar group (p>0.05). Patient comfort was equal in both groups with 2.94+/-0.92 in the topical group and 2.92+/-0.99 in the retrobulbar group (p>0.05). Mean sedation requirements were similar in both groups: 26.4% of patients in the topical group and 19.2% in the retrobulbar group did not request any sedation (not significant, p>0.05). CONCLUSIONS: Sedation requirements were similar for cataract surgery under topical and retrobulbar anesthesia.

Colour Doppler assessment of blood flow in eyes with central retinal vein occlusion.

PURPOSE: To assess the blood flow changes in eyes with central retinal vein occlusion (CRVO) and compare these values with values of fellow eyes and eyes of normal subjects. METHODS: 25 eyes of 25 consecutive newly diagnosed patients with CRVO comprised the study group. Their fellow eyes and those of 25 healthy subjects were the control group. All patients underwent a complete ophthalmological examination. Eyes with CRVO were classified into two groups as non-ischaemic and ischaemic by fundus fluorescein angiography. Colour Doppler imaging was performed with a Toshiba Sonolayer SSH-140A and 7.5-MHz linear array probe. Maximum systolic velocity (V(max)), end-diastolic velocity (V(min)) and resistive index (R(i)) values were noted for each of the central retinal artery (CRA), central retinal vein (CRV) and ophthalmic artery (OA). These parameters were compared with those of the fellow eyes and both eyes of the control group. RESULTS: Mean ages were 63.55 and 61.45 years in the CRVO and control groups, respectively. Age and sex distributions were statistically identical in both groups. When we compared the eyes with CRVO to the control group, no statistically significant difference existed between the two groups with regard to the V(min) and R(i )values of the CRA and CRV. However, V(max ) values of the CRA and CRV were significantly lower in CRVO eyes when compared to the control group. The CRVO group and control group had similar V(max), V(min ) and R(i) values for the OA. Only the V(max) was significantly lower in the CRV in eyes with CRVO when compared to the unaffected fellow eyes. No statistically significant difference could be detected between any of the parameters of CRA, CRV and OA of the ischaemic and non-ischaemic CRVO groups. CONCLUSIONS: More data on broader series need to be obtained in order to decide on the practical use of colour Doppler imaging in the differentiation of ischaemic eyes from non-ischaemic eyes in CRVO.

Effects of garlic extract on oxidant/antioxidant status and atherosclerotic plaque formation in rabbit aorta.

BACKGROUND AND AIM: The results of a number of studies suggest that garlic (or garlic extracts) may have favourable effects against the development of atherosclerosis. The aim of this study was to investigate the effects of garlic extract supplementation on oxidant/antioxidant status and atherosclerotic plaque formation in rabbit aortic tissue. METHODS AND RESULTS: Twenty-two male New Zealand White rabbits were fed a cholesterol-supplemented diet (0.5 g/Kg/day) and nine control rabbits a regular diet for four months. At the end of this period, atherosclerotic plaque formation and antioxidant activity were measured in the aortic tissue of the controls and seven of the cholesterol-fed animals. Of the remaining 15 experimental animals, seven were fed normal laboratory diet and eight a normal diet plus garlic extract (1.5 ml/Kg/day) for a further three months before atherosclerotic plaque formation and antioxidant activity were measured in the aortic tissue of both groups. The cholesterol-fed animals showed a significantly impaired antioxidant system associated with increased plaque formation. However, garlic extract supplementation significantly improved antioxidant status and reduced the plaque surface area. CONCLUSIONS: In this experimental model, garlic extract dietary supplementation activated the antioxidant system and decreased peroxidation in aortic tissue. There was also a reduction in atherosclerotic plaque area. Although further studies are required to elucidate the mechanisms involved, the protective activity of garlic extract may be due to its antioxidant properties.