Disinfection of Microorganisms by Use of Electrochemically Regenerated Periodate

A new method for disinfection of microorganisms by electrochemically regenerated periodate was developed. Oxidation of iodate to periodate was observed at 1.25 V versus a silver/silver chloride electrode in a cyclic voltammogram of potassium iodate. When 1.25 V was applied in 1.0 mM potassium iodate, approximately 4-log inactivation of Escherichia coli was observed in 30 min.     

Effects of lodine in Various Formulations on the Growth of Barley and Pea Plants in Nutrient Solution Culture

The forms of iodine added to cultures of barley were potassiumiodide, potassium iodate, potassium periodate, and iodoaceticacid at iodine concentrations of 1.0 ppm and 10.0 ppm. Withpea, only iodide and iodate at 1.0 ppm iodine concentrationwere used. For both species, comparisons were made with culturesto which no iodine was added. In barley, growth was increased by 1.0 ppm iodine, the relativeeffectiveness of the different formulations being in the order:iodoacetic acid > iodide > iodate > periodate. With10.0 ppm, iodide and iodoacetic acid treatments gave reducedgrowth, iodate was without effect, and periodate enhanced growth. In pea, 1.0 ppm iodine was inhibitory, iodide being more toxicthan iodate. Analysis of dry matter showed iodine content according to treatmentto be in the order: iodide > iodoacetic acid > iodate> periodate     

Oxidation of thymidylate synthase by inorganic compounds

Thymidylate synthase from methotrexate-resistant Lactobacillus casei was rapidly and completely inactivated by low concentrations of permanganate, periodate, or potassium triiodide at 0 degree C. The enzyme was not inactivated to any appreciable extent by iodate, iodide, ferricyanate, iodosobenzoate, or hydrogen peroxide. The inactivation by permanganate was retarded by the substrate 2'-deoxyuridylate and, to a lesser extent, by phosphate. Titration of enzyme activity with permanganate showed that two moles of permanganate were required to completely inactivate one mole of thymidylate synthase.     

Estimation of in vivo aminoacylation by periodate oxidation: tRNA alterations and iodate inhibition.

Two problems associated with periodate oxidation in determining the extent of aminoacylation of tRNA are discussed. One of the products of this reaction, sodium iodate, was found to inhibit tRNA charging. In addition, periodate oxidation also appears to alter sites other than the 3′-end on at least two isoacceptor species of tRNA^Leu.     

A spectrophotometric method for the microdetermination of periodate

1. A method is described for measuring the concentration of periodate over the range 0.2-20mum by adding 1,2-di-(p-dimethylaminophenyl)ethane-1,2-diol to a sample solution. Periodate cleaves this compound to from two molecules of p-dimethylaminobenzaldehyde, the extinction of which is then read at 352mmu. 2. The method has been used to follow the course of periodate oxidations of serine methyl ester, ribonuclease A and ribonuclease S-protein. Addition of the reagent stops further periodate reaction by reducing the remaining periodate to iodate. 3. The presence of protein does not interfere with the assay.     

Isotachophoresis for periodate oxidation analysis of a small amount of carbohydrate.

The present study demonstrates that formate, periodate, and iodate, in a reaction mixture for periodate oxidation of carbohydrates, are simultaneously and conveniently determined by isotachophoretic analysis. The operating condition of the electrophoretic method involves the addition of 0.3 vol of dioxane and 0.2% Triton X-100 to a deoxygenated leading electrolyte of 10 mm HCl buffered with 20 mm imidazole, pH 7.0. These additives are essential for complete resolution of formate and periodate in respective zones. It has been shown that the analyzable amounts of these products in the oxidation reaction are less than 5 nmol which corresponds to less than μg of carbohydrates. This value is about one-thousandth of that required for the conventional methods of periodate oxidation analysis.     

Rigid structural requirement of the 5' terminus of mRNA for translational activity.

Oxidation by sodium periodate of the ribose cis-diol of the 5′ terminal of liver mRNA to the corresponding dialdehyde virtually destroyed its template activity in the wheat germ translation system. The rigid structural requirement for the ribose cis-diol is indicated by the failure of reduction of the dialdehyde to the corresponding primary alcohols to restore the template activity of the mRNA. Sodium periodate alone inhibited the translational system at concentrations above 0.25 mM. Purification of the periodate oxidized mRNA by sucrose density gradient centrifugation or exclusion on Sephadex G-100 did not increase its template activity. Periodate oxidized mRNA was not inhibitory to translation of untreated mRNA.     

Induction of an Inhibitor of Influenza Virus Hemagglutination by Treatment of Serum with Periodate

Serum is commonly treated with potassium periodate to destroy nonspecific inhibitors of influenza virus hemagglutination. We have observed, however, that such treatment of serum without pre-existing inhibitor produced high titers of inhibitor against certain strains of influenza virus. Inhibitor was induced in the serum from several different animal species but not in hamster or mouse serum. Periodate treatment of serum albumin, fraction V, from several animals, including man, creates this inhibitor. Our data indicate that the inhibitor induced in the serum of various animal species differs in its mechanism of induction and in its resistance to receptor-destroying enzyme and trypsin. Hemagglutination by B/Singapore/3/64, B/Colorado/2/65, B/Georgia/1/65, and B/Massachusetts/3/66 strains of influenza virus is inhibited by periodate-treated human serum at dilutions as high as 1:5,120. The routine use of periodate treatment of serum in diagnostic and surveillance studies of influenza virus infections is not recommended.     

Post‐chemiluminescence determination of chloramphenicol based on luminol–potassium periodate system

A post‐chemiluminescence (PCL) phenomenon was observed when chloramphenicol was injected into a mixture of luminol and potassium periodate after the chemiluminescence (CL) reaction of luminol–potassium periodate had finished. The possible reaction mechanism was proposed based on studies of the CL kinetic characteristics, the CL spectra, the fluorescence spectra and the UV‐vis absorption spectra of the related substances. Based on the PCL reaction, a rapid and sensitive method for the determination of chloramphenicol was established. The linear response range was 6.0 × 10^?7–1.0 × 10^?5 mol/L, with a correlation coefficient of 0.9986. The relative standard deviation (RSD) for 5.0 × 10^?6 mol/L chloramphenicol was 2.3% (n = 11). The detection limit was 1.6 × 10^?7 mol/L. The method has been applied to the determination of chloramphenicol in pharmaceutical samples with satisfactory results. Copyright © 2011 John Wiley & Sons, Ltd.     

Reduction of iodate in iodated salt to iodide during cooking with iodine as measured by an improved HPLC/ICP–MS method

Background: Iodate is a strong oxidant, and some animal studies indicate that iodate intake may cause adverse effects. A key focus of the safety assessment of potassium iodate as a salt additive is determining whether iodate is safely reduced to iodide in food. Objective: To study the reduction of iodate in table salt to iodide and molecular iodine during cooking. Materials and Methods: Fifteen food samples cooked with and without iodated salt were prepared in duplicate. The iodine in the cooked food was extracted with deionized water. The iodine species in the extracts were determined by using an improved high-performance liquid chromatography/inductively coupled plasma–mass spectrometry (HPLC/ICP–MS). The cooking temperature and the pH of the food were determined. Results: The conversion rate of iodate in iodated salt to iodide and molecular iodine was 96.4%±14.7% during cooking, with 86.8%±14.5% of the iodate converted to iodide ions and 9.6% ±6.2% converted to molecular iodine to lose. The limit of detection, limit of quantification, relative standard deviation and recovery rate of the method HPLC/ICP–MS were 0.70 μg/L for I⁻ (0.69 μg/L for IO₃⁻), 2.10 μg/L for I⁻ (2.06 μg/L for IO₃⁻), 2.6% and 101.6%±2.6%, respectively. Conclusion: Almost all iodate added to food was converted into iodide and molecular iodine during cooking. The improved HPLC/ICP–MS was reliable in the determination of iodine species in food extracts.     

几种常用药物对锦鲤的急性中毒试验

本试验用甲醛、硫酸铜、孔雀石绿与高锰酸钾四种药物对锦鲤进行了急性试验,结果表明：甲醛24TLm32.89mg/L,48TLm32.58mg/L,安全浓度为9．59mg/L,硫酸酮24TL0.35mg/L,48TL0.30mg/L,安全浓度为0．066mg/L;孔雀石绿24TLm0.13mg/L,48TLm0.10mg/L,安全浓度为0．018mg／L ;高锰酸钾24TLm3.55mg/L,48TLm2.75mg/L安全浓度为0．50mg/L。根据实验结果,建议孔雀石绿、硫酸铜不宜作为锦鲤苗药物使用,高锰酸钾、甲醛可作为苗种药物使用。     

The development of voltage-dependent ionic conductances in murine spinal cord neurones in culture

The development of voltage-dependent ionic conductances of foetal mouse spinal cord neurones was examined using the whole-cell patch-clamp technique on neurones cultured from embryos aged 10-12 days (E10-E12) which were studied between the first day in vitro (V1) to V10. A delayed rectifier potassium conductance (Ik) and a leak conductance were observed in neurones of E10, V1, E11, V1, and E12, V1 as well as in neurones cultured for longer periods. A rapidly activating and inactivating potassium conductance (IA) was seen in neurones from E11. V2 and E12, V1 and at longer times in vitro. A tetrodotoxin (TTX) sensitive sodium-dependent inward current was observed in neurones of E11 and E12 from V1 onwards. Calcium-dependent conductances were not detectable in these neurones unless the external calcium concentration was raised 10-to 20-fold and potassium conductances were blocked. Under these conditions calcium currents could be observed as early as E11. V3 and E12, V2 and at subsequent times in vitro. The pattern of development of voltage-dependent ionic conductances in murine spinal neurones is such that initially leak and potassium currents are present followed by sodium current and subsequently calcium current.     

蔬菜吸收不同形态外源碘的动力学特性

采用水培法,研究了两种蔬菜(小白菜和芹菜)对两种不同形态碘源(I-,IO-3)的吸收和积累特性.结果表明:供试蔬菜吸收碘的速率表现为在短时间(＜60 min)内迅速增加,随着时间的延长蔬菜对碘的吸收速率逐渐下降;在低浓度范围内(0.01～0.50 mg/L)蔬菜对IO-3的吸收速率与碘浓度变化曲线符合饱和吸收动力学特征(表现为遵循酶学方程),进一步研究表明,解偶联剂2,4-二硝基苯酚(DNP)对低浓度(＜0.50 mg/L)下蔬菜IO-3吸收速率具有明显的抑制作用,说明两种蔬菜对低浓度的IO-3可能存在主动吸收,而在高浓度范围内(0.50～10.0 mg/L),蔬菜对碘的吸收速率随着碘浓度的提高呈现直线上升的趋势.两种蔬菜相比,在同样条件下芹菜对碘的吸收速率明显大于小白菜.蔬菜可食部分中碘的含量随着碘浓度的提高而增加,在一次加碘条件下表现为先增加后降低的趋势,而在持续加碘条件下蔬菜中碘的含量在整个处理期间表现为不断增加; Cl-的添加对低浓度下蔬菜碘的吸收具有明显的抑制作用,而随着碘浓度的提高Cl-的抑制作用逐渐减弱.供试蔬菜对碘的富集系数随碘浓度的提高而降低,碘在蔬菜不同器官的分配次序表现为根＞叶＞茎.     

Schistosoma mansoni: localization of calcium-detecting reagents in electron-lucent areas of specific preacetabular gland granules

In an attempt to establish the exact location of calcium within the preacetabular glands of cercariae of Schistosoma mansoni, these larvae were exposed to reagents (potassium oxalate, potassium pyroantimonate, chloranilic acid, and silver nitrate) useful in the detection of calcium, and were subsequently observed with the aid of light and electron microscopes. Cercariae incubated in potassium oxalate and viewed in polarized light showed birefringence only in the preacetabular gland funduses. At the ultrastructural level, the preacetabular glands of potassium oxalate-treated cercariae had no electron-dense precipitate, but instead had translucent, irregularly shaped inclusions, similar to spaces left by volatilized calcium oxalate as described by others. Pyroantimonate treatment, on the other hand, localized the reaction in the electron-lucent areas of the light-spotted granules. The von Kossa silver nitrate procedure destroyed the secretory granules; therefore, an electron-dense precipitate was distributed throughout the gland. However, pretreatment with chloranilic acid before fixation preserved the granules, and subsequent exposure to the von Kossa silver nitrate gave a reaction identical to that obtained with the pyroantimonate alone. When viewed in polarized light, chloranilic acid-incubated cercariae showed birefringence in the fundus and duct areas.     

An FIA biosensor system for the determination of phosphate.

A flow injection analysis (FIA) biosensor system for the determination of phosphate was constructed using immobilized nucleoside phosphorylase and xanthine oxidase and an amperometric electrode (platinum vs silver/silver chloride, polarized at 0.7 V). When a phosphate-containing sample was injected into the detection cell, phosphate reacted with inosine in the carrier buffer to produce hypoxanthine and ribose-1-phosphate in the presence of nucleoside phosphorylase. Hypoxanthine was then oxidized by xanthine oxidase to uric acid and hydrogen peroxide, which were both detected by the amperometric electrode. The response of the FIA biosensor system was linear up to 100 microM phosphate, with a minimum detectable concentration of 1.25 microM phosphate. Each assay could be performed in 5-6 min and the system could be used for about 160 repeated analyses. This system was applicable for the determination of phosphate in various food products and plasma, and the results obtained agreed well with those of the enzymatic assay.     

Flow injection chemiluminescence determination of isoniazid using the lucigenin-periodate system.

A weak chemiluminescence (CL) signal was observed during the mixing of isoniazid with lucigenin in alkaline aqueous solution. The CL signal was enhanced more than 100 times in the presence of potassium periodate. This CL system was developed for the determination of isoniazid using a flow injection mode. The CL intensity is proportional to the concentration of isoniazid in the range 0.005-1.0 mg/L. The limit of detection is 0.0034 mg/L and the relative standard deviation is 2.0% for 0.2 mg/L isoniazid solution in 11 repeated measurements. The method was applied to the determination of isoniazid in pharmaceutical preparations and satisfactory results were obtained.     

New glutathione peroxidase mimetics—Insights into antioxidant and cytotoxic activity

A series of N-alkyl benzisoselenazol-3(2H)-ones has been obtained and transformed to corresponding diselenides by the reduction with sodium borohydride. Additionally, efficient methodology for the oxidative Se–N bond formation by potassium iodate has been presented, new conversion of diselenide to benzisoselenazolone was observed. The GPx-like activity of all synthetized derivatives has been evaluated by NMR. N-Allyl diselenide was up to five times better antioxidant than ebselen. Anticancer capacity towards MCF7 and DU145 cancer cells has been also tested. The highest antiproliferative activity was obtained for N-cyclohexyl benzisoselenazolone.     

Effects of some chemical reagents on sodium current inactivation in myelinated nerve fibers of the frog.

The effect of several chemical reagents on the sodium current was studied in voltage-clamped single nerve fibers of the frog. The oxidants halazone and hypochlorous acid drastically inhibited inactivation. Their effect was similar to that of chloramine T (Wang, 1984a). The curve relating the steady-state inactivation parameter h infinity to the conditioning potential E became nonmonotonic after treatment with the oxidants, i.e., dh infinity/dE greater than 0 for E greater than -20 mV. By contrast, the oxidants periodate, iodate, and hydrogen peroxide (applied for the same time, but at higher concentrations) merely produced a parallel shift of the h infinity(E) curve to more negative values of membrane potential. Diethylpyrocarbonate, a reagent that preferentially modifies histidine groups, had one marked effect: a strong shift of the h infinity(E) curve to more negative values of membrane potential. Almost no effect was observed after application of the tyrosine-reactive reagent N-acetylimidazole. Similarly, the arginine-reactive reagent glyoxal had only minor effects on the Na permeability. The results suggest that methionine is not critically involved in the kinetics of Na current inactivation. Similarly, an essential tyrosine or arginine residue seems to be unavailable to chemical reagents from outside on the frog node of Ranvier. Deduced from the reactivities of (some of) the reagents used, modification of membrane lipids is a tentative explanation for the effects observed on inactivation kinetics.     

The kinetics of suppression of proliferation of oxidized murine lymphoid cells by sodium borohydride reduction.

Murine splenic lymphoid cells are stimulated to proliferate following mild oxidation with sodium periodate. To assess the class of cells responding, we used periodate treatment alone or in association with concanavalin A, a T-cell mitogen, or lipopolysaccharide (LPS), primarily a B-cell mitogen. Brief periodate treatment followed by culturing with concanavalin A gave no additive proliferative response to that seen using concanavalin A alone, while culturing periodate-treated cells with LPS gave approximately an additive response. Furthermore, periodate failed to stimulate spleen cells from neonatally thymectomized mice while LPS produced significant stimulation of proliferation, suggesting that periodate is stimulating a class of T lymphoid cells or a subpopulation of T cells. Studies were performed to determine an optimal concentration of borohydride which would suppress proliferation in lymphoid cells initially oxidized with periodate. It was observed that 2 mM borohydride would suppress proliferation of oxidized cells yet permit a normal response of these cells to another T-cell mitogen, concanavalin A. Higher concentrations of borohydride, from 3 to 5 mM, would also suppress proliferation of oxidized cells but would interfere with the ability of these cells to respond to concanavalin A, perhaps due to cell damage. Studies were performed to determine when it was possible to suppress periodate-induced mitogenesis by reducing with borohydride at various times after the initial oxidation. It was observed that 2 mM borohydride treatment could suppress stimulation through 8 hr after the original periodate oxidation and that from 12 hr through 20 hr after the initial periodate oxidation, borohydride was incapable of inhibiting proliferation. Additional studies demonstrate that optimal mitogenesis induced by periodate or concanavalin A is contingent upon a serum factor.     

A New Method Using a Modified Mayer's Hemalum at pH 6 for Demonstrating Mucous Neck Cells

The mucous neck cells of gastric glands were stained with a modified Mayer's hemalum adjusted to pH 6 with saturated aqueous lithium carbonate. One gram of hematoxylin was dissolved in 1000 ml distilled water and 200 mg sodium iodate, 3 g potassium alum, 50 g chloral hydrate and 1 g citric acid were added to the solution. Prior to staining, the solution was adjusted to pH 6 with saturated aqueous lithium carbonate. Bromine oxidation and urea abolished the alum hematoxylin reactivity of the mucous neck cells.