Application of n-dodecane as an oxygen vector to enhance the activity of fumarase in recombinant Escherichia coli: role of intracellular microenvironment

Abstract The effect of the intracellular microenvironment in the presence of an oxygen vector during expression of a fusion protein in Escherichia coli was studied. Three organic solutions at different concentration were chosen as oxygen vectors for fumarase expression. The addition of n-dodecane did not induce a significant change in the expression of fumarase, while the activity of fumarase increased significantly to 124% at 2.5% n-dodecane added after 9 h induction. The concentration of ATP increased sharply during the first 6 h of induction, to a value 7600% higher than that in the absence of an oxygen-vector. NAD/NADH and NADP/NADPH ratios were positively correlated with fumarase activity. n-Dodecane can be used to increase the concentration of ATP and change the energy metabolic pathway, providing sufficient energy for fumarase folding.

Effects of plasma on polyethylene fiber surface for prosthodontic application

ABSTRACT Plasma technology has the potential to improve the adherence of fibers to polymeric matrices, and there are prospects for its application in dentistry to reinforce the dental particulate composite. Objectives This study aimed to investigate the effect of oxygen or argon plasma treatment on polyethylene fibers. Material and Methods Connect, Construct, InFibra, and InFibra treated with oxygen or argon plasma were topographically evaluated by scanning electron microscopy (SEM), and chemically by X-ray photoelectron spectroscopy (XPS). For bending analysis, one indirect composite (Signum) was reinforced with polyethylene fiber (Connect, Construct, or InFibra). The InFibra fiber was subjected to three different treatments: (1) single application of silane, (2) oxygen or argon plasma for 1 or 3 min, (3) oxygen or argon plasma and subsequent application of silane. The samples (25x2x2 mm), 6 unreinforced and 60 reinforced with fibers, were subjected to three-point loading tests to obtain their flexural strength and deflection. The results were statistically analyzed with ANOVA and the Bonferroni correction for multiple comparison tests. Results SEM analysis showed that oxygen and argon plasma treatments promote roughness on the polyethylene fiber surface. X-ray photoelectron spectroscopy (XPS) analysis shows that both plasmas were effective in incorporating oxygenated functional groups. Argon or oxygen plasma treatment affected the flexural strength and deflection of a fiber reinforced composite. The application of silane does not promote an increase in the flexural strength of the reinforced composites. Conclusions Oxygen and argon plasma treatments were effective in incorporating oxygenated functional groups and surface roughness. The highest strength values were obtained in the group reinforced with polyethylene fibers treated with oxygen plasma for 3 min.

El Profesor Doctor Hernán Alessandri: su legado para las nuevas generaciones de / Professor Hernán Alessandri, M.D.: his legacy for the new generations of physicians

Professor Alessandri died in 1980. We started our residency in Internal Medicine about 30 years later. Considering the profound changes our society has witnessed, including medical practice, I would like to approach the meaning of his work for our generation. It is not the Father’s figure nor his Aura what inspires us today. Neither is his personality nor his shape. His universality comes from his transcendent image as a teacher. Today’s teachers live rough times, their social status has changed, their professional requirements have grown exponentially, they have to adapt to social phenomena like the Internet and multiculturalism. Being a teacher nowadays demands to be a multifaceted expert. Things have changed since Professor Alessandri made rounds with his patients. But a deeper look allows us to understand that everything returns to where it started: professional deontology of the teacher, never fading but transcendent. We know that Doctor Alessandri had the natural gift to keep faithful to that code with consistency and perseverance. He excelled with integrity in every aspect including professional betterment, constructive work for his institution, collegiality, a warm relationship with students and a model of social values. Beyond virtues and personal defects he will keep on being the mould in which present teachers should be formed, engraved in their souls and in the subconscious of students that seek to learn.

Effect of Vanillin on lipid profile in a model of hyperlipidemia, a preliminary study.

To evaluate the effect of vanillin on the lipid profile of high fat diet induced hyperlipidemia in rats, the hyperlipidemia was induced by feeding cholesterol-rich high fat diet for 45 days in wistar rats of either sex. The reduction in the triglycerides and VLDL-C was significant at 200 & 400 mg/kg dose of vanillin compared to atorvastatin group. Reduction in total cholesterol was significant at 200 and 400 mg/kg doses compared to hyperlipidemic control. The results demonstrate that vanillin at a dose of 200 and 400 mg/kg body weight lowers the serum triglyceride, VLDL-C and total cholesterol level significantly in high fat diet induced hyperlipidemic rats. However there was no significant effect on the lipid profile at 100 mg/kg dose. There were no statistically significant changes in the HDL-C and LDL-C levels at any of the given doses.

Role of ERK1/2 Kinase in the expression of iNOS by NDMA in human neutrophils.

Potential role of ERK1/2 kinase in conjunction with p38 in the regulation of inducible nitric oxide synthase (iNOS) expression and nitric oxide (NO) production, and superoxide anion generation by human neutrophils (PMNs) exposed to N-nitrosodimethylamine (NDMA) was determined. Increased synthesis of NO due to the involvement of iNOS in neutrophils exposed to NDMA was observed. In addition, intensified activation of ERK1/2 and p38 kinases was determined in these cells. Inhibition of kinase regulated by extracellular signals (ERK1/2) pathway, in contrast to p38 pathway, led to an increased production of NO and expression of iNOS in PMNs. Moreover, as a result of inhibition of ERK1/2 pathway, a decreased activation of p38 kinase was observed in neutrophils, while inhibition of p38 kinase did not affect activation of ERK1/2 pathway in these cells. An increased ability to release superoxide anion by the studied PMNs was observed, which decreased after ERK1/2 pathway inhibition. In conclusion, in human neutrophils, ERK1/2 kinase is not directly involved in the regulation of iNOS and NO production induced by NDMA; however, the kinase participates in superoxide anion production in these cells.

Synthesis of biologically active O-substituted derivatives of 1-[[3, 5-dichloro-2-hydroxyphenyl]sulfonyl]piperidine

In the present work, a series of 2-O-substituted derivatives of 1-[[3,5-dichloro-2-hydroxy phenyl] sulfonyl]piperidine [5a-j] were synthesized. These derivatives were geared up by the coupling of 3,5-dichloro-2-hydroxy benzenesulfonyl chloride [1] with piperidine [2] under dynamic pH control in aqueous media to form parent compound 1-[[3,5-dichloro-2-hydroxyphenyl]sulfonyl]piperidine [3], followed by the substitution at oxygen atom with different electrophiles [4a-j] in the presence of sodium hydride [NaH] and dimethyl formamide [DMF] to give a series of Osubstituted derivatives of sulfonamides bearing piperidine nucleus 5a-j. The synthesized O-substituted sulfonamides were spectrally characterized. The bioactivity of all the synthesized compounds were evaluated against lipoxygenase [LOX], acetylcholinesterae [AChE] and butyrylcholinesterase [BChE] enzymes and found to be having talented activity against butyrylcholinesterase enzyme

Chemical oxygen demand fractions of municipal wastewater for modeling of wastewater treatment

When a new wastewater treatment plant is being designed by computer simulation, detailed data about organic fractions of influent wastewater [measured as chemical oxygen demand] are usually not available, but knowledge of the typical ranges of these fractions is indispensable. The influent chemical oxygen demand fractions can substantially influence the results of simulation-based design such as reactor volumes, solids residence time, effluent quality, oxygen demand, sludge production, etc. This article attempts to give an overview of wastewater organic fractions as modeling parameters and presents new chemical oxygen demand fractionation results from Hungary. According to the data from literature, the ratio of chemical oxygen demand components in raw wastewater is very different and the average composition is as follows: Inert particulate = 17.1%, slowly biodegradable = 57.9%, inert soluble = 7.8% and readily biodegradable = 17.5%. The Hungarian wastewater samples were analyzed according to STOWA [Dutch foundation for applied water research] protocol and the obtained results were not much different from those of literature [inert particulate = 23.7%, slowly biodegradable = 49.8%, inert soluble = 4.6% and readily biodegradable = 21.9%], but some typical characteristics were observed

Ultra-low luminescence of humid air and its possible role in negative air ion therapy.

One of the unresolved questions related to the mechanism of action of light negative air ions (reactive oxygen species) produced by air ionizers upon humans and animals is transmission of these short-living chemical species upon long distances from the place of their origin. We discovered the phenomenon which may probably resolve this problem. When a thin layer of water hydrating a hygroscopic surface absorbs rare UV-photons capable to split water molecules a flash of photon emission in UV- and visible regions of spectrum is observed. This flash (or oxygen-dependent oxidative processes underlying it) initiate reactions accompanied with generation of electronic excitation in the air contacting water film. Excitation propagates through the air at macroscopic distances, and the level of propagating excitation increases with elevation of air humidity. When air humidity exceeds 50% air excitation gains oscillatory-wave character. This phenomenon may endow into the mechanism of action of air ions generated artificially, and also into some natural processes where ordered water films may form and the latter may serve targets for energy impulses initiating oxygen-dependent oxidative processes in these films.

Imaging of biophoton emission from electrostimulated skin acupuncture point jg4: effect of light enhancers.

Using an ultrasensitive CCD camera, an extremely low light intensity from the acupuncture-sensitive point JG4 at the left hand was recorded. As the intensity of the light was very weak and the time of electrostimulation exceeded the recommended period, the quality of biophoton images was poor. Chemiluminescent and fluorescent hydrophilic, hydrophobic and amphyphilic molecular probes were used to: (i) ensure penetration of probes into skin, (ii) enhance the intensity of BP emission, (iii) shorten time and (iv) obtain information about mechanisms of biophotons generation in EAP-sensitive points and channels. The results obtained partially fulfilled expectations and indicate on the necessity to elaborate special techniques of probes deposition on the skin.

Free radicals and low-level photon emission in human pathogenesis: state of the art.

Convincing evidence supports a role for oxidative stress in the pathogenesis of many chronic diseases. The model includes the formation of radical oxygen species (ROS) and the misassembly and aggregation of proteins when three tiers of cellular defence are insufficient: (a) direct antioxidative systems, (b) molecular damage repairing systems, and (c) compensatory chaperone synthesis. The aim of the present overview is to introduce (a) the basics of free radical and antioxidant metabolism, (b) the role of the protein quality control system in protecting cells from free radical damage and its relation to chronic diseases, (c) the basics of the ultraweak luminescence as marker of the oxidant status of biological systems, and (d) the research in human photon emission as a non-invasive marker of oxidant status in relation to chronic diseases. In considering the role of free radicals in disease, both their generation and their control by the antioxidant system are part of the story. Excessive free radical production leads to the production of heat shock proteins and chaperone proteins as a second line of protection against damage. Chaperones at the molecular level facilitate stress regulation vis-à-vis protein quali y control mechanisms. The manifestation of misfolded proteins and aggregates is a hallmark of a range of neurodegenerative disorders including Alzheimer's disease, Parkinson's disease, amylotrophic lateral sclerosis, polyglutamine (polyQ) diseases, diabetes and many others. Each of these disorders exhibits aging-dependent onset and a progressive, usually fatal clinical course. The second part reviews the current status of human photon emission techniques and protocols for recording the human oxidative status. Sensitive photomultiplier tubes may provide a tool for non-invasive and continuous monitoring of oxidative metabolism. In that respect, recording ultraweak luminescence has been favored compared to other indirect assays. Several biological models have been used to illustrate the technique in cell cultures and organs in vivo. This initiated practical applications addressing specific human pathological issues. Systematic studies on human emission have presented information on: (a) procedures for reliable measurements, and spectral analysis, (b) anatomic intensity of emission and left-right symmetries, (c) biological rhythms in emission, (d) physical and psychological influences on emission, (e) novel physical characteristics of emission, and (f) the identification of ultraweak photon emission with the staging of ROS-related damage and disease. It is concluded that both patterns and physical properties of ultraweak photon emission hold considerable promise as measure for the oxidative status.

Pollution level in distillery effluent and its phytotoxic effect on seed germination and early growth of maize and rice.

The effluent from a Lucknow- based distillery (Mohan Meakin Distillery) was analyzed for physico-chemical and biological parameters of pollution and concentration of potentially toxic heavy metals (Cd, Cr, Ni and Zn) and the effect of the distillery effluent, as such and on 50% dilution with tap water was studied on seed germination and seedling growth of maize (Zea mays L.) and rice (Oryza sativa L.). The effluent was wine red in colour and highly acidic (pH approximately 55) and possessed decaying alcoholic smell. The effluent contained high values of different pollution parameters, particularly total solids, 3450 mgl(-1) (soluble plus suspended solids), alkalinity 1500 mgl(-1), biological oxygen demand (BOD, 1649 mgl(-1)) and chemical oxygen demand (COD, 2036 mgl(-1)). It had very low values of dissolved oxygen (DO, 0.34 mgl(-1)). The heavy metals (Cd, Cr, Ni and Zn) content, particularly the nickel concentration (0.029 mg l(-1)) was high. Use of the distillery effluent, even on 1:1 dilution with tap water inhibited germination and early seedling growth of maize and rice. In both maize and rice, more so in the former germination % of seeds, length of radicle and plumule and the fresh and dry weight of the seedlings were significantly reduced. The emerging leaves of the seedlings also developed visible effects of toxicity some of which resembled the symptoms of nickel toxicity. Our observations suggest that the effluent, as discharged from the distillery carry a heavy load of pollutants. Its discharge into the river Gomti poses a potential threat to the aquatic life, perticularly during the summer months when the water flow in the river is drastically reduced. The distillery effluentis also harmful for irrigating crops grown along the drain carrying it.

Coliform MPN counts of municipal raw sewage and sewage treatment plant in relation to the water of Buckingham Canal at Kalpakkam (Tamil Nadu, India).

Most Probable Number (MPN) of Total Coliforms (TC) and Faecal Coliforms (FC), and the physicochemical variables - temperature, Dissolved Oxygen (D.O.), Biochemical Oxygen Demand (B.O.D.), Chemical Oxygen Demand (C.O.D.), nitrates, phosphates and chlorides of municipal raw sewage and that of aeration tank and secondary clarifier of the Sewage Treatment Plant (STP), in relation to water at the treated sewage out-fall point, down-stream and up-stream of the Buckingham Canal at Kalpakkam were analyzed. Total Coliform and Faecal Coliform MPN counts were higher, 170 and 70/100 mL respectively in the raw sewage. However, the counts of the former in the aeration tank though remained similar, that of FC decreased to 50/100 mL; both of the counts further decreased to 30 and 44/100 mL respectively, in the secondary clarifier and were 110 and 23/100 mL, respectively at the treated sewage out-fall point in the canal. Total coliforms MPN was more than 18 times less in the water at the up-stream than that of the treated sewage out-fall point in the canal. Interestingly MPN of the FC in the up-stream water was nil while it was 8/100 mL in the canal's down-stream point. It is concluded that the FC, B.O.D., C.O.D., nitrates, phosphates and chlorides decreased and the D.O. increased in the treated-sewage due to the treatment of raw sewage through the STP.

Impact of Tehri Dam on aquatic macroinvertebrate diversity of Bhagirathi, Uttarakhand (India).

Aquatic macroinvertebrate diversity in the Bhagirathi river was monitored for the period of twelve months (September 2004 to August 2005) for assessing the impact of Asia's highest dam, Tehri Dam. Comparative data on diversity of macroinvertebrates revealed that the number of taxa in the downstream stretch, especially close to the dam was significantly reduced. The velocity of water current, hydromedian depth, turbidity, dissolved oxygen and the bottom substrates of the river were found drastically influenced due to the construction activities of the dam. Macroinvertebrate diversity (Shannon-Wiener Index) was altered from 3.44 to 1.98. The members of ephemeroptera and trichoptera were drastically influenced in comparison to other macroinvertebrates.

Effect of carbon and nitrogen source amendment on synthetic dyes decolourizing efficiency of white-rot fungus, Phanerochaete chrysosporium.

Decolourization activity of Phanerochaete chrysosporium for three synthetic dyes viz., congo red, malachite green and crystal violet and impact of additional carbon and nitrogen supply on decolourization capacity of fungus were investigated. Maximum decolourizing capacity was observed up to 15 ppm. Addition of urea as nitrogen source and glucose as carbon source significantly enhanced decolourizing capacity (up to 87%) of fungus. In all the cases, both colour and COD were reduced more in non-sterilized treatments as compared to sterilized ones. Significant reductions in COD content of dye solutions (79-84%) were recorded by fungus supplied with additional carbon and nitrogen. A highly significant correlation (r = 0.78, p < 0.001) between colour and COD of dye solutions was recorded. Thus, a readily available carbon and nitrogen source is imperative to enhance the bioremediation activity of this fungus which has been the most suitable for synthetic dyes and textile industry wastewater treatment.

Testicular protein profile (SDS-PAGE) study of zinc deficient Wistar albino rat.

Present study has revealed that zinc plays important role in regulating the production and secretion of proteins at transcriptional or translational level. Study has firmly depicted the change in the levels of polypeptide of 70 kDa in zinc deficient group. The protein pattern in pair fed group has been affected mainly to combat the insult due to low food intake.

Mycosporine-like amino acids (MAAs): chemical structure, biosynthesis and significance as UV-absorbing/screening compounds.

Continuous depletion of the stratospheric ozone layer has resulted in an increase in ultraviolet-B (UV-B; 280-315 nm) radiation on the earth's surface which inhibits photochemical and photobiological processes. However, certain photosynthetic organisms have evolved mechanisms to counteract the toxicity of ultraviolet or high photosynthetically active radiation by synthesizing the UV-absorbing/screening compounds, such as mycosporine-like amino acids (MAAs) and scytonemin besides the repair of UV-induced damage of DNA and accumulation of carotenoids and detoxifying enzymes or radical quenchers and antioxidants. Chemical structure of various MAAs, their possible biochemical routes of synthesis and role as photoprotective compounds in various organisms are discussed.

Quantitative structure-activity relationship of some pesticides.

Herbicides (benzodiazepinediones), insecticides (dioxatricyclododecenes) and larvicides (N-oxalyl derivatives of tebufenozide) have been quantitatively investigated to explore the relationship between the molecular structure and their biological activity using molecular operating environment (MOE) software. The study provides good predictive models, cross-validated by leave-out-one method (Loo). The positive contribution of the descriptor n-O (count of oxygen atom) suggests the additional oxygen atom substitution at R1 position, in addition to benzodiazepine moiety is favorable for herbicidal activity, whereas the negative contribution of y component of dipole moment (Dip(y)) indicates that electronic interactions are also crucial for the activity. The negative correlation of V(SA)2 and globularity (Glo) descriptors clearly indicates that the volume, shape, and rigidity of tebufenozide derivatives determine their larvicidal activity. The biparametric model for insecticides shows that the indicator variable l(CH-CH3) and R(PC) (negative partial charge) are detrimental for its activity. Most of the active compounds in the series have shown less value for these descriptors. The derived QSAR models also provide valuable insights to optimize their toxicity, which remains a major concern for environment safety.

Iron and manganese contamination: sources, adverse effects and control methods.

This article discusses the problem of iron and manganese contamination, the adverse effects and available control methods. The presence of iron and manganese in water causes serious commercial and health problems. Various treatment methods are available to treat water contaminated with these elements. However, catalytic media is an excellent choice particularly increasing given the preference for non-chemical water treatment. INDION ISR and BIRM are the most popularly used synthetically manufactured catalytic media.

Colour and COD removal from pulp and paper mill effluent by q Fenton's oxidation.

Colour and COD removal studies of pulp and paper mill effluent were carried out by Fenton's oxidation. Fenton's oxidation process was employed in four distinct stages interrelated to each other. In the first stage, FeSO4 concentration, pH and temperature were kept constant to determine H2O2 dose for maximum color and COD removal. In the second stage, dose of H2O2 obtained from first stage and same oxidation conditions were applied to determine the optimum FeSO4 concentration. Optimum pH, temperature and contact time were investigated in third and fourth stages considering the results of optimum doses of first and second stage. Maximum color up to 98% and COD removal up to 62% were obtained for Fenton reagents of 600 mg/L of H2O2 and 100 mg/L of Fe2+ dose at pH 3.0 for 300 min of contact period between reagents and effluent.

Bioremediation of industrial waste by using bat guano.

The present investigation is an attempt to study the effect of bat guano with its rich microbial flora on bioremediation of industrial waste effluents. The results revealed that within a period of 15 days, there was a remarkable reduction in the Chemical Oxygen Demand (COD) values up to 50%-70%, thus stabilizing the industrial effluents. In addition to this,values of various physico-chemical parameters were notably found to reduce suggesting that industrial effluents can be effectively treated by bat guano.