Flexible transbronchial optical frequency domain imaging smart needle for biopsy guidance.

Transbronchial needle aspiration (TBNA) is a procedure routinely performed to diagnose peripheral pulmonary lesions. However, TBNA is associated with a low diagnostic yield due to inappropriate needle placement. We have developed a flexible transbronchial optical frequency domain imaging (TB-OFDI) catheter that functions as a "smart needle" to confirm the needle placement within the target lesion prior to biopsy. The TB-OFDI smart needle consists of a flexible and removable OFDI catheter (430 µm dia.) that operates within a standard 21-gauge TBNA needle. The OFDI imaging core is based on an angle polished ball lens design with a working distance of 160 µm from the catheter sheath and a spot size of 25 µm. To demonstrate the potential of the TB-OFDI smart needle for transbronchial imaging, an inflated excised swine lung was imaged through a standard bronchoscope. Cross-sectional and longitudinal OFDI results reveal the detailed network of alveoli in the lung parenchyma suggesting that the TB-OFDI smart needle may be a useful tool for guiding biopsy acquisition to increase the diagnostic yield.

Co-registered spectrally encoded confocal microscopy and optical frequency domain imaging system.

Spectrally encoded confocal microscopy and optical frequency domain imaging are two non-contact optical imaging technologies that provide images of tissue cellular and architectural morphology, which are both used for histopathological diagnosis. Although spectrally encoded confocal microscopy has better transverse resolution than optical frequency domain imaging, optical frequency domain imaging can penetrate deeper into tissues, which potentially enables the visualization of different morphologic features. We have developed a co-registered spectrally encoded confocal microscopy and optical frequency domain imaging system and have obtained preliminary images from human oesophageal biopsy samples to compare the capabilities of these imaging techniques for diagnosing oesophageal pathology.

Combining passive samplers and biomonitors to evaluate endocrine disrupting compounds in a wastewater treatment plant by LC/MS/MS and bioassay analyses.

Two types of integrative sampling approaches (passive samplers and biomonitors) were tested for their sampling characteristics of selected endocrine disrupting compounds (EDCs). Chemical analyses (LC/MS/MS) were used to determine the amounts of five EDCs (nonylphenol, bisphenol A, estrone, 17beta-estradiol and 17alpha-ethinylestradiol) in polar organic chemical integrative samplers (POCIS) and freshwater mussels (Unio pictorum); both had been deployed in the influent and effluent of a municipal wastewater treatment plant (WWTP) in Genoa, Italy. Estrogenicity of the POCIS samples was assessed using the yeast estrogen screen (YES). Estradiol equivalent values derived from the bioassay showed a positive correlation with estradiol equivalents calculated from chemical analyses data. As expected, the amount of estrogens and EEQ values in the effluent were lower than those in the influent. Passive sampling proved to be the preferred method for assessing the presence of these compounds since employing mussels had several disadvantages both in sampling efficiency and sample analyses.

Preliminary evaluation of noninvasive microscopic imaging techniques for the study of vocal fold development.

Understanding pediatric voice development and laryngeal pathology is predicated on a detailed knowledge of the microanatomy of the layered structure of the vocal fold. Our current knowledge of this microanatomy and its temporal evolution is limited by the lack of pediatric specimen availability. By providing the capability to image pediatric vocal folds in vivo, a noninvasive microscopy technique could greatly expand the existing database of pediatric laryngeal microanatomy and could furthermore make longitudinal studies possible. A variety of natural-contrast optical imaging technologies, including optical frequency domain imaging (OFDI), full-field optical coherence microscopy (FF-OCM), and spectrally encoded confocal microscopy (SECM) have been recently developed for noninvasive diagnosis in adult patients. In this paper, we demonstrate the potential of these three techniques for laryngeal investigation by obtaining images of excised porcine vocal fold samples. In our study, OFDI allowed visualization of the vocal fold architecture deep within the tissue, from the superficial mucosa to the vocalis muscle. The micron-level resolution of SECM allowed investigation of cells and extracellular matrix fibrils from the superficial mucosa to the intermediate layer of the lamina propria (LP) (350 microm penetration depth). The large field of view (up to 700 microm), penetration depth (up to 500 microm), and resolution (2x2x1microm [XxYxZ]) of FF-OCM enabled comprehensive three-dimensional evaluation of the layered structure of the LP. Our results suggest that these techniques provide important and complementary cellular and structural information, which may be useful for investigating pediatric vocal fold maturation in vivo.

Effect of corn root exudates on the degradation of atrazine and its chlorinated metabolites in soils.

DIMBOA (3,4-dihydro-2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3-one), a major benzoxazinone of Poaceae plants, was isolated and purified from corn seedlings. The effect of isolated and purified DIMBOA on the degradation of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine], and its toxic breakdown products, desethylatrazine [2-chloro-4-amino-6-(isopropylamino)-s-triazine; DEA] and desisopropylatrazine [2-chloro-4-(ethylamino)-6-amino-s-triazine; DIA], was studied in the absence of plants using batch experiments, while the effect of corn root exudates on these compounds was determined in hydroponic experiments. Degradation experiments were performed in the presence and absence of 50 microM, 1 mM, or 5 mM DIMBOA resulting in ratios of DIMBOA to pesticide of 1:1, 20:1, and 100:1. We observed a 100% degradation of atrazine to hydroxyatrazine within 48 h at a ratio of DIMBOA to atrazine of 100:1. DIMBOA had the largest effect on atrazine, while it was about three times less effective on DEA and DIA. Corn (Zea mays L. cv. LG 2185) was exposed to 10 mg L(-1) of either atrazine, DEA, or DIA for 11 d in a growth chamber experiment. Up to 4.3 micromol L(-1) d(-1) of hydroxyatrazine were formed in the nutrient solutions by plants exposed to atrazine, while the formation of hydroxylated metabolites from plants exposed to DEA and DIA was smaller and also delayed. The formation of hydroxylated metabolites increased in the solution with plant age in all atrazine, DEA, and DIA treatments. HMBOA (3,4-dihydro-2-hydroxy-7-methoxy-2H-1,4-benzoxazin-3-one), the lactam precursor of DIMBOA, and a tentatively identified derivative of MBOA (2,3-dihydro-6-methoxy-benzoxazol-2-one) were detected in the corn root exudates. Mass balance calculations revealed that up to 30% of the disappearance of atrazine and DEA, and up to 10% of DIA removal from the solution medium in our study could be explained by the formation of hydroxylated metabolites in the solution itself. Our results show that higher plants such as corn have the potential to promote the hydrolysis of triazine residues in soils by exudation of benzoxazinones.

Comparing steroid estrogen, and nonylphenol content across a range of European sewage plants with different treatment and management practices.

The effluent of 17 sewage treatment works (STW) across Norway, Sweden, Finland, The Netherlands, Belgium, Germany, France and Switzerland was studied for the presence of estradiol (E2), estrone (E1), ethinylestradiol (EE2) and nonylphenol (NP). Treatment processes included primary and chemical treatment only, submerged aerated filter, oxidation ditch, activated sludge (AS) and combined trickling filter with activated sludge. The effluent strength ranged between 87 and 846 L/PE (population equivalent), the total hydraulic retention time (HRT) ranged between 4 and 120 h, sludge retention time (SRT) between 3 and 30 d, and water temperature ranged from 12 to 21 degrees C. The highest estrogen values were detected in the effluent of the STW which only used primary treatment (13 ng/L E2 and 35 ng/L E1) and on one occasion in one of the STW using the AS system (6.5 ng/L E2, 50.5 ng/L E1, but on three other occasions the concentrations in this STW were at least a factor of 6 lower). For the 16 STW employing secondary treatment E2 was only detected in the effluent of six works during the study period (average 0.7-5.7 ng/L). E1 was detected in the effluent of 13 of the same STW. The median value for E1 for the 16 STW with secondary treatment was 3.0 ng/L. EE2 was only detected in two STW (1.1, <0.8-2.8 ng/L). NP could be detected in the effluent of all 14 STW where this measurement was attempted, with a median of 0.31 microg/L and values ranging from 0.05 to 1.31 microg/L. A comparison of removal performance for E1 was carried out following prediction of the probable influent concentration. A weak but significant (alpha<5%) correlation between E1 removal and HRT or SRT was observed.

MTBE oxidation by conventional ozonation and the combination ozone/hydrogen peroxide: efficiency of the processes and bromate formation.

The present study investigates the oxidation of methyl tert-butyl ether (MTBE) by conventional ozonation and the advanced oxidation process (AOP) ozone/hydrogen peroxide under drinking water treatment conditions. The major degradation products identified were tert-butyl formate (TBF), tert-butyl alcohol (TBA), 2-methoxy-2-methyl propionaldehyde (MMP), acetone (AC), methyl acetate (MA), hydroxyisobutyraldehyde (HiBA), and formaldehyde (FA). The rate constants of the reaction of ozone and OH radicals with MTBE were found to be 0.14 and 1.9 x 10(9) M(-1) s(-1), respectively. The rate constants for the same oxidation processes were also measured for the degradation products TBF, MMP, MA, and HiBA (k(O3-TBF) = 0.78 M(-1) s(-1); k(OH-TBF) = 7.0 x 10(8) M(-1) s(-1); k(O3-MMP) = 5 M(-1) s(-1); k(OH-MMP) = 3 x 10(9) M(-1) s(-1), k(O3-MA) = 0.09 M(-1) s(-1), k(O3-HiBA) = 5 M(-1) s(-1); k(OH-HiBA) = 3 x 10(9) M(-1) s(-1)). Since all compounds reacted slowly with molecular ozone, only the degradation pathway of MTBE with OH radicals has been determined, including the formation of primary degradation products. In experiments performed with several natural waters, the efficiency of MTBE elimination and the formation of bromate as disinfection byproduct have been measured. With a bromide level of 50 microg/L, only 35-50% of MTBE could be eliminated by the AOP O3/H2O2 without exceeding the current drinking water standard of bromate (10 microg/L). The transient concentrations of MTBE and its primary degradation products were modeled using a combination of kinetic parameters (degradation product distribution and rate constants) together with the ozone and OH radical concentration and were in good agreement with the experimental results.

Rapid determination of sulfonated naphthalenes and their formaldehyde condensates in aqueous environmental samples using synchronous excitation fluorimetry.

Sulfonated naphthalenes and their formaldehyde condensates (SNFC) were determined in aqueous environmental samples by spectrofluorimetry. A clean-up step using n-hexane to extract possibly interfering nonpolar compounds such as naphthalene is the only preparatory procedure. Synchronous excitation mode with a gammalambda of 105 nm allows the determination of SNFC in environmental samples without additional clean-up or analyte enrichment. Interferences by humic acids and nitrate occurred only at concentrations higher than 1 mg C L(-1) and 10 mg NO3- L(-1), respectively. The limit of detection was 0.2 microg L(-1), the average recovery was 104% and the confidence interval (95% certainty) was 24%. The response factor for the quantitative determination of total SNFC, depending on the distribution of the different SNFC components, was validated for groundwater from two field sites using an HPLC-FD (fluorescence detection) method as a reference method.

Hydroxyhydroquinone reductase, the initial enzyme involved in the degradation of hydroxyhydroquinone (1,2,4-trihydroxybenzene) by Desulfovibrio inopinatus.

The recently isolated sulfate reducer Desulfovibrio inopinatus oxidizes hydroxyhydroquinone (1,2,4trihydroxybenzene; HHQ) to 2 mol acetate and 2 mol CO2 (mol substrate)-1, with stoichiometric reduction of sulfate to sulfide. None of the key enzymes of fermentative HHQ degradation, i.e. HHQ-1,2,3,5-tetrahydroxybenzene transhydroxylase or phloroglucinol reductase, were detected in cell-free extracts of D. inopinatus, indicating that this bacterium uses a different pathway for anaerobic HHQ degradation. HHQ was reduced with NADH in cell-free extracts to a nonaromatic compound, which was identified as dihydrohydroxyhydroquinone by its retention time in HPLC separation and by HPLC-mass spectrometry. The compound was identical with the product of chemical reduction of HHQ with sodium borohydride. Dihydrohydroxyhydroquinone was converted stoichiometrically to acetate and to an unknown coproduct. HHQ reduction was an enzymatic activity which was present in the cell-free extract at 0.25-0.30 U (mg protein)-1, with a pH optimum at 7.5. The enzyme was sensitive to sodium chloride, potassium chloride, EDTA, and o-phenanthroline, and exhibited little sensitivity towards sulfhydryl group reagents, such as copper chloride or p-chloromercuribenzoate.

Selective determination of aromatic sulfonates in landfill leachates and groundwater using microbore liquid chromatography coupled with mass spectrometry.

Aromatic sulfonates (AS) are large-volume chemicals used in many technical processes of, for instance, the textile industry or construction. A LC/MS method for the selective determination of AS in environmental samples, based on a single-quadrupole MS, was developed and validated. The central point of this technique is the use of the compound-specific fragment ion SO3.- as marker for aromatic sulfonates. This negatively charged SO3 radical, together with the fact that AS undergo loss of SO2, allows screening for AS in complex matrixes, even in the presence of sulfate anions. Calibration curves generated from LC/MS data showed good linearity over 3 orders of magnitude, with an absolute limit of detection of approximately 1 ng. The relative standard deviation for mean areas obtained from reconstructed ion chromatograms ranged from 2.9 to 8.6%. Unlike UV detection, this LC/MS method gives similar response for both naphthalene- and benzene-sulfonates. The method presented was successfully applied to landfill leachates and groundwater, downstream of a landfill. Furthermore, this technique allowed identification of an unknown AS found in drain samples.

Metabolism of the new liposomal anticancer drug N4-octadecyl-1-beta-D-arabinofuranosylcytosine in mice.

Metabolism and excretion of the new antitumor drug N4-octadecyl-1-beta-D-arabinofuranosylcytosine (NOAC) was investigated in mice. Mice were injected i.v. with tritium-labeled liposomal NOAC (4 micromol/mouse). Analysis of HPLC-purified extracts of liver homogenates by liquid chromatography coupled with mass spectrometry revealed only the presence of unmetabolized drug. To study the excretion of the administered drug, mice were injected with tritium-labeled liposomal NOAC or as comparison with 1-beta-D-arabinofuranosylcytosine (ara-C; 4 micromol/mouse) and housed up to 48 h in metabolic cages. Urine and feces were collected at different time points and the kinetics of excreted radioactivity were determined. After 48 h, 39% of the injected [5-3H]NOAC radioactivity was excreted in urine and 16% in feces, whereas ara-C radioactivity was only found in urine with 48% of the injected dose. Feces extracts and urine were purified by HPLC and radioactive fractions were further analyzed by liquid chromatography coupled with mass spectrometry. The radioactivity of feces extracts of NOAC-treated mice was composed of unmetabolized NOAC, hydroxylated NOAC (NOAC + OH), its sulfated derivative (NOAC + OSO3H), and unidentified metabolites, whereas in urine, the hydrophilic molecules ara-C and ara-U were found. During the period of 48 h only 2% of the injected NOAC was eliminated in its unmetabolized form, whereas 25% was identified as main metabolite ara-C. Urine collected during 48 h in ara-C-treated mice contained 33% of the injected dose as unmetabolized drug and 13% as the main metabolite ara-U. Thus, NOAC is metabolized by two major pathways, one leading to the hydrophilic metabolites ara-C and ara-U and the other to hydroxylated and sulfated NOAC.

Fate of the herbicides mecoprop, dichlorprop, and 2,4-D in aerobic and anaerobic sewage sludge as determined by laboratory batch studies and enantiomer-specific analysis.

Aerobic degradation experiments with the racemic mixtures of mecoprop and dichlorprop revealed that activated sludge collected from the aeration tank of a municipal waste water treatment plant degraded both enantiomers of mecoprop and dichlorprop within 7 days, albeit in an enantioselective manner; the (S) enantiomers were preferentially degraded. Mecoprop, dichlorprop, and 2,4-D were completely metabolized under aerobic conditions, as shown by the 86-98% elimination of dissolved organic carbon. Under anaerobic conditions, the concentration of 2,4-D decreased exponentially with a first-order reaction rate constant of 0.24 per day and without a lag-phase. After an incubation time of 17 days, 2,4-D was completely removed. 2,4-Dichlorophenol was the main metabolite of anaerobic 2,4-D degradation; only traces of 4-chlorophenol were detected. In contrast, the chiral phenoxypropionic acid herbicides mecoprop and dichlorprop persisted under anaerobic conditions during 49 days of incubation.

Involvement of two alpha-ketoglutarate-dependent dioxygenases in enantioselective degradation of (R)- and (S)-mecoprop by Sphingomonas herbicidovorans MH.

Cell extracts of Sphingomonas herbicidovorans MH grown on (R)-mecoprop contained an enzyme activity that selectively converted (R)-mecoprop to 4-chloro-2-methylphenol, whereas extracts of cells grown on (S)-mecoprop contained an enzyme activity selective for the S enantiomer. Both reactions were dependent on alpha-ketoglutarate and ferrous ions. Besides 4-chloro-2-methylphenol, pyruvate and succinate were detected as products of the reactions. Labeling experiments with (18)O2 revealed that both enzyme activities catalyzed a dioxygenation reaction. One of the oxygen atoms of pyruvate and one of the oxygen atoms of succinate were derived from molecular oxygen. Analysis of cell extracts obtained from cells grown on different substrates by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that growth on (R)-mecoprop and (S)-mecoprop caused the appearance of prominent protein bands at 34 and 32 kDa, respectively. Both protein bands were present when cells grew on the racemic mixture. The results demonstrate that S. herbicidovorans initiated the degradation of each enantiomer of mecoprop by a specific alpha-ketoglutarate-dependent dioxygenase. By comparing conversion rates of various phenoxy herbicides, we confirmed that the two enzyme activities were distinct from that of TfdA, which catalyzes the first step in the degradation of 2,4-dichlorophenoxyacetic acid in Ralstonia eutropha JMP134.

Determination of the quaternary ammonium surfactant ditallowdimethylammonium in digested sludges and marine sediments by supercritical fluid extraction and liquid chromatography with postcolumn ion-pair formation.

To study the phasing-out of the quaternary ammonium surfactant ditallowdimethylammonium cation (DTDMAC), concentrations of the cation in anaerobically stabilized sewage sludges were determined before and after its replacement by better degradable compounds. DTDMAC was quantitatively extracted from digested sludges using 380 atm of supercritical CO(2) modified with 30% methanol at 100 °C. Determination of DTDMAC was performed by normal-phase HPLC with postcolumn ion-pair formation and extraction with no sample cleanup. Mean concentrations of DTDMAC in sludges from five different municipal sewage treatment plants in Switzerland decreased from 3.67 g/kg (in 1991) to 0.96, 0.47, and 0.21 g/kg of dry sludge in 1992, 1993, and 1994, respectively. The precision of the method in digested sludge for 0.1-6.0 g/kg of dry matter, as indicated by the relative standard deviation, was typically 7%. The influence of the sample matrix was studied by performing supercritical fluid extraction (SFE) in coastal marine sediments. While SFE and a conventional liquid extraction method gave equal DTDMAC concentrations in sludges, the extraction of marine sediment samples yielded 30-40% higher DTDMAC values for SFE compared to those obtained by liquid extraction. The 94% drop in DTDMAC concentrations in digested sludges is due to the replacement of this substance and is a clear result of the producers' voluntary ban on its use in Europe.

An integral probe for capillary zone electrophoresis/continuous-flow fast atom bombardment mass spectrometry.

An integral probe for capillary zone electrophoresis/continuous-flow fast atom bombardment mass spectrometry was constructed and operated in either the coaxial or liquid-junction interface mode. Results using these interfaces for the analyses of synthetic peptides are presented. The coaxial arrangement attains the best electrophoretic performance, generally providing a greater number of theoretical plates. However, in that the electrophoresis times are generally greater for the liquid-junction interface because there is no mechanical flow resulting from the source vacuum, the overall separation efficiency of the liquid-junction interface is equal to or greater than that of the coaxial interface. In addition, the liquid-junction interface is easier to set up and operate, and allows larger inner diameter capillaries to be used to achieve higher sample loads.

Recent advances in liquid chromatography-mass spectrometry and capillary zone electrophoresis-mass spectrometry for protein analysis.

The utility of the combination of separations techniques, such as liquid chromatography and capillary zone electrophoresis, with mass spectrometry in applications involving protein analysis is discussed. The use of continuous-flow fast atom bombardment and electrospray ionization mass spectrometry is compared for the analysis of tryptic digests. For liquid chromatography, both microbore and slurry-packed capillary bore columns were used to separate peptides from proteolytic digests.