Monoiodacetic Acid Research Articles

Degradation of iopamidol by three UV-based oxidation processes: Kinetics, pathways, and formation of iodinated disinfection byproducts

In this study, the degradation kinetics of iopamidol (IPM) by three different UV-based oxidation processes including UV/hydrogen peroxide (H2O2), UV/persulfate (PDS) and UV/chlorine (NaClO) were examined and the potential formation of iodinated disinfection byproducts (I-DBPs) in these processes followed by sequential chlorination was comparatively investigated. Increasing pH led to the decrease of IPM degradation rate in UV/NaClO, while it showed negligible impact in UV/PDS and UV/H2O2. Common background constituents such as chloride ions (Cl−), carbonate (HCO3−) and natural organic matter (NOM) inhibited IPM degradation in UV/H2O2 and UV/PDS, while IPM degradation in UV/NaClO was only suppressed by NOM but not Cl− and HCO3−. The differences in transformation products of IPM treated by hydroxyl radical (HO*), sulfate radical (SO4*-), as well as Cl2*- and ClO* generated in these processes, respectively, were also analyzed. The results suggested that hydroxyl radical (HO*) preferred to form hydroxylated derivatives. Sulfate radical (SO4*-) preferred to oxidize amino group of IPM to nitro group, while Cl2*- and ClO* favored the generation of chlorine-containing products. Moreover, specific I-DBPs (i.e., iodoform (IF) and monoiodacetic acid (MIAA)) were detected in the three processes followed by chlorination. The addition of NOM had little effect on IF formation of three processes, while MIAA formation decreased in all processes except UV/H2O2. Given that the formation of I-DBPs in UV/NaClO was less than those formed in the other two processes, UV/NaClO seems to be a more promising strategy for effectively removing IPM with alleviation of I-DBPs in treated water effluents.

Reparative mechanisms in retina and hypothalamus contributing to rhodopsin recovery in rabbit eyes with retinal dystrophy

To study the molecular reparatory mechanisms of the retina and hypothalamus in the context of experimental dystrophy of receptor apparatus in rabbit retina. Retinal dystrophy was induced in rabbit eyes by injecting monoiodacetic acid (MIA) intravenously. Indirect ELISA test was used to evaluate the levels of rhodopsin, heat shock protein 70 kDa (HSP70) in the retina, and serotonin-modulating anticonsolidation protein (SMAP) - that directly correlates with serotonin level - in the hypothalamus. The 1st series of studies showed that 12 days after the administration of MIA, rhodopsin in the retina was down-regulated by 27% (p<0.001), and heat shock protein 70 kDa (HSP70) was up-regulated by 47% (p<0.001), whereas in the hypothalamus up-regulation of SMAP by 22% (p<0.01) was observed. In the 2nd series, on the 22nd day after MIA administration, significant down-regulation (by 9.5 times) of HSP70 (p<0.001) was noticed in control rabbits, though intravitreal administration of SMAP on the 15th day after MIA administration led to sharp (23 times) up-regulation of HSP70 (p<0.001) in the retina 7 days later. In the 3rd series, 7 days after intravitreal administration of inactivated SMAP, the animals getting injections of MIA had noticeable down-regulation of rhodopsin (p<0.01) in the retina. In the 4th series, 7 days after intravitreal administration of polyclonal antibodies to SMAP in the rabbits that has had MIA injections, up-regulation of rhodopsin (p<0.01) and HSP70 (p<0.01) in the retina compared with levels in the control animals (MIA and non-immune γ-globulins) was observed. The results indicate the influence of the hypothalamic serotonergic system on HSP70 level in the receptor cells of the retina. The results of the 4th series of studies also give evidence for possible feedback from the retinal cells onto hypothalamus.

Mikrobiologie pivovarské výroby - Divoké kvasinky a metody jejich detekce.

This survy is focused on the techniques of detection of wild yeasts in brewery laboratory. The experimental part of the work deals with the ability of 19 strains of culture and wild yeasts to grow on wort, hopped-wort and lysine agar, and on media containing monoiodacetic acid, crystal violet and copper sulphate. Growth of yeasts on WLN agar, on MYGP agar with actidione and on MYPG agar at 37C was also monitored. Photographs of representative colonies of yeast strains on various agar media ar presented. The practical usefulness of the media in brewery laboratory was evaluated.

Antibody to Cryptococcus neoformans capsular glucuronoxylomannan promotes expression of interleukin-12Rbeta2 subunit on human T cells in vitro through effects mediated by antigen-presenting cells.

The results reported herein show that T cells responding to encapsulated Cryptococcus neoformans cells had reduced expression of interleukin-12 receptor beta2 (IL-12Rbeta2) in comparison to those responding to non-encapsulated cells. This suggested that encapsulation with glucuronoxylomannan (GXM), the principal constituent of the C. neoformans polysaccharide antiphagocytic capsule, inhibited expression of the IL-12Rbeta2 subunit on T cells responding to cryptococcal antigens. Addition of GXM-binding monoclonal antibody (mAb) overcame this effect by promoting IL-12Rbeta2 expression and by decreasing IL-1R expression on T cells. This effect may be a consequence of mAb-induced changes on antigen-presenting cells (APC) that are closely related to increased phagocytosis. Blocking of phagocytosis with monoiodacetic acid (MIA) precluded up-regulation of B7 expression on APC and was associated with diminished IL-12Rbeta2 expression on T cells. The observed effects on T cells were interpreted as a consequence of increased APC function due to enhanced phagocytosis. These findings suggest a mechanism by which specific antibody can promote the polarization of the cellular immune response towards a Th1-like response and thus contribute to an enhanced cellular immune response against C. neoformans.

The purification and properties of a thiaminase I enzyme from nardoo ( Marsilea drummondii)

Fronds of the fern nardoo ( Marsilea drummondii) contain a thiaminase I enzyme at very high levels of activity. Highest levels of enzyme activity were found in vigorously growing plant material. The thiaminase I has been purified to a final sp act value of 2.07 μkat/mg protein at 30° and pH 6.5. It was shown to have similar properties to thiaminase I enzymes purified from bracken fern, rock fern and freshwater mussels. These enzymes have MW values in the range 93 000–115 000, energies of activation of 14 000 cal mol, pH optima of 8–9 and are quite stable in the pH range 3 to 12 and to extended incubation at 55°. The temperature for 50 % denaturation is 60–65°. p-CMB, mersalyl acid and HgCl 2 (10 t-6 M) are potent inhibitors, but monoiodacetic acid (10 −4 M) has no effect. A wide range of heterocyclic bases, sulphydryl compounds, and amines, including the non-aromatic amines 6-aminohexanoic acid and ethanolamine, act as co-substrates in the thiaminase I reaction; however, their effectiveness is dependent on both their degrees of basicity and to some extent, their stereochemistry. When the co-substrate activity of a range of substituted anilines were compared, no correlation was found between the degree to which the base activates the reaction and the p K b (or Hammett's sigma constant) of the base.

Radiosensitization by monoiodacetic acid. I. Study of the radiation sensitizing mechanism of monoiodoacetic acid

SummaryPour preciser le mecanisme de la radiosensibilisation des mammiferes par l'acide monoiodoacetique on a effectue les investigations experimentales suivantes:1. Action de l'acide monoiodoacetique sur l'effet lethal de l'irradiation totale.2. Etude histopathologique des organes de rats radiosensibilises a l'aide de l'acide monoiodoacetique.3. Variation en fonction du temps de la distribution de l'acide monoiodoacetique-131I chez les rats.4. Action de l'acide monoiodoacetique associe a la thyroxine sur l'effet lethal de l'irradiation totale.5. Incorporation de l'acide monoiodoacetique-131I chez les rats thyroxines.6. Action de l'acide monoiodoacetique sur l'incorporation des aminoacides marques au 14C (L-leucine, DL-serine et DL-phenylalanine).7. Action de la cysteine sur la toxicite de l'acide monoiodoacetique, en fonction de la dose de cysteine.8. Action de la cysteine sur l'effet radiosensibilisateur de l'acide monoiodoacetique.9. Action de l'acide monoiodoacetique sur l'activite de la catalase et d...

INVESTIGATION ON THE VESTIBULAR RECRUITMENT PHENOMENON. 2. EXPERIMENTAL OBSERVATION

The author elucidated, as described in the first report the existance of the vestibular recruitment in Meniere's disease from a number of clinical observations. In the present experiment, in order to further clarify the relationship between the realization of the vestibular recruitment and the incidence of vestibular disturbances, histological changes in the vestibular labyrinth of the rabbit were studied by means of intratympanic injections of a local anesthetic (lidocaine) and some metabolic inhibitors (FNa, KCI, CaC12 and monoiod acetic acid) or by an ultrasonic beam directed to the vestibular labyrinth.The results obtained are summarized as follows :1. The vestibular recruitments were observed in many cases which showed reversible histological changes in the labyrinth, but not in cases with irreversible changes.2. The histological changes in cases with positive vestibular recruitment were well localized in the crista ampullaris in cupula but other parts were intact.3. The histological changes in cases with negative vestibular recruitment were intensively extended to all the labyrinthine structure.4. Therefore, from both clinical and experimental observations, the author presumed that the origin of the vestidular recruitment is the disturbance of the hair cells in the peripheral cupular organ.

The effect of some enzyme poisons on the secretion of bile

Experiments were stated on albino rats and guinea pigs with a common bile duct fistula. The effect of enzymatic poisons on bile secretion, its qualitative composition and bromsulfalein (BSF) excretion were studied. Sodium fluoride monoiodacetic acid (MIA) and 2,4-dinitrophenol decrease bile secretion; 2,4-dinitrophenol has no effect on bilirubin and BSF bile excretion, whereas MIA and sodium fluoride inhibit these processes. MIA considerably reduces the bile concentration of bile acids.

Investigation of the mechanism of chemoreception

The author investigated the effect of different concentrations of monoiodacetic acid (MIA) on the reception of nicotine and acids. It was shown that during the action of MIA in weak concentration (0.0005 M) the excitability in response to both stimuli augments at first and then becomes irreversibly disturbed; the action of nicotine changes but insignificantly. Higher MIA concentrations disturb the nicotine reception as well, however, this effect is reversible. A conclusion is drawn on the existence of separate reactive systems— for nicotine and for acids, with different metabolism.

Die Wirkung von Monojodessigsäure auf Atmung und Photosynthese von Chlorella

The distribution of radioactivity after feeding labeled glucose, as well as the change of the poolsize of intermediates, in Chlorella poisoned with monoiodacetic acid (MIA), showed that triosephosphate dehydrogenase is the most sensitive Enzyme in respiration. MIA leads to a large accumulation of fructose diphosphate (FDP) and a large decrease in phosphoglyceric acid (PGA). Also, the breakdown of glucose via 6-phospho-gluconate is inhibited by MIA, as shown by the small change of the C1/C6 ratio. FDP piles up during MIA poisoning in the dark and is quickly transformed to ribulose diphosphate (RuDP), in the light; subsequently, RuDP is transformed to PGA and its derivatives (pyruvate and other acids) by carboxylation and hydrolysis of the ketoacid. Thus, a third pathway of glucose breakdown, by passing glycolysis and the 6-phosphogluconate pathway, is induced by MIA in the light. The photosynthetic CO2 assimilation of Chlorella is about 100 fold more sensitive toward MIA than respiration. By feeding labeled CO2 and determining the concentration of the intermediates formed during MIA poisoning in the light, it is found that, in contrast to the behavior of broken chloroplasts, the reduction of the fixed CO2 is the most sensitive reaction of photosynthesis in Chlorella, rather than the formation of RuDP. It is assumed that the energy-rich phosphate formed in the light may be used for a relatively MIA-insensitive reaction leading to the formation of RuDP, and that the carboxylated RuDP is directly reduced to sugar by a highly ΜΙΑ-sensitive reaction. Hydrolysis to PGA occurs only if the reduction of the ketoacid proceeds too slowly, i. g., during MIA-inhibition.

Ca-EDTA知見補遺 : 2 pbと結合した赤血球及びpbを除去した赤血球の変化について

Studies on combination of erythrocytes with lead were made physically or chemically through hemolysis. Normal erythrocytes (A), erythrocytes bound with lead (B), and erythrocytes whose bound lead was removed with Ca-EDTA (C) were respectively hemolysed by the use of hypotonic saline solution, saponin, monoiodacetic acid, heat, and ultrasonic wave for comparative studies of their behavior to the hemolytic factors. (A) consisted of normal human erythrocytes rinsed with physiological saline solution and suspended in physiological saline solution at a rate of 2%; (B) was prepared by putting 5×10-4 M of Pb into (A); and (C) was obtained by adding into (B) Ca-EDTA twice the equivalent of Pb. 1) Resistance to hypotonic saline solution was the highest in (A), followed in order by (C) and (B). 2) Resistance to saponin was the highest in (A), followed in order by (B) and (C). As a result of the removal of Pb, the recovery of resistance was not observed. 3) Erythrocytes bound with lead showed remarkably increased resistance to the hemolytic activity of monoiodacetic acid; and the resistance was lost following the removal of Pb. 4) Erythrocytes bound withlead as well as Pb-freed erythrocytes were more apt to undergo hemolysis by heat. 5) Hemolysis by ultrasonic wave showed no difference among three. The above findings suggest that Pb has the greatest effect upon the blood cell membrane. The results of the experiments with saponin and monoiodacetic acid indicate that the combination between Pb and blood cell membrane is a chemical phenomenon, suggesting the presence of a close relationship of Pb with lipoid and SH groups of protein in the cell menbrane. The combination velocity of Pb with erythrocytes is very high. However, the effect of the above binding does not appear so soon, and becomes increasingly noted with the lapse of time.

On the bioenergetics of bile secretion

Experiments were performed on animals with fistula of the common bile duct and on isolated liver with fistula of the gall bladder. It was established with the aid of enzyme poisons (sodium cyanide, sodium fluoride, monoiodacetic acid, 2,4-dinitrophenol, sodium arsenate) that tissue respiration of liver and oxidative phosphorylation connected with it are the main origins of energy in bile secretion.

The Increase of Methyl Glyoxal=like Substance and the Change of Arakawa's Reaction in Rabbits' Milk on an Administration of Monoiod=acetic Acid; Recovery through Vitamin B&lt;sub&gt;1&lt;/sub&gt; and Yakriton

As stated above, all the 4 rabbits used showed methyl glyoxal like substance in the milk, which showed a certain decrease (up to 2.0 mgrms. %) on a subcutaneous use of vitamin B, until the qualitative tests became negative. When monoiodacetic acid was subcutaneously injected, the methyl glyoxal like substance increased gradually, which was proved both quantitatively and qualitatively. Arakawa's reac-tion became weaker and weaker, as the substance increased. Body weight showed a decrease. These changes due to monoiodacetic acid were recovered by vitamin B1 alone when they were of a light degree (as in Rabbit 2), but, when they were of a serious degree (as in Rabbits 3 and 4), only a combined use of yakriton and vitamin B1 was able to improve the condition. It is to be remarked here, especially because Geiger and Rosenberg10) reported that an administration of vitamin B caused a temporary increase of methyl glyoxal in urine of B-avitaminotic dogs, that temporary increase of methyl glyoxal like substance soon after the use of vitamin B1 was seen in the rabbit's milk (Cf. Rabbits 2 and 3) in my own experiment.

Effect of Bromcaproic Acid on Rat Sarcoma 39

Respiration in tumor cells is characterized by marked aerobic glycolysis, as shown by Warburg (1). Crabtree (2), Dickens (3), and others have observed, moreover, that aerobic glycolysis is a manifestation not only of malignant growth but of abnormal cellular proliferation generally. Warburg has suggested that there can be no growth in the absence of glycolysis, and that if this is inhibited or reduced to normal, the riotous proliferation of tumor cells ceases. Numerous attempts have been made, therefore, to suppress glycolysis in these cells. The halogen derivatives of certain fatty acids have been found to inhibit glycolysis of both normal and cancerous tissues. Lundsgaard (4) showed that muscle poisoned with monoiodacetic acid contracts without producing lactic acid, while Haarmann (5) observed that monobromacetic acid in exceedingly low concentrations (as low as 1:4000) inhibits lactic acid formation from glucose in muscle, brain, and liver, but not from glycogen. Brisou (6) found that the addition of a mixture of halogen acids to the diet of rats, or the injection of an ester of either monoiodacetic or monobromacetic acid decreases glycolysis in the tissues by 70 per cent or more. In in vitro experiments, this author found that monoiodacetic or monobromacetic acid inhibits glycolysis of tumors at concentrations of N/2000.