Comparison of RNA- and DNA-based bacterial communities in a lab-scale methane-degrading biocover

Methanotrophs must become established and active in a landfill biocover for successful methane oxidation. A lab-scale biocover with a soil mixture was operated for removal of methane and nonmethane volatile organic compounds, such as dimethyl sulfide (DMS), benzene (B), and toluene (T). The methane elimination capacity was 211?±?40 g?m^?2 d^?1 at inlet loads of 330–516 g?m^?2 d^?1. DMS, B, and T were completely removed at the bottom layer (40–50 cm) with inlet loads of 221.6?±?92.2, 99.6?±?19.5, and 23.4?±?4.9 mg m^?2 d^?1, respectively. The bacterial community was examined based on DNA and RNA using ribosomal tag pyrosequencing. Interestingly, methanotrophs comprised 80 % of the active community (RNA) while 29 % of the counterpart (DNA). Types I and II methanotrophs equally contributed to methane oxidation, and Methylobacter, Methylocaldum, and Methylocystis were dominant in both communities. The DNA vs. RNA comparison suggests that DNA-based analysis alone can lead to a significant underestimation of active members.     

Neutral Proteinase II of Aspergillus sojae: An Enzyme Specifically Active on Protamine and Histone

To identify the compounds in machine cutting-fluid emulsion that have an obnoxious odor, we separated volatile components from the emulsion using both steam distillation with a Nickerson–Likens apparatus and vacuum distillation. These components were analyzed by gas chromatography and gas chromatography-mass spectrometry using a fused silica capillary column coated with cross-linked 5% phenylmethyl silicone. 2,6-Dimethyl-3-methoxypyrazine was detected. The main odorous compounds were dimethyl disulfide, dimethyl trisulfide, and 2-butene-1-thiol, the last compound being tentatively identified by its mass spectrum.     

Study on the Traffic Air Pollution inside and outside a Road Tunnel in Shanghai,China

To investigate the vehicle induced air pollution situations both inside and outside the tunnel, the field measurement of the pollutants concentrations and its diurnal variations was performed inside and outside the Xiangyin tunnel in Shanghai from 13:00 on April 24th to 13:00 on April 25th, 2013. The highest hourly average concentrations of pollutants were quantified that CO, NO, NO₂ and NO_X inside the tunnel were 13.223 mg/m³, 1.829 mg/m³, 0.291 mg/m³ and 3.029 mg/m³, respectively, while the lowest ones were 3.086 mg/m³, 0.344 mg/m³, 0.080 mg/m³ and 0.619 mg/m³. Moreover, the concentrations of pollutants were higher during the daytime, and lower at night, which is relevant to the traffic conditions inside the tunnel. Pollutants concentrations inside the tunnel were much higher than those outside the tunnel. Then in a case of slow wind, the effect of wind is much smaller than the impact of pollution sources. Additionally, the PM_2.5 concentrations climbed to the peak sharply (468.45 µg/m³) during the morning rush hours. The concentrations of organic carbon (OC) and elemental carbon (EC) in PM_2.5 inside the tunnel were 37.09–99.06 µg/m³ and 22.69–137.99 µg/m³, respectively. Besides, the OC/EC ratio ranged from 0.72 to 2.19 with an average value of 1.34. Compared with the results of other tunnel experiments in Guangzhou and Shenzhen, China, it could be inferred that the proportion of HDVs through the Xiangyin tunnel is relatively lower.     

Identification of the Volatile Compounds Produced in Sterile Fish Muscle (Sebastes melanops) by Pseudomonas fragi

Volatile compounds produced by Pseudomonas fragi strain 18 in sterile fish muscle (Sebastes melanops) were identified by combined gas-liquid chromatography and mass spectrometry. Compounds positively identified included dimethyl sulfide, acetaldehyde, ethyl acetate, ethyl alcohol, and dimethyl disulfide. Methyl mercaptan, ethyl butyrate, ethyl hexanoate, and butanone were tentatively identified by relative retention times of the authentic compounds. The fruity odor that developed in fish muscle during incipient spoilage was attributed to a synergistic flavor interaction involving the ethyl esters of acetate, butyrate, and hexanoate.     

Anaerobic versus Aerobic Degradation of Dimethyl Sulfide and Methanethiol in Anoxic Freshwater Sediments

Degradation of dimethyl sulfide and methanethiol in slurries prepared from sediments of minerotrophic peatland ditches were studied under various conditions. Maximal aerobic dimethyl sulfide-degrading capacities (4.95 nmol per ml of sediment slurry · h⁻¹), measured in bottles shaken under an air atmosphere, were 10-fold higher than the maximal anaerobic degrading capacities determined from bottles shaken under N₂ or H₂ atmosphere (0.37 and 0.32 nmol per ml of sediment slurry · h⁻¹, respectively). Incubations under experimental conditions which mimic the in situ conditions (i.e., not shaken and with an air headspace), however, revealed that aerobic degradation of dimethyl sulfide and methanethiol in freshwater sediments is low due to oxygen limitation. Inhibition studies with bromoethanesulfonic acid and sodium tungstate demonstrated that the degradation of dimethyl sulfide and methanethiol in these incubations originated mainly from methanogenic activity. Prolonged incubation under a H₂ atmosphere resulted in lower dimethyl sulfide degradation rates. Kinetic analysis of the data resulted in apparent K_m values (6 to 8 μM) for aerobic dimethyl sulfide degradation which are comparable to those reported for Thiobacillus spp., Hyphomicrobium spp., and other methylotrophs. Apparent K_m values determined for anaerobic degradation of dimethyl sulfide (3 to 8 μM) were of the same order of magnitude. The low apparent K_m values obtained explain the low dimethyl sulfide and methanethiol concentrations in freshwater sediments that we reported previously. Our observations point to methanogenesis as the major mechanism of dimethyl sulfide and methanethiol consumption in freshwater sediments.     

A Study on Low-boiling Compounds of Essential Oil of Geranium Species

From the first crop of P. graveolens and the first and third ones of P. roseum Bourbon, low-boiling compounds escaping during the steam distillation were collected, and examined through gas chromatography and the preparation of their derivatives. Nine hydrocarbons, five carbonyl compounds, three alcohols, two esters and one sulfide were identified. Among these twenty compounds, sixteen compounds except dimethyl sulfide, α-pinene, myrcene and limonene were newly identified in the geranium species. Appreciable variation between the species was observed in contents of methanol, acetone, dimethyl sulfide and terpene hydrocarbons.     

Toxicological screening of chemical emissions from municipal solid waste landfills. application of a predictive framework to a state‐of‐the‐art facility

A screening‐level risk assessment was used to identify chemicals of potential health concern emitted during the normal operation of an hypothetical state‐of‐the‐art municipal solid waste landfill. Data on the amount of contaminants (carcinogens, non‐carcinogenic systemic toxicants, odorous compounds, and particulate‐bound metals) were obtained from existing facilities and used to estimate ground‐level air concentrations of airborne chemicals at the point of maximum impact (property line) and at year 20 (year of maximum emissions from the landfill). Concentrations of leachate components present in the corresponding underlying aquifer were also estimated. Intakes of chemicals experienced by a series of human receptors were then computed using either single‐media or multi‐media algorithms. Carcinogens of concern were selected as those contributing to a lifetime excess cancer risk (LECR) greater than 10^‐6; for non‐carcinogenic systemic toxicants and odorous volatiles an Exposure Ratio (ER=intake or concentration/RfD, RfC, odor threshold) greater than 0.1 was used as cut‐off. The results obtained identified a final set of air emission components (n = 25) constituted mainly of carcinogenic and odorous substances whereas 2 leachate components were retained. Additional analysis using more refined risk‐based approaches are necessary to verify the relevance of these projections.     

Studies on the Flavor of Green Tea

With an assumption that the laver-like odor of green tea is due to dimethyl sulfide, an attempt to isolate dimethyl sulfide from commercial green tea was made, and the identification of dimethyl sulfide was successful by making the co-ordinated compound with mercuric chloride, 2 (CH₃) ₂S·3HgCl₂. In addition, the presence of methylmethionine sulfonium salt in tea extract as a precursor of dimethyl sulfide was examined.     

Investigation of mercaptans,organic sulfides,and inorganic sulfur compounds as sulfur sources for the growth of methanogenic bacteria

A variety of compounds were investigated for use as sulfur sources for the growth of methanogenic bacteria.Methanococcus (Mc.) deltae, Mc. maripaludis, Methanobacterium (Mb.) speciesGC-2B, GC-3B, andMMY, Methanobrevibacter (Mbr.) ruminantium, andMethanosarcina (Ms.) barkeri strain 227 grew well with sulfide, S^o, thiosulfate, or cysteine as sole sulfur source.Mbr. ruminatium was able to grow on SO ₄ ⁼ or SO ₃ ⁼ , andMs. barkeri strain 227 was able to grow on SO ₃ ⁼ , but not on SO ₄ ⁼ as a sole sulfur source.Mc. jannaschii grew with sulfide, S^o, thiosulfate or SO ₃ ⁼ , but not on cysteine or SO ₄ ⁼ as sole surface source.Mc. thermolithotrophicus, Mc. jannaschii, Mc. deltae, andMb. thermoautotrophicum strains Marburg and H were able to grow with methanethiol, ethanethiol,n-propanethiol,n-butanethiol, methyl sulfide, dimethyl sulfoxide, ethyl sulfide, or CS₂ as a sulfur source, when very low levels (20–30 M) of sulfide were present; no growth occurred on 5–100 M sulfide alone. Methanethiol, ethanethiol, and methyl sulfide-using cultures produced sulfide during growth.     

Dissimilatory Iron Reduction and Odor Indicator Abatement by Biofilm Communities in Swine Manure Microcosms

Animal waste odors arising from products of anaerobic microbial metabolism create community relations problems for livestock producers. We investigated a novel approach to swine waste odor reduction: the addition of FeCl₃, a commonly used coagulant in municipal wastewater treatment, to stimulate degradation of odorous compounds by dissimilatory iron-reducing bacteria (DIRB). Two hypotheses were tested: (i) FeCl₃ is an effective source of redox-active ferric iron (Fe³⁺) for dissimilatory reduction by bacteria indigenous to swine manure, and (ii) dissimilatory iron reduction results in significant degradation of odorous compounds within 7 days. Our results demonstrated that Fe³⁺ from FeCl₃ was reduced biologically as well as chemically in laboratory microcosms prepared with prefiltered swine manure slurry and limestone gravel, which provided pH buffering and a substrate for microbial biofilm development. Addition of a 1-g liter⁻¹ equivalent concentration of Fe³⁺ from FeCl₃, but not from presynthesized ferrihydrite, caused initial, rapid solids flocculation, chemical Fe³⁺ reduction, and E_h increase, followed by a 2-day lag period. Between 2 and 6 days of incubation, increases in Fe²⁺ concentrations were accompanied by significant reductions in concentrations of volatile fatty acids used as odor indicators. Increases in Fe²⁺ concentrations between 2 and 6 days did not occur in FeCl₃-treated microcosms that were sterilized by gamma irradiation or amended with NaN₃, a respiratory inhibitor. DNA sequences obtained from rRNA gene amplicons of bacterial communities in FeCl₃-treated microcosms were closely related to Desulfitobacterium spp., which are known representatives of DIRB. Use of iron respiration to abate wastewater odors warrants further investigation.     

Production of methyl sulfide and dimethyl disulfide from soil-incorporated plant materials and implications for controlling soilborne pathogens

Soil-incorporated plant materials have been associated with reduction in soilborne pathogens and diseases. Mechanisms of the biocidal actions are complex and not well understood. A glasshouse experiment, a non replicated field demonstration, and a field experiment were conducted to determine volatile compounds after incorporation of various plant species and their effect on pest control. Cabbage (Brassica oleracea), canola (Brassica rapa), kale (Brassica oleracea var. acephala), lettuce (Lactuca sativa var. valmaine), two mustard varieties -Caliente (Brassica juncea) and Green wave (Brassica juncea), two radish varieties - Oil seed (Raphanus sativus var. oleiformis) and Cherriette (Raphanus sativus), common rye (Secale cereale), and sorghum Sudan grass (Sorghum bicolor var. sudanese) were used in the glasshouse experiment. Caliente 199 mustard (Brassica hirta) was planted in the field demonstration and white mustard (Sinapis alba) was used in the field experiment. Fresh plant materials were chopped manually in the glasshouse experiment and mechanically in the field studies at the flowering stage before incorporation in natural field soils. In the glasshouse experiment, the equivalent biomass dry weight ranged from a minimum of 573 g?m^?2 for L. sativa var. valmaine to a maximum of 1851 g?m^?2 for S. bicolor var. sudanese. The average biomass was 792 g?m^?2 for B. hirta and 804 g?m^?2 for S. alba in the two field studies, respectively. The glasshouse experiment used a loamy sand field soil inoculated with a natural fine sandy loam soil that was known to contain high populations of Verticillium dahliae. Soils at both field sites belonged to the sandy loam series, and efforts were made to maintain sufficient soil moisture for plant growth. Although the interest was to determine all volatile compounds in general, only methyl sulfide and dimethyl disulfide were identified and subsequently quantified. Depending on plant species and time of sampling (one to seven days after soil incorporation), 2.7 to 346.4?μg g ^?1 plant dry weight for methyl sulfide and 0 to 283.2?μg g ^?1 plant dry weight for dimethyl disulfide were found in the glasshouse experiment. In general, high concentrations of dimethyl disulfide and methyl sulfide appeared to have reduced V. dahliae colony counts in bioassay potato stem saps in the glasshouse experiment. However, the correlation was weak (R ² ?=?0.31), but a relatively stronger correlation was obtained (R ² ?=?0.58) when excluding B. oleracea and B. rapa from the regression. Dimethyl disulfide and methyl sulfide were nearly non-detectable in the field demonstration, consequently no disease assessment was made. In the field experiment, a production of 5.2?μg g ^?1 plant dry weight for methyl sulfide and 1.2?μg g ^?1 dry weight for dimethyl disulfide was found two days after soil incorporation of S. alba. Compared to the untreated control, total Fusarium oxysporum counts in field soil were significantly lower 39 days after S. alba incorporation. However, no significant impact was found on total Pythium counts. Soil population of citrus nematode (Tylenchulus semipenetrans) in the S. alba plots was significantly reduced to similar levels found in the untreated control 112 days after S. alba incorporation. Compared to the untreated control, soil density of non plant parasitic freeliving nematodes was higher 39 days after S. alba incorporation. The study demonstrated quantifiable production of methyl sulfide and dimethyl disulfide gases from a variety of plant species in glasshouse and natural field environments. Some beneficial effects against V. dahliae, F. oxysporum, and T. semipenetrans were observed. Additional studies are needed to further elucidate these complex chemical and biological interactions.     

大陈岛海域浮游动物群落季节变化及其影响因素

为探究大陈岛海域浮游动物群落的季节变化,于2020年9月（夏季）、11月（秋季）和2021年1月（冬季）、4月（春季）分别对大陈岛海域的浮游动物及环境因子进行了4个航次的调查。结果共鉴定浮游动物90种,包括浮游幼体15类,其中夏季种类数最多（68种）,冬季最少（20种）,常见的优势种有：百陶箭虫（Sagitta bedoti）、微刺哲水蚤（Canthocalanus pauper）、中华哲水蚤（Calanus sinicus）等12种（Y>0.02）。浮游动物的年平均丰度和生物量分别为（153.40±214.73）个/m³、（411.93±561.76） mg/m³,二者存在明显的季节变化,平均丰度为春季（380.17±296.14）个/m³>夏季（135.30±112.59）个/m³>秋季（67.88±90.52）个/m³>冬季（25.30±19.11）个/m³;平均生物量为夏季（895.01±802.54） mg/m³>春季（623.39±358.73） mg/m³>秋季（91.08±82.36） mg/m³>冬季（45.96±84.95） mg/m³。多样性指数（H''）和均匀度指数（J''）的年平均值分别为1.71±0.96和0.53±0.20,均表现出夏秋季较高、冬春季较低的特征。聚类分析结果表明调查海域的浮游动物可划分为夏季类群、秋季类群、冬季类群和春季类群4组类群。Pearson相关性分析和冗余分析（RDA）结果表明,海水温度、盐度、叶绿素a浓度是影响大陈岛海域浮游动物群落特征的重要环境因素。此外,夏季大陈岛海域水母类浮游动物暴发的现象值得关注。研究结果将为大陈岛海域的生物多样性保护及渔业资源可持续开发利用提供可参考的数据资料。     

Aerobic turnover of dimethyl sulfide by the anoxygenic phototrophic bacterium Thiocapsa roseopersicina

This is the first report describing the complete oxidation of dimethyl sulfide (DMS) to sulfate by an anoxygenic, phototrophic purple sulfur bacterium. Complete DMS oxidation was observed in cultures of Thiocapsa roseopersicina M11 incubated under oxic/light conditions, resulting in a yield of 30.1 mg protein mmol^–1. No oxidation of DMS occurred under anoxic/light conditions. Chloroform, methyl butyl ether, and 3-amino-1,2,4-triazole, which are specific inhibitors of aerobic DMS oxidation in thiobacilli and hyphomicrobia, did not affect DMS oxidation in strain M11. This could be due to limited transport of the inhibitors through the cell membrane. The growth yield on sulfide as sole electron donor was 22.2 mg protein mmol^–1 under anoxic/light conditions. Since aerobic respiration of sulfide would have resulted in yields lower than 22 mg protein mmol^–1, the higher yield on DMS under oxic/light conditions suggests that the methyl groups of DMS have served as an additional carbon source or as an electron donor in addition to the sulfide moiety. The kinetic parameters V _max and K _m for DMS oxidation under oxic/light conditions were 12.4 ± 1.3 nmol (mg protein)^–1 min^–1 and 2 μM, respectively. T. roseopersicina M11 also produced DMS by cleavage of dimethylsulfoniopropionate (DMSP). Specific DMSP cleavage rates increased with increasing initial substrate concentrations, suggesting that DMSP lyase was only partly induced at lower initial DMSP concentrations. A comparison of T. roseopersicina strains revealed that only strain M11 was able to oxidize DMS and cleave DMSP. Both strain M11 and strain 5811 accumulated DMSP intracellularly during growth, while strain 1711 showed neither of these characteristics. Phylogenetic comparison based on 16S rRNA gene sequence revealed a similarity of 99.0% between strain M11 and strain 5811, and 97.6% between strain M11 and strain 1711. DMS and DMSP utilization thus appear to be strain-specific. Received: 26 March 1999 / Accepted: 18 June 1999     

Effects of Methylated, Organic, and Inorganic Substrates on Microbial Consumption of Dimethyl Sulfide in Estuarine Waters

We examined the effects of a variety of amendments on the consumption of [U-¹⁴C]dimethyl sulfide in a Georgia salt marsh. Methylated compounds, particularly those with dimethyl groups, significantly inhibited dimethyl sulfide consumption, while nonmethylated substrates had little effect. Dimethyl disulfide and dimethyl ether were the most effective inhibitors tested.     

Removal and determination of trimethylsilanol from the landfill gas

The removal and determination of trimethylsilanol (TMSOH) in landfill gas has been studied before and after the special E3000-ITC System. The system works according to principle of temperature swing. The performance of TMSOH and humidity removal was 20% and more than 90%, respectively. The six of active carbons and impinger method were tested on the full-scale landfill in Poland for TMSOH and siloxanes determination. The extraction method and absorption in acetone were used. The concentration of TMSOH and siloxanes were found in range from 23.6 to 29.2 mg/m³ and from 18.0 to 38.9 mg/m³, respectively. The content of TMSOH in biogas originating from landfill was 41% out of all siloxanes. Moreover, the used system is alternative to other existing technique of landfill gas purification.     

Seasonal changes in fluxes of methane and volatile sulfur compounds from rice paddies and their concentrations in soil water

Rice paddies emit not only methane but also several volatile sulfur compounds such as dimethyl sulfide (DMS: CH₃SCH₃). However, little is known about DMS emission from rice paddies. Fluxes of methane and DMS, and the concentrations of methane and several volatile sulfur compounds including hydrogen sulfide (H₂S), carbonyl disulfide (CS₂), methyl mercaptan (CH₃SH) and DMS in soil water and flood water were measured in four lysimeter rice paddies (2.5 × 4 m, depth 2.0 m) once per week throughout the entire cultivation period in 1995 in Tsukuba, Japan. The addition of exogenous organic matter (rice straw) was also examined for its influence on methane or DMS emissions. Methane fluxes greatly differed between treatments in which rice straw had been incorporated into the paddy soil (rice straw plot) and plots without rice straw (mineral fertilizer plot). The annual methane emission from the rice straw plots (37.7 g m^-2) was approximately 8 times higher than that from the mineral fertilizer plots (4.8 g m^-2). Application of rice straw had little influence on DMS fluxes. Significant diurnal and seasonal changes in DMS fluxes were observed. Peak DMS fluxes were found around noon. DMS was emitted from the flood water in the early growth stage of rice and began to be emitted from rice plants during the middle stage. DMS fluxes increased with the growth of rice plants and the highest flux, 15.1 µg m^-2 h^-1, was recorded before heading. DMS in the soil water was negligible during the entire cultivation period. These facts indicate that the DMS emitted from rice paddies is produced by metabolic processes in rice plants. The total amount of DMS emitted from rice paddies over the cultivated period was estimated to be approximately 5–6 mg m^-2. CH₃SH was emitted only from flood water during the first month after flooding.     

Preliminary survey of indoor and outdoor airborne microfungi at coastal buildings in Egypt

Forty six species and two sterile fungi and yeast species were isolated from samples collected both indoors and outdoors of coastal buildings located in an Egyptian coastal city. Twenty flats from ten buildings were investigated; children living in these buildings have been reported to suffer from respiratory illnesses. Samples were taken using a New Brunswick sampler (model STA-101) operating for 3.0 min at a flow rate of 6.0 l/min. Most of the species isolated have been associated with symptoms of respiratory allergies. Indoors the total culturable fungal count was 1548 CFU/m³; outdoors, it was 1452 CFU/m³. Indoor values of culturable fungal count, total spores count and ergosterol content ranged from 52 to 124 CFU/m³, 100 to 400 spore/m³ and 5 to 27.7 mg/m³, respectively, whereas outdoor levels typically varied between 25 and 222 CFU/m³, 110 and 900 spore/m³ and 3.3 and 67.2 mg/m³, respectively. The maxima for these parameters were detected indoors in house no. 6 and outdoors, outside of house no. 7. The most abundant species were primarily mitosporic (2832 CFU/m³). The most frequent species in both the indoor and outdoor samples were Cladosporium cladosporioides followed by Alternaria alternata and Penicillium chrysogenum,with inside:outside ratios of 1.4, 1.8 and 1.9, respectively. The patterns of fungal abundance were influenced to some extent by changes in the relative humidity and temperature. Other factors, such as type of culture media, rate of sedimentation, size, survival rates of spore and species competition,also affected fungal counts and should be taken into consideration during any analysis of bioaerosol data.     

Simultaneous biological removal of sulfur, nitrogen and carbon using EGSB reactor

High-rate biological conversion of sulfide and nitrate in synthetic wastewater to, respectively, elemental sulfur (S⁰) and nitrogen-containing gas (such as N₂) was achieved in an expanded granular sludge bed (EGSB) reactor. A novel strategy was adopted to first cultivate mature granules using anaerobic sludge as seed sludge in sulfate-laden medium. The cultivated granules were then incubated in sulfide-laden medium to acclimate autotrophic denitrifiers. The incubated granules converted sulfide, nitrate, and acetate simultaneously in the same EGSB reactor to S⁰, N-containing gases and CO₂ at loading rates of 3.0 kg S m⁻³ d⁻¹, 1.45 kg N m⁻³ d⁻¹, and 2.77 kg Ac m⁻¹ d⁻¹, respectively, and was not inhibited by sulfide concentrations up to 800 mg l⁻¹. Effects of the C/N ratio on granule performance were identified. The granules cultivated in the sulfide-laden medium have Pseudomonas spp. and Azoarcus sp. presenting the heterotrophs and autotrophs that co-work in the high-rate EGSB-SDD (simultaneous desulfurization and denitrification) reactor.     

Fumigant toxicity of cassia bark and cassia and cinnamon oil compounds to <Emphasis Type="Italic">Dermatophagoides </Emphasis><Emphasis Type="Italic">farinae </Emphasis>and <Emphasis Type="Italic">Dermatophagoides pteronyssinus</Emphasis> (Acari: Pyroglyphidae)

The toxicity to adults of the American house dust mite, Dermatophagoides farinae, and the European house dust mite, Dermatophagoides pteronyssinus, of cassia bark and cassia and cinnamon oil compounds was examined using residual contact and vapour-phase toxicity bioassays. Results were compared with those of the currently used acaricides: benzyl benzoate and dibutyl phthalate. The acaricidal principles of cassia bark were identified as (E)-cinnamaldehyde and salicylaldehyde. In fabric-circle residual contact bioassays with adult D. farinae, salicylaldehyde (17.3 mg/m²) and (E)-cinnamaldehyde (25.8 mg/m²) were 2.5 and 1.7 times more toxic than benzyl benzoate (43.7 mg/m²), respectively, based on 24-h LD₅₀ values. The acaricidal activity was more pronounced in benzaldehyde, menthol, α-terpineol, and thymol (70.8–234.3 mg/m²) than in dibutyl phthalate (281.0 mg/m²). Against adult D. pteronyssinus, salicylaldehyde (17.3 mg/m²) and (E)-cinnamaldehyde (19.3 mg/m²) were 2.4- and 2.2-fold more active than benzyl benzoate (41.9 mg/m²). The toxicity of benzaldehyde, menthol, α-terpineol, and thymol (75.3–179.2 mg/m²) was higher than that of dibutyl phthalate (285.1 mg/m²). In vapour-phase toxicity tests with adult D. farinae, the test compounds described were much more effective in closed—but not in open—containers, indicating that the effect of these compounds was largely a result of action in the vapour phase.     

A phase I biological study of azacitidine (VidazaTM) to determine the optimal dose to inhibit DNA methylation

This study aims to determine the optimal dosing and administration route for azacitidine to reduce global DNA methylation levels in the peripheral blood of patients with hematologic malignancies. Seventeen patients were enrolled into one of five dose level treatment groups (3 at 25mg/m², 4 at 50mg/m², 4 at 75mg/m², 3 at 100mg/m², and 3 at 150mg/m²) and received IV azacitidine at their respective dose on days 1-5 of cycle one. All patients received 75mg/m²/day IV on days 1-5 of cycle 2. Subcutaneous dosing of 75mg/m²/day on days 1-5 was used in cycle 3. Peripheral blood was collected on days 1, 3, and 5 of each cycle, and global DNA methylation was measured using bisulfite-PCR pyrosequencing of the DNA repetitive element LINE-1. 14 patients were evaluable for response with 2 CR, 2 PR, 7 SD and 3 PD reported. LINE-1 DNA methylation decreased by 1.37, 2.29, 4.81, 1.94 and 4.05% on day 5 for the 25mg/m², 50mg/m2, 75mg/m², 100mg/m² and 150mg/m² cycle one dose levels respectively. Mean decrease in LINE-1 DNA methylation was 3.7% with 75mg/m² IV and 3.4% by subcutaneous adminstration. The data indicates that 75mg/m² azacitidine given IV or SC effectively leads to global DNA methylation reduction by LINE-1 analysis.