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Background Recently, skeletal muscle atrophy, impairment of iron metabolism, and insulin signalling have been reported in rats suffering from amyotrophic lateral sclerosis (ALS). However, the interrelationship between these changes has not been studied. We hypothesize that an impaired Akt-FOXO3a signalling pathway triggers changes in the iron metabolism in the muscles of transgenic animals. Methods In the present study, we used transgenic rats bearing the G93A hmSOD1 gene and their non-transgenic littermates. The study was performed on the muscles taken from animals at three different stages of the disease: asymptomatic (ALS I), the onset of the disease (ALS II), and the terminal stage of the disease (ALS III). In order to study the molecular mechanism of changes in iron metabolism, we used SH-SY5Y and C2C12 cell lines stably transfected with pcDNA3.1, SOD1 WT and SOD1 G93A, or FOXO3a TM-ER. Results A significant decrease in P-Akt level and changes in iron metabolism were observed even in the group of ALS I animals. This was accompanied by an increase in the active form of FOXO3a, up-regulation of atrogin-1, and catalase. However, significant muscle atrophy was observed in ALS II animals. An increase in ferritin L and H was accompanied by a rise in PCBP1 and APP protein levels. In SH-SY5Y cells stably expressing SOD1 or SOD1 G93A, we observed elevated levels of ferritin L and H and non-haem iron. Interestingly, insulin treatment significantly down-regulated ferritin L and H proteins in the cell. Conversely, cells transfected with small interfering RNA against Akt 1, 2, 3, respectively, showed a significant increase in the ferritin and FOXO3a levels. In order to assess the role of FOXO3a in the ferritin expression, we constructed a line of SH-SY5Y cells that expressed a fusion protein made of FOXO3a fused at the C-terminus with the ligand-binding domain of the oestrogen receptor (TM-ER) being activated by 4-hydroxytamoxifen. Treatment of the cells with 4-hydroxytamoxifen significantly up-regulated ferritin L and H proteins level. Conclusions Our data suggest that impairment of insulin signalling and iron metabolism in the skeletal muscle precedes muscle atrophy and is mediated by changes in Akt/FOXO3a signalling pathways.

Objectives: In dentistry, silver nanoparticles (AgNPs) have drawn particular attention because of their wide antimicrobial activity spectrum. However, controversial information on AgNPs toxicity limited their use in oral infections. Therefore, the aim of the present study was to evaluate the antibacterial activities against a panel of oral pathogenic bacteria and bacterial biofilms together with potential cytotoxic effects on human gingival fibroblasts of 10 nm AgNPs: non-functionalized - uncapped (AgNPs-UC) as well as surface-functionalized with capping agent: lipoic acid (AgNPs-LA), polyethylene glycol (AgNPs-PEG) or tannic acid (AgNPs-TA) using silver nitrate (AgNO3) as control. Methods: The interaction of AgNPs with human gingival fibroblast cells (HGF-1) was evaluated using the mitochondrial metabolic potential assay (MTT). Antimicrobial activity of AgNPs was tested against anaerobic Gram-positive and Gram-negative bacteria isolated from patients with oral cavity and respiratory tract infections, and selected aerobic Staphylococci strains. Minimal inhibitory concentration (MIC) values were determined by the agar dilution method for anaerobic bacteria or broth microdilution method for reference Staphylococci strains and Streptococcus mutans. These strains were also used for antibiofilm activity of AgNPs. Results: The highest antimicrobial activities at nontoxic concentrations were observed for the uncapped AgNPs and the AgNPs capped with LA. It was found that AgNPs-LA and AgNPs-PEG demonstrated lower cytotoxicity as compared with the AgNPs-TA or AgNPs-UC in the gingival fibroblast model. All of the tested nanoparticles proved less toxic and demonstrated wider spectrum of antimicrobial activities than AgNO3 solution. Additionally, AgNPs-LA eradicated Staphylococcus epidermidis and Streptococcus mutans 1-day biofilm at concentration nontoxic to oral cells. Conclusions: Our results proved that a capping agent had significant influence on the antibacterial, antibiofilm activity and cytotoxicity of AgNPs. Clinical significance: This study highlighted potential usefulness of AgNPs against oral anaerobic Gram-positive and Gram-negative bacterial infections and aerobic Staphylococci strains provided that pharmacological activity and risk assessment are carefully performed.

Purpose Pharmacological inhibition of the renin-angiotensin-aldosteron system (RAAS) may have a beneficial impact on proteinuria and chronic kidney diseases (CKD) progression. Despite recent progress by means of angiotensin-converting enzyme inhibitors (ACEI) and angiotensin II receptor blockers (ARB), there is still no optimal therapy which can stop progression of the nephropathy. Recently introduced aliskiren is the first orally bioavailable direct renin inhibitor approved for the treatment of hypertension. The purpose was to evaluate the extent of oxidative stress and tubular injury after the direct renin inhibitor, aliskiren compared with placebo and perindopril in patients with non-diabetic chronic kidney disease (NDCKD). Material/methods A randomized, double-blind, cross-over trial was performed in 14 patients receiving 300 mg aliskiren, 10 mg perindopril and placebo in random order. The end point was a change in the urinary excretion of N-acetyl-β-D-glucosaminidase (NAG) and α1-microglobulin (α1m) and 15-F 2α -isoprostane. Results Aliskiren reduced excretion of 15-F 2α -isoprostane ( p = 0.03) and α1m ( p = 0.01) as compared to placebo. There were no differences between aliskiren and perindopril in this regard. NAG urine excretion did not change after aliskiren and perindopril. Conclusions Aliskiren attenuates oxidative stress and may improve functional status of tubules in patients with NDCKD.

Diallyl trisulfide (DATS) is an organosulfur compound isolated from garlic, and has been shown to have anticancer activity both in vitro and in vivo. The aim of this study was to compare cytotoxic effects of DATS on prostate cancer cells PC-3 and noncancerous human prostate epithelial cells PNT1A. PC-3 prostate cancer and noncancerous human prostate epithelial cells PNT1A were used in the study. We observed that PNT1A cells had higher resistance to DATS-induced cell death than PC-3 cells. Investigating signaling pathways involved in the cell death we observed that p66Shc phosphorylation at serine 36 and extracellular signal-regulated kinase 1/2 activation induced by DATS, were significantly attenuated in PNT1A cells as compared to PC-3 cells. Moreover, DATS-induced Akt inactivation was also significantly reduced in PNT1A cells. In addition to that, DATS-induced reactive oxygen species generation was nearly completely abolished in PNT1A cells. Interestingly, DATS induced only slight decrease in the level of ferritin H, whereas ferritin L was elevated. These data suggest that cytotoxicity of DATS toward PNT1A cells is strongly reduced as opposed to PC-3 cancer cells, which corresponds to the lower activation of prodeath signaling pathway mediated by the adaptor protein p66Shc in the noncancerous PNT1A cells.

Objectives: In dentistry, silver nanoparticles (AgNPs) have drawn particular attention because of their wide antimicrobial activity spectrum. However, controversial information on AgNPs toxicity limited their use in oral infections. Therefore, the aim of the present study was to evaluate the antibacterial activities against a panel of oral pathogenic bacteria and bacterial biofilms together with potential cytotoxic effects on human gingival fibroblasts of 10 nm AgNPs: non-functionalized - uncapped (AgNPs-UC) as well as surface-functionalized with capping agent: lipoic acid (AgNPs-LA), polyethylene glycol (AgNPs-PEG) or tannic acid (AgNPs-TA) using silver nitrate (AgNO3) as control. Methods: The interaction of AgNPs with human gingival fibroblast cells (HGF-1) was evaluated using the mitochondrial metabolic potential assay (MTT). Antimicrobial activity of AgNPs was tested against anaerobic Gram-positive and Gram-negative bacteria isolated from patients with oral cavity and respiratory tract infections, and selected aerobic Staphylococci strains. Minimal inhibitory concentration (MIC) values were determined by the agar dilution method for anaerobic bacteria or broth microdilution method for reference Staphylococci strains and Streptococcus mutans. These strains were also used for antibiofilm activity of AgNPs. Results: The highest antimicrobial activities at nontoxic concentrations were observed for the uncapped AgNPs and the AgNPs capped with LA. It was found that AgNPs-LA and AgNPs-PEG demonstrated lower cytotoxicity as compared with the AgNPs-TA or AgNPs-UC in the gingival fibroblast model. All of the tested nanoparticles proved less toxic and demonstrated wider spectrum of antimicrobial activities than AgNO3 solution. Additionally, AgNPs-LA eradicated Staphylococcus epidermidis and Streptococcus mutans 1-day biofilm at concentration nontoxic to oral cells. Conclusions: Our results proved that a capping agent had significant influence on the antibacterial, antibiofilm activity and cytotoxicity of AgNPs. Clinical significance: This study highlighted potential usefulness of AgNPs against oral anaerobic Gram-positive and Gram-negative bacterial infections and aerobic Staphylococci strains provided that pharmacological activity and risk assessment are carefully performed.

Purpose: The aim of this study is to search for more effective derivatives of the superoxide dismutase mimetic tempol (4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl). Although tempol is neuroprotective in a rat partial optic nerve crush (PONC) model, relatively high doses are required to exert this effect. Methods: Tempol acyl esters with different-length fatty acids (tempol-C4, tempol-C8, tempol-C12 and tempol-C16) were synthesized and the following properties were evaluated: water-octanol partition coefficient, liposome-liposome energy transfer, and electron paramagnetic resonance (EPR). Brown Norway rats underwent PONC and received tempol or acyl esters intraperitoneally once daily for 7 consecutive days. We then compared the effects of tempol and its four esters on retinal ganglion cell (RGC) damage using a retrograde labelling method. Results: The water-octanol partition coefficient increased with increasing length of attached acyl chain. However, the energy of the liposome–liposome transfer seemed to be optimal for tempol-C8 and tempol-C12. The EPR signal was very similar for all tested compounds, suggesting similar efficiency of superoxide scavenging. Partial optic nerve crush in vehicle-treated animals reduced RGC numbers by approx. 59% when compared with sham-operated eyes. Tempol did not affect RGC loss at a dose of 1 mg/kg. In contrast, at molar doses equivalent to 1 mg/kg of tempol, tempol-C8 showed a significant neuroprotective effect, whereas tempol-C4, tempol-C12 and tempol-C16 did not act neuroprotectively. Conclusion: Manipulating the hydrophobicity of tempol seems to be a promising tool for developing more potent neuroprotectants in the PONC degeneration model. However, the resulting compounds need further pharmacological evaluation.

Beneficial effects of natural plant polyphenols on the human body have been evaluated in a number of scientific research projects. Bioactive polyphenols are natural compounds of various chemical structures. Their sources are mostly fruits, vegetables, nuts and seeds, roots, bark, leaves of different plants, herbs, whole grain products, processed foods (dark chocolate), as well as tea, coffee, and red wine. Polyphenols are believed to reduce morbidity and/or slow down the development of cardiovascular and neurodegenerative diseases as well as cancer. Biological activity of polyphenols is strongly related to their antioxidant properties. They tend to reduce the pool of reactive oxygen species as well as to neutralize potentially carcinogenic metabolites. A broad spectrum of health-promoting properties of plant polyphenols comprises antioxidant, anti-inflammatory, anti-allergic, anti-atherogenic, anti-thrombotic, and anti-mutagenic effects. Scientific studies present the ability of polyphenols to modulate the human immune system by affecting the proliferation of white blood cells, and also the production of cytokines or other factors that participate in the immunological defense. The aim of the review is to focus on polyphenols of olive oil in context of their biological activities.

Background/Aims: Acetaminophen overdose causes hepatotoxicity mediated by toxic metabolites generated through the cytochrome P450 enzyme. The objective of this study was to investigate whether acetaminophen (AAP) can enhance cisplatin (CDDP) cytotoxicity against human hepatocarcinoma and hepatoblastoma cells in vitro and whether this effect can be prevented by N-acetylcysteine (NAC). Methods: In vitro studies (glutathione [GSH] level, cell viability, and immunoblot assays) were performed using human hepatocarcinoma and hepatoblastoma cells cultured in AAP, CDDP, and the combination of both with or without delayed NAC administration. The pharmacology and toxicology of high-dose AAP in rats were also examined. Results: Acetaminophen decreased GSH levels in liver cancer cells in a dose- and time-dependent manner. Acetaminophen combined with CDDP had enhanced cytotoxicity over CDDP alone. The cytotoxicity caused by AAP plus CDDP was decreased by NAC, with the effectiveness being time-dependent. The GSH level was lowered in the liver but not in the blood or the brain in rats treated with a high dose of AAP (1000 mg/kg). The expression of CYP2E1 protein, a key cytochrome P450 enzyme, varies among species but is not correlated to AAP sensitivity in liver cancer cells. Conclusions: Our results suggest that a chemotherapeutic regimen containing both AAP and CDDP with delayed NAC rescue has the potential to enhance chemotherapeutic efficacy while decreasing adverse effects. This would be a promising approach particularly for hepatoblastomas regardless of cellular CYP2E1 protein level but could also be beneficial in other malignancies.

A randomized prospective clinical study performed on a group of 74 pregnant women (43 presenting with severe preeclampsia) proved that urinary levels of 15-F(2t)-isoprostane were significantly higher in preeclamptic patients relative to the control (3.05 vs. 2.00 ng/mg creatinine). Surprisingly enough, plasma levels of 25-hydroxyvitamin D3 in both study groups were below the clinical reference range with no significant difference between the groups. In vitro study performed on isolated placental mitochondria and placental cell line showed that suicidal self-oxidation of cytochrome P450scc may lead to structural disintegration of heme, potentially contributing to enhancement of oxidative stress phenomena in the course of preeclampsia. As placental cytochrome P450scc pleiotropic activity is implicated in the metabolism of free radical mediated arachidonic acid derivatives as well as multiple Vitamin D3 hydroxylations and progesterone synthesis, we propose that Vitamin D3 might act as a competitive inhibitor of placental cytochrome P450scc preventing the production of lipid peroxides or excess progesterone synthesis, both of which may contribute to the etiopathogenesis of preeclampsia. The proposed molecular mechanism is in accord with the preliminary clinical observations on the surprisingly high efficacy of high-dose Vitamin D3 supplementation in prevention and treatment of preeclampsia.

Contemporary fluoride research is largely focused on potential neurotoxicity. In the past three decades, over a hundred studies have found that excessive exposure to fluoride may be associated with central the dysfunction of nervous system. Fluoride is known to cross the blood–brain barrier, accumulate within various parts of the brain, and especially in the hippocampus altering its structure and function. Many epidemiological, animal and cell culture studies demonstrated that fluoride is harmful to the hippocampus and causes nonreversible neuronal damage leading to the loss of neurons. It was observed that chronic or subchronic fluoride exposure might lead to changes in behavior and neurodegeneration. The intelligence quotient (IQ) as assessed in children exposed to high fluoride levels in drinking water was proven to decrease. Fluoride exerts a deleterious effect on the hippocampus through complex and multidirectional cellular signaling mechanisms. Oxidative stress is a well-recognized mechanism of fluoride neurotoxicity. In our previous study we have observed that exposition to fluoride (50, 100, and 250 µM) for 3 days decreased viability, enhanced apoptosis, increased reactive oxygen/nitrogen species (ROS/RNS) generation and impaired antioxidative defence system in the mouse hippocampal cell line (HT22). Based on our study and literature data the impact of fluoride exposure on the hippocampus/hippocampal cells is presented in this chapter.

The discovery of isoprostanes, which are products of non-enzymatic lipid peroxidation, resulted in the research on the new role of free radicals in physiology and pathophysiology. Isoprostane quantitative analysis is a great achievement in the evaluation of free radical impact on many diseases in human. Isoprostanes were also found to be elevated in end-stage renal disease, another condition associated with increased oxidative stress. The aim of the study was to evaluate the influence of nephroprotective treatments on the urinary excretion of 15-F2alpha-isoprostane in the treated patients with Chronic Kidney Disease (CKD).84 patients (32 females and 52 males); age 18-65 years (average 39.06 +/- 4.92), with chronic non-diabetic proteinuric nephropathy, normal or slightly impaired stable renal function expressed as estimated creatinine cleamace above 30 mi/min, were selected from the cohort that attended our renal outpatients department. Clinical evaluation and laboratory tests were performed at the randomization point and after each period of the study A commercial ELISA Kit (Cayman Chemical Co) was used to measure the urinary excretion of 15-F2alpha-isoprostane in the treated patients.It was found that the blockade of renin-angiotensin-aldosteron system (with aliskiren, cilazapril, perindopril, spironolakton) and the treatment with atorwastatin significantly reduced urinary levels of 15-F2alpha-isoprostane relatively to the control group. It was not observed for pentoxyfilline treatment.Urine levels of isoprostanes are significantly decreased in patients with Chronic Kidney Disease during nephroprotective treatments.

This study was undertaken to investigate, the effect of 6 weeks treatment with acetaminophen (AAP) and fluoride (F), administered either separately or together, on nitric oxide generation, lipid and protein peroxidation, total antioxidant status and level of reduced glutathione in the liver and kidney of male and female Wistar Han rats. Also, the influence of AAP on F excretion in urine was determined.Thirty adult male and female rats were divided into five equal groups of six each: (I) controls drinking tap water; (II) controls drinking tap water and receiving 1 ml of tap water intragastrically; (III) animals receiving 12 mg F/L in drinking water; (IV) animals receiving 150 mg AAP /kg b.w./day; (V) animals receiving 12 mg F/L in drinking water and 150 mg AAP /kg b.w./day.F and AAP given separately and both together enhanced oxidative and nitrosative stress in investigated tissues. No gender differences were observed in oxidative/nitrosative stress parameters during treatment with F and/or AAP. Interestingly, the combined exposure to F and AAP resulted in an enhancement of oxidative/nitrosative stress in kidney of male and female rats compared to the group treated separately with F and AAP. No additive effect in the measured parameters in the liver during co-exposure to both xenobiotics was noticed.As expected, the urinary F excretion increased in an exposure time-dependent manner in rats receiving F or a combination of F and AAP. The study also showed that AAP significantly decreased urinary F.

We have designed a useful method of assessing reactive oxygen species generation in biological fluids. The novel assay utilizes tyrosine phosphatase CD45 as a biosensor of oxidative stress. Applying this new method, we examined oxygen species generation in the following cell culture media: RPMI 1640, DMEM, DMEM enriched with pyruvate and MEM. We discovered that the media (especially RPMI 1640) significantly reduced the activity of protein tyrosine phosphatase. The media-caused inactivation of CD45 was reversible after treatment with dithiothreitol being a powerful reducing agent. Interestingly, the media supplemented with catalase did not exhibit any inhibitory effect on CD45 activity which suggests a hydrogen peroxide-mediated mechanism of the enzyme inactivation. In addition to that, we assessed the impact of oxidative stress level on the activity of CD45 as measured in Jurkat cells cultured in RPMI 1640 either exposed or not exposed to the light of laminar flow cabinet fluorescent lamp. We found that Jurkat cells that were exposed to light displayed ca. 20% lower activity of CD45 than the cells protected against the light. The obtained results indicate that production of hydrogen peroxide in the medium leading to inhibition of CD45 was light-dependent, and that careful protection of cell culture media from the light may help to prevent the artifact in cell studies. Hydrogen peroxide, responsible for CD45 inactivation, can be generated in cell culture media after exposition to light due to photoreactive amino acids present in the media.

The aim of this study is to search for more effective derivatives of the superoxide dismutase mimetic tempol (4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl). Although tempol is neuroprotective in a rat partial optic nerve crush (PONC) model, relatively high doses are required to exert this effect.Tempol acyl esters with different-length fatty acids (tempol-C4, tempol-C8, tempol-C12 and tempol-C16) were synthesized and the following properties were evaluated: water-octanol partition coefficient, liposome-liposome energy transfer, and electron paramagnetic resonance (EPR). Brown Norway rats underwent PONC and received tempol or acyl esters intraperitoneally once daily for 7 consecutive days. We then compared the effects of tempol and its four esters on retinal ganglion cell (RGC) damage using a retrograde labelling method.The water-octanol partition coefficient increased with increasing length of attached acyl chain. However, the energy of the liposome-liposome transfer seemed to be optimal for tempol-C8 and tempol-C12. The EPR signal was very similar for all tested compounds, suggesting similar efficiency of superoxide scavenging. Partial optic nerve crush in vehicle-treated animals reduced RGC numbers by approx. 59% when compared with sham-operated eyes. Tempol did not affect RGC loss at a dose of 1 mg/kg. In contrast, at molar doses equivalent to 1 mg/kg of tempol, tempol-C8 showed a significant neuroprotective effect, whereas tempol-C4, tempol-C12 and tempol-C16 did not act neuroprotectively.Manipulating the hydrophobicity of tempol seems to be a promising tool for developing more potent neuroprotectants in the PONC degeneration model. However, the resulting compounds need further pharmacological evaluation.

The reversible phosphorylation of structural and regulatory proteins in eucaryotic cells is one of the most important regulatory mechanisms. Protein tyrosine phosphatases (PTP) regulate a wide range of signal transduction pathways that control many cellular processes such as cell proliferation, differentiation and growth. Disorder in PTP gene expression is implicated in the development of cancer, autoimmune and neurodegenerative diseases. The active sites of these enzymes are characterized by the consensus sequence containing cysteine which is essential for enzyme activity and highly susceptible to oxidation. Reversible oxidation of the catalytic cysteine is becoming recognized as a general mechanism for regulation of PTP enzymatic activity. These findings suggest that protein tyrosine phosphatases may be considered as very sensitive markers of oxidative stress. Many studies have demonstrated that the production of reactive oxygen species during oxidative stress can inactivate protein tyrosine phosphatases.

BACKGROUND Inhibition of the renin-angiotensin-aldosterone system (RAAS) with angiotensin converting enzyme inhibitors (ACEI) and/or angiotensin II subtype 1 receptor antagonists (ARB) is a common strategy used in the management of patients with chronic kidney disease (CKD). However, there is no universal therapy that can stop progression of CKD. Pentoxifylline (PTE) is a non-specific phosphodiesterase inhibitor with anti-inflammatory properties. It has been reported to have promising effects in CKD treatment. METHODS In a placebo-controlled, randomized, cross-over study we evaluated the influence of PTE (1200 mg/day) added to RAAS blockade on proteinuria, surrogate markers of tubular injury and oxidative stress-dependent products in 22 non-diabetic patients with proteinuria (0.4-4.3 g per 24 h) with normal or declined kidney function [eGFR 37-178 mL/min]. In an eight-week run-in period, therapy using ACEI and/or ARB was adjusted to achieve a blood pressure below 130/80 mm Hg. Next, patients were randomly assigned to one of two treatment sequences: PTE/washout/placebo or placebo/washout/PTE. Clinical evaluation and laboratory tests were performed at the randomization point and after each period of the study. RESULTS The PTE therapy reduced proteinuria (by 26%) as compared to placebo. There were no differences in alpha(1)-microglobulin, urine excretion of N-acetyl-beta-d-glucosaminidase (NAG), hsCRP, the urinary excretion of 15-F(2)t-isoprostane, blood pressure (BP), eGFR and serum creatinine between the PTE and placebo groups. CONCLUSION Pentoxifylline may decrease proteinuria in non-diabetic patients with CKD.

To the Editor: In one of the latest issues of Hypertension , Michea et al1 reported that the mineralocorticoid receptor antagonist spironolactone attenuates cardiac hypertrophy and oxidative stress of the heart in uremic rats. The results of our recent clinical study indicate that spironolactone acts to decrease the amount of oxidative stress in patients being treated for chronic kidney disease. In an open, randomized, crossover study, 16 white adult patients (10 men and 6 women; mean age: 41 years) with nondiabetic proteinuric …

The objective of this study was to assess the dynamics of oxidative damage to cellular macromolecules such as proteins, lipids, and DNA under conditions of oxidative stress triggering early stages of estrogen-dependent carcinogenesis. A rodent model of carcinogenesis was used. Syrian hamsters were sacrificed after 1, 3, 5 h and 1 month from the initial implantation of 17beta-estradiol (E2). Matching control groups were used. Kidneys as target organs for E2-mediated oxidative stress were excised and homogenized for biochemical assays. Subcellular fractions were isolated. Carbonyl groups (as a marker of protein oxidation) and lipid hydroxyperoxides were assessed. DNA was isolated and 8-oxodGuo was assessed. Electron paramagnetic resonance spectroscopy was used to confirm the results for lipid peroxidation. Exposition to E2 in rodent model leads to a damage of macromolecules of the cell, including proteins and DNA, but not lipids. Proteins appear to be primary target of the damage but are shortly followed by DNA. It has previously been speculated that protein peroxides can increase DNA modifications. This time sequence was observed in our study. Nevertheless, direct relation between protein and DNA damage still remains unsolved.

The objective of this study was to assess the dynamics of oxidative damage to cellular macromolecules such as proteins, lipids, and DNA under conditions of oxidative stress triggering early stages of estrogen-dependent carcinogenesis. A rodent model of carcinogenesis was used. Syrian hamsters were sacrificed after 1, 3, 5h and 1 month from the initial implantation of 17β-estradiol (E2). Matching control groups were used. Kidneys as target organs for E2-mediated oxidative stress were excised and homogenized for biochemical assays. Subcellular fractions were isolated. Carbonyl groups (as a marker of protein oxidation) and lipid hydroxyperoxides were assessed. DNA was isolated and 8-oxodGuo was assessed. Electron paramagnetic resonance spectroscopy was used to confirm the results for lipid peroxidation.

The profile and normal concentrations of nucleotide metabolites in human saliva and reproducibility of these determinations were analyzed. Samples of human saliva collected from healthy individuals at weekly intervals, were deproteinized and analysed for the content of adenine nucleotides and their metabolites by reversed-phase HPLC. Initial ATP, hypoxanthine and uric acid concentrations were 0.52 +/- 0.15 microM, 1.91 +/- 0.37 microM and 184 +/- 22 microM respectively. A substantial individual variation persisted within 3 weeks of sampling excepted hypoxanthine which showed some unrelated variations. Determination of nucleotides and their catabolites in saliva due to its simplicity and reproducibility, may be of clinical value in diagnosis of local or systemic disorders.

Protein tyrosine phosphatases (PTPs) modulate the cellular level of tyrosine phosphorylation under normal and pathological conditions, and thus exert either stimulatory or inhibitory effect on signal transduction. Hence, PTPs are potential pharmacological targets for novel drugs being developed in order to treat numerous pathologies including cancer. For example, PTPs have been found to play a key role in pathogenesis of autoimmune disorders, allergic response, cardiovascular or neurodegenerative diseases, among others Alzheimer\'s disease. Moreover, since many PTPs fine-tune subtle regulation of microbial biochemistry controlling the viability and virulence, they can be candidates for new therapies of infection diseases. In this review, authors summarize the current knowledge on PTPs implication in etiopathogenesis of most common human diseases focusing on PTPs as potential therapeutical targets.