Treatment of Cresol, Phenol and Formalin using Fixed-film Reactors

The degradability of phenol, cresol and formalin, separately or in mixtures, was studied in a laboratory-scale, submerged fixed-film reactor and in a prototype trickling-tower plant with recirculation of aerated effluent. The rates of degradation could be increased by 10–15 times by acclimating the reactors to increasing concentrations of disinfectants in the feed increasing daily from 10 to 1000 mg/1. After acclimation, detectable levels of disinfectants were only found in the liquor of the batch-operated fixed-film reactor after 24 h when the concentration of the daily dose exceeded 1100–1500 mg/1 and in the continuously-fed trickling tower plant, when the feed concentration exceeded 1500 mg/1. It was possible in the reactor to treat cresol efficiently after acclimation to formalin and vice versa. Acclimation was shown to reduce diversity of bacterial species, the dominant isolates being Pseudomonos aeruginosa and other pseudomonads.     

Methylmalonic Acid and Homocysteine as Indicators of Vitamin B-12 Deficiency in Cancer

Background/Aims

Normal or high serum vitamin B-12 levels can sometimes be seen in a B-12 deficient state, and can therefore be misleading. High levels of Methymalonic Acid (MMA) and Homocysteine (HC) have been identified as better indicators of B-12 deficiency than the actual serum B-12 level itself. We evaluated the prevalence of vitamin B-12 deficiency using appropriate cut-off levels of vitamin B-12, MMA and HC, and determined the relationship between serum levels of vitamin B-12, MMA and HC in cancer.

Methods

This is a cross-sectional study using a consecutive case series of 316 cancer patients first seen at Cancer Treatment Centers of America^® (CTCA) at Midwestern Regional Medical Center between April 2014 and June 2014. All patients were evaluated at baseline for vitamin B-12 (pg/mL), MMA (nmol/L) and HC (μmol/L) levels. In accordance with previously published research, the following cut-offs were used to define vitamin B-12 deficiency: <300 pg/mL for vitamin B-12, >260 nmol/L for MMA and >12 μmol/L for HC. The relationship between B-12, MMA and HC was evaluated using Spearman''s rho correlation coefficient and cross-tabulation analysis. Receiver Operating Characteristic (ROC) curves were estimated using the non-parametric method to further evaluate the diagnostic accuracy of vitamin B-12 using Fedosov quotient as the "gold standard".

Results

Mean age at presentation was 52.5 years. 134 (42.4%) patients were males while 182 (57.6%) were females. Median vitamin B-12, MMA and HC levels were 582.5 pg/mL, 146.5 nmol/L and 8.4 μmol/L respectively. Of 316 patients, 28 (8.9%) were vitamin B-12 deficient based on vitamin B-12 (<300pg/mL), 34 (10.8%) were deficient based on MMA (>260 nmol/L) while 55 (17.4%) were deficient based on HC (>12 μmol/L). Correlation analysis revealed a significant weak negative correlation between vitamin B-12 and MMA (rho = -0.22) as well as B-12 and HC (rho = -0.35). ROC curves suggested MMA to have the best discriminatory power in predicting B-12 deficiency.

Conclusion

Vitamin B-12 is poorly correlated with MMA and HC in cancer. Using serum vitamin B-12 alone to evaluate B-12 status in cancer may fail to identify those with functional deficiency. A thorough clinical assessment is important to identify patients that may have risk factors and/or symptoms suggestive of deficiency. These patients should have additional testing of MMA and HC regardless of their B-12 levels.     

Cyanide Insensitive Respiration of Sporobolomyces Red Yeast

The respiration of a Sporobolomyces red yeast is investigated with intact cells. The results show that the respiration is not inhibited at all, but moderately accelerated by cyanide and CO. Although the chemical nature of this fact is not yet clarified, the existence of a heat-labile and cyanide-insensitive oxidative enzyme system in this yeast is presumable.     

Growth and Respiration in Plants from Various Adaptation Groups as Affected by Mineral Nutrient Deficiency

The effect of the deficiency in mineral nutrients was investigated in plant species representing various adaptation groups (stress-tolerant, competitive, and ruderal plants). Dry and fresh weight, as well as the length of shoots and underground organs, were determined in 20- to 50-day-old seedlings. The ratio between the dry weights of shoot and root (SRR), relative growth rate (RGR), the rate of total dark respiration (R), gross photosynthesis (P _g), and the proportion of the respiratory expenditures to gross photosynthesis (R/P _g) were calculated. When affected by a deficiency in mineral nutrients, the weight of the whole plant decreased. In resistant species of clover (Trifolium pratense L.) and alfalfa (Medicago sativa L.), this reduction was insignificant, whereas, in the ruderal species amaranth (Amaranthus retroflexus L.), it was at its highest. In all the species investigated, the ratio R/P _g was 38–46%. Under stress conditions, this index increased. Given a deficiency in mineral nutrients, the changes in SRR, RGR, and R/P _g were greater in amaranth, suggesting that this plant species is less tolerant to stress. The correlation between RGR and R observed in amaranth under normal conditions indicates that the major energy expenditures are associated with growth. Under stress conditions, such a correlation was not observed. In more resistant species of clover and alfalfa, a weak positive correlation between RGR and R was observed both under normal and stress conditions. In these species, the deficiency in mineral nutrients probably brought about a reduction in the growth component of total dark respiration and a rise in the adaptation component. The complex of indices (R/P _g, RGR, and SRR) and the extent of their variation in the seedlings describe the potential productivity and resistance of particular species to a deficiency in mineral nutrients and may characterize the adaptation type of the plants.     

Inhibition of Respiration of Yeast by Photosynthesis Inhibiting Herbicides

In order to elucidate the mode of action of some herbicides, effect of several anilide type herbicides on the respiration of yeast cells was studied. The results obtained were as follows: 1) DCPA (3,4-dichloropropionanilide) and DCMU (3-(3,4-dichlorophenyl)-1,1- dimethylurea), the powerful inhibitors of the Hill reaction in photosynthesis, inhibited the oxygen uptake of yeast cells at low concentrations. 2) DCPA and DCMU inhibited the enzymic reduction of cytochrome-c by the yeast cell-free preparation, but not the reduction of dye. 3) The oxidation of cytochrome-b was inhibited in the yeast cells treated with DCPA or DCMU.     

The Action of Nitrophenols on Respiration and on Glucose Assimilation in Yeast

The consumption of 2·25 mg. glucose by a resting suspensionof baker's yeast in the presence of finely graded concentrationsof 3:5 -dinitro-o-cresol was followed at pH 2·4 and 5·0by measuring oxygen uptake and carbon-dioxide output; at pH8·5 oxygen uptake alone was measured. At each pH certainconcentrations of dinitrocresol stimulated respiration and increasedthe ratio of glucose oxidized to glucose assimilated; at higherconcentrations, assimilation was reduced to zero, but respirationbecame inhibited and the whole of the glucose was then metabolizedby aerobic fermentation. Dinitrocresol is believed to be actingin these experiments as an uncoupling agent, lowering the netrate of formation of energy-rich phosphate and so allowing respirationto proceed faster while assimilation, an endergonic process,is inhibited. The maximum respiratory stimulation obtainable at pH 8·5,325 per cent, of the control, is greater than can be obtainedat pH 2·6 or 5·0, which may be due to the slowerrespiration rate of controls at pH 8's. The slow endogenousrespiration can also be stimulated more than the exogenous.With o- and p-nitrophenols similar relations are obtained, butphenol does not stimulate respiration, although it inhibitsassimilation in lower concentrations than respiration. Undernitrogen, a stimulation of fermentation can be obtained withdinitrocresol at pH 5·0 but not at 2·6. At bothpH levels, assimilation is more easily suppressed than fermentationrate.     

肾阳虚生化指标的现代研究进展

肾阳虚证是一种虚寒证候,其病因主要为肾阳虚衰、肾脏温煦、气化功能下降等,常见于西医的慢性肾炎、肾上腺皮质功能减退、慢性前列腺炎、肾病综合证等慢性虚弱性疾病。它作为中医理论体系中的重要证候之一,已有几十年的研究历史。在该证的动物模型、作用机理、基因表达、代谢组学等研究中,曾采用下丘脑-垂体-靶线轴功能、免疫系统、肾功能、能量代谢、环核苷酸、核苷酸系统变化、自由基代谢、细胞信号系统、特殊蛋白功能等作为主要评价指标。但尚未有公认、规范的肾阳虚生化指标评判标准。本文以肾阳虚生化指标为分类依据,全面总结以不同生化指标为检测依据的肾阳虚症的相关研究情况,为今后肾阳虚症的深入研究提供一定的参考。笔者认为代谢组学以先进分析检测技术结合模式识别等分析方法,对生物体内代谢物进行定量分析,可以有效提高诊断的科学化、定量化,避免人为主观因素的干扰和不确定性,可以为证候标准化的研究提供一种可行的方法。     

Brilliant Blue as an alternative dye to Fast Green for in ovo electroporation

Chick embryo electroporation is a powerful tool for the introduction of transgenes into tissues of interest for the study of developmental biology. This method often uses Fast Green to visualize the injected area by staining the solution containing DNA green. Here, we show that Fast Green fluoresces in a red color after electroporation, suggesting that researchers need to be cautious when detecting red fluorescence. Fast Green solution did not show any fluorescence before injection into chick embryos, but fluoresced red within 3 min post-injection into chick embryos. We identified Brilliant Blue as suitable alternative dye for use as an indicator of injection sites in ovo electroporation. We found that 0.2% of Brilliant Blue was sufficient to track the area of DNA injection. In addition, this chemical did not show red fluorescence after electroporation. Our findings demonstrate that Brilliant Blue can be used for detecting red fluorescent proteins introduced into chick embryos by electroporation. Our study also shows useful examples for the application of Brilliant Blue for the precise quantification of two fluorescence intensities after EGFP and mCherry co-electroporation.     

Interactions between Photosynthesis and Respiration in the Green Alga Chlamydomonas reinhardtii (Characterization of Light-Enhanced Dark Respiration)

The rate of respiratory O2 consumption by Chlamydomonas reinhardtii cell suspensions was greater after a period of photosynthesis than in the preceding dark period. This "light-enhanced dark respiration" (LEDR) was a function of both the duration of illumination and the photon fluence rate. Mass spectrometric measurements of gas exchange indicated that the rate of gross respiratory O2 consumption increased during photosynthesis, whereas gross respiratory CO2 production decreased in a photon fluence rate-dependent manner. The rate of postillumination O2 consumption provided a good measure of the O2 consumption rate in the light. LEDR was substantially decreased by the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea or glycolaldehyde, suggesting that LEDR was photosynthesis-dependent. The onset of photosynthesis resulted in an increase in the cellular levels of phosphoglycerate, malate, and phosphoenolpyruvate, and a decrease in whole-cell ATP and citrate levels; all of these changes were rapidly reversed upon darkening. These results are consistent with a decrease in the rate of respiratory carbon flow during photosynthesis, whereas the increase in respiratory O2 consumption during photosynthesis may be mediated by the export of photogenerated reductant from the chloroplast. We suggest that photosynthesis interacts with respiration at more than one level, simultaneously decreasing the rate of respiratory carbon flow while increasing the rate of respiratory O2 consumption.     

Cryptochrome as a Sensor of the Blue/Green Ratio of Natural Radiation in Arabidopsis

Green light added to blue light has been proposed to shift cryptochromes from their semireduced active form to the reduced, inactive state. Whether the increased proportion of green light observed under leaf canopies compared to open places reduces cryptochrome-mediated effects remained to be elucidated. Here we report that the length of the hypocotyl of Arabidopsis (Arabidopsis thaliana) seedlings grown under controlled conditions decreased linearly with increasing blue/green ratios of the light within the range of ratios found in natural environments. This effect was stronger under higher irradiances. We developed a model, parameterized on the basis of field experiments including photoreceptor mutants, where hypocotyl growth of seedlings exposed to different natural radiation environments was related to the action and interaction of phytochromes and cryptochromes. Adding the blue/green ratio of the light in the term involving cryptochrome activity improved the goodness of fit of the model, thus supporting a role of the blue/green ratio under natural radiation. The blue/green ratio decreased sharply with increasing shade by green grass leaves to one-half of the values observed in open places. The impact of blue/green ratio on cryptochrome-mediated inhibition of hypocotyl growth was at least as large as that of irradiance. We conclude that cryptochrome is a sensor of blue irradiance and blue/green ratio.The extension growth of the hypocotyl is strongly regulated by light signals (Chen et al., 2004). If a seed germinates beneath the soil, hypocotyl extension growth proceeds in darkness at a maximum rate and this reduces the time needed by the apex and the cotyledons to emerge from the soil. The rate of extension growth decreases when the upper region of the hypocotyl becomes exposed to light. A refined adjustment of hypocotyl length is important because if it is too short the foliage can be easily covered even by weak disturbances of the soil and if the hypocotyl is too long the shoot can be damaged by the excessive exposure to wind impact (Casal et al., 1994).Hypocotyl growth in Arabidopsis (Arabidopsis thaliana) is controlled mainly by the red and far-red photoreceptors phytochrome A (phyA) and B (phyB; Quail et al., 1995) and the blue UV-A photoreceptors cryptochromes 1 (cry1) and 2 (cry2; Cashmore et al., 1999). The length of the hypocotyl is largely unaffected by light in the phyA phyB cry1 cry2 quadruple mutant of Arabidopsis (Mazzella et al., 2001). Phototropins (Briggs and Christie, 2002) exert a more transient control of hypocotyl growth (Folta and Spalding, 2001). Genetic experiments have revealed a significant dependency of the action of one photoreceptor on the presence of the others. Under suboptimal light conditions, phyB and cry act synergistically (Casal and Mazzella, 1998; Hennig et al., 1999), allowing the inhibition of hypocotyl growth to persist during the night (Sellaro et al., 2009). Under red light, phyA negatively regulates phyB signaling (Cerdán et al., 1999). In the Landsberg erecta background, inhibition of hypocotyl growth by cry2 requires the presence of phyA and phyB and the absence of cry1 (Mazzella et al., 2001). These interactions operate under natural radiation not filtered by leaf canopies or layers of soil (Mazzella and Casal, 2001), where the ratio between red light and far-red light is approximately 1.1. However, the selective absorption of red light compared to far-red light by photosynthetic pigments of green canopies (Holmes and Smith, 1977b) or by soil layers (Mandoli et al., 1990) can also reduce the red/far-red ratio. The quantitative impact of changes in the red/far-red ratio on the action and interactions of phyA and phyB remains largely unexplored.A number of responses to green light have been reported in the literature (Folta and Maruhnich, 2007). In particular, the flavin chromophore of cry is in the oxidized state in darkness, is driven to the semireduced form by blue light, and this semireduced form is shifted to the reduced state by the absorption of green light, because green light is particularly absorbed by the neutral semiquinone form of FAD (Banerjee et al., 2007; Bouly et al., 2007). Since the biologically active form is that in the semireduced state, green light is able to counteract cry-mediated effect of blue light in vivo (Banerjee et al., 2007; Bouly et al., 2007). The potential role of these green-light effects under natural radiation remains to be elucidated.The aim of this article is (1) to generate a database of hypocotyl length and light environment for a series of conditions under natural radiation, (2) to use this information to produce a model and analyze the contribution of each photoreceptor and their interactions under shadelight, and (3) to test the role of cry-mediated effects of green light under natural radiation.     

Heat Shock–Induced Changes in the Respiration of the Yeast Saccharomyces cerevisiae

The incubation of Saccharomyces cerevisiaeat elevated temperature (45°C) stimulated the respiration of yeast cells and decreased their survival rate. The respiration-deficient mutant of this yeast was found to be more tolerant to the elevated temperature than the wild-type strain. At the same time, the cultivation of the wild-type strain in an ethanol-containing medium enhanced the respiration, catalase activity, and thermotolerance of yeast cells, as compared with their growth in a glucose-containing medium. It is suggested that the enhanced respiration of yeast cells at 45°C leads to an intense accumulation of reactive oxygen species, which may be one of the reasons for the heat shock–induced cell death.     

Glutathione Deficiency Leads to Riboflavin Oversynthesis in the Yeast Pichia guilliermondii

The Pichia guilliermondii GSH1 and GSH2 genes encoding Saccharomyces cerevisiae homologues of glutathione (GSH) biosynthesis enzymes, γ-glutamylcysteine synthetase and glutathione synthetase, respectively, were cloned and deleted. Constructed P. guilliermondii Δgsh1 and Δgsh2 mutants were GSH auxotrophs, displayed significantly decreased cellular GSH+GSSG levels and sensitivity to tert-butyl hydroperoxide, hydrogen peroxide, and cadmium ions. In GSH-deficient synthetic medium, growths of Δgsh1 and Δgsh2 mutants were limited to 3–4 and 5–6 cell divisions, respectively. Under these conditions Δgsh1 and Δgsh2 mutants possessed 365 and 148 times elevated riboflavin production, 10.7 and 2.3 times increased cellular iron content, as well as 6.8 and 1.4 fold increased ferrireductase activity, respectively, compared to the wild-type strain. Glutathione addition to the growth medium completely restored the growth of both mutants and decreased riboflavin production, cellular iron content, and ferrireductase activity to the level of the parental strain. Cysteine also partially restored the growth of the Δgsh2 mutants, while methionine or dithiothreitol could not restore the growth neither of the Δgsh1, nor of the Δgsh2 mutants. Besides, it was shown that in GSH presence riboflavin production by both Δgsh1 and Δgsh2 mutants, similarly to that of the wild-type strain, depended on iron concentration in the growth medium. Furthermore, in GSH-deficient synthetic medium P. guilliermondii Δgsh2 mutant cells, despite iron overload, behaved like iron-deprived wild-type cells. Thus, in P. guilliermondii yeast, glutathione is required for proper regulation of both riboflavin and iron metabolism.