Adsorption of domoic acid to marine sediments and clays.

Conditional solid-water distribution coefficients (K(d)) for the adsorption of domoic acid (DA) to a series of complex sediments and clays were determined in artificial seawater. K(d) ranged from 5.11 L g(-1) to 0.

Investigation of the Methanosarcina thermophila acetate kinase mechanism by fluorescence quenching.

Acetate kinase, a member of the acetate and sugar kinase/Hsc 70/actin (ASKHA) structural superfamily, catalyzes the reversible transfer of the gamma-phosphoryl group from ATP to acetate, yielding ADP and acetyl phosphate. A catalytic mechanism for the enzyme from Methanosarcina thermophila has been proposed on the basis of the crystal structure and kinetic analyses of amino acid replacement variants. The Gln43Trp variant was generated to further investigate the catalytic mechanism via changes in fluorescence.

Photostability of kainic acid in seawater.

The environmental degradation of a mixture of domoic acid (DA) and kainic acid (KA) in seawater with and without added transition metals is reported. The association constants for kainic acid with Fe (III) and Cu (II) were determined using (1)H nuclear magnetic resonance (NMR; K1,Fe(III) = 2.27 x 10(12), K2,Fe(III) = 8.

Crystal structure of the NADH:quinone oxidoreductase WrbA from Escherichia coli.

The flavoprotein WrbA, originally described as a tryptophan (W) repressor-binding protein in Escherichia coli, has recently been shown to exhibit the enzymatic activity of a NADH:quinone oxidoreductase. This finding points toward a possible role in stress response and in the maintenance of a supply of reduced quinone. We have determined the three-dimensional structure of the WrbA holoprotein from E.

Conjunctival marginal zone B-cell lymphoma (MALT lymphoma) with amyloid and relapse in the stomach.

The authors report a localized (primary) conjunctival marginal zone B-cell lymphoma (mucosa-associated lymphoid tissue (MALT)-type), with amyloid deposition with relapse in the stomach, 14 months after the initial diagnosis. Ocular adnexal marginal zone B-cell MALT lymphoma is often localized at diagnosis; some relapse in typical MALT sites. There are few reports of localized conjunctival lymphoma with a relapse in the stomach.

HHV-8+, EBV+ multicentric plasmablastic microlymphoma in an HIV+ Man: the spectrum of HHV-8+ lymphoproliferative disorders expands.

Human herpesvirus-8 (HHV-8) is associated with several distinct lymphoproliferative disorders: primary effusion lymphoma, multicentric Castleman disease (MCD), MCD-associated plasmablastic lymphoma and HHV-8+, Epstein-Barr virus (EBV)+ germinotropic lymphoproliferative disorder. We report the case of a human immunodeficiency virus (HIV)+ male with fever, generalized lymphadenopathy, and splenomegaly. Two peripheral lymph nodes were excised and showed features of MCD and a prominent proliferation of HHV-8+, EBV+, CD20, CD138, MUM1+, lambda dim+, Ig heavy chain plasmablasts and immunoblasts replacing some follicles.

The archaeon Methanosarcina acetivorans contains a protein disulfide reductase with an iron-sulfur cluster.

Methanosarcina acetivorans, a strictly anaerobic methane-producing species belonging to the domain Archaea, contains a gene cluster annotated with homologs encoding oxidative stress proteins. One of the genes (MA3736) is annotated as a gene encoding an uncharacterized carboxymuconolactone decarboxylase, an enzyme required for aerobic growth with aromatic compounds by species in the domain Bacteria. Methane-producing species are not known to utilize aromatic compounds, suggesting that MA3736 is incorrectly annotated.

Primary follicular lymphoma of the testis and epididymis in adults.

Primary testicular lymphomas typically occur in patients over 60 years of age. Most are diffuse large B-cell lymphomas with frequent dissemination and a poor prognosis. Primary follicular lymphoma of the adult testis has not been well characterized.

Inhibition of the archaeal beta-class (Cab) and gamma-class (Cam) carbonic anhydrases.

Five independently evolved classes (alpha-, beta-, gamma-, delta-, zeta-) of carbonic anhydrases facilitate the reversible hydration of carbon dioxide to bicarbonate of which the alpha-class is the most extensively studied. Detailed inhibition studies of the alpha-class with the two main classes of inhibitors, sulfonamides and metal-complexing anions, revealed many inhibitors that are used as therapeutic agents to prevent and treat many diseases. Recent inhibitor studies of the archaeal beta-class (Cab) and the gamma-class (Cam) carbonic anhydrases show differences in inhibition response to sulfonamides and metal-complexing anions, when compared to the alpha-class carbonic anhydrases.

Classical Hodgkin's lymphoma presenting as a testicular mass: report of a case.

Hodgkin's lymphoma almost always presents with lymphadenopathy. Presentation with extranodal disease is quite unusual, although Hodgkin's lymphoma is known to occasionally involve extranodal sites. However, no well-documented cases of testicular Hodgkin's lymphoma have been described.

The effect of methanogen growth on mineral substrates: will Ni markers of methanogen-based communities be detectable in the rock record?

Methanogens, thought to be present on early Earth, have a high requirement for Ni, suggesting that Ni utilization could be a potential biosignature for methanogens if enhanced Ni extraction from surrounding minerals accompanies methanogenic growth. To test the potential for such Ni extraction from minerals by methanogens, Ni release from Ni-containing silicate glass was measured in Ni-free growth medium in the presence of the methanogen Methanothermobacter thermoautotrophicus (average pH ∼7.0) and observed to be higher than an abiotic control (average pH ∼6.

Aqueous in situ derivatization of carboxylic acids by an ionic carbodiimide and 2,2,2-trifluoroethylamine for electron-capture detection.

We report a technique for the rapid, room temperature derivatization of aqueous carboxylic acids to the corresponding 2,2,2-trifluoroethylamide derivative. 3-Ethyl-1-[3-(dimethylamino)propyl]carbodiimide hydrochloride (EDC) and 2,2,2-trifluoroethylamine hydrochloride (TFEA) were added to aqueous samples of several acids of interest in environmental analytical chemistry, including benzoic acid, ibuprofen, clofibric acid, monochloroacetic acid, dicholoroacetic acid, bromoacetic acid, monochlorophenoxy acetic acid, dichlorophenoxy acetic acid, trichlorophenoxy acetic acid, acetylsalicylic acid, and cholorobenzoic acid. Amidization was essentially complete within ten minutes, and subsequent liquid-liquid extraction of the amides with methyl tert-butyl ether (MTBE) demonstrated recoveries of over 85%.

Quantitative proteomic and microarray analysis of the archaeon Methanosarcina acetivorans grown with acetate versus methanol.

Methanosarcina acetivorans strain C2A is an acetate- and methanol-utilizing methane-producing organism for which the genome, the largest yet sequenced among the Archaea, reveals extensive physiological diversity. LC linear ion trap-FTICR mass spectrometry was employed to analyze acetate- vs methanol-grown cells metabolically labeled with 14N vs 15N, respectively, to obtain quantitative protein abundance ratios. DNA microarray analyses of acetate- vs methanol-grown cells was also performed to determine gene expression ratios.

Lymphoma of the ocular adnexa: A study of 353 cases.

We studied the cases of 353 patients with lymphoma involving the ocular adnexa diagnosed at the Massachusetts General Hospital between 1974 and 2005. The patients included 153 males and 200 females, aged 7 to 95 years, with a mean age of 64 years. In 277 cases, there was no known history of lymphoma.

An unconventional pathway for reduction of CO2 to methane in CO-grown Methanosarcina acetivorans revealed by proteomics.

Methanosarcina acetivorans produces acetate, formate, and methane when cultured with CO as the growth substrate [Rother M, Metcalf WW (2004) Proc Natl Acad Sci USA 101:], which suggests novel features of CO metabolism. Here we present a genome-wide proteomic approach to identify and quantify proteins differentially abundant in response to growth on CO versus methanol or acetate. The results indicate that oxidation of CO to CO2 supplies electrons for reduction of CO2 to a methyl group by steps and enzymes of the pathway for CO2 reduction determined for other methane-producing species.

New algorithm for 15N/14N quantitation with LC-ESI-MS using an LTQ-FT mass spectrometer.

A new algorithm (QN) for the (15)N /(14)N quantitation of relative protein abundances in complex proteomic samples is described. QN takes advantage of the high resolution, mass accuracy and throughput of the hybrid mass spectrometer LTQ-FT MS. Peptide quantitation is based on MS peak intensity (measured in the FT MS), while peptide identification is performed in the MS/MS mode (measured in the LTQ linear ion trap).

Risk assessment of the National Institute of Standards and Technology petroleum crude oil standard water accommodated fraction: further application of a copepod-based, full life-cycle bioassay.

The U.S. National Institute of Standards and Technology (NIST) petroleum crude oil was used to generate NIST water-accommodated hydrocarbon fractions (WAFs) for standardized assessment of crude oil effects on the copepod Amphiascus tenuiremis.

A multifactor exploration of the photobleaching of Suwannee River dissolved organic matter across the freshwater/saltwater interface.

A four factor central composite experimental design was applied to explore the photobleaching of Suwannee River dissolved organic matter (SRDOM) at 350 nm as a function of the tetravariate system of [SRDOM], total [Fe(III)], [NO3-], and salinity. The ranges of each factor were setto cover their likely concentrations atthe freshwater/ saltwater interface, to encompass the possible conditions encountered during the transition from the terrestrial to marine environment. Each experiment was carried out using a minimum of 25 different initial conditions, with 3-6 replicates/condition.

WrbA from Escherichia coli and Archaeoglobus fulgidus is an NAD(P)H:quinone oxidoreductase.

WrbA (tryptophan [W] repressor-binding protein) was discovered in Escherichia coli, where it was proposed to play a role in regulation of the tryptophan operon; however, this has been put in question, leaving the function unknown. Here we report a phylogenetic analysis of 30 sequences which indicated that WrbA is the prototype of a distinct family of flavoproteins which exists in a diversity of cell types across all three domains of life and includes documented NAD(P)H:quinone oxidoreductases (NQOs) from the Fungi and Viridiplantae kingdoms. Biochemical characterization of the prototypic WrbA protein from E.

Role of Fe(III), phosphate, dissolved organic matter, and nitrate during the photodegradation of domoic acid in the marine environment.

The photodegradation of domoic acid in model seawater containing varying amounts of total Fe(lll) (expressed as Fe(lll)), NO(3-), total phosphate (expressed as P04(3-)), and dissolved organic matter (DOM) is reported. A multivariate, microscale, high-throughput experimental approach is described for evaluating how these components interact to control the removal of domoic acid from natural waters. Under the nominal conditions of the study ([Fe(lll)]o 0-4 microM; [N03-]o 0-35 microM; [P04(3-)]o 0-4 microM; [DOM]o 0-10 mg/ L), it is apparent that Fe(lll) and DOM are significant promoters of domoic acid photooxidation.

Interaction of iron-sulfur flavoprotein with oxygen and hydrogen peroxide.

The dimeric iron-sulfur flavoprotein (Isf) from Methanosarcina thermophila contains one 4Fe-4S center and one FMN per monomer, and is the prototype of a family widely distributed among strictly anaerobic prokaryotes. Although Isf is able to oxidize ferredoxin, the physiological electron acceptor is unknown; thus, the ability of Isf to reduce O2 and H2O2 was investigated. The product of O2 or H2O2 reduction by Isf was determined to be water.

Proposal for a hydrogen bond network in the active site of the prototypic gamma-class carbonic anhydrase.

The crystal structure of Cam, the prototypic gamma-class carbonic anhydrase, reveals active site residues Gln75, Asn73, and Asn 202 previously hypothesized to participate in catalysis. These potential roles were investigated for the first time by kinetic analyses of site-specific replacement variants of the zinc and cobalt forms of Cam. Gln75 replacement variants showed large decreases in k(cat)/K(m) relative to wild-type.

Burkitt's lymphoma: clinicopathologic features and differential diagnosis.

Burkitt's lymphoma is a highly aggressive lymphoma identified and described in the last century by Denis Burkitt in Africa, in areas endemic for malaria. Since its description in African children, it has been recognized outside areas with endemic malaria, frequently also in children as well as among individuals with an underlying immunodeficiency. Since its initial designation as Burkitt's lymphoma, this type of lymphoma and lymphomas closely resembling it have received a variety of names in different classifications of lymphomas and leukemias: undifferentiated lymphoma, Burkitt's and non-Burkitt's type in the modified Rappaport Classification, malignant lymphoma, small non-cleaved cell, Burkitt's type in the Working Formulation, Burkitt's lymphoma and high-grade B-cell lymphoma, Burkitt-like in the REAL Classification, and acute lymphoblastic leukemia, L3 type in the FAB Classification.