LATS2 degradation promoted fibrosis damage and rescued by vitamin K3 in lupus nephritis

BACKGROUND

Lupus nephritis (LN) is the most common complication of systemic lupus erythematosus (SLE). The limited treatment options for LN increase the economic burdens on patients. Because fibrotic progression leads to irreversible renal damage in LN patients and further progresses to chronic kidney disease (CKD) and the end stage of renal disease (ESRD), developing new targets to prevent LN fibrotic progression could lead to a feasible treatment strategy for LN patients.

METHODS

In this study, we examined YAP activation and LATS2 downregulation in LN kidney biopsy samples (LN: n = 8, normal: n = 2) and lupus-prone MRL/lpr mice (n = 8 for each disease stage). The function of LATS2 was further investigated by in situ injection of Ad-LATS2 into mice with LN (n = 6 mice per group). We examined the role of SIAH2-LATS2 regulation by IP-MS and co-IP, and the protective effect of the SIAH2 inhibitor was investigated in mice with LN.

RESULTS

Restoring LATS2 by an adenovirus in vivo alleviated renal fibrotic damage in mice with LN. Moreover, we found that LATS2 was degraded by a K48 ubiquitination-proteasome pathway mediated by SIAH2 and promoted YAP activation to worsen fibrosis progression in LN. The H150 region of the substrate binding domain (SBD) is an important site for SIAH2-LATS2 binding. The SIAH2-specific inhibitor vitamin K3 protected against LN-associated fibrotic damage in vivo.

CONCLUSION

In summary, we identified the SIAH2-LATS2 axis as an attractive intervention target in LN to alter the resistance to fibrosis.

Identification of ethyl-6-bromo-2((phenylthio)methyl)imidazo[1,2-a]pyridine-3-carboxylate as a narrow spectrum inhibitor of Streptococcus pneumoniae and its FtsZ

Filamentous temperature-sensitive mutant Z (FtsZ) is a key cell-division protein recognized as an important target for anti-bacterial drug discovery, especially in the context of rising multi-drug resistance. A respiratory pathogen, Streptococcus pneumoniae, is rapidly evolving antibiotic resistance, thus posing a clinical risk in the developing world. Inhibiting the conserved protein FtsZ, leading to the arrest of cell division, is an attractive alternative strategy for inhibiting S. pneumoniae. Previously, Vitamin K3 was identified as an FtsZ-targeting agent against S. pneumoniae. In the present work, docking studies were used to identify potential anti-FtsZ agents that bind to the Vitamin K3-binding region of a homology model generated for S. pneumoniae FtsZ. Compounds with imidazo[1,2-a]pyridine-3-carboxylate core were synthesized and screened for their anti-proliferative activity against S. pneumoniae. Remarkably, the hit compound IP-01 showed anti-bacterial action against S. pneumoniae without any activity on other bacteria. In S. pneumoniae, IP-01 showed similar inhibitory action on FtsZ and cell division as Vitamin K3. Sequence alignment identified three unique residues within S. pneumoniae FtsZ that IP-01 binds to, providing a structural basis for the observed specificity. IP-01 is one of the first narrow-spectrum agents identified against S. pneumoniae that targets FtsZ, and we present it as a promising lead for the design of narrow-spectrum anti-FtsZ anti-pneumococcal compounds.

Reduction of neutral lipid reservoirs, bioconversion and untargeted metabolomics reveal distinct roles for vitamin K isoforms on lipid metabolism

Vitamin K isoforms are known as co-factors for the synthesis of blood-clotting proteins, but several other bioactivities were reported. In this work, we isolated a vitamin K1-analogue (OH-PhQ) from the cyanobacterium Tychonema sp. LEGE 07196 with lipid reducing activity. OH-PhQ reduced neutral lipid reservoirs with an EC50 value of 31 μM after 48 h exposure in zebrafish larvae, while other vitamin K isoforms had EC50 values of 21.1 μM (K2) and 1.2 μM (K3). No lipid reducing activity was observed for K1 up to 50 μM. The presence of vitamin K isoforms was studied in zebrafish after exposure (OH-PhQ, K1, K2 and K3), and a clear preference for bioconversion was observed to retain K1 and OH-PhQ. Untargeted metabolomics revealed different biological effects for vitamin K isoforms on the subclass and metabolite level, but similarities were present on the compound class level, particularly on the regulation of glycerophospholipids. Our data showed for the first time a lipid reducing activity of OH-PhQ and performed a comparative analysis of vitamin K isoforms, which could be important for the development of future nutraceuticals or food supplements.

Sulfonated vitamin K3 mediated bimetallic metal-organic framework for multistage augmented cancer therapy

Chemodynamic therapy (CDT) relying on Fenton reaction has emerged as a promising strategy for tumor treatment. However, its clinical efficacy is hindered by the inadequate reactive oxygen species (ROS) and the potential cytotoxicity towards normal cells. To address these challenges, we have successfully developed a multistage augmented cancer therapy system based on bimetallic metal-organic framework (BMOF) that amplifies ROS and facilitates tumor-specific therapeutic effects. By employing a simple one-pot self-assembly approach, we synthesized SVK3@ZnCo-ZIF in which sulfonated vitamin K3 (SVK3) was encapsulated within ZnCo-ZIF BMOF. The results revealed that the incorporation of Zn atoms significantly diluted the Fenton activity of Co atoms towards normal cells. Notably, SVK3@ZnCo-ZIF underwent pH-controlled decomposition triggered by the tumor microenvironment (TME), thus releasing SVK3, Co2+ and Zn2+. Specifically, the H2O2 levels in tumors was effectively elevated by the interaction of SVK3 with NAD(P)H quinone oxidoreductase-1 (NQO-1). It thus enhanced the Fenton activity of Co2+. Moreover, the release of Zn2+ ions can induce cellular dysfunction and mitochondrial damage, thereby promoting the generation of ROS and subsequent cell death. The synergistic combination of CDT, SVK3 chemotherapy, and Zn2+-interfered therapy greatly facilitated apoptosis of tumor cells. Collectively, our investigations demonstrate the efficacy of such system in selectively inducing toxicity in cancer cells while minimizing detrimental effects on normal cells.

Topical glutathione amino acid precursors protect skin against environmental and oxidative stress

BACKGROUND

Although glutathione (GSH) has long been considered a master antioxidant, poor stability and bioavailability limit its application in skin protection. To overcome the challenges, Unilever R&D formulated a Glutathione Amino acid Precursors blend (named GAP) to boost GSH de novo synthesis.

OBJECTIVE

Determine whether GAP can boost GSH levels and provide skin protection against stressors.

METHODS

Normal human epidermal keratinocytes were treated with GAP, with or without stressors, namely, menadione, blue light or pollutants. Ascorbic acid was used as a benchmark. The levels of GSH, glutathione disulfide (GSSG), adenosine triphosphate (ATP) and reactive oxygen species (ROS) were quantified. A placebo-controlled clinical study was conducted on 21 female subjects who received product applications and subsequent UV radiation. Tape strip samples were collected from the subjects for GSH and GSSG quantification using ultra-performance liquid chromatography-mass spectrometry/mass spectrometry (UPLC-MS/MS). The UV-protective effect of GAP was investigated using ex vivo skin. Biomarkers related to DNA damage and the skin barrier were analysed using immunohistochemistry.

RESULTS

Glutathione amino acid precursors significantly increased the GSH levels and GSH/GSSG ratio in normal human epidermal keratinocytes. Menadione treatment resulted in excessive ROS production and a decline in ATP levels, which were effectively abrogated by GAP. The protective effects of GAP against menadione-induced oxidative stress were superior to those of ascorbic acid. In addition, GAP effectively protected the cells against blue light-induced ROS production and pollutant-induced ATP depletion. Topical application of the GAP formulation significantly elevated the skin GSH/GSSG ratio in a clinical study. Ex vivo skin treated with the GAP formulation displayed a reduction in DNA damage and high levels of barrier proteins after UV exposure.

CONCLUSIONS

Glutathione amino acid precursors effectively increases cellular GSH levels to protect the skin from oxidative and environmental stresses.

Observation of the neuroprotective efficacy of vitamin K in a streptozocin-induced diabetes model in chick embryos

Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia due to insulin deficiency and/or resistance. Vitamin K (VK) is a group of fat-soluble molecules, including naturally occurring vitamin K1 (phylloquinone). vitamin K2 (menaquinone), and synthetic vitamin K3 (menadione). Beyond coagulation, the health benefits of VK have been described to play different roles in both physiological and pathological processes such as inflammation, energy metabolism, neuroprotection, cellular growth, and survival. It was aimed to observe the antioxidant and/or neuroprotective activity of vitamin K1 in our model of chick embryo diabetic neuropathy (DN) induced by streptozotocin (STZ). Ninety White Leghorn, fertile and 0-day-old SPF (specific pathogen-free) eggs (57 ± 4 gr) were used in the study. Chick embryo blood brain tissues were taken for biochemical evaluation. Plasma insulin and glucose levels were measured. In addition, brain tissue total antioxidant level (TAS), total oxidant level (TOS), malondialdehyde (MDA), and vascular endothelial growth factor (VEGF) levels were measured. Plasma glucose levels were higher in the STZ-treated groups and lower in the treatment groups. Plasma insulin levels were observed to be higher in STZ groups in groups treated with high VK. Low TAS, high MDA, TOS, and VEGF levels were recorded in brain tissue STZ groups. Low VEGF, TOS, and MDA levels were recorded in the group treated with the highest VK, while high TAS levels were observed. In our STZ-induced chick embryo diabetic neuropathy model, we observed that VK1 reduced oxidant damage by showing antioxidant properties or by modulating antioxidant enzymes.

Vitamin K3 promotes CCL5 expression to recruit preadipocytes deposition to skeletal muscle

Intramuscular fat (IMF), also known as ectopic fat deposits in skeletal muscle. Researches of IMF mainly focus on increasing the number and size of intramuscular adipocytes in situ. However, recent studies have shown that chemokines secreted by skeletal muscle recruit adipocytes to increase intramuscular fat content. Chemokine ligand 5 (CCL5), a member of chemokine family, is involved in the regulation of cell migration, inflammatory responses, and energy metabolism. In this study, we determined Vitamin K3 (VK3) enhanced Ccl5 transcription and expression, thus resulting in increased preadipocyte migration. VK3-injected vastus lateralis (VL) was observed an increased CCL5 concentration and IMF deposition, whereas blockade of the CCL5/CCR5 axis decreased IMF deposition.VK3 treatment also increased the body weight and VL ratio in mice. In summary, VK3, which targets CCL5, is expected to be a novel pharmacological regulator for promoting IMF content.

Effects of dietary vitamin K3 supplementation on production performance, egg quality, vitamin K-dependent proteins, and antioxidant properties in breeding geese during the laying period

The aim of this work was to investigate the effects of dietary vitamin K3 (VK3) supplementation on production performance, egg quality, vitamin K-dependent proteins, and antioxidant properties in breeding geese during the laying period. A total of one hundred twenty 82-wk-old Wulong geese with similar body weights were randomly divided into 6 groups with 4 replicates and 5 geese each (1 male and 4 female). The geese in the control group were fed a basal diet, and the geese in the treatment groups were fed diets supplemented with different levels of VK3 (2.5, 5.0, 7.5, 10.0, and 12.5 mg/kg) for 11 wk. Dietary VK3 supplementation linearly and quadratically increased feed intake, egg mass, egg weight, and egg production (P < 0.05). Increasing VK3 levels linearly and quadratically increased albumen height, shell thickness and Haugh unit of eggs (P < 0.05). VK3 reduced osteocalcin (OC) and uncarboxylated osteocalcin (ucOC) levels in the serum. Dietary VK3 addition linearly decreased serum malondialdehyde (MDA) levels (P < 0.01). There was linear and quadratic effect in the activity of serum total superoxide dismutase (T-SOD) (P < 0.01), and linear effect in serum total antioxidant capacity (T-AOC) (P < 0.01). In conclusion, dietary VK3 supplementation enhanced the production performance, egg quality, vitamin K-dependent proteins, and antioxidant properties in breeding geese during the laying period. The optimal dose of dietary VK3 supplementation was 10.0 mg/kg.

Assessment of Rhizobium anhuiense Bacteria as a Potential Biocatalyst for Microbial Biofuel Cell Design

The development of microbial fuel cells based on electro-catalytic processes is among the novel topics, which are recently emerging in the sustainable development of energetic systems. Microbial fuel cells have emerged as unique biocatalytic systems, which transform the chemical energy accumulated in renewable organic fuels and at the same time reduce pollution from hazardous organic compounds. However, not all microorganisms involved in metabolic/catalytic processes generate sufficient redox potential. In this research, we have assessed the applicability of the microorganism Rhizobium anhuiense as a catalyst suitable for the design of microbial fuel cells. To improve the charge transfer, several redox mediators were tested, namely menadione, riboflavin, and 9,10-phenanthrenequinone (PQ). The best performance was determined for a Rhizobium anhuiense-based bio-anode mediated by menadione with a 0.385 mV open circuit potential and 5.5 μW/cm² maximal power density at 0.35 mV, which generated 50 μA/cm² anode current at the same potential.

An Oxidative Stress-Related Gene Signature in Granulosa Cells Is Associated with Ovarian Aging

Ovarian aging is associated with a decrease in fecundity. Increased oxidative stress of granulosa cells (GCs) is an important contributor. We thus asked whether there is an oxidative stress-related gene signature in GCs associated with ovarian aging. Public nonhuman primate (NHP) single-cell transcriptome was processed to identify GC cluster. Then, a GC signature for ovarian aging was established based on six oxidative stress-related differentially expressed genes (MAPK1, STK24, AREG, ATG7, ANXA1, and PON2). Receiver operating characteristic (ROC) analysis confirmed good discriminating capacity in both NHP single-cell and human bulk transcriptome datasets. Gene expression levels were investigated using qPCR in the human ovarian granulosa-like tumor cell line (KGN) and mouse GCs. In an oxidative stress model, KGN cells were treated with menadione (7.5 μM, 24 h) to induce oxidative stress, after which upregulation of MAPK1, STK24, ATG7, ANXA1, and PON2 and downregulation of AREG were observed (p < 0.05). In an aging model, KGN cells were continuously cultured for 3 months, leading to increased expressions of all genes (p < 0.05). In GCs of reproductively aged (8-month-old) Kunming mice, upregulated expression of Mapk1, Stk24, Atg7, and Pon2 and downregulated expression of Anxa1 and Areg were observed (p < 0.01). We therefore here identify a six-gene GC signature associated with oxidative stress and ovarian aging.

Culturomics of Bacteria from Radon-Saturated Water of the World's Oldest Radium Mine

Balneotherapeutic water springs, such as those with thermal, saline, sulfur, or any other characteristics, have recently been the subject of phylogenetic studies with a closer focus on the description and/or isolation of phylogenetically novel or biotechnologically interesting microorganisms. Generally, however, most such microorganisms are rarely obtained in pure culture or are even, for now, unculturable under laboratory conditions. In this culture-dependent study of radioactive water springs of Jáchymov (Joachimstahl), Czech Republic, we investigated a combination of classical cultivation approaches with those imitating sampling source conditions. Using these environmentally relevant cultivation approaches, over 1,000 pure cultures were successfully isolated from 4 radioactive springs. Subsequent dereplication yielded 121 unique taxonomic units spanning 44 genera and 9 taxonomic classes, ~10% of which were identified as hitherto undescribed taxa. Genomes of the latter were sequenced and analyzed, with a special focus on endogenous defense systems to withstand oxidative stress and aid in radiotolerance. Due to their origin from radioactive waters, we determined the resistance of the isolates to oxidative stress. Most of the isolates were more resistant to menadione than the model strain Deinococcus radiodurans DSM 20539T. Moreover, isolates of the Deinococcacecae, Micrococcaceae, Bacillaceae, Moraxellaceae, and Pseudomonadaceae families even exhibited higher resistance in the presence of hydrogen peroxide. In summary, our culturomic analysis shows that subsurface water springs contain diverse bacterial populations, including as-yet-undescribed taxa and strains with promising biotechnological potential. Furthermore, this study suggests that environmentally relevant cultivation techniques increase the efficiency of cultivation, thus enhancing the chance of isolating hitherto uncultured microorganisms. IMPORTANCE The mine Svornost in Jáchymov (Joachimstahl), Czech Republic is a former silver-uranium mine and the world's first and for a long time only radium mine, nowadays the deepest mine devoted to the extraction of water which is saturated with radon and has therapeutic benefits given its chemical properties. This healing water, which is approximately 13 thousand years old, is used under medical supervision for the treatment of patients with neurological and rheumatic disorders. Our culturomic approach using low concentrations of growth substrates or the environmental matrix itself (i.e., water filtrate) in culturing media combined with prolonged cultivation time resulted in the isolation of a broad spectrum of microorganisms from 4 radioactive springs of Jáchymov which are phylogenetically novel and/or bear various adaptive or coping mechanisms to thrive under selective pressure and can thus provide a wide spectrum of capabilities potentially exploitable in diverse scientific, biotechnological, or medical disciplines.

Inhibition of Autophagy Negates Radiofrequency-Induced Adaptive Response in SH-SY5Y Neuroblastoma Cells

In the last years, radiofrequency (RF) has demonstrated that it can reduce DNA damage induced by a subsequent treatment with chemical or physical agents in different cell types, resembling the adaptive response, a phenomenon well documented in radiobiology. Such an effect has also been reported by other authors both in vitro and in vivo, and plausible hypotheses have been formulated, spanning from the perturbation of the cell redox status, to DNA repair mechanisms, and stress response machinery, as possible cellular mechanisms activated by RF pre-exposure. These mechanisms may underpin the observed phenomenon, and require deeper investigations. The present study aimed to determine whether autophagy contributes to RF-induced adaptive response. To this purpose, SH-SY5Y human neuroblastoma cells were exposed for 20 h to 1950 MHz, UMTS signal, and then treated with menadione. The results obtained indicated a reduction in menadione-induced DNA damage, assessed by applying the comet assay. Such a reduction was negated when autophagy was inhibited by bafilomycin A1 and E64d. Moreover, CRISPR SH-SY5Y cell lines defective for ATG7 or ATG5 genes did not show an adaptive response. These findings suggest the involvement of autophagy in the RF-induced adaptive response in human neuroblastoma cells; although, further investigation is required to extend such observation at the molecular level.

Detecting Validated Intracellular ROS Generation with 18F-dihydroethidine-Based PET

PURPOSE

To determine the sensitivity of the 18F-radiolabelled dihydroethidine analogue ([18F]DHE) to ROS in a validated ex vivo model of tissue oxidative stress.

PROCEDURES

The sensitivity of [18F]DHE to various ROS-generating systems was first established in vitro. Then, isolated rat hearts were perfused under constant flow, with contractile function monitored by intraventricular balloon. Cardiac uptake of infused [18F]DHE (50-150 kBq.min-1) was monitored by γ-detection, while ROS generation was invoked by menadione infusion (0, 10, or 50 μm), validated by parallel measures of cardiac oxidative stress.

RESULTS

[18F]DHE was most sensitive to oxidation by superoxide and hydroxyl radicals. Normalised [18F]DHE uptake was significantly greater in menadione-treated hearts (1.44 ± 0.27) versus control (0.81 ± 0.07) (p < 0.05, n = 4/group), associated with concomitant cardiac contractile dysfunction, glutathione depletion, and PKG1α dimerisation.

CONCLUSION

[18F]DHE reports on ROS in a validated model of oxidative stress where perfusion (and tracer delivery) is unlikely to impact its pharmacokinetics.

Root treatment with a vitamin K3 derivative: a promising alternative to synthetic fungicides against Botrytis cinerea in tomato plants

BACKGROUND

Botrytis cinerea, the causal agent of gray mold has a great economic impact on several important crops. This necrotrophic fungus causes disease symptoms during vegetative growth and also into postharvest stages. The current method to combat this disease is fungicide application, with high economic costs and environmentally unsustainable impacts. Moreover, there is an increasing general public health concern about these strategies of crop protection. We studied the protection of tomato plants against B. cinerea by previous root treatment with menadione sodium bisulfite (MSB), a known plant defense activator.

RESULTS

Root treatment 48 h before inoculation with MSB 0.6 mmol L^-1 reduced leaf lesion diameter by 30% and notably cell deaths, compared to control plants 72 h after inoculation. We studied the expression level of several pathogenesis-related (PR) genes from different defense transduction pathways, and found that MSB primes higher PR1 expression against B. cinerea. However, this stronger induced resistance was impaired in transgenic salicylic acid-deficient NahG line. Additionally, in the absence of pathogen challenge, MSB increased tomato plant growth by 28% after 10 days. Our data provide evidence that MSB protects tomato plants against B. cinerea by priming defense responses through the salicylic acid (SA)-dependent signaling pathway and reducing oxidative stress.

CONCLUSION

This work confirms the efficacy of MSB as plant defense activator against B. cinerea and presents a novel alternative to combat gray mold in important crops.

Menadione sodium bisulfite alleviated chromium effects on wheat by regulating oxidative defense, chromium speciation, and ion homeostasis

Menadione sodium bisulfite (MSB) is a crucial growth regulator mediating plant defense response. MSB-mediated regulation of defense mechanisms in wheat under chromium (Cr) toxicity has not been reported in the literature. Therefore, the present study was undertaken to appraise the efficacy of exogenous MSB on circumventing Cr phytotoxic effects on wheat. We also compared the effects of water-soluble MSB with that of water-insoluble menadiol diacetate (MD). The levels used in the present investigation for MSB and MD were 100 and 200 mg L-1. Wheat plants grown in soil contaminated with 25 mg kg-1 Cr in the form of K2Cr2O7 showed a notable reduction in growth, chlorophyll molecules, relative water contents, grain yield, total soluble sugars, phenolics, flavonoids, ascorbic acid, activities of antioxidant enzymes (SOD, POD, CAT), and uptake of essential nutrients (K, P, and Ca). Cr toxicity caused a noticeable accretion in total free amino acids, proline, malondialdehyde, H2O2, O2•-, relative membrane permeability, methylglyoxal contents, activities of enzymes (lipoxygenase, glutathione-S-transferase, and ascorbate peroxidase), nitric oxide and H2S contents, glutathione and oxidized glutathione contents, total Cr contents, and Cr6+ and Cr3+ accumulation. MSB application significantly reduced lipid peroxidation, ROS overproduction, methylglyoxal levels, total Cr contents, and maintained higher Cr3+:Cr6+ ratio in aerial parts. Besides, Cr-mediated inhibition in essential nutrient uptake was significantly circumvented by exogenous MSB. Consequently, MSB enhanced wheat growth by lessening oxidative damage, total Cr contents in aerial parts, and strengthening antioxidant enzyme activities. MD was not effective in mediating defense responses in wheat under Cr toxicity.

Menadione sodium bisulfite neutralizes chromium phytotoxic effects in okra by regulating cytosolutes, lipid peroxidation, antioxidant system and metal uptake

Chromium (Cr) is a major abiotic stress for plant species that significantly impacted plant development and impeded agricultural production. Menadione sodium bisulfite (MSB) has recently manifested a remarkable role in modulating plant defense responses. In the present experiment, Cr caused a significant decrease in growth, relative water contents, and chlorophyll in okra cultivars (Shabnam 786 and Arka Anamika). Cr produced an increase in proline, total soluble proteins, total free amino acids, phenolics, flavonoids, ascorbic acid, hydrogen peroxide (H₂O₂), malondialdehyde (MDA), and Cr accumulation. Besides, activities of antioxidant enzymes were also higher in Cr-stressed plants. MSB application (50, 100, 150, and 200 µM) profoundly impacted growth and important physio-biochemical characteristics in okra under Cr stress. Better growth in MSB treated plants was associated with lower oxidative damage and better oxidative defense system reflected in the form of higher antioxidant enzyme activities alongside the concentrations of non-enzymatic antioxidant compounds. In this background, cv. Shabnam-786 exhibited greater Cr tolerance over Arka Anamika. The degree of oxidative damage measured in the form of H₂O₂ and MDA was greater in cv. Arka Anamika. Lower MSB levels (50 and 100 µM) circumvented inhibitory Cr effects in okra, while higher doses proved lethal for plant growth and development.

[Long term results of laser refractive operations--methods Epi-LASIK or LASEK]

PURPOSE

To compare and evaluate postoperative results of two methods of refractive laser surgery, Epi-LASIK and LASEK, performed at the Department of Ophthalmology and Optometry of St. Anne's University Hospital Brno, Czech Republic.

METHODS

128 eyes operation were performed on patients with myopia, 102 with the Epi-LASIK method and 26 with the LASEK method. The preoperative mean spherical equivalent was -4.8 +/- 2.6 D (range -2.3 to -7.5) in the Epi-LASIK eyes and -3.5 +/- 3.1 D (range -1.6 to -7.8) in the LASEK eyes. The average preoperative uncorrected visual acuity (UCVA) was 0,129 (from 0.02 to 0.8) with the Epi-LASIK method and 0,246 (from 0.02 to 0.8) with the LASEK method. The best average corrected visual acuity was 1,139 (from 0.63 to 1.6) with the Epi-LASIK method and 1.115 (from 0.25 to 1.25) with the LASEK method. The average cylindrical refraction of the Epi-LASIK patients before the operation was -1.52 +/- 0.80 D (range -1.0 to -3.5) and the LASEK patients was -1.55 +/- 0.89 D (range -1.0 to -3.0), except of those who have astigmatism up to +/- 0.75D. In both methods was used the excimer laser Mel 80 Meditec-Zeiss with 193 nm wavelength and the frequency of 250 Hz and active eye-tracking system.

RESULTS

The postoperative mean spherical equivalent was 0 +/- 0.5 D (range -0.6 to 0.6) in the Epi-LASIK eyes and 0.3 +/- 0.4 D (range -0.3 to 0.7) in the LASEK eyes. The average uncorrected visual acuity was 0.745 with Epi-LASIK and 0.687 with LASEK after first week, 0.996 and 1,083 after month, 1.068 and 1.063 after 3 months, 1.147 and 1,082 after 6 months, 1.090 and 1.031 after one year. The average cylindrical refraction after the operation was -0.82 +/- 0.69 D (range 0 to -1.7) with Epi-LASIK and -0.59 +/- 0.55 D (range 0 to -1.5) with LASEK. Average "haze", evaluated by the Gartry's scale, was 0.39 with Epi-LASIK and 0.46 with LASEK after week, 0.21 and 0.06 after one year.

CONCLUSIONS

The Epi-LASIK and LASEK methods have comparable postoperative results of visual acuity, astigmatism, "haze". They are effective too in worse form of the myopia.

Shotgun redox proteomics in sub-proteomes trapped on functionalised beads: Identification of proteins targeted by oxidative stress

If reactive oxygen species (ROS) levels exceed antioxidant defences, oxidative stress occurs; a common response to environmental pollutants. Proteins absorb ∼70% of ROS, altering amino acid side-chains. Cys (-SH) oxidises to sulphenic (-SOH), sulphinic (-SO(2)H), cysteic (-SO(3)H) acids and disulphide bridges (-S-S-). Two-dimensional electrophoresis (2DE) under-selects certain protein categories (e.g. extreme pI, small proteins) so activated thiol sepharose (ATS) was used to select sub-proteomes of thiol-containing proteins in menadione-exposed Escherichia coli. ATS bound thiol-containing proteins (but not oxidised thiols) via mixed disulphides. Tryptic digestion of bead-bound proteins was followed by LC-tandem MS. Many proteins were identified in controls with significantly fewer in menadione-treated cells (e.g. chaperonins, transcription/translation-related and ribosomal proteins; aminoacyl tRNA synthetases and metabolic enzymes. Non-denaturing ATS capture (followed by reduction) demonstrated lower specific activities of key enzymes which is attributed to thiol oxidation. This method may be generally useful in ecotoxicology for identification of oxidative stress targets.

Evaluation of the probe dihydrocalcein acetoxymethylester as an indicator of reactive oxygen species formation and comparison with oxidative DNA base modification determined by modified alkaline elution technique

Reactive oxygen species (ROS) play a predominant role in various diseases and the development of fast and easy methods for the quantification of intracellular ROS represents an important goal. Therefore, the aim of the present study was the evaluation of the fluorogenic probe dihydrocalcein acetoxymethylester (AM) for the detection of intracellular ROS. A flow cytometric method was developed using MCF-7 cells and the kinetics of ester hydrolysis and the cellular distribution and stability of calcein were characterized using calcein AM. Then, MCF-7 cells were challenged with model agents for the generation of singlet oxygen (illumination with visible light), peroxyl and hydroxyl radicals (tert-butylhydroperoxide, tBHP), superoxide anion radicals (potassium dioxide), and the intracellular formation of superoxide anion radicals by redox cycling (menadione) and the formation of calcein was compared with the induction of oxidative DNA base modifications assessed by modified alkaline elution technique. Every model agent significantly induced formamidopyrimidine-DNA glycosylase-sensitive sites (i.e. oxidative DNA base modifications) and most also induced DNA strand breaks. In contrast, exclusively tBHP and illumination with visible light induced the intracellular formation of calcein. In conclusion, though intracellular oxidation of dihydrocalcein represents a fast screening method, it detects a limited spectrum of ROS.

Screening of natural product biocides for control of non-indigenous species

Several benzo-, naphtho- and anthraquinones were tested for their efficacy as biocides in controlling aquatic nuisance species in ships' ballast water. A requirement of this application was broad spectrum aquatic toxicity, coupled with a relatively rapid rate of degradation, in order to comply with coastal discharge requirements. Compounds were screened using a suite of toxicity bioassays designed to establish their relative toxicity to an array of planktonic organisms including larval bivalves Dreissena and Crassostrea, various developmental stages of the estuarine copepod Eurytemora affinis, brine shrimp larvae (Artemia salina), the freshwater invasive water flea Bythotrephes, larval sheepshead minnows CCyprinodon variegates) and two unicellular algal genera Isochrysis and Neochloris.. The majority of the data were recorded as the lowest concentration of the test compound resulting in complete mortality or inactivation of test organisms (LC ,m). The naphthoquinones juglone, plumbagin, menadione and naphthazarin showed the highest toxicity to the broadest range of organisms, often at levels much less than 1 mg l(-1), and most of the attention was focused on this group. While plumbagin and juglone appeared overall to be the most toxic compounds, it was concluded that menadione was probably the most cost-effective candidate compound for shipboard use for controlling invasive species in ballast water, particularly in view of the large volumes of water that would require treatment.

Selective susceptibility of different populations of sympathetic neurons to diabetic neuropathy in vivo is reflected by increased vulnerability to oxidative stress in vitro

Diabetes is the major cause of autonomic neuropathy in humans. Sympathetic neurons from the celiac/superior mesenteric ganglia (CG/SMG) develop neuropathic changes in diabetes whereas sympathetic superior cervical ganglion (SCG) neurons do not. Glucose-induced oxidative stress is proposed as a major factor in the development of diabetic neuropathy. The aim of this study was to investigate whether sympathetic neurons that develop neuropathy in diabetes are more susceptible to oxidative stress. Explants of CG/SMG and SCG from control adult rats were cultured in media free of serum and NGF, exposed to menadione for 48 h to induce oxidative stress and assessed for neuronal viability, TUNEL-positive nuclei and tyrosine hydroxylase- (TH)-immunoreactivity. TH-immunoreactivity was also assessed in ganglia from control and 8 week streptozotocin-diabetic rats. Menadione caused a concentration-dependent loss of neuronal viability and increase in TUNEL staining in both ganglia. However, at low concentrations, menadione had a significantly greater effect (p<0.01) on CG/SMG neurons than SCG neurons. At 1 nM, menadione caused a significant increase (p<0.05) in the number of CG/SMG neurons containing intense TH-immunoreactivity without affecting SCG neurons. Similarly, 8 weeks streptozotocin-induced diabetes resulted in a significant increase (p<0.05) in intensely fluorescent TH-containing CG/SMG neurons but not SCG neurons. This is the first demonstration that oxidative stress in vitro causes the same accumulation of TH in CG/SMG neurons as is observed following streptozotocin-induced diabetes in vivo. Furthermore, the selective vulnerability of CG/SMG neurons to diabetes is reflected by increased sensitivity to oxidative stress.

Introducing glutathione biosynthetic capability into Lactococcus lactis subsp. cremoris NZ9000 improves the oxidative-stress resistance of the host

This study describes how a metabolic engineering approach can be used to improve bacterial stress resistance. Some Lactococcus lactis strains are capable of taking up glutathione, and the imported glutathione protects this organism against H(2)O(2)-induced oxidative stress. L. lactis subsp. cremoris NZ9000, a model organism of this species that is widely used in the study of metabolic engineering, can neither synthesize nor take up glutathione. The study described here aimed to improve the oxidative-stress resistance of strain NZ9000 by introducing a glutathione biosynthetic capability. We show that the glutathione produced by strain NZ9000 conferred stronger resistance on the host following exposure to H(2)O(2) (150 mM) and a superoxide generator, menadione (30 microM). To explore whether glutathione can complement the existing oxidative-stress defense systems, we constructed a superoxide dismutase deficient mutant of strain NZ9000, designated as NZ4504, which is more sensitive to oxidative stress, and introduced the glutathione biosynthetic capability into this strain. Glutathione produced by strain NZ4504(pNZ3203) significantly shortens the lag phase of the host when grown aerobically, especially in the presence of menadione. In addition, cells of NZ4504(pNZ3203) capable of producing glutathione restored the resistance of the host to H(2)O(2)-induced oxidative stress, back to the wild-type level. We conclude that the resistance of L. lactis subsp. cremoris NZ9000 to oxidative stress can be increased in engineered cells with glutathione producing capability.

Hepatoprotective effect of Sabina przewalskii against menadione-induced toxicity

Sabina przewalskii is a Tibetan medicinal plant. Pretreatment with an ethyl acetate-soluble fraction of the plant suppressed the plasma alanine aminotransferase activity in menadione-intoxicated mice. In vitro studies showed that the Sabina extract could inhibit NADH-induced superoxide production in isolated hepatocytes as indicated by a decrease of lucigenin-amplified chemiluminescence. In addition, the extract inhibited tert-butyl hydroperoxide-induced lipid peroxidation in isolated hepatocytes dose-dependently. These results suggested that the protective action of the Sabina extract against menadione-induced hepatotoxicity is associated with its antioxidant activities including the scavenging of superoxide anion radicals and inhibition of lipid peroxidation.

[Vitamin K as a stimulator of microbial growth]

The stimulating action of vitamin K, contained in medicinal plants as vitamin K natural complexes and in Vikasol and Menadion, the pharmaceutical preparations of vitamin K, on the growth of pathogenic microorganisms was determined. The stimulating action of group K vitamins should be taken into consideration in the development of nutrient media.