Salivary Antioxidants and Oxidative Stress in Psoriatic Patients: Can Salivary Total Oxidant Status and Oxidative Status Index Be a Plaque Psoriasis Biomarker?

The aim of our research was to evaluate redox balance parameters and biomarkers of oxidative stress (OS) in nonstimulated and stimulated saliva as well as the blood of patients with plaque psoriasis compared to healthy controls. The study involved 40 patients with plaque psoriasis and 40 generally healthy subjects matched by age and gender to the study group patients. We assayed the concentration/activity of antioxidant enzymes: salivary peroxidase (Px), catalase (CAT), and superoxide dismutase (SOD) measured in unstimulated saliva (NWS), stimulated saliva (SWS), and erythrocytes. In plasma as well as NWS and SWS, we measured the concentration/activity of reduced glutathione (GSH), total antioxidant potential (TAC), total oxidative status (TOS), oxidative stress index (OSI), and markers of oxidative modification of proteins: advanced glycation end products (AGE), advanced oxidation protein products (AOPP), and lipid oxidation products: malondialdehyde (MDA) and total lipid hydroperoxide (LOOH). In NWS and SWS, we also evaluated the rate of reactive oxygen species (ROS) production. The concentration of Px, CAT, and SOD was significantly higher in NWS of patients with plaque psoriasis vs. healthy subjects. In SWS of psoriatic patients, we observed considerably higher concentration of Px and CAT, and in erythrocytes of patients with plaque psoriasis, the concentration of GPx and CAT was significantly higher compared to that in the controls. The levels of AOPP, AGE, MDA, and LOOH were considerably higher in NWS, SWS, and plasma of the study group compared to the controls. The concentration of total protein and salivary amylase was significantly lower in NWS and SWS of psoriatic patients compared to the healthy control. In the course of plaque psoriasis, we observed redox imbalances with prevalence of oxidation reactions. Mechanisms involved in the synthesis/secretion of proteins and activity of amylase were depressed in both glands of psoriatic patients; however, they were more inhibited in the parotid gland compared to the submandibular gland. TOS concentration and OSI value in NWS and SWS may serve as diagnostic biomarkers of plaque psoriasis.

Chronic high-protein diet induces oxidative stress and alters the salivary gland function in rats.

OBJECTIVE: Chronic high protein intake leads to an increase in reactive oxygen species (ROS) generation. However, there is no data on the impact of high-protein diet on the antioxidant barrier, oxidative stress and secretory function in the salivary glands of healthy individuals. DESIGN: 16 male Wistar rats were randomly divided into 2 groups (n=8): normal protein (C) and high-protein diet (HP) for 8 weeks. Salivary antioxidants: peroxidase (Px), catalase (CAT), superoxide dismutase 1 (SOD 1), uric acid (UA), total antioxidant status (TAS), total oxidant status (TOS) and the oxidative stress index (OSI), as well as protein carbonyls (PC), 4-hydroxynonenal protein adduct (4-HNE protein adduct), 8-isoprostanes (8-isoP), 8-hydroxy-2'-deoxyguanosine (8-OHdG) and protein content were determined in the salivary glands and plasma. Salivary unstimulated and stimulated flow rates were examined. RESULTS: Parotid Px, TAS, UA, TOS, OSI, PC were significantly higher, the total protein content was statistically lower in the HP group as compared to the control. Submandibular UA, TOS, OSI, 8-isoP, 4-HNE-protein adduct, 8-OHdG were statistically elevated, SOD 1 and Px were significantly lower in the HP group as compared to the control rats. The unstimulated salivary flow rate was significantly depressed in the HP group as compared to the controls. CONCLUSIONS: Higher antioxidant capacity in the parotid glands of HP rats vs. control rats seems to be a response to a higher ROS formation. In the submandibular glands severe oxidative modification of almost all cellular components was observed. Administration of HP resulted in the weakening of the salivary gland function.

Oxidative Modification in the Salivary Glands of High Fat-Diet Induced Insulin Resistant Rats.

Still little is known about the role of oxidative stress (OS) in the pathogenesis of the salivary gland dysfunction in the course of insulin resistance (IR). To induce IR rats was fed with a high fat diet (HFD) during 8 weeks. Stimulated and non-stimulated salivary flow rate, total protein, as well as oxidative damage markers: 4-HNE protein adduct, 8-isoprostanes (8-isoP), 8-hydroxy-D-guanosine (8-OHdG), advanced oxidation protein product (AOPP), and protein carbonyls (PC) were determined in the plasma and submandibular and parotid glands of IR and control rats. We have shown a significant decrease (45%) of the stimulated salivary flow rate, and in the total protein concentration in the parotid (35%) and submandibular (10%) glands of HFD IR as compared to the control rats. The level of 4-HNE protein adduct (15%) and 8-isoP (20%) in the submandibular glands of IR rats as well as total level of 4-HNE protein adduct (39%), 8-isoP (27%), AOPP (25%), PC (32%), and 8-OHdG (18%) in the parotid glands of IR rats were significantly higher as compared to the control group. We showed no correlation between the assessed OS parameters in the plasma and salivary glands. However, the redox balance in both glands shifted toward the oxidative status, parotid glands of IR rats are exposed to greater intensity OS. Stimulated secretory ability and mechanisms involved in the synthesis/secretion of proteins in the salivary glands are depressed in the course of IR. Oxidative damage in the salivary glands arises independently from the general OS in the course of insulin resistance induced by a high fat diet.

Phenotypic and genotypic characteristics of Pseudomonas aeruginosa strains isolated from hospitals in the north-west region of Poland.

A total of 90 Pseudomonas aeruginosa strains isolated from 4 hospitals in the west-north region of Poland were studied by arbitrarily primed polymerase chain reaction (AP-PCR). AP-PCR results revealed the presence of 11 main groups of patterns (A-K) and 5 unique patterns among isolates. Generally, they were characterized by high resistance to antibiotics tested and significant differences in serogroups and types of growth on Cetrimide Agar medium. It was observed that clonally related strains were isolated from patients within the same ward, among different wards as well as in distant hospitals.

The possible effect of a sanitization program on intraspecies differentiation of Listeria monocytogenes strains isolated from a fish processing plant.

Forty-seven Listeria monocytogenes strains isolated during a year in a selected Polish fish-processing plant as well as 7 L. monocytogenes strains of different origins (including a reference strain) were analyzed in our studies. Strains were isolated from raw fish fillets (flounder), frozen coated flounder fillets, coating ingredients, and the processing environment. Isolation of strains covered the period of a sanitization program introduced in the plant. L. monocytogenes was identified using conventional microbiological methods and the PCR technique. RAPD (random amplified polymorphic DNA) technique for fingerprinting was applied to analyze the intraspecies diversity. Six RAPD types (A-F) and seven unique strains were revealed as a result of fingerprinting with one persistent type isolated from July 1999 to February 2000. It was detected for the first time after one month of sanitization. Its occurrence could have been promoted by clone selection either due to ineffective disinfection or to resistance against the disinfectant. As L. monocytogenes mostly occurred on frozen products, this indicates that contamination could start during product freezing, cold storage, or handling. The results revealed that there is a crucial need for preparing sanitization schemes precisely targeted at L. monocytogenes to avoid its recurrence as persistent 'in-house' strains. The possibility of incorrect interpretations of classical microbiological test results as well as the necessity to introduce assays based on nucleic acid analysis into epidemiological investigations were emphasized.

Optimisation of AP-PCR fingerprinting discriminatory power for clinical isolates of Pseudomonas aeruginosa.

Recently methods based on analysis of arbitrarily amplified target sites of microorganism genomes have been extensively applied in microbiological studies. The range of their applications is limited by problems with discrimination and reproducibility resulting from lack of standardised and reliable methods of optimisation. By orthogonal-array optimisation most advantageous and optimal parameters for highly discriminatory primers (CagA2+CMVin2) were selected and efficient AP-PCR (arbitrarily primed-polymerase chain reaction) fingerprinting conditions for Pseudomonas aeruginosa isolates were set up. Stable and multiplex amplicon profiles obtained in this study revealed high level of intraspecies DNA polymorphism among 20 analysed clinical strains of P. aeruginosa proving optimised AP-PCR fingerprinting to be useful in epidemiological typing of the species.