Aerobic dissipation of the novel cyanoacrylate fungicide phenamacril in soil and sludge incubations

The cyanoacrylate ethyl (2Z)-3-amino-2-cyano-3-phenylacrylate (phenamacril), has been introduced as an effective agent against several fungi species belonging to the Fusarium genus. However, in current literature, knowledge about the environmental behavior of this fungicide is limited and there are no data on the degradation in the environment. By performing tests on inherent degradability as well as degradation studies in soils this study provides the only published information regarding the environmental stability and degradation kinetics of this compound. Tests for inherent/ready biodegradation revealed the phenamacril is inherently degradable with zero order kinetics, even though the degradation is comparatively slow. Degradation of phenamacril in soil was found to occur following first order kinetics with a final plateau with a half live of 17.1 days (i.e. more rapidly than tebuconazole but less rapidly than octylisothiazolinone).

Resistance and Stability of A New Method for Bonding Biological Materials Using Sutures and Biological Adhesives

The valve leaflets of cardiac bioprostheses are secured and shaped by sutures which, given their high degree of resistance and poor elasticity, have been implicated in the generation of stresses within the leaflets, contributing to the failure of the bioprostheses. Bioadhesives are bonding materials that have begun to be utilized in surgery, although there is a lack of experience in their use with inert tissues or bioprostheses.

Tensile testing is performed until rupture in samples of calf pericardium, a biomaterial employed in the manufacture of bioprosthetic heart valve leaflets.

One hundred and thirty-two trials are carried out in three types of samples: intact or control tissue ( n = 12); samples transected and glued in an overlapping manner with a cyanoacrylate ( n = 60); and samples transected, sewn with a commercially available suture material and reinforced at the suture holes with the same cyanoacrylate ( n = 60). Seven days after their preparation, 12 samples from each group, including the controls, are subjected to tensile testing until rupture and the findings are compared.

In the stability study, groups of 12 each of the remaining 48 glued and 48 sutured and glued samples underwent tensile testing until rupture on days 30, 60, 90, and 120, after their preparation.

The results show that bonding with the adhesive provided a resistance ranging between 1.04 and 1.87 kg, probably insufficient for use in valve leaflets, but also afforded a high degree of elasticity. After 120 days, both the glued and the sutured and glued series show excellent elastic behavior, with no rigidity or hardening of the pericardium. These samples present reversible elongation, or strain, when they surpass their elastic limit at rupture. This finding may be due to a load concentration that is damaging to the pericardium, to the behavior of the tissue as an amorphous material, or perhaps to both circumstances.

These results need to be confirmed in future studies as they may be of value in the design and manufacture of cardiac bioprostheses.

[Preparation and in vitro release characteristics of vincristine sulphate loaded poly (butylcyanoacrylate) nanoparticles]

OBJECTIVE

To prepare vincristine sulphate loaded poly (butylcyanoacrylate) nanoparticles (VCR-PBCA-NPs) and to investigate the in vitro release charactersitics.

METHOD

VCR-PBCA-NPs were prepared by emulsion polymerization method, and characterized for morphology, particle size, drug encapsulation efficiency and loading efficiency. The formulation was optimized using central composite design and response surface methodology. In vitro release study of VCR-PBCA-NPs was performed by dialysis technique. Model fitting was used to determine the kinetics and to discuss the mechanism.

RESULT

The nanoparticles were spherical and uniform with a mean diameter of (98.9 +/- 3.05) nm. The drug encapsulation efficiency and loading efficiency were (55.23 +/- 0.96)% and (7.87 +/- 0.11)%, respectively. In vitro release results showed that 63.66% of VCR was released from VCR-PBCA-NPs in 4 h, and the Weibull model fitted VCR release pattern best.

CONCLUSION

The VCR-PBCA-NPs prepared in this study showed sustained release compared with VCR solution.

In vitro toxicity test of ethyl 2-cyanoacrylate, a tissue adhesive used in cardiovascular surgery, by fibroblast cell culture method

BACKGROUND

The aim of this study was to evaluate the cytotoxicity of cyanoacrylate polymers (ethyl 2-cyanoacrylate) by an elution test system. In such systems, the material is extracted with a cell culture medium, which is subsequently added onto cultured cells, resulting in an indirect contact between the biomaterial and cells.

METHODS

A cell line commonly utilized for cytotoxicity experiments; L929 mouse fibroblasts were used in this study. The effects of extract dilutions on cells were evaluated by two experiments: (a) The cells were suspended and seeded in a medium containing the extract, followed by a short incubation to observe the effects on cell attachment; (b) cells were seeded in a normal medium. Following cell attachment, this was replaced with a medium containing the extract and long-term effects on cell proliferation were measured. The cytotoxicity was quantified using a cell viability assay, well established for use in the evaluation of cell-biomaterial interactions.

RESULTS

These results indicate that, in the test system utilized, a tenfold dilution of the extract results in an approximately 10% decrease in cells; this increases to between 30% and 45% in a 1:1 dilution. When a large number of cells (3000/well) were used, proliferation of cells overcame the cytotoxic effect and consistent results could not be observed.

CONCLUSIONS

In this study, the observed outcomes follow a similar trend on cell attachment and proliferation with acute effects (4 hours incubation) of the extracts on the cells, producing slightly higher toxicity. Our findings are parallel with the literature findings.

Shewanella loihica sp. nov., isolated from iron-rich microbial mats in the Pacific Ocean

A novel marine bacterial strain, PV-4(T), isolated from a microbial mat located at a hydrothermal vent of Loihi Seamount in the Pacific Ocean, has been characterized. This micro-organism is orangey in colour, Gram-negative, polarly flagellated, facultatively anaerobic and psychrotolerant (temperature range, 0-42 degrees C). No growth was observed with nitrate, nitrite, DMSO or thiosulfate as the electron acceptor and lactate as the electron donor. The major fatty acid detected in strain PV-4(T) was iso-C(15 : 0). Strain PV-4(T) had ubiquinones consisting mainly of Q-7 and Q-8, and possessed menaquinone MK-7. The DNA G+C content of the strain was 53.8 mol% and the genome size was about 4.5 Mbp. Phylogenetic analyses based on 16S rRNA gene sequences placed PV-4(T) within the genus Shewanella. PV-4(T) exhibited 16S rRNA gene sequence similarity levels of 99.6 and 97.5 %, respectively, with respect to the type strains of Shewanella aquimarina and Shewanella marisflavi. DNA from strain PV-4(T) showed low mean levels of relatedness to the DNAs of S. aquimarina (50.5 %) and S. marisflavi (8.5 %). On the basis of phylogenetic and phenotypic characteristics, the bacterium was classified in the genus Shewanella within a distinct novel species, for which the name Shewanella loihica sp. nov. is proposed. The type strain is PV-4(T) (=ATCC BAA-1088(T)=DSM 17748(T)).

Actinospica robiniae gen. nov., sp. nov. and Actinospica acidiphila sp. nov.: proposal for Actinospicaceae fam. nov. and Catenulisporinae subord. nov. in the order Actinomycetales

Two novel Gram-positive, acidophilic bacterial strains were isolated from forest soil. According to their 16S rRNA gene sequences, these strains are related closely to each other and form a distinct cluster within the order Actinomycetales. They show the typical features of filamentous actinomycetes, with branched vegetative hyphae and production of aerial hyphae. The distinct phylogenetic positions and the combination of chemotaxonomic characteristics of these strains justify the proposal of Actinospica gen. nov. Both strains display 3-hydroxydiaminopimelic acid plus traces of meso-diaminopimelic acid, the phospholipids diphosphatidylglycerol, phosphatidylethanolamine, methylphosphatidylethanolamine and phosphatidylinositol, the predominant cellular fatty acids i-C15 : 0, i-C16 : 0 and ai-C15 : 0 and the whole-cell sugars mannose and rhamnose. They differ in the fatty acid profiles, in the quantitative ratios of the major menaquinones MK-9(H4), MK-9(H6) and MK-9(H8) and in the occurrence of additional whole-cell sugars (arabinose and xylose in strain GE134766T and galactose in strain GE134769T). Differences in the phenotypic characteristics and in the 16S rRNA gene sequences suggest the description of two species, Actinospica robiniae gen. nov., sp. nov. (the type species) and Actinospica acidiphila sp. nov., with the type strains GE134769T (=DSM 44927T=NRRL B-24432T) and GE134766T (=DSM 44926T=NRRL B-24431T), respectively. The DNA G+C contents of strains GE134769T and GE134766T are 70.8 and 69.2 mol%, respectively. Due to the large phylogenetic distance from known actinomycete genera, it is proposed to accommodate Actinospica gen. nov. in Actinospicaceae fam. nov. In addition, Catenulisporineae subord. nov. is proposed to harbour Actinospicaceae fam. nov. and the newly proposed family Catenulisporaceae, described in the accompanying paper.

Amycolatopsis taiwanensis sp. nov., from soil

An actinomycete strain (0345M-7T) was isolated from a soil sample from Yilan county, Taiwan. The isolate displayed substrate mycelia, upon which were borne short spore chains. The spore chains were composed of non-motile, smooth-surfaced, oval spores. Strain 0345M-7T had meso-diaminopimelic acid in its peptidoglycan. Whole-cell sugars were galactose, glucose, arabinose and ribose. The only phospholipid found was phosphatidylethanolamine. The predominant menaquinone was MK-9(H4). Mycolic acids were not detected. Major cellular fatty acids were iso-C16 : 0 (38.1 %) and C17 : 1 (25.4 %). The DNA G+C content of strain 0345M-7T was 68.9 mol%. On the basis of phenotypic and genotypic data, it is proposed that strain 0345M-7T (=BCRC 16802T=KCTC 19116T) should be classified as the type strain of a novel species of the genus Amycolatopsis, Amycolatopsis taiwanensis sp. nov.

Niastella koreensis gen. nov., sp. nov. and Niastella yeongjuensis sp. nov., novel members of the phylum Bacteroidetes, isolated from soil cultivated with Korean ginseng

Two novel strains, GR20-10T and GR20-13T, were isolated from soil using R2A medium. The soil sample was collected from a field in the Yeongju region of Korea that was cultivated with Korean ginseng. Phylogenetic analysis based on 16S rRNA gene sequences indicated that these strains formed a cluster with several uncultured bacterial clones and with Flexibacter filiformis, Flexibacter sancti, Flexibacter japonensis, Cytophaga arvensicola and Flavobacterium ferrugineum (recently reclassified as Terrimonas ferruginea) in the phylum Bacteroidetes. The level of 16S rRNA gene sequence similarity between the two novel strains was 98.9 %. Isolates GR20-10T and GR20-13T showed the highest sequence similarities to Flexibacter japonensis IFO 16041T (91.8 and 91.9 %, respectively) and T. ferruginea ATCC 13524T (90.4 and 90.6 %, respectively). The whole-cell fatty acid profiles of the two isolates were similar and their major fatty acids were 15 : 0 iso, 17 : 0 iso 3-OH and 15 : 1 iso G. The major isoprenoid quinone of both strains was MK-7. The G+C contents of GR20-10T and GR20-13T were 45.8 and 44.3 mol%, respectively. DNA–DNA hybridization (57 % DNA–DNA hybridization value) and phenotypic data indicated that strains GR20-10T and GR20-13T each belong to a separate species. On the basis of phenotypic and phylogenetic data and genomic distinctiveness, strains GR20-10T and GR20-13T represent two novel species in a novel genus in the phylum Bacteroidetes; the names Niastella koreensis gen. nov., sp. nov. (the type species; type strain GR20-10T=KACC 11465T=DSM 17620T) and Niastella yeongjuensis sp. nov. (type strain GR20-13T=KACC 11466T=DSM 17621T) are proposed.

Brooklawnia cerclae gen. nov., sp. nov., a propionate-forming bacterium isolated from chlorosolvent-contaminated groundwater

Two novel facultatively anaerobic bacterial strains, BL-34T and BL-35, isolated from groundwater contaminated by a mixture of chlorosolvents were characterized using a polyphasic approach. The two strains exhibited essentially identical taxonomic features except for a vitamin B12 requirement by strain BL-35 for optimal growth. Phylogenetically, the isolates were affiliated with members of the family Propionibacteriaceae and were placed in a phylogenetic branch adjacent to, but distinct from, those of the genera Propionimicrobium, Propionibacterium, Luteococcus, Propioniferax and Tessaracoccus. The cells of the novel strains were Gram-positive, non-motile, non-spore-forming pleomorphic rods. They produced catalase but not oxidase, and nitrate reduction did not occur in peptone/yeast extract/glucose medium. Propionate and acetate were the predominant products of glucose fermentation. Fermentation occurred in the presence of 1,2-dichloroethane and 1,1,2-trichloroethane at concentrations up to at least 9.8 mM. The genomic DNA G+C content was 67.5–67.9 mol%. Menaquinone MK-9(H4) was the predominant respiratory quinone and meso-diaminopimelic acid was present in the cell-wall peptidoglycan layer. The major cellular fatty acids were C15 : 0 and anteiso-C15 : 0. On the basis of the results obtained in this study, strains BL-34T and BL-35 should be classified within a novel taxon, for which the name Brooklawnia cerclae gen. nov., sp. nov. is proposed. The type strain of Brooklawnia cerclae is BL-34T (=LMG 23248T=NRRL B-41418T). An additional strain, BL-35 (=LMG 23249=NRRL B-41419), was also characterized.

Bacillus seohaeanensis sp. nov., a halotolerant bacterium that contains l-lysine in its cell wall

A halotolerant, round-endospore-forming, aerobic, Gram-positive bacterium, designated BH724T, was isolated from a solar saltern at Taean in Korea. Cells of this strain were rod-shaped and found to be non-motile. Strain BH724T grew at salinities of 0–10 % (w/v) NaCl with an optimum of 3 % (w/v) NaCl and at temperatures of 15–50 °C with an optimum of 40 °C. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain BH724T belonged to the genus Bacillus and that Bacillus aquimaris TF-12T, Bacillus marisflavi TF-11T and Bacillus vietnamensis JCM 11124T were its closest neighbours, sharing 97.3, 97.2 and 97.0 % 16S rRNA gene sequence similarity, respectively. The genomic DNA G+C content was 39 mol% and the predominant menaquinone was MK-7. Its major cellular fatty acids were anteiso-C15 : 0, iso-C15 : 0, iso-C16 : 0 and iso-C14 : 0. The peptidoglycan type was A1α, linked directly through l-lysine. On the basis of morphological, chemotaxonomic, physiological and phylogenetic properties, strain BH724T represents a novel species of the genus Bacillus, for which the name Bacillus seohaeanensis sp. nov. is proposed. The type strain is BH724T (=KCTC 3913T=DSM 16464T).

Lentibacillus halophilus sp. nov., from fish sauce in Thailand

Fifteen strains of extremely halophilic bacteria were isolated from fish sauce (nam-pla) collected in Thailand at various stages of the fish-fermentation process. The isolates were strictly aerobic, spore-forming, Gram-positive rods. They grew optimally in the presence of 20–26 % NaCl. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The predominant menaquinone was MK-7. The major cellular fatty acids were anteiso-C15 : 0 and anteiso-C17 : 0. Polar lipid analysis revealed the presence of phosphatidylglycerol, diphosphatidylglycerol and two unidentified glycolipids. The DNA G+C content was 42.1–43.1 mol%. On the basis of the 16S rRNA gene sequence, a representative strain, PS11-2T, was found to be closely related to Lentibacillus juripiscarius JCM 12147T (97.3 % similarity). The 15 strains were included in the same species on the basis that the levels of DNA–DNA relatedness with strain PS11-2T were greater than 70 %. They could be distinguished from L. juripiscarius and other Lentibacillus species on the basis of several phenotypic characteristics and low levels of DNA–DNA relatedness (⩽19.4 %). Therefore, the strains represent a novel species of the genus Lentibacillus, for which the name Lentibacillus halophilus sp. nov. is proposed. The type strain is PS11-2T (=JCM 12149T=TISTR 1549T=PCU 240T).

Catenulispora acidiphila gen. nov., sp. nov., a novel, mycelium-forming actinomycete, and proposal of Catenulisporaceae fam. nov

A novel, Gram-positive bacterial strain was isolated from forest soil. Among species with validly published names, the 16S rRNA gene sequence is related most closely (approx. 93 % similarity) to that of Sporichthya polymorpha DSM 43042T. However, differently from this species, it forms both vegetative and aerial mycelia. The aerial hyphae are straight to slightly flexuous, starting to septate to form chains of more than 20 cylindrical spores with a rugose surface. The strain is acidophilic, with a pH range for robust growth between 4.3 and 6.8 and an optimum around 6.0. The peptidoglycan type is A3γ ll-Dpm–Gly. The polar lipids are phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannosides and two unknown phospholipids. Predominant menaquinones are MK-9(H6) and -9(H4), and iso- and anteiso-branched C16 : 0 and C17 : 0 are the main cellular fatty acids. The DNA G+C content is 71.9 mol%. The distinct phylogenetic position and the unusual combination of chemotaxonomic characteristics justify the proposal of Catenulispora gen. nov., with the type species Catenulispora acidiphila sp. nov. (type strain, ID139908T =DSM 44928T=NRRL B-24433T). Catenulisporaceae fam. nov. is also proposed.

Brevibacterium samyangense sp. nov., an actinomycete isolated from a beach sediment

A novel actinomycete, strain SST-8T, was isolated from sand sediment of Samyang Beach in Jeju, Korea, and subjected to a polyphasic taxonomic study. The organism, which produced opaque, circular, yellow colonies, with a coryneform morphology, showed the following chemotaxonomic characteristics:meso-diaminopimelic acid as the diamino acid in the peptidoglycan, MK-8(H2) as the major menaquinone, phosphatidylglycerol as the only polar lipid, anteiso-C15 : 0and anteiso-C17 : 0as major fatty acids and a DNA G+C content of 70.7 mol%. The combination of morphological and chemotaxonomic features supported its classification in the genusBrevibacterium. Phylogenetic analyses, based on 16S rRNA gene sequence studies, showed that strain SST-8Tformed an intermediate branch between theBrevibacterium luteolum/Brevibacterium otitidisandBrevibacterium mcbrellneri/Brevibacterium paucivoransclusters. Sequence similarity calculations based on a neighbour-joining analysis revealed that the closest relatives of strain SST-8Twere the type strains ofB. paucivorans(96.6 %),B. luteolum(96.5 %),B. mcbrellneri(96.3 %),Brevibacterium avium(96.0 %) andB. otitidis(95.9 %). Based on a broad set of phenotypic and genetic data, it was evident that the strain represents a novel species of the genusBrevibacterium. The nameBrevibacterium samyangensesp. nov. is proposed, with SST-8T(=NRRL B-41420T=KCCM 42316T) as the type strain.

Dyadobacter ginsengisoli sp. nov., isolated from soil of a ginseng field

A Gram-negative, aerobic, non-motile, non-spore-forming and rod-shaped bacterium, strain Gsoil 043T, was isolated from soil from a ginseng field in Pocheon province, South Korea. The novel isolate was characterized in order to determine its taxonomic position. On the basis of 16S rRNA gene sequence similarity, strain Gsoil 043T was shown to belong to the family ‘Flexibacteraceae’ and was related to Dyadobacter fermentans (96.7 %), Dyadobacter crusticola (96.3 %) and Dyadobacter hamtensis (95.8 %). The 16S rRNA gene sequence similarity of the novel strain to other recognized species within the family ‘Flexibacteraceae’ was less than 87.0 %. The G+C content of genomic DNA was 48 mol%. Phenotypic and chemotaxonomic data (major menaquinone, MK-7; major fatty acids, C16 : 1 ω7c, iso-C15 : 0 and C16 : 0) supported the affiliation of strain Gsoil 043T to the genus Dyadobacter. The results of physiological and biochemical tests enabled strain Gsoil 043T to be differentiated genotypically and phenotypically from the three Dyadobacter species with validly published names. The novel isolate therefore represents a novel species for which the name Dyadobacter ginsengisoli sp. nov. is proposed, with the type strain Gsoil 043T (=KCTC 12589T=LMG 23409T).

Occupational exposure to airborne solvents during nail sculpturing

This study describes occupational exposure to acrylates and other solvents during nail sculpturing, including comparative measurements of the exposure using four different sculpturing methods: The acrylic method, the UV-gel method, the acrylic powder method and the resin method. Thirty-two nail technicians working in 22 different salons participated in the study. In total, 92 measurements were performed, comprising 70 solvent measurements and 22 measurements of ethyl 2-cyanoacrylate. The solvents most frequently present in all samples were acetone, ethyl acetate, toluene and n-butyl acetate, measured in 96%, 94%, 91% and 81% of the samples, respectively. The study shows that the overall solvent exposure was low, with all measurements calculated as the additive effect (n = 70) below 20% of the OEL (arithmetic mean 0.06 and range 0.01-0.19). No statistically significant difference between sculpturing methods were observed (p = 0.05).

Interactions of blood proteins with poly(isobutylcyanoacrylate) nanoparticles decorated with a polysaccharidic brush

The aim of this work was to examine the in vitro interactions of core-shell poly(isobutylcyanoacrylate)-polysaccharide nanoparticles (NP) with blood proteins. The particles were prepared by initiating the emulsion polymerization of isobutylcyanoacrylate (IBCA) in the presence of dextran 71 or 15 kDa, heparin, a blend of dextran 71 and heparin, or dextran sulphate in aqueous medium at pH 1. The mechanisms of polymerisation were redox radical (Rad) or anionic (An), resulting in differences in the spatial arrangement of the polysaccharide chains at the NP surface, i.e. "loops" and "trains" by anionic polymerization, "brush" by radical polymerization. Surface composition of NPs was determined by X-ray photo-electron spectroscopy (XPS) and surface charge by zeta potential measurements. In the presence of citrated blood plasma, efficacy of the steric repulsive effect of the NP dextran shell towards protein adsorption decreased in the order: Dex71-Rad > Dex15-Rad > Dex71-AnDex15-An. Dextran-coated NPs adsorbed ApoA-I and fibrinogen from plasma. Concerning activation of complement in serum, the effect was sharp: Dex71-Rad was a very low activator whereas Dex15-An, Dex15-Rad and Dex71-An were strong activators. In citrated plasma, the steric repulsive effects of Hep-Rad and Dex-Hep-Rad NPs were similar to Dex71-An, and Dex-Sulph-Rad NPs adsorbed twice more proteins than Hep-Rad. Hep-Rad, Dex-Hep-Rad and Dex-Sulph-Rad NPs adsorbed IgG and fibrinogen. Complement was not activated in serum in the presence of Hep-Rad and Dex-Hep-Rad and a slight adsorption of C3 was noted. C3 was completely adsorbed on Dex-Sulph-Rad. The exquisite sensitivity of blood proteins to differences in the nature and outermost structure of the polysaccharides-coated NPs is highlighted by the present results.

Pontibacillus marinus sp. nov., a moderately halophilic bacterium from a solar saltern, and emended description of the genus Pontibacillus

A moderately halophilic, Gram-positive, rod-shaped bacterium (BH030004T) was isolated from a solar saltern in Korea. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain BH030004T belonged to the genus Pontibacillus. Chemotaxonomic data (DNA G+C content, 42 mol%; major isoprenoid quinone, MK-7; cell-wall type, A1γ-type meso-diaminopimelic acid; major fatty acids, iso-C15 : 0 and anteiso-C15 : 0) also supported the affiliation of the isolate to the genus Pontibacillus. Although the 16S rRNA gene sequence similarity between strain BH030004T and Pontibacillus chungwhensis DSM 16287T was relatively high (99·1 %), physiological properties and DNA–DNA hybridization (about 7 % DNA–DNA relatedness) allowed genotypic and phenotypic differentiation of strain BH030004T from the type strain of P. chungwhensis. Therefore, strain BH030004T represents a novel species of the genus Pontibacillus, for which the name Pontibacillus marinus sp. nov. is proposed. The type strain is BH030004T (=KCTC 3917T=DSM 16465T).

Bacillus arsenicus sp. nov., an arsenic-resistant bacterium isolated from a siderite concretion in West Bengal, India

Strain Con a/3T is a Gram-positive, motile, endospore-forming, rod-shaped and arsenic-resistant bacterium, which was isolated from a concretion of arsenic ore obtained from a bore-hole. The bacterium grew in the presence of 20 mM arsenate and 0·5 mM arsenite. Diaminopimelic acid was present in the cell wall peptidoglycan, MK-7 was the major menaquinone, and iso-C15 : 0, anteiso-C15 : 0, iso-C16 : 0 and C16 : 1(δ7cis) were the major fatty acids. Based on its phenotypic, chemotaxonomic and phylogenetic characteristics, strain Con a/3T was identified as a member of the genus Bacillus. It exhibited maximum similarity (97 %) at the 16S rRNA gene level with Bacillus barbaricus (DSM 14730T); however, the DNA–DNA relatedness value with B. barbaricus was 60 %. Strain Con a/3T also exhibited a number of phenotypic differences from B. barbaricus (DSM 14730T). Strain Con a/3T was therefore identified as representing a novel species of the genus Bacillus, for which the name Bacillus arsenicus sp. nov. is proposed. The type strain is Con a/3T (=MTCC 4380T=DSM 15822T=JCM 12167T).

Nocardioides aestuarii sp. nov., isolated from tidal flat sediment

A strictly aerobic, non-motile, rod-shaped actinomycete, designated strain JC2056T, was isolated from a sediment sample of getbol, the tidal flat of Korea. Results of 16S rRNA gene sequence analysis indicated that the isolate belonged to the genus Nocardioides, with the highest similarity being to Nocardioides luteus KCTC 9575T (95·7 %). The major menaquinone was MK-8(H4), and predominant cellular fatty acids were iso-16 : 0 and iso-16 : 1 H. The DNA G+C content was 70 mol%. Based on the morphological, physiological, biochemical and chemotaxonomical data presented in this study, strain JC2056T should be classified as a novel species, for which the name Nocardioides aestuarii sp. nov. is proposed; the type strain is JC2056T (=IMSNU 14029T=KCTC 9921T=JCM 12125T).

Jonesia quinghaiensis sp. nov., a new member of the suborder Micrococcineae

A coryneform strain isolated from soda lake mud in China corresponded in chemotaxonomic characteristics such as peptidoglycan type A4α l-lys–l-ser–d-Glu and major menaquinone MK-9, as well as in its DNA base composition (57 mol% G+C), to its phylogenetic neighbour Jonesia denitrificans. Differences in phenotypic characteristics and the phylogenetic distance (96·6 % 16S rRNA gene sequence similarity) from J. denitrificans justify the proposal of a second species of the genus Jonesia, Jonesia quinghaiensis sp. nov., with the type strain QH3A7T (=DSM 15701T=CGMCC 1.3459T).

Identification of some polymeric materials by low-temperature pyrolysis mass spectrometry

The application of low-temperature pyrolysis mass spectrometry to the identification of some commercial and synthetic polymers using a direct insertion probe and electron ionization has been studied. The polymers were analyzed directly in the solid probe of a mass spectrometer within the ion source at 70 eV electron impact. The quadrupole mass spectrometer, equipped with a gas chromatogram software and library of low molecular weight compounds, was used to characterize the polymers by measuring the chemical structure of the repeat units and the end groups, and to examine the thermal degradation pathways. The polymers investigated show different degradation pathways. Investigation of sequences and determination of composition of copolymers were studied. Total ion pyrogram and spectrum subtractions were used to separate and measure spectra of pyrolysis steps at distinctly different temperatures.

Peripheral neuropathy in workers exposed to nitromethane

BACKGROUND

Two workers from a headlight subassembly plant developed severe peripheral neuropathy. These workers had extensive, but brief (1-2 months) dermal and inhalational exposure to nitromethane, a solvent.

METHODS

Environmental sampling was performed for nitromethane and ethyl cyanoacrylate. Medical records, including electrodiagnostic studies, were reviewed. Literature on nitromethane, ethyl cyanoacrylate, and other exposures in the workplace was reviewed.

RESULTS

Electromyography and nerve conduction studies performed on these patients were consistent with a severe, axonal neuropathy. No etiology was discovered despite an extensive medical evaluation. Environmental sampling revealed exposure to nitromethane at the threshold limit value.

CONCLUSIONS

The history of acute onset of severe peripheral neuropathy temporally associated with exposure to nitromethane is suggestive of a toxic neuropathy. While it cannot be definitively concluded that these two workers developed peripheral neuropathy secondary to exposures at work, occupational exposure to nitromethane appears to be the most likely etiology.

Occupational asthma caused by exposure to cyanoacrylate

BACKGROUND

Exposure to acrylates may give rise to rhinitis and asthma in both industrial and domestic environments. The mechanisms underlying these respiratory conditions caused by acrylates remain largely unknown.

METHODS

We studied two assembly operators exposed to cyanoacrylate glue who developed rhinitis and asthma symptoms. The causal relationship of these symptoms to cyanoacrylate glue exposure was investigated by serial peak expiratory flow (PEF) monitoring at work and off work. Moreover, inhalation testing was performed by asking the patients to mimic exposure at work with the cyanoacrylate glue in a 7-m3 challenge chamber.

RESULTS

Serial PEF monitoring at work and away from work was consistent with occupational asthma in both patients. The methacholine inhalation test was negative in patient 1 (off work) and showed bronchial hyperresponsiveness in patient 2. After 20-min exposure to cyanoacrylate, the patients had late and progressive asthmatic reactions, respectively, and the methacholine test became positive in patient 1. Induced-sputum samples obtained 3 and 24 h after the cyanoacrylate challenge showed a marked increase in sputum eosinophils.

CONCLUSION

Exposure to cyanoacrylate in these patients provoked not only variable airflow limitation and bronchial hyperresponsiveness, but also pronounced eosinophilia in sputum.

Airborne concentrations of ethyl and methyl cyanoacrylate in the workplace

A survey was conducted of persons who manufacture, mix, bottle, and package methyl 2-cyanoacrylate (MCA) and ethyl 2-cyanoacrylate (ECA). Airborne concentrations of these cyanoacrylates also were measured during waste-handling operations. During a 1-week period, 162 personal and area samples were collected. About 90% of the samples were analyzed for ECA (the predominant adhesive being manufactured at the facility). About 50% of the samples were collected during periods of 15 min or less, the remainder for 15 to 240 min. Some 8-hour time-weighted average (TWA) samples also were collected. Samples were collected using Tenax tubes with subsequent analysis by high-performance liquid chromatography. Most samples were collected where highest exposure was likely (e.g., during mixing, bottling, and packaging). Peak concentrations of exposure (duration of 15 min or less), measured during a variety of tasks, ranged from 0.003 to 1.5 ppm. In particular, personal mean short-term airborne concentrations of ECA for the mixing operators ranged from 0.039 ppm to 0.650 ppm, while various 10-min to 1-hour activities were performed, with a TWA concentration of 0.07 ppm. Personal short-term airborne concentrations of ECA for bottling and packaging workers (n = 60) were 0.040 ppm +/- 0.016 ppm (mean +/- standard deviation), with similar 8-hour TWA concentrations due to the continuous nature of bottling and packaging. Other personal samples were not significantly different. The area samples were normally within a factor of 2 of the peak personal sampling results. These data indicate that, when handled at room temperature and relative humidity ranging from 40-69%, both MCA and ECA produce airborne concentrations that are nearly always less than about 0.1 ppm, which is less than the threshold of irritation.

[Identification of synthetic adhesives by simultaneous pyrolysis methylation gas chromatography]

At present, pyrolysis gas chromatography (Py-GC) is an effective analytical method for trace synthetic adhesives. Synthetic adhesives are usually composed of polar components. Thus, the polar pyrolysis products are normally difficult to measure by Py-GC due to their partial or complete adsorption in the pyrolysis zone, injection system or capillary column and the accuracy of results is seriously affected. Simultaneous pyrolysis methylation gas chromatography (Py-Me-GC) is a fast analytical method which was developed in recent years for polar compounds. The five synthetic adhesives have been identified by using Py-Me-GC in our study. Analytical conditions were: filament pyrolysis apparatus, flame ionization detector (FID), gas chromatograph, FFAP capillary column (30 m x 0.25 mm i.d.) and a quaternary ammonium salt as methylating agent. Major peaks of the products of pyrolysis were analysed qualitatively by GC/MS and comparisons were also made between the results by Py-Me-GC and those by Py-GC. The information gained from the components of substances by Py-Me-GC is more than that by Py-GC. The method is suitable for identifying synthetic adhesives of trace evidence in forensic science.

Measurement of airborne cyanoacrylates

The behaviour of common alkyl-2-cyanoacrylates in air has been investigated. Increasing humidity was found to increase the rate of polymerisation, although polymerisation is not instantaneous, even at high humidities. Sampling methods for these compounds have been studied and we are able to recommend a pumped Tenax sampling tube, although certain sampling limitations apply, notably that specified flow rates must be applied and that a maximum sampling time of four hours is recommended. Significant errors can occur if sampling is performed outside the range of conditions specified. Upon completion of sampling the tube is desorbed into 0.2% phosphoric acid in acetonitrile. The resulting solution is analysed by HPLC.

Decreased circulating levels of vitamin K and 25-hydroxyvitamin D in osteopenic elderly men

Changes in the circulating factors participating in involutional osteoporosis have been intensively investigated in women, but little is known about this in men. We investigated the possible participation of circulating factors including testosterone, vitamin D metabolites, and vitamins K1 and K2 in osteopenia in elderly men. In a group of 27 ambulatory men aged 74 +/- 10 years (mean +/- SD; range, 60 to 90), the bone mineral density (BMD) of the second to fourth lumbar vertebrae was measured by dual-energy x-ray absorptiometry (DXA) and expressed as a Z score, the age-adjusted BMD value for the Japanese population (mean +/- SD, 0 +/- 1). Although the plasma level of total testosterone significantly decreased with age in the group, it did not significantly correlate with the Z score. However, the plasma levels of 25-hydroxyvitamin D (25-OHD), phylloquinone, menaquinone-7 (MK-7), and albumin were significantly positively correlated with the Z score. Moreover, plasma 25-OHD and both phylloquinone and MK-7 were significantly positively correlated in the subjects. These observations suggest that depressed circulating levels of 25-OHD and vitamin K concomitantly and cooperatively participate in osteopenia in elderly men, which may reflect the etiology of the type II moiety of involutional osteoporosis.

An analytical methodology to quantify the incorporation of enzymes in polyalkylcyanoacrylate nanoparticles based on size exclusion chromatography

The performances of different methods of quantification of protein (methods based on direct spectrophotometric and spectrofluorimetric analysis, chemical reactions and liquid chromatography) to quantify the amount of enzyme incorporated into polyalkylcyanoacrylate nanoparticles, were compared. A methodology based on size exclusion chromatography was selected. The performances of the analytical method to quantify the enzymes L-asparaginase and superoxide dismutase in different polymerization media of poly-isobutilcyanoacrylate, were evaluated. The quantification of superoxide dismutase in the presence of esterase, enzyme used to solubilize nanoparticles, was attempted. An adequate separation between enzyme and the other components of polymerization media was achieved, so the selectivity of the method is adequate to the quantification of an enzyme in polymerization medium, either before or after polymerization. Although lack of selectivity of the column to separate enzymes was observed. The retention time of L-asparaginase and superoxide dismutase in polymerization medium are, respectively, 7.4 and 7.5. Linear correlation between peak area and enzyme concentration were observed for both enzymes in the concentration range from 10 to 80 micrograms ml-1, either before or after polymerization and in different polymerization media. This SE-HPLC analytical methodology is adequate to determine the degree of incorporation of enzymes in polyalkylcyanoacrylate nanoparticles as evidenced by the linear responses of the chromatographic method, the reproductibility of repeated sample injections and the precision of the quantification of enzyme concentration.

Europium aryl-beta-diketone complexes as fluorescent dyes for the detection of cyanoacrylate developed fingerprints on human skin

The application of europium luminescence to the visualisation of cyanoacrylate developed fingerprints is reported. Extremely fluorescent europium chelates are produced by the reaction of Eu3+ ions with aryl-beta-diketones. Excitation of the organic ligand occurs at 350 nm for europium tris(thenoyltrifluoroacetone) (TEC) and europium narrow band (10 nm) emission is observed at 614 nm as a result of an intramolecular energy transfer. The europium aryl-beta-diketone complexes are transferred into the interior of the polymeric cyanoacrylate from an aqueous methyl ethyl ketone solution. A two phase system is established with methyl ethyl ketone, water and chelate outside the polymer and methyl ethyl ketone and chelate inside. As the print dries the ketone evaporates 'locking' the chelate inside the cyanoacrylate. Sufficient TEC is deposited in the polymer so that the print is easily seen under 7 mW/cm2 of Hg light. Washing away of background contamination does not harm the fluorescent print. Prints deposited on cadaver skin and fumed with cyanoacrylate have been detected with good detail by this method.

Strengthening of feldspathic porcelain by ion exchange and tempering

This study investigated the effectiveness of tempering and ion-exchange treatments on crack growth and bi-axial flexural strength of seven feldspathic porcelains. The results showed that tempering treatment was more effective in strengthening porcelain than was the ion-exchange process as measured by the bi-axial flexural strength. However, the results of initial crack size induced by a microhardness tester showed that ion-exchange yielded a surface that was more resistant to crack initiation than was that yielded by the tempering treatment. EDX and microprobe analyses showed that there was evidence of exchange between Na+ within the porcelain surface and K+ from the ion-exchange agent applied on the surface.

Indirect determination of isocyanates by gas chromatography

A gas chromatographic method was developed to determine the purity of synthesized isocyanate monomers, specifically isocyanatoacrylates, and to determine the isocyanate content of synthesized polymers and prepolymers. The method is a modification of an ASTM procedure in which an isocyanate is allowed to react with excess di-n-butylamine. In the ASTM method, the amount of isocyanate present is calculated indirectly from the amount of unreacted di-n-butylamine, determined by back titration with standard hydrochloric acid. Determination of the excess di-n-butylamine by the gas chromatographic method developed has the advantages of providing better precision and requiring less sample than the titrimetric method. The two methods were compared using phenyl isocyanate as a model test compound. A synthesized monomer, methyl alpha-isocyanatoacrylate, was also analyzed, for comparison by both methods.

Gas chromatographic determination of ethyl 2-cyanoacrylate in the workplace environment

Low levels of airborne ethyl 2-cyanoacrylate (ECA) were monitored by drawing air through sampling tubes containing Tenax GC. After desorption with acetone, ECA was quantified by gas chromatography using a thermionic specific detector in the nitrogen mode. Polymerised ECA was shown to yield ECA monomer under the conditions of gas chromatographic analysis.

Monolayer studies on poly(isobutylcyanoacrylate)-ampicillin association

Surface pressure-area isotherms (pi-A) of poly(isobutylcyanoacrylate) monolayers with or without glucose and dextran as polymerization adjuvants used in the preparation of nanoparticles have been derived from measurements made at the air-water interface with the subphase pH at 2.7, 5.5 or 8.8. The isotherms were characteristic of the expanded type of polymer monolayer curves, yielding unusually low limiting area values compared with those of other known poly(acrylate) derivatives. This behaviour may be explained by the folding of polar moieties of the polymer groups in the water subphase. Ampicillin incorporated during preparation of nanoparticles had a negligible effect on the general behaviour of adjuvant-free monolayers, but a significant one on the adjuvant-loaded polymer monolayer system which showed an increase in surface area throughout the compression cycle, as compared with the surface area of the adjuvant-free polymer system although the collapse pressure was practically the same at 67 mN m-1.

Physicochemical and morphological characterization of polyisobutyl cyanoacrylate nanocapsules

Two different polymerization mechanisms of alkyl cyanoacrylates were compared with regard to their morphological and physico-chemical characteristics. Cyanoacrylates were polymerized by simple emulsification into an aqueous medium or by interfacial polymerization in an o/w type emulsion. Suspensions of particles obtained by these two mechanisms show dramatic differences when studied for their turbidity, refractive index, and stability following centrifugation. These observations are consistent with the fact that nanoparticles obtained by emulsion polymerization are known to be formed by a full polymer core, while nanocapsules obtained by interfacial polymerization were thought to consist of an internal oil droplet surrounded by a polymeric wall. This theory was further confirmed by an electron microscopic examination of the internal structures of the two types of polymeric aggregates.

Polyalkyl cyanoacrylate nanocapsules

In-situ polymerized methyl cyanoacrylate (MCA), ethyl cyanoacrylate (ECA), and butyl cyanoacrylate (BCA) were used to prepare nanocapsules of fluorescein or doxorubicin as markers by a w/o emulsion interfacial polymerization technique. Different concentrations of MCA were also used to show the effect of monomer concentration. The nanocapsules were characterized by electron microscopy, particle size analysis, holding capacity and in-vitro release of the marker substances. After selection of the polymerization solvent system, nearly spherical nanocapsules were obtained using each of the monomers. Most of the nanocapsules prepared were in the particle size range 500-1500 nm diameter. They were able to hold 55-74% of the marker initially present in aqueous solution. In-vitro dissolution studies showed that release of marker was retarded variably in an increasing order from nanocapsules containing MCA, ECA then BCA. Increasing the concentration of the monomer in the nanocapsules led to retardation of marker release.

In vivo uptake of polyisobutyl cyanoacrylate nanoparticles by rat liver Kupffer, endothelial, and parenchymal cells

Polyalkyl cyanoacrylate nanoparticles were previously developed as a biodegradable, ultrafine, solid drug carrier. Distribution studies in the rat showed an intense and rapid hepatic uptake. This liver accumulation appears to represent, to a certain extent, extracellularly bound nanoparticles. During liver perfusion, 15-20% of the liver-associated nanoparticles were washed out. The cellular distribution of strongly cell-associated nanoparticles was determined. At different intervals after injection of radioactive nanoparticles to rats, the cells were isolated according to a recently developed, low-temperature procedure during which processing of the carrier was inhibited. At all tested times, a relatively intense capture by Kupffer cells in comparison with endothelial and especially parenchymal cells was observed. This distribution pattern was not influenced by the size of the nanoparticles (0.08-0.215-micron diameter). This specific interaction of nanoparticles with Kupffer cells opens possibilities for the treatment of some parasitic diseases involving this cell type.

Detection of cyanoacrylate tissue adhesives in histological sections

Previous histological studies of cyanoacrylate in wound healing have all used Oil-Red-O staining of paraffin sections prepared by routine method. In the course of our studies we began to suspect that artifact was being introduced because of dissolution of cyanoacrylate during processing. Accordingly, biopsis of wounds sealed with cyanoacrylate and pieces of cyanoacrylate of a standard known dimension with no associated tissue were observed after every stage of histological preparation. It was observed that approximately 80% of the cyanoacrylate was lost at the deparaffinization in xylene stage. Accordingly, a number of solvents were tested, and it was found that petroleum ether could be used to remove paraffin completely without the loss of any of the cyanoacrylate from the specimen. This technique has been used to view the location and ultimate fate of cyanoacrylate applied to wounds and examined at different stages in healing process. It is concluded that previous histological studies of cyanoacrylate in wound healing have been inaccurate due to leaching out of most of the tissue adhesive during deparaffinization of the specimen.

Isocyanato urethane methacrylates derived from hydroxyethyl methacrylate

Isocyanato urethane methacrylates were synthesized from five diisocyanates and hydroxyethyl methacrylate. They may be homopolymerized or copolymerized with other methacrylates by the usual free radical methods of initiation and have potential as adhesion-promoting agents for dentin.