Bacterial tolerance and detoxification of cyanide, arsenic and heavy metals: Holistic approaches applied to bioremediation of industrial complex wastes.

Cyanide is a highly toxic compound that is found in wastewaters generated from different industrial activities, such as mining or jewellery. These residues usually contain high concentrations of other toxic pollutants like arsenic and heavy metals that may form different complexes with cyanide. To develop bioremediation strategies, it is necessary to know the metabolic processes involved in the tolerance and detoxification of these pollutants, but most of the current studies are focused on the characterization of the microbial responses to each one of these environmental hazards individually, and the effect of co-contaminated wastes on microbial metabolism has been hardly addressed. This work summarizes the main strategies developed by bacteria to alleviate the effects of cyanide, arsenic and heavy metals, analysing interactions among these toxic chemicals. Additionally, it is discussed the role of systems biology and synthetic biology as tools for the development of bioremediation strategies of complex industrial wastes and co-contaminated sites, emphasizing the importance and progress derived from meta-omic studies.

Boron deficiency energizes cyanide uptake and assimilation through activating plasma membrane H+-ATPase in rice plants.

The effect of boron (B) deficiency on mediating the contribution of H+-ATPase in the uptake and assimilation of exogenous cyanide (CN-) is investigated. Under CN- treatments, rice seedlings with B-deficient (-B) conditions exhibited significantly higher CN- uptake and assimilation rates than B-supplemented (+B) seedlings, whereas NH4+ uptake and assimilation rates were slightly higher in -B rice seedlings than in +B. In this connection, the expression pattern of genes encoding ß-CAS, ST, and H+-ATPase was assessed to unravel their role in the current scenario. The abundances of three ß-CAS isogenes (OsCYS-D1, OsCYS-D2, and OsCYS-C1) in rice tissues are upregulated from both "CN--B" and "CN-+B" treatments, however, only OsCYS-C1 in roots from the "CN--B" treatments was significantly upregulated than "CN-+B" treatments. Expression patterns of ST-related genes (OsStr9, OsStr22, and OsStr23) are tissue specific, in which significantly higher upregulation of ST-related genes was observed in shoots from "CN--B" treatments than "CN-+B" treatments. Expression pattern of 7 selected H+-ATPase isogenes, OsA1, OSA2, OsA3, OsA4, OsA7, OsA8, and OsA9 are quite tissue specific between "CN-+B" and "CN--B" treatments. Among these, OsA4 and OsA7 genes were highly activated in the uptake and assimilation of exogenous CN- in -B nutrient solution. These results indicated that B deficiency disturbs the pattern of N cycles in CN--treated rice seedlings, where activation of ST during CN- assimilation decreases the flux of the innate pool of NH4+ produced from CN- assimilation by the ß-CAS pathway in plants. Collectively, the B deficiency increased the uptake and assimilation of exogenous CN- through activating H+-ATPase.

Effect of cyanide-utilizing bacteria and sulfur on feed utilization, microbiomes, and cyanide degradation in cattle supplemented with fresh cassava root.

This study aimed to compare the effects of adding cyanide-utilizing bacteria (CUB) and sulfur on rumen fermentation, the degradation efficiency of hydrogen cyanide (HCN), feed utilization, and blood metabolites in beef cattle fed two levels of fresh cassava root (CR). A 2 × 2 factorial arrangement in a 4 × 4 Latin square design was used to distribute four male purebred Thai native beef cattle (2.5-3.0 years old) with an initial body weight (BW) of 235 ± 15.0 kg. Factor A was Enterococcus faecium KKU-BF7 oral direct fed at 108 CFU/ml and 3% dry matter (DM) basis of pure sulfur in concentrate diet. Factor B was the two levels of CR containing HCN at 300 and 600 mg/kg on DM basis. There was no interaction effect between CUB and sulfur supplementation with CR on feed utilization (p > 0.05). Similarly, CUB and sulfur supplementation did not affect (p > 0.05) DM intake and apparent nutrient digestibility. However, the high level of CR supplementation increased (p < 0.05) feed intake and neutral detergent fiber digestibility. The ruminal pH, microbial population, ammonia-nitrogen, blood urea nitrogen, and blood thiocyanate concentrations were unaffected by the addition of CUB and sulfur at two CR concentrations (p > 0.05). The addition of CUB or sulfur had no effect on the efficiency of HCN degradation in the rumen (p > 0.05). However, cattle given CR with HCN at 600 mg/kg DM had considerably higher degradation efficiency than those fed CR containing HCN at 300 mg/kg DM (p < 0.05). The group fed CUB had a considerably greater CUB population (p < 0.05) than the sulfur group. Cyanide-utilizing bacteria or sulfur supplementation with CR had no interaction effect between total VFAs and their profiles (p > 0.05). However, the study observed a significant positive correlation between the amount of CR and the concentration of propionate in the rumen (p < 0.05). The levels of nitrogen absorption and nitrogen retention did not differ significantly among the treatments (p > 0.05). Hence, it may be inferred that the administration of a high concentration of CR at a dosage of 600 mg/kg DM HCN could potentially provide advantageous outcomes when animals are subjected to oral CUB incorporation.

Bacterial respiratory inhibition triggers dispersal of Pseudomonas aeruginosa biofilms.

Pseudomonas aeruginosa grows as a biofilm under many environmental conditions, and the bacterium can disperse from biofilms via highly regulated, dynamic processes. However, physiologic triggers of biofilm dispersal remain poorly understood. Based on prior literature describing dispersal triggered by forms of starvation, we tested bacterial respiratory inhibitors for biofilm dispersal in two models resembling chronic airway infections. Our underlying hypothesis was that respiratory inhibitors could serve as a model for the downstream effects of starvation. We used two experimental conditions. In the first condition, biofilms were grown and dispersed from the surface of airway epithelial cells, and the second condition was a model where biofilms were grown on glass in cell culture media supplemented with host-relevant iron sources. In both biofilm models, the respiratory inhibitors potassium cyanide and sodium azide each triggered biofilm dispersal. We hypothesized that cyanide-induced dispersal was due to respiratory inhibition rather than signaling via an alternative mechanism, and, indeed, if respiration was supported by overexpression of cyanide-insensitive oxidase, dispersal was prevented. Dispersal required the activity of the cyclic-di-GMP regulated protease LapG, reinforcing the role of matrix degradation in dispersal. Finally, we examined the roles of individual phosphodiesterases, previously implicated in dispersal to specific triggers, and found signaling to be highly redundant. Combined deletion of the phosphodiesterases dipA, bifA, and rbdA was required to attenuate the dispersal phenotype. In summary, this work adds insight into the physiology of biofilm dispersal under environmental conditions in which bacterial respiration is abruptly limited. IMPORTANCE The bacterium Pseudomonas aeruginosa grows in biofilm communities that are very difficult to treat in human infections. Growing as a biofilm can protect bacteria from antibiotics and the immune system. Bacteria can leave a biofilm through a process called "dispersal." Dispersed bacteria seed new growth areas and are more susceptible to killing by antibiotics. The triggers for biofilm dispersal are not well understood, and if we understood dispersal better it might lead to the development of new treatments for infection. In this paper, we find that inhibiting P. aeurginosa's ability to respire (generate energy) can trigger dispersal from a biofilm grown in association with human respiratory epithelial cells in culture. The dispersal process requires a protease which is previously known to degrade the biofilm matrix. These findings give us a better understanding of how the biofilm dispersal process works so that future research can discover better ways of clearing bacteria growing in biofilms.

Antineoplastic effects of cassava-cyanide extract on human glioblastoma (LN229) cells.

Several natural compounds reduce tumour cell growth and metastasis by inducing programmed cell death. Cassava (Manihot esculenta Crantz) contains cyanogenic glycosides such as, linamarin and lotaustralin, can be enzymatically cleaved by linamarase to release hydrogen cyanide (HCN), which can have therapeutic benefits against hypertension, asthma, and cancer. We have developed a technology for isolating bio-active principles from cassava leaves.The present study is designed to analyze the cytotoxic effect of cassava cyanide extract (CCE) against human glioblastoma cells (LN229). The treatment of CCE demonstrated a dose dependent toxicity on glioblastoma cells. At higher concentration tested, the CCE (400 µg/mL) was found to be cytotoxic, reducing the cell viability to 14.07 ± 2.15% by negatively influencing the mitochondrial activity, and lysosomal and cytoskeletal integrity. Coomassie's brilliant blue staining confirmed cells' morphological aberration after 24 h of treatment with CCE. Moreover, DCFH-DA assay and Griess reagent showed an increase in ROS but a decrease in RNS production at a concentration of CCE. Flow cytometry analysis revealed that CCE interfered with G0/G1, S, and G2/M stages of the cell cycle of glioblastoma, and Annexin/PI staining indicated a dose-dependent increase in cell death, confirming the toxic nature of CCE on LN229 cells. These findings suggest that cassava cyanide extract has potential as an antineoplastic agent against glioblastoma cells, which is an aggressive and difficult-to-treat type of brain cancer. However, it is important to note that the study was conducted in vitro, and further research is necessary to assess the safety and efficacy of CCE in vivo. Additionally, it is essential to establish the optimal dose and potential side effects before considering its use as a therapeutic agent.

Fluorophores-rich natural powder from selected medicinal plants for detection latent fingerprints and cyanide.

Forensic science is currently fast-growing for the development detection of the latent fingerprint. Currently, chemical dust quickly enters the body through touch or inhalation and will be affected by the user. In this research, a study on the comparison of natural powder from four species of medicinal plants (Zingiber montanum, Solanum Indicum L., Rhinacanthus nasutus, and Euphorbia tirucall) for the detection of latent fingerprints is carried out that has fewer adverse effects on the user's body by using such natural substances instead. In addition, the fluorescence properties of the dust have been found in some natural powder for sample detection and appear on multi-colored surfaces to show that the latent fingerprints are more pronounced than ordinary dust. In this study, medicinal plants have also been applied to detect cyanide, as it has been known that it is hazardous for humans and can be used as a poisonous compound to kill someone. The characteristics of each powder have also been analyzed using naked-eye detection under UV light, Fluorescence spectrophotometer, FIB-SEM, and FTIR. All the powder obtained can then be used for high potential detection of latent fingerprints on the non-porous surface with their specific characteristics and trace amounts of cyanide using turn-on-off fluorescent sensing method.

Cobaloxime Photocatalysis for the Synthesis of Phosphorylated Heteroaromatics.

Herein, cobaloxime is used for the first time as a catalyst for the synthesis of phosphorylated heteroaromatics, which is an intriguing and versatile functional motif. With visible-light irradiation, cobaloxime not only oxidizes phosphine oxides to form phosphorus radicals (P-radicals) for a subsequent reaction with radical acceptor isocyanides or heteroaromatics, but also combines the radical intermediate with ß-H elimination, thereby producing phosphorylated heteroaromatics with only H2 or CH4 as byproduct. Phosphine oxides with dialkyl, alkylaryl, and diaryl substituents could be directly transformed into phosphorylated phenanthridines, benzothiazoles, isoquinolines, and common heteroaromatics. This catalytic system features extremely mild conditions, broad substrate scope and good to excellent yields. Scale-up reaction and sunlight reaction show the great application potential in the green synthesis of important organophosphorus chemicals.

Simple and simultaneous quantification of cyanide, ethanol, and 1-propanol in blood by headspace GC-MS/NPD with Deans switch dual detector system.

Cyanide is a powerful and rapidly acting poison. In Japan, cyanide poisoning is rare, and regular cyanide testing can be costly and time consuming. In contrast, alcohol analysis is routinely performed in most forensic laboratories. In this study, we attempted to develop a method for the simultaneous quantification of cyanide and alcohols in blood using headspace gas chromatography (HS-GC). As nitrogen-phosphorus detection (NPD) is more sensitive to hydrogen cyanide than mass spectrometry (MS), a Deans switch was used to switch the detectors during a single run. The separation provided by three analytical columns, PoraBOND Q, CP-Sil 5 CB, and HP-INNOWax, was investigated, and PoraBOND Q was selected. The use of HS-GC-MS/NPD with a Deans switch enabled the simple and simultaneous quantification of cyanide, ethanol, and 1-propanol. Eighteen other volatile compounds were detected in the SIM/scan mode of the MS.

A critical review of current technologies used to reduce ginkgotoxin, ginkgotoxin-5'-glucoside, ginkgolic acid, allergic glycoprotein, and cyanide in Ginkgo biloba L. seed.

The Ginkgo biloba has astonished scholars globally with enormous bioactives, with sales exceeding $10 billion since 2017. The Ginkgo biloba seed (GBS) is an essential part of culinary culture. Nevertheless, toxins in fresh Ginkgo biloba seed (GBS) have limited GBSs' daily consumption. Ginkgotoxin and ginkgotoxin-5-glucoside cause poisoning, tonic-clonic convulsions, and neurotoxic effects. Ginkgolic acid causes cytotoxicity and allergies. Allergic glycoprotein in GBS causes nausea, seizures, dyspnea, mydriasis, vomiting, and bellyache. The amygdalin-derived hydrocyanic acid cause dizziness, vomiting, cramping, and sleeping disorders. Food products are frequently exposed to various processing techniques to increase food safety and functionality. As a result, this review focused on the technologies that have been used to minimize toxins in GBS. In addition, a comparison of these techniques was made based on their benefits, drawbacks, feasibility, pharmacological activities, and future direction or opportunities to improve current ones were provided.

Protein composition, chlorophyll, carotenoids, and cyanide content of cassava leaves (Manihot esculenta Crantz) as influenced by cultivar, plant age, and leaf position.

The variation of proximate compositions, amino acids, carotenoids, chlorophyll, and total cyanide contents in cassava leaves was studied to identify the most suitable leaves for human consumption. The cassava leaves from 4 cultivars were analysed at 3 leaf positions as well as at 2 plant ages. The leaves of 'Rayong 5' cultivar from the middle position at 6 months after planting contained the highest crude protein, amino acids, carotenoids, and chlorophyll. The total cyanide content was high and therefore, an effective detoxification method is needed. Protein from the cassava leaves was rich in glutamine, aspartic acid, and leucine, but low in methionine and cysteine. Additionally, cassava leaves were found to be a rich source of carotenoids and chlorophyll. This study provided the evidences that cassava leaves can be an alternative source as protein supplement and for carotenoids and chlorophyll extraction and paves the way to valorise this abundant agricultural by-product.

Life-Threatening Cyanide Intoxication after Ingestion of Amygdalin in Prehospital Care.

Amygdalin is originally a natural cyanogenic glycoside available as a dietary supplement used in the alternative treatment of cancer patients. Amygdalin hydroxylates to toxic cyanide in the body, which can cause life-threatening intoxication. The case report presents a 72-year-old patient with life-threatening cyanide poisoning after ingesting a dietary supplement containing amygdalin identified in prehospital care, which was successfully treated with hydroxocobalamin.

Alkaline-extracted cyanide from cassava wastewater and its sole induction of chromosomal aberrations in Allium cepa L. root tips.

Cassava, a staple crop in Nigeria, processed by numerous factories in rural and suburban locations is known to contain some level of cyano compounds. Lack of stringent environmental regulations on the management of cassava wastewater (CWW) from cassava-processing factories had led to its indiscriminate discharge on the environment. CWW samples were obtained from cassava-processing factories from selected states (Lagos (A), Oyo (B), Ogun 1 (C1), Ogun 2 (C2) and Cross River (D)) in Nigeria to determine the cytotoxic and genotoxic effects of extracted cyanide from the wastewaters. The cyanide was hydrolysed via chemical degradation utilizing 1.25 M NaOH and subsequently titrated using silver nitrate with p-dimethylaminobenzalrhodamine as indicator. Further, in order to explore the potential toxicity of this pollutant present in the effluent, a battery of short-term biological assay (Allium cepa chromosomal aberration test) was used. Bulbs with roots of Allium cepa L. were treated with different concentrations (0.05%, 0.1%, 0.2%, 0.4% and 0.8%) of CWW, and after 48 h, the root tips were processed for cytological studies by the aceto-orcein squash procedure. The results revealed that cyanide concentrations on re-fluxing were in the range of 1.0 and 1.3 mg/L. All concentrations induced a number of chromosomal aberrations in the root tip cells. The mitotic index decreased significantly (p < 0.05) with increasing concentration. The cytotoxic effects showed strong concentration-dependent root growth inhibition with EC50 values of 30%, 20%, 37%, 43% and 22% for A, B, C1, C2 and D, after 72 h. The findings thus indicate that alkali treatment is very efficient in degrading the cyanide content of CWW and has shown that the combination of physico-chemical analysis along with the sole toxicity assessment could provide valuable information about the sole toxicity of cyanide as a chemical pollutant present in the cassava effluent.

Benzoindoxazine derivatives containing carbazole for detection of CN- and its application in plant seed extracts and cell imaging.

Cyanide (CN-) is a highly toxic compound that exists in many substances and is harmful to the environment and human health. Therefore, it is of great significance to develop excellent CN- ion probes, especially solvent-induced on-off fluorescent probes. Based on the condensation reaction of indolo[2,1-b][1,3]oxazine molecules with aldehydes, probes (E)-13a-(2-(9-ethyl-9H-carbazol-3-yl)vinyl)-14,14-dimethyl-10-nitro-13a,14-dihydro-8H-benzo[e]benzo[5,6][1,3]oxazino[3,2-a]indole (NCO) and (E)-13a-(2-(9-benzyl-9H-carbazol-3-yl)vinyl)-14,14-dimethyl-10-nitro-13a,14-dihydro-8H-benzo[e]benzo[5,6][1,3]oxazino[3,2-a]indole (NBO) were synthesized to detect CN-. Compared with other cyanogen ion probes, NCO and NBO have special carbazole ring structures and large conjugate systems. When CN- is added to the probe-detection solution, color changes that are visible to the naked eye can occur. The UV-vis spectrum test using differential spectroscopy shows that the probe (i) has excellent solvent-induced switching characteristics and stability (CH3OH-H2O) and (ii) high selectivity, anti-interference ability, and sensitivity for the detection of CN-. The fluorescence limit of detections (LODs) are 1.05 µM for NCO and 1.34 µM for NBO. The UV LODs are 0.83 µM for NCO and 0.87 µM for NBO. Fluorescence spectroscopy shows that the probe has remarkable fluorescence properties. Fluorescence titration experiments, liver cancer cell (Hep G2) imaging, and cytotoxicity experiments all show that the probes have high biocompatibility, low toxicity, high cell permeability, and high sensitivity for the detection of CN- in cells. In addition, NCO and NBO have been successfully used for the detection of cyanogenic glycosides in the seeds of ginkgo, crabapple, apple, and cherry. Test strips were fabricated to detect CN-. After adding CN-, the color of the test strip changed significantly-from brown to light yellow; thus, the test strips have a high application value in the fields of drug quality control, drug safety testing, and pharmacological research.

Effect of cyanide ions (CN-) extracted from cassava (Manihotesculenta Crantz) on Alveolar Epithelial Cells (A549 cells).

Cassava (Manihotesculenta Crantz) is one of the most important root crops in tropical countries. It is a major source of cyanogenic glycosides viz. linamarin and lotaustralin, and these on breakdown liberate HCN and ketone. Cassava cyanide extract (CCE) from cassava leaves and tuber rinds were formulated as a biopesticide against certain borer insect pests of horticultural crops. Adenocarcinomic human alveolar basal epithelial cells (A549) were treated with three different concentrations (100, 200, 400 ppm) of CCE. The MTT and NRU assays showed dose-dependent cytotoxicity. The DCFH-DA assay does not show any free radical scavenging activity, whereas the NRR assay showed a reduction in the nitrile radicals with an increase in the concentration of the bioactive compound. A negative correlation was found between the concentration of the bioactive principles and mitochondrial and lysosomal functions. Various cellular assays demonstrated the cellular response of the CCE, and it was found that at higher concentration (400 ppm), the CCE exert a significant necrotic cell death rather than apoptosis. The results of the study indicated that the CCE have a remarkable tendency of anti-proliferative ability.

Physiological concentrations of cyanide stimulate mitochondrial Complex IV and enhance cellular bioenergetics.

In mammalian cells, cyanide is viewed as a cytotoxic agent, which exerts its effects through inhibition of mitochondrial Complex IV (Cytochrome C oxidase [CCOx]). However, the current report demonstrates that cyanide's effect on CCOx is biphasic; low (nanomolar to low-micromolar) concentrations stimulate CCOx activity, while higher (high-micromolar) concentrations produce the "classic" inhibitory effect. Low concentrations of cyanide stimulated mitochondrial electron transport and elevated intracellular adenosine triphosphate (ATP), resulting in the stimulation of cell proliferation. The stimulatory effect of cyanide on CCOx was associated with the removal of the constitutive, inhibitory glutathionylation on its catalytic 30- and 57-kDa subunits. Transfer of diluted Pseudomonas aeruginosa (a cyanide-producing bacterium) supernatants to mammalian cells stimulated cellular bioenergetics, while concentrated supernatants were inhibitory. These effects were absent with supernatants from mutant Pseudomonas lacking its cyanide-producing enzyme. These results raise the possibility that cyanide at low, endogenous levels serves regulatory purposes in mammals. Indeed, the expression of six putative mammalian cyanide-producing and/or -metabolizing enzymes was confirmed in HepG2 cells; one of them (myeloperoxidase) showed a biphasic regulation after cyanide exposure. Cyanide shares features with "classical" mammalian gasotransmitters NO, CO, and H2S and may be considered the fourth mammalian gasotransmitter.

Protective properties of Spondias mombin Linn leaves on redox status, cholinergic dysfunction and electrolyte disturbance in cyanide-intoxicated rats.

Cyanide is an environmental neurotoxin which has been reported to arrest the normal functioning of the brain. This study investigated the protective properties of methanol and flavonoid-rich extracts of the leaves of Spondias mombin on redox status, cholinergic dysfunction and electrolyte disturbance in cyanide-induced neurotoxicity in rats. Male Wistar rats were orally pre-treated with Spondias mombin methanol leaf extract (SMC) (50, 100 and 150 mg/kg), flavonoid-rich extract (SMF) (25, 50 and 75 mg/kg) or quercetin (20 mg/kg), followed by intraperitoneal administration of 2 mg/kg potassium cyanide. Cyanide intoxication caused brain damage in rats as echoed in the deleterious alterations to activities/levels of endogenous antioxidants and biomarkers/enzymes linked with electrolyte imbalance and neurotoxicity. Pre-treatment with SMC and SMF significantly attenuated these KCN-induced imbalances (p < 0.05). The results suggested that the protection conferred by SMC and SMF probably involves attenuation of oxidative stress and regulation of ionic homeostasis. SMF displayed a better apparent ameliorative activity than SMC and 75 mg/kg SMF offered the best protection suggesting that flavonoids probably contributed to the protective effect of Spondias mombin leaf.

Assimilation of exogenous cyanide cross talk in Oryza sativa L. to the key nodes in nitrogen metabolism.

Exogenous cyanide (CN-) effects on nitrogen (N) uptake, transport, and assimilation in rice seedlings were investigated at the biochemical and molecular levels. Seedlings were treated with either a 2-d or 4-d supply of potassium cyanide (KCN) in the nutrient solution containing nitrate (NO3-) or ammonium (NH4+). Although a KCN-induced increase was recorded in the activity of ß-cyanoalanine synthase (ß-CAS) in rice tissues of both NH4+-fed and NO3--fed seedlings, the former showed a significantly greater assimilation rate for CN- than the latter. The addition of KCN decreased NO3- uptake and assimilation, whereas a negligible impact was observed in NH4+ treatments. Enzymatic assays showed a marked activities enhancement of glutamine synthetase (GS), glutamate synthase (GOGAT), and glutamate dehydrogenase (GDH) in NH4+-fed seedlings after KCN exposure. Similarly, the rises occurring in nitrate reductase (NR) and GDH activity in NO3--fed seedlings were also detected after 2-d exposure to KCN, whereas a significant reduction of GS and GOGAT activities was determined. The results suggest that although exogenous KCN at moderate or high concentrations caused repressively effects on biomass growth of both NH4+-fed and NO3--fed rice seedlings, the nontoxic concentration of KCN supplied can serve as a supplemental N source in plant nutrition and N metabolism.

A novel ratiometric near-infrared fluorescent probe for monitoring cyanide in food samples.

Cyanide is a highly toxic anion. Nonetheless, many food plants could produce endogenous cyanide, which causes great danger to human health. Thus, monitoring cyanide in food samples is critically significant. Herein, we rationally developed the first ratiometric near-infrared fluorescent probe for sensing cyanide in food samples. The probe displayed noticeable fluorescence in near-infrared region. Moreover, upon treatment with cyanide, the probe exhibited highly selective and sensitive ratiometric fluorescence response, with limit of detection determined to be 0.075 µM and limit of quantification determined to be 0.25 µM. The ratios of fluorescent intensities at 519 and 688 nm (I519/I688) was linear with added cyanide concentrations from 0 to 80 µM. The relative standard deviations for repeatability and reproducibility varied from 0.55 to 8.94 and from 1.17 to 9.46, respectively. Significantly, probe Hy has been successfully applied for monitoring cyanide in various food samples, such as almonds, sprouting potatoes, and bamboo shoots.

Carbon monoxide poisoning.

Despite established exposure limits and safety standards as well as the availability of carbon monoxide (CO) alarms, each year 50,000 people in the United States visit emergency departments for CO poisoning. Carbon monoxide poisoning can occur from brief exposures to high levels of CO or from longer exposures to lower levels. Common symptoms can include headaches, nausea and vomiting, dizziness, general malaise, and altered mental status. Some patients may have chest pain, shortness of breath, and myocardial ischemia, and may require mechanical ventilation and treatment of shock. Individuals poisoned by CO often develop brain injury manifested by neurological problems, including cognitive sequelae, anxiety and depression, persistent headaches, dizziness, sleep problems, motor weakness, vestibular and balance problems, gaze abnormalities, peripheral neuropathies, hearing loss, tinnitus, Parkinsonian-like syndrome, and other problems. In addition, some will have cardiac issues or other ailments. While breathing oxygen hastens the removal of carboxyhemoglobin (COHb), hyperbaric oxygen (HBO2) hastens COHb elimination and favorably modulates inflammatory processes instigated by CO poisoning, an effect not observed with breathing normobaric oxygen. Hyperbaric oxygen improves mitochondrial function, inhibits lipid peroxidation transiently, impairs leukocyte adhesion to injured microvasculature, and reduces brain inflammation caused by the CO-induced adduct formation of myelin basic protein. Based upon three supportive randomized clinical trials in humans and considerable evidence from animal studies, HBO2 should be considered for all cases of acute symptomatic CO poisoning. Hyperbaric oxygen is indicated for CO poisoning complicated by cyanide poisoning, often concomitantly with smoke inhalation.