Methanol Levels Research Articles

Metabolic changes in 1-methylcyclopropene (1-MCP)-treated ‘Empire’ apple fruit during storage

‘Empire’ apple fruit are more susceptible to flesh browning at 3.3°C if treated with 1-methylcyclopropene (1-MCP), an inhibitor of ethylene perception. To better understand the metabolic changes associated with this browning, untargeted metabolic profiling with partial least squares analysis has been used to visualize changes in metabolic profile during hypoxic controlled atmosphere (CA) storage, ethylene insensitivity, and disorder development. Overall, most carbohydrates and organic acids were not appreciably affected, but the levels of amino acids and volatile metabolites were significantly affected, by 1-MCP treatment. Sorbitol and levels of some amino acids were elevated towards the end of storage in 1-MCP treated fruit. CA storage reduced the levels of many volatile components and 1-MCP reduced these levels further. Additionally multiple metabolites were associated with the development of flesh browning symptoms. Unlike other volatile compounds, methanol levels gradually increased with storage duration, regardless of 1-MCP treatment, while 1-MCP decreased ethanol production. Results reveal metabolic changes during storage that may be associated with development of flesh browning symptoms.

Microwave spectroscopy of methanol between 248 and 277 THz

Methanol is the prototypical intermediate C3V barrier to the internal rotation molecule. It is also one of the primary sources of line confusion in the interstellar medium where it is observed in a variety of regions with temperatures approaching room temperature in the more extreme cases. Recently, a fairly comprehensive rotational study of methanol was performed that analyzed the available data to J=30 in the first three torsional states with a rho axis method (RAM) Hamiltonian. The availability of a new frequency source covering 2.48 to 2.77 THz offered a unique opportunity to rigorously test the ability of the RAM Hamiltonian model in extrapolation in both J and K quantum numbers and an opportunity to confirm a number of newly assigned methanol levels. It also facilitated a unique opportunity for a direct comparison of results obtained with a frequency multiplier, Fourier transform infrared, laser sideband, tunable far infrared, and quantum cascade lasers at terahertz frequencies. The spectrum of methanol is presented and assigned for the 2.48-2.77 THz band. Lines in the first four torsional states are identified and compared to predictions of the RAM model for the first three torsional states and available energy levels for the vt=3 state. A number of previously unidentified subbands are assigned for the first time, providing some unique insight into the difficulties of extrapolating with a rho axis C3V internal rotation Hamiltonian.

An unusual case of homicide by chronic methanol poisoning

An unusual case of homicide by chronic methanol poisoning is presented. A 37-year-old man with a month-long illness of intermittent nausea, vomiting, and shortness of breath presented in the emergency department with severe gastrointestinal pain, diaphoresis, tachycardia, metabolic acidosis, and tachypnea with labored breathing. Stat toxicology testing disclosed a serum methanol level of 750 mg/l. Despite appropriate medical treatment the patient developed multi-organ failure and died. The investigation revealed that bottles of a sport drink ingested regularly by the victim and prepared by a family member were the source of the methanol. The family member was convicted of murder. The use of methanol as an agent for murder is extremely rare.

Conductive polymer gas sensor for quantitative detection of methanol in Brazilian sugar-cane spirit

A low-cost chemiresistive gas sensor is described, made by the deposition of a thin film of a conductive polymer, poly(2-dodecanoylsulfanyl-p-phenylenevinylene), doped with dodecylbenzenesulfonic acid (10%, w/w), onto interdigitated electrodes. The sensor exhibits linear electrical conductance changes in function of the concentration of methanol present in sugar-cane spirit in the range between 0.05% and 4.0%. Since the sensor is cheap, easy to fabricate, durable, presents low power consumption, and is not sensitive to ethanol, acetic acid or water, it can be used in portable equipments for monitoring methanol levels in distilled alcoholic beverages such as Brazilian sugar-cane spirit (cachaça).

Nutritional and feeding value of crude glycerin for poultry. 1. Nutritional value of crude glycerin

Glycerin is the main by-product of biodiesel production and it has been speculated that it may be a good energy source in poultry diets. However, knowledge is limited on the nutritional value of crude glycerin. Thus, the objective of this study was to determine the nutritional and chemical characteristics of various glycerin samples from diverse production facilities. Seven samples of crude glycerin from an array of biodiesel producers were analyzed for gross energy and TMEn. Ten crude glycerin samples were analyzed for glycerol, methanol, nutritional, and mineral composition. Considerable variation was found in the composition of the crude glycerin samples. The gross energy ranged from 3,337 to 6,742 kcal/kg, with a mean of 4,648 kcal/kg, and TMEn ranged from 2,950 to 6,711 kcal/kg, with a mean of 4,206 kcal/kg. Mean concentration values for glycerol, methanol, moisture, fat, salt, and ash were 63.7, 1.33, 18.2, 8.1, 2.19, and 4.35%, respectively. Phosphorus was the highest mineral component, with an average of 0.1% in the crude glycerin samples, and the average calcium, potassium, copper, zinc, iron, magnesium, and manganese levels were 328, 2,090, 3.20, 5.21, 18.6, 43.6, and 1.26 ppm, respectively. The range in glycerol, methanol, moisture, fat, salt, and potassium levels were from 34.2 to 86.1%, from 0.01 to 3.10%, from 7.85 to 34.9%, from 0.01 to 30.0%, from 0.01 to 4.21%, and from 120 to 11,200 ppm, respectively. Based on the variation observed among samples, we suggest that confirmatory analyses be conducted before using any crude glycerin product in poultry diets.

Misconceptions About the Safety of Ingesting Methanol-Based Solid Fuels

To the Editor: Consumption of nonbeverage ethanols, such as hand-sanitizers, mouthwash, hairspray, aftershave lotion, cold remedies, and fuel, for the purpose of intoxication has been reported in the literature.1 Consumption of nonbeverage alcohols, such as ethylene glycol, isopropanol, and methanol, has also been reported, although the majority of such instances occur in the context of accidental ingestions by children.2 Of those individuals ingesting methanol intentionally, a significant portion do so for the purposes of a suicide attempt.3 We present here a case of a man who intentionally ingested methanol-based fuel for intoxication due to his erroneous belief that such fuels are harmless. Case report. Mr A, a 50-year-old white man with a history of alcohol dependence and no other significant medical history, presented to a general hospital in 2009 with complaints of blurred vision, nausea and vomiting, headaches, and difficulty walking that had worsened over the previous several days. On examination, he was found to be in profound metabolic acidosis with an anion gap, a negative serum ethanol level, and a serum methanol level of 89 mg/dL. Neurologic examination showed almost complete blindness in both visual fields, bilaterally nonreactive pupils, and no blink to threat. Computed tomography scan of the head showed bilateral hemorrhagic putaminal infarcts. He received fomepizole and 2 courses of hemodialysis for presumed methanol ingestion. Upon further questioning, the patient admitted he had ingested several cans of methanol fuel, identified as FancyHeat Methanol Blue with methanol content of 70%. He admitted to knowing he was ingesting methanol, but did not believe the warnings printed on the label based on his prior experiences with other solid fuels. He denied that the ingestion was a suicide attempt. He remained almost completely blind during the hospital stay, and his vision loss was likely to be permanent according to the neurology consultant. While most intentional methanol ingestions appear to be due to inhalation of volatile vapors, consumption of solid fuels for the purpose of intoxication has also been noted in the literature.4 The patient was aware of the dangers of consuming methanol, but was under the mistaken belief that consuming canned fuels (even those containing methanol) is not dangerous, based on his prior episodes of nonbeverage alcohol or nonbeverage ethanol consumption. Some brands of solid fuel, sold for chafing dishes or camping stoves, are composed almost entirely of ethanol (Sterno), while others contain mostly methanol (FancyHeat). Although ethanol-based solid fuels are “denatured” and contain small quantities (3%–4%) of methanol, ingestion rarely leads to methanol toxicity because ethanol will competitively inhibit the bioactivation of methanol by alcohol dehydrogenase.5 Therefore, his prior experiences with ethanol-based solid fuels likely did not result in significant problems, leading him to believe in the safety of alcohol-based solid fuels. This case illustrates how such an erroneous belief can lead to devastating effects. Clinicians should correct any misconceptions patients have about the toxicity of nonbeverage alcohols and nonbeverage ethanols and provide education when appropriate.

Evaluation of a method to measure long term cortisol levels

Introduction Elevated levels of cortisol are known to induce various symptoms and diseases, e.g. abdominal obesity, type 2 diabetes, osteoporosis and cardiovascular disease. Measuring serum, saliva and urine cortisol is limited to one time point. Measurement of cortisol in scalp hair is a recently developed method to measure long term cortisol levels. The aim of this study was to investigate whether hair cortisol is a feasible parameter to measure cortisol exposure. Experimental We collected hair samples of 195 healthy individuals, 9 hypercortisolemic and one hypocortisolemic patient and measured hair cortisol levels. Cortisol was extracted from scalp hair using methanol and cortisol levels were measured using a salivary ELISA kit. Measurement of waist and hip circumferences and blood pressure was performed in 46 healthy subjects. Results We found a positive correlation between hair cortisol and both waist circumference ( r = 0.392, p = 0.007) and waist-to-hip ratio (WHR) ( r = 0.425, p = 0.003). No correlations were found between hair cortisol levels and BMI, blood pressure or age. There was no decline in cortisol levels in six consecutive hair segments. Hair cortisol levels were elevated in patients with known hypercortisolism ( p < 0.0001). Conclusions Hair cortisol was positively correlated with WHR, suggesting that hair cortisol reflects cortisol exposure at tissue level, which was also supported by elevated hair cortisol levels in hypercortisolemic patients and concordance between hair cortisol levels and clinical disease course. Cortisol levels in hair are slightly influenced by hair treatment but not by natural hair colour, use of hair products, gender or age.

Is elevated creatinine a reliable marker for methanol toxicity in nitromethane-containing model fuel ingestions in children?

Context. In the absence of a rapid serum methanol level estimation, it is difficult to assess the risk from unintentional childhood ingestion of model fuels containing methanol and nitromethane (MFNM). Previous reports have documented false elevations of serum creatinine from the nitromethane in these fuels, suggesting its utility as a readily available marker of significant methanol ingestion. Method. We performed a 2-year retrospective chart review of cases of ingestion of MFNM in children, with both a methanol level and measured creatinine level. Results. Seven children, ages 19 months to 3 years, ingested MFNM. All seven children were seen in a hospital and had measured methanol and creatinine levels. All blood samples for methanol and creatinine were drawn within 3 hours of ingestion with methanol estimation delayed up to 24 hours. Creatinine ranged from 0.39 (0.034 mmol/l) to 10.7 mg/dl (0.95 mmol/l). All methanol levels were <10 mg/dl (0.31 mmol/l) or reported as negative. Fomepizole was initiated empirically in two patients due to delay in obtaining methanol analysis results. Discussion. Transient elevations of creatinine occurred in five of the seven children. Blood urea nitrogen was within normal limits, and there was no history of renal impairment in these children, suggesting the elevated creatinine was mostly related to nitromethane ingestion. No child had a significantly elevated methanol level. Conclusion. Elevated creatinine level, as measured by Jaffe colorimetric method, is not a reliable marker for elevated methanol levels after unintentional ingestion of MFNM.

Determination of residual solvents in 7-amino-3-chloro cephalosporanic acid by gas chromatography

To develop a gas chromatography method for determination of residual solvents in 7-amino-3-chloro cephalosporanic acid (7-ACCA). The residual levels of acetone, methanol, dichloromethane, ethyl acetate, isobutanol, pyridine and toluene in 7-ACCA were measured by gas chromatography using Agilent INNOWAX capillary column (30 m × 0.32 mm,0.5 μm). The initial column temperature was 70° maintained for 6 min and then raised (10°C/min) to 160°C for 1 min. Nitrogen gas was used as carrier and FID as detector. The flow of carrier was 1.0 ml/min, the temperature of injection port and detector was 200°C and 250°C, respectively. The limits of detection for acetone, methanol, dichloromethane, ethyl acetate, isobutanol, pyridine, toluene in 7-ACCA were 2.5 μg/ml, 1.5 μg/ml, 15 μg/ml, 2.5 μg/ml, 2.5 μg/ml, 2.5 μg/ml and 11 μg/ml, respectively. Only acetone was detected in the sample, and was less than the limits of Ch.P. The method can effectively detect the residual solvents in 7-ACCA.

Letter to the Editor: A Case of Optic Nerve Atrophy with Severe Disc Cupping after Methanol Poisoning

Dear Editor, We read with great interest the interesting case report titled 'A case of optic nerve atrophy with severe disc cupping after methanol poisoning' presented by Yong Woon Shin and Ki Bang Uhm published in the last issue of Korean Journal of Ophthalmology [1]. In the description of the case, the authors mentioned that the patient had metabolic acidosis and mildly elevated methanol levels at presentation; however, only conservative therapy was performed. It seems that the patient was in the acute phase of methanol toxicity at presentation and antidotal therapy (fomepizole or ethanol in association with hypertonic sodium bicarbonate, folic or folinic acid, and even hemodialysis) should have been initiated. Was the patient managed in the ophthalmology department or was he transferred to a clinical toxicology unit for treatment? Were corticosteroids or other treatment modalities initiated for the treatment of his visual disturbance? We would like to ask the authors if the conservative therapy consisted of these modalities or not. And if these treatments were not performed for the patient, what was the reason? According to our experience [2], these treatment modalities could have improved the ophthalmologic signs and symptoms of the patient and even prevented the progression of ophthalmologic sequelae. In such cases, it is acceptable and even necessary to focus on the toxicological management of the methanol-poisoned patient rather than just focusing on the ophthalmologic signs. Furthermore, the authors did not mention anything about the visual condition of the patient during the 4-year period before re-examination of his ophthalmologic status except by history taking. According to our experience [2], patients who present with blindness may experience recovery of vision anytime between a few days until 1 month after hospital discharge which may persist for 1 to 9 months. After this period, they may re-experience reduced vision which may progress to total blindness. Finally, the authors missed the most important follow-up studies mentioned in the literature regarding ocular abnormalities after methanol poisoning, by Dethlefs and Naraqi [3], Ingemansson [4], Onder et al. [5], and Paasma et al. [6].

Methanol and Major Volatile Compounds of Turkish Raki and Effect of Distillate Source

Turkish Raki is the traditional anise flavoured distillate beverage produced mainly from a grape distillate called suma. Two types of Raki are produced in Turkey according to the distillate source. They are Type I — a fresh grape Raki produced only from suma and Type II — a Raki produced from a blended distillate of suma and alcohol of agricultural origin (mainly molasses). In this study the content of ethanol, methanol, distillate based major volatile compounds (aldehydes, esters, higher alcohols), aniseed based anethole and estragole, volatile acid and sugar values in two types of commercial Raki samples (40 samples) was determined and the effect of distillate source on the composition was examined. The distillate and the aniseed based major compounds of the Raki samples were analysed by direct injection with a GC-MS-FID according to the European Commission Reference Method. The results of variance analysis and PCA showed that there was a significant difference between the two types of Raki samples. Total volatiles (esters and higher alcohols), methanol, trans-anethole, estragole and sugar values were higher in the samples made from suma alone. All of the analysed component levels of the Turkish Raki samples were in compliance with Turkish Distilled Beverage Regulations. The methanol levels ranged between 28.00–50.87 g/hL absolute alcohol (AA) in Type I samples and 22.03–41.06 g/hL AA in Type II samples. Distillate based total volatiles levels ranged between 136.12–147.88 g/hL AA, with a mean value of 142.88 g/hL AA, in Type I samples and 102.44–113.45 g/hL, with a mean value of 107.9 g/hL, in the Type II samples. The anise based compound trans-anethole levels were significantly higher in the Type I samples (1,298–1,570 mg/L) than in the Type II samples (1,014–1,199 mg/L). According to distillate based volatiles, the Turkish Raki has a valuable content of volatile substances compared to other anise flavoured spirits.

NMR metabolomics of esca disease-affected Vitis vinifera cv. Alvarinho leaves

Esca is a destructive disease that affects vineyards leading to important losses in wine production. Information about the response of Vitis vinifera plants to this disease is scarce, particularly concerning changes in plant metabolism. In order to study the metabolic changes in Vitis plants affected by esca, leaves from both infected and non-affected cordons of V. vinifera cv. Alvarinho (collected in the Vinho Verde region, Portugal) were analysed. The metabolite composition of leaves from infected cordons with visible symptoms [diseased leaves (dl)] and from asymptomatic cordons [healthy leaves (hl)] was evaluated by 1D and 2D (1)H-nuclear magnetic resonance (NMR) spectroscopy. Principal component analysis (PCA) of the NMR spectra showed a clear separation between dl and hl leaves, indicating differential compound production due to the esca disease. NMR/PCA analysis allowed the identification of specific compounds characterizing each group, and the corresponding metabolic pathways are discussed. Altogether, the study revealed a significant increase of phenolic compounds in dl, compared with hl, accompanied by a decrease in carbohydrates, suggesting that dl are rerouting carbon and energy from primary to secondary metabolism. Other metabolic alterations detected comprised increased levels of methanol, alanine, and gamma-aminobutyric acid in dl, which might be the result of the activation of other defence mechanisms.

Quality and volatile attributes of attached and detached ‘Pluk Mai Lie’ papaya during fruit ripening

The ‘Pluk Mai Lie’ papaya ( Carica papaya L.) is a promising cultivated fruit for use in fresh and processed products due to its firm flesh, but the aroma it releases is flat. Changes in quality and volatile profiles were analyzed during on- and off-tree fruit ripening. Detached fruit ripened faster than attached fruit, accumulating high internal ethylene levels. Aside from peel color, which was redder in on-tree ripened fruit, most quality attributes changed similarly in the two ripening situations. A slight increase in total soluble solids (TSS) was measured from the onset of the preclimacteric stage, whereas titratable acidity (TA) remained stable throughout the development. Whereas 2-ethyl-1-hexanol was found specifically in green fruit, ethyl octanoate emerged only in fully-ripe fruit. Furthermore, benzyl isothiocyanate was the most abundant volatile and was present in fruit at every stage except full ripening. The production of total esters, highly correlated with a loss of firmness and an increase in cavity ethylene accumulation, was about 10-fold higher in off-tree ripened fruit. The levels of methanol and ethanol sources in fruit increased steadily throughout ripening, with esters formed from ethyl alcohol predominating from the half-ripe through the senescence phases. The alcohol dehydrogenase activity in the mesocarp increased dramatically during the early ripening stages, whereas alcohol acetyltransferase was active throughout ripening. No difference in volatile profiles was found in the papaya fruit during on-tree and postharvest ripening.

THE ADDITION OF PETROLEUM BENZIN IN MIXING OF CRUDE PALM OIL AND METHANOL ON BIODIESEL PRODUCTION

Research on transesterification of crude palm oil (CPO) using petroleum benzin as solvent has been done. This research aims to determine the optimum concentration of catalyst KOH and NaOH, mole ratio of methanol to oil, volume ratio of solvent to oil, and temperature range of solvent. This research also observes the influence of changing in methanol concentration and levels of palm oil free fatty acids (FFA) on biodiesel production. In this research, transesterification was preceded by esterification for 10 min using sulphuric acid catalyst. The results showed that KOH gave better results than NaOH as catalyst with optimum concentration was 1.75% (w/v). Mole ratio of methanol to palm oil optimum was 6:1, and volume ratio of solvent to palm oil optimum was 2:5. Optimum temperature range of the solvent was 70-90 °C. Decreasing on concentration of methanol, and increasing of free fatty acids (FFA) level gave negative impact on the biodiesel production, more over on transesterification without solvent. The characteristics (phosphor content, density, water content, ash content, carbon residue, energy content and chemical components) of biodiesel which was produced using petroleum benzin relatively similar to biodiesel produced in the normal way (without solvent). Decreasing on concentration of methanol, and increasing on level of free fatty acids (FFA) gave a negative impact on the biodiesel, more over on transesterification without solvent. Keywords: transesterification, CPO, solvent, petroleum benzin

Control of specific growth rate to enhance the production of a novel disintegrin, saxatilin, in recombinant Pichia pastoris

The methylotrophic yeast Pichia pastoris is one of the best hosts for the production of foreign proteins because of the presence of a strong alcohol oxidase 1 (AOX1) promoter that can be induced by methanol. Feeding the yeast, methanol induces protein production and provides an energy source for the host cells. However, excessive levels of methanol inhibit the growth of host cells, and insufficient methanol levels lead to poor growth and protein production. We have used various methanol feeding strategies to enhance the production of saxatilin. Saxatilin is a novel snake venom-derived disintegrin that inhibits tumor angiogenesis and metastasis and has been shown to suppress ovarian cancer cell invasion. A two-step increase feeding strategy to control the specific growth rate led to the best results in terms of specific protein production rates and final saxatilin amounts within the limited fermentation time.

Spectral scan of the star-forming region DR21(OH). Observations and LTE analysis

Seventy-eight molecules have been detected as a result of a spectral survey of the star-forming region DR21(OH) at 84-115 GHz. The abundances of most molecules are typical of those in the dense cores of molecular clouds. The rotational temperatures derived using the lines of most molecules fall in the range 9-56 K, which is also typical for dense cores. However, emission from high-lying levels of methanol and sulfur dioxide was detected; since the rotational temperatures for methanol and sulfur dioxide are 252 and 186 K, this indicates the presence of hot regions. Another fact indicating the existence of hot regions is the detection of CH3OCHO, CH3CH2OH, and CH3OCH3, which have thus far been observed only in hot cores and shock-heated regions. An interesting result is the tentative detection of the J = 2 - 1, v = 1 SiO line, with the upper level energy of 1775 K. This is probably a maser line, similar to but weaker than the well-known SiO masers in the star-forming regions Orion-KL,W51(N), and Sgr B2(N).

Ultrasound enhanced permeation of methanol into zebrafish, Danio rerio, embryos

Only vitrification is likely to result in successful cryopreservation of teleost embryos, requiring a high level of cryoprotectant penetration into the cell. This study determined the effect of ultrasound on methanol (MeOH) penetration in three types (dechorionated, soft chorion and intact embryos) and three stages (90% epiboly, bud and 4-somite stages) of zebrafish ( Danio rerio) embryos. Three types of embryos were first exposed to varying levels of methanol and optimized for survival. Dechorionated embryos were then exposed to 20%, soft chorion embryos were exposed to 30% and the intact embryos were exposed to 40% methanol for 3 min with or without ultrasound treatment. High performance liquid chromatography (HPLC) was used to measure methanol levels in the treated embryos. The total MeOH recovery from zebrafish embryo samples spiked with MeOH was 100.62 ± 3.99%. The overall penetration of methanol into zebrafish embryo ranged from 85.3 ± 8.1 μmol (in soft chorion embryos at 90% epiboly stage treated with ultrasound) to 3.1 ± 1.0 μmol (in dechorionated embryos at 90% epiboly stage treated without ultrasound). Ultrasound clearly helped to improve the permeation level of methanol into zebrafish embryos ( p < 0.05). A high level of methanol was found in soft chorion embryos. Dechorionated embryos had the highest relative difference in methanol levels between ultrasound and controls. Although, ultrasound significantly affected survival ( p < 0.05), survival was generally high (64 ± 2% to 100%). Even the highest level of methanol (85.3 ± 8.1 μmol) in the best treatment was far lower than that needed for vitrification. Further studies using novel and non-invasive methods are needed to achieve greater methanol penetration for successful vitrification.

Methanol Levels in Saliva--A Non-Invasive Parameter That May Be Useful in Detection of Alcohol Intoxication

Non-invasive screening parameters proving alcohol intoxication are necessary especially in forensic contexts. Results obtained by common measurement methods like the ethanol breath analyzer may be falsified by several parameters like hypoventilation. Therefore, we undertook a pilot study investigating the usefulness and applicability of methanol levels measured in saliva. Our results show that methanol levels in saliva are closely linked to ethanol levels in saliva (r = 0.971, P < 0.0001, t = 5.622, P = 0.000) as well as to ethanol levels in serum (r = 0.786, P = 0.001, t = -1.106, P = 0.058). Therefore, methanol levels measured in saliva might be applicable in order to increase the validity of other non-invasive measurement methods like the ethanol breath analyzer.

Uncoventional Views on Certain Aspects of Toxin-Induced Metabolic Acidosis

This discussion will highlight the following 9 specific points that related to metabolic acidosis caused by various toxins. The current recommendation suggests that alcohol dehydrogenase inhibitor fomepizole is preferred to ethanol in treatment of methanol and ethylene glycol poisoning, but analysis of the enzyme kinetics indicates that ethanol is a better alternative. In the presence of a modest increase in serum osmolal gap (<30 mOsm/L), the starting dose of ethanol should be far less than the usual recommended dose. One can take advantage of the high vapor pressure of methanol in the treatment of methanol poisoning when hemodialysis is not readily available. Profuse sweating with increased water ingestion can be highly effective in reducing methanol levels. Impaired production of ammonia by the proximal tubule of the kidney plays a major role in the development of metabolic acidosis in pyroglutamic acidosis. Glycine, not oxalate, is the main final end product of ethylene glycol metabolism. Metabolism of ethylene glycol to oxalate, albeit important clinically, represents less than 1% of ethylene glycol disposal. Urine osmolal gap would be useful in the diagnosis of ethylene glycol poisoning, but not in methanol poisoning. Hemodialysis is important in the treatment of methanol poisoning and ethylene glycol poisoning with renal impairment, with or without fomepizole or ethanol treatment. Severe leucocytosis is a highly sensitive indicator of ethylene glycol poisoning. Uncoupling of oxidative phosphorylation by salicylate can explain most of the manifestations of salicylate poisoning.

Improved production of polygalacturonate lyase by combining a pH and online methanol control strategy in a two-stage induction phase with a shift in the transition phase

Polygalacturonate lyase is a kind of enzyme that is abundantly used in the textile industry for cotton scouring. Previously, we reconstructed the polygalacturonate lyase gene in Pichia pastoris for the expression of this enzyme. To enhance the production of polygalacturonate lyase (PGL), a combined strategy was formulated by combining online methanol control and two-stage pH control strategies. For the two-stage pH control strategy during the growth phase, the pH was controlled at 5.5, and in the induction phase different pH levels were investigated for the optimum enzyme production. During the online methanol control strategy, the different levels of methanol (v/v) were investigated for the best enzyme production at pH 5.5. These two strategies were combined together for enhanced PGL productivity, and the induction phase was divided into two stages in which methanol concentrations were maintained at different levels online. The transition phase was introduced during the induction phase instead of introducing it after the growth phase. The two-stage combination strategy was formulated on the bases of methanol consumption of cells, optimal pH, cell viability and the production of polygalacturonate lyase by P. pastoris. By using this strategy, the production was doubled compared with common conditions, and the highest polygalacturonate lyase activity reached 1,631 U/ml. This strategy proved to be very useful for the enhancement of polygalacturonate lyase production by achieving higher cell viability, alcohol oxidase activity and phosphate-related compounds of the cells during the induction phase.