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Brominated organic compounds (BOCs) are of great interest in atmospheric chemistry, natural products, geochemistry, and marine chemistry. The Br isotope ratios ((81)Br and (79)Br; average (81)Br/(79)Br = 0.97277) have significant potential for the study of the source, transport, and fate of these compounds. Currently, there is no published method for determining the Br isotopic content of BOCs in complex mixtures. To measure the ratios of stable Br in BOCs on a compound-specific basis, we assembled a gas chromatography/multicollector inductively coupled plasma mass spectrometry (GC/MCICPMS) system. Background signals, the formation of Ar dimers from organic hydrogen, and the solvent peak did not affect the results. The analysis of three brominated benzenes revealed that 0.3 per thousand precision can be attained when 0.3 nmol of Br are injected. For samples larger than 0.3 nmol Br, the isotopic precision was within a factor of 3 of the shot-noise limit, which is the best possible statistical precision attainable avoiding all other sources of noise., (Copyright (c) 2007 John Wiley & Sons, Ltd.)

Three novel halogenated organic compounds (HOCs) have been identified in the blubber of marine mammals from coastal New England with the molecular formulae C(9)H(3)N(2)Br(6)Cl, C(9)H(3)N(2)Br(7), and C(9)H(4)N(2)Br(5)Cl. They were identified using high and low resolution gas chromatography mass spectrometry (GCMS) and appear to be highly brominated analogues of Q1, a heptachlorinated HOC suspected to be naturally produced. These compounds were found in Atlantic white sided dolphin (Lagenorhynchus acutus), bottlenose dolphin (Tursiops truncatus), common dolphin (Delphinus delphis), Risso's dolphin (Grampus griseus), harbor porpoise (Phocoena phocoena), beluga whale (Delphinapterus leucas), fin whale (Balaenoptera physalus), grey seal (Halichoerus grypus), harp seal (Phoca groenlandica) and a potential food source (Loligo pealei) with concentrations as high as 2.7 microg/g (lipid weight). The regiospecificity of C(9)H(3)N(2)Br(6)Cl is suggestive of a biogenic origin. Debromination of C(9)H(3)N(2)Br(6)Cl may be significant in the formation of C(9)H(4)N(2)Br(5)Cl.

Marine hydrocarbon seepage emits oil and gas, including methane ( approximately 30 Tg of CH(4) per year), to the ocean and atmosphere. Sediments from the California margin contain preserved tar, primarily formed through hydrocarbon weathering at the sea surface. We present a record of variation in the abundance of tar in sediments for the past 32,000 years, providing evidence for increases in hydrocarbon emissions before and during Termination IA [16,000 years ago (16 ka) to 14 ka] and again over Termination IB (11-10 ka). Our study provides direct evidence for increased hydrocarbon seepage associated with deglacial warming through tar abundance in marine sediments, independent of previous geochemical proxies. Climate-sensitive gas hydrates may modulate thermogenic hydrocarbon seepage during deglaciation.

Blubber samples from male California sea lions (Zalphophus californianus) stranded between 1993 and 2003 were analyzed for 27 polybrominated diphenyl ether (PBDE) congeners, three isomers of hexabromocyclododecane (HBCD) and 14 methoxylated polybrominated diphenyl ether (MeO-BDE) congeners. Total PBDEs ranged from 450 ng/g to 4740 ng/g wet mass and total HBCD ranged from < 0.3 ng/g to 12 ng/g wet mass. The concentration of HBCD increased from 0.7 ng/g to12.0 ng/g wet mass in sea lion blubber between 1993 and 2003. However, no significant temporal trend was observed for any of the other brominated compounds over this 10 year period. Only one of the 14 MeO-BDE congeners was detected in the blubber samples, 6-methoxy-2,2',4,4'-tetrabromodiphenyl ether (6-MeO-BDE 47), and concentrations ranged from < 0.2 ng/g to 12 ng/g wet mass. A bromo-, chloro-heterocyclic compound, 1,1'-dimethyl-tetrabromo-dichloro-2,2'-bipyrrole (DBP-Br4Cl2), previously reported in marine species along the Pacific coast, was also identified in the sea lion blubber. DBP-Br4Cl2 ranged from 44 ng/g wet mass to 660 ng/g wet mass and was present at concentrations rivaling the dominant PBDE congener, BDE 47 (2,2',4,4'-tetrabromodiphenyl ether). Concentrations of DBP-Br4Cl2 were positively correlated with 6-MeO-BDE 47 (r = 0.7; p < 0.05). Both of these compounds have been identified in marine algae and sponges, and studies suggest they are both produced from natural sources. This study demonstrates that brominated compounds from both anthropogenic and biogenic sources can accumulate to similar levels in marine mammals. In addition, HBCD concentrations appear to be increasing in California sea lion populations, whereas PBDE concentrations, between 1993 and 2003, were highly variable.

Cytochrome P450 1A (CYP1A) induction is used widely as a biomarker of exposure to pollutants, such as petroleum hydrocarbons, yet CYP1A inducibility has been characterized in few tropical fish. Using Western blot analysis, catalytic assay, and immunohistochemistry, we evaluated CYP1A induction in an Amazonian fish (tambaqui; Colossoma macropomum) acclimated to humic substances (HS) and acutely exposed to crude oil. HS are ubiquitous in Amazonian waters, and they are known to affect the bioavailability of pollutants. CYP1A activity was also measured in fish exposed for 10 days to a range of concentrations of HS from both natural and commercial sources. Crude oil induced CYP1A expression in tambaqui, as expected. Exposure to both HS and crude oil resulted in greater levels of CYP1A expression relative to that in fish exposed to petroleum alone. Interestingly, CYP1A induction was also observed in fish exposed to HS alone. Induction by HS was concentration-dependent, and activity was higher in fish exposed to HS from the commercial source than in fish exposed to the HS from the natural source. The use of CYP1A as a biomarker of exposure to pollutants such as petroleum hydrocarbons in fish living in environments rich in humic substances should be considered with caution given that HS themselves induce CYP1A expression. Our results suggest that there may be as yet unknown CYP1A inducing components (aryl hydrocarbon receptor agonists) in humic substances.

The nature of intermolecular interactions between halogen atoms, X...X (X = Cl, Br, I), continues to be of topical interest because these interactions may be used as design elements in crystal engineering. Hexahalogenated benzenes (C6Cl(6-n)Br(n), C6Cl(6-n)I(n), C6Br(6-n)I(n)) crystallise in two main packing modes, which take the monoclinic space group P2(1)/n and the triclinic space group P1. The former, which is isostructural to C6Cl6, is more common. For molecules that lack inversion symmetry, adoption of this monoclinic structure would necessarily lead to crystallographic disorder. In C6Cl6, the planar molecules form Cl...Cl contacts and also pi...pi stacking interactions. When crystals of C6Cl6 are compressed mechanically along their needle length, that is, [010], a bending deformation takes place, because of the stronger interactions in the stacking direction. Further compression propagates consecutively in a snakelike motion through the crystal, similar to what has been suggested for the motion of dislocations. The bending of C6Cl6 crystals is related to the weakness of the Cl...Cl interactions compared with the stronger pi...pi stacking interactions. The triclinic packing is less common and is restricted to molecules that have a symmetrical (1,3,5- and 2,4,6-) halogen substitution pattern. This packing type is characterised by specific, polarisation-induced X...X interactions that result in threefold-symmetrical X3 synthons, especially when X = I; this leads to a layered pseudohexagonal structure in which successive planar layers are inversion related and stacked so that bumps in one layer fit into the hollows of the next in a space-filling manner. The triclinic crystals shear on application of a mechanical stress only along the plane of deformation. This shearing arises from the sliding of layers against one another. Nonspecificity of the weak interlayer interactions here is demonstrated by the structure of twinned crystals of these compounds. One of the compounds studied (1,3,5-tribromo-2,4,6-triiodobenzene) is dimorphic, adopting both the monoclinic and triclinic structures, and the reasons for polymorphism are suggested. To summarise, both chemical and geometrical models need to be considered for X...X interactions in hexahalogenated benzenes. The X...X interactions in the monoclinic group are nonspecific, whereas in the triclinic group some X...X interactions are anisotropic, chemically specific and crystal-structure directing.

Two methoxylated polybrominated diphenyl ethers (MeO-PBDEs) were isolated from a True's beaked whale (Mesoplodon mirus) and identified by NMR (1H, 1H-1H and 1H-13C) and high resolution mass spectrometry as 2-(2',4'-dibromophenoxy)-3,5-dibromoanisole (6-MeO-BDE47) and 2-(2',4'-dibromophenoxy)-4,6-dibromoanisole (2'-MeO-BDE68). Previously the structures of these bioaccumulated compounds have been determined by comparison of their mass spectra and gas chromatographic (GC) retention times with those of authentic standards. While this method is accepted and generally successful, NMR of the isolated compounds allows us to definitively identify the congeners. Our characterizations are consistent with those made for MeO-PBDEs in other organisms, identified by chromatographic methods.

Comprehensive two-dimensional gas chromatography (GCxGC) provides nearly complete composition data for some complex mixtures such as petroleum hydrocarbons. However, the potential wealth of physical property information contained in the corresponding two-dimensional chromatograms is largely untapped. We developed a simple but robust method to estimate GCxGC retention indices for diesel-range hydrocarbons. By exploiting n-alkanes as reference solutes in both dimensions, calculated retention indices were insensitive to uncertainty in the enthalpy of gas-stationary-phase transfer for a suite of representative diesel components. We used the resulting two-dimensional retention indices to estimate the liquid vapor pressures, aqueous solubilities, air-water partition coefficients, octanol-water partition coefficients, and vaporization enthalpies of a nearly complete set of diesel fuel hydrocarbons. Partitioning properties were typically estimated within a factor of 2; this is not as accurate as some previous estimation or measurement methods. However, these relationships may allow powerful and incisive analysis of phase-transfer processes affecting petroleum hydrocarbon mixtures in the environment. For example, GCxGC retention data might be used to quantitatively deconvolve the effects of water washing and evaporation on environmentally released diesel fuels.

Petroleum-derived hydrocarbons continue to persist in Wild Harbor, West Falmouth, MA, following a spill of No. 2 fuel oil in 1969 from the barge Florida. Recent analysis of marsh sediments revealed that residues of degraded oil are present with concentrations of total petroleum hydrocarbons as high as approximately 9 mg g(-1). Polycyclic aromatic hydrocarbons (PAHs) constitute only a minor fraction of these residues with maximum concentrations of 134 mirog g(-1), but their fate is of interest because of their potential toxicity to organisms. As compared to typical unweathered No. 2 fuel oil, the current distribution of PAHs in the sediments reflects substantial weathering by abiotic and biotic processes, specifically a preferential loss of naphthalenes relative to phenanthrenes, as well as isomer-specific biodegradation of alkylated PAHs. Based on comparison to results from an earlier study, it appears that little or no change has occurred to the distribution of PAHs since 1989, indicating that weathering at this site has stalled or is now proceeding at a significantly slower rate. To assess whether sediment-water partitioning and molecular diffusion in the interstitial medium are now the dominant processes controlling the vertical distribution of PAHs, downcore profiles were compared to a numerical model. While in some cases the model accurately reproduced the measured data, there were instances where the distribution of PAHs was slightly under or overestimated. Reasons for these discrepancies are discussed and are likely due to bioturbation, colloid-facilitated transport, or both. Assessment of the influence of these processes on the spilled oil expands our understanding of the overall fate of these compounds and their potential long-term effects on the environment.

Bending is observed in organic crystals when the packing is anisotropic in such a way that strong and weak interaction patterns occur in nearly perpendicular directions.

Mechanical shearing of crystals of a polymorph with a layered structure may be used to separate them from harder crystals of a visually indistinguishable polymorph that resist such shearing.

Radiocarbon analysis of atmospheric polycyclic aromatic hydrocarbons (PAHs) from three background areas in Sweden, Croatia, and Greece was performed to apportion their origin between fossil and biomass combustion. Diagnostic ratios of PAHs implied that wood and coal combustion was relatively more important in the northern European site, while combustion of fossil fuels was the dominant source of PAHs to the two central-southern European background sites. The radiocarbon content (delta14C) of atmospheric PAHs in Sweden ranged between -388 per thousand and -381 per thousand, while more depleted values were observed for Greece (-914 per thousand) and Croatia (-888 per thousand). Using a 14C isotopic mass balance model it was calculated that biomass burning contributes nearly 10% of the total PAH burden in the studied southern European atmosphere with fossil fuel combustion making up the 90% balance. In contrast, biomass burning contributes about 50% of total PAHs in the atmosphere at the Swedish site. Our results suggest that the relative contributions of biomass burning and fossil fuels to atmospheric PAHs may differ considerably between countries, and therefore, different national control strategies might be needed if a further reduction of these pollutants is to be achieved on a continental-global scale.

To provide a new perspective on the fate of petroleum in the marine environment, we utilized variations in the natural abundance of radiocarbon (14C) to detect and quantify petroleum residues that have persisted in Wild Harbor sediments, West Falmouth, MA, for more than 30 years. The 5730-yr half-life of 14C makes this isotope ideal for the detection of fossil-fuel-derived contaminants (14C free) within different fractions of natural organic matter (modern 14C content) in environmental matrixes. Samples of both contaminated and uncontaminated sediments were sequentially treated, first by solvent extraction, followed by saponification, and then acid hydrolysis. Radiocarbon analysis of the sediment residues and select extracts was performed to probe for the presence of fossil fuel contaminants and/or their metabolites in different pools of sedimentary organic matter. Our results indicate that the majority of fossil carbon is solvent-extractable and has not been incorporated in the insoluble organic matter in sediment. Unextracted sediments contaminated with petroleum contain significantly less 14C than extracted sediments, and isotope mass balance calculations suggest that up to approximately 9% of the total organic carbon (TOC) in the petroleum contaminated sediment horizons is derived from solvent-extractable petroleum. These estimates are similar to values calculated when the total quantities of oil (measured by gas chromatography with flame ionization detector (GC-FID)) are compared to TOC content (determined by elemental analysis). These results pave the way for applications of this isotopic approach to more complex environmental systems where the fate of contaminants is less certain.

Understanding microbial carbon sources is fundamental to elucidating the role of microbial communities in carbon cycling and in the biodegradation of organic contaminants. Because the majority of anthropogenic contaminants are either directly or indirectly derived from fossil fuels that are devoid of 14C, radiocarbon can be used as a natural inverse tracer of contaminant carbon in the contemporary environment. Here, 14C analysis of individual microbial phospholipid fatty acids (PLFA) was used to characterize the carbon sources utilized bythe active microbial community in salt marsh sediments contaminated by the Florida oil spill of 1969 in Wild Harbor, West Falmouth, MA. A specific goal was to determine whether this community is actively degrading petroleum residues that persist in these sediments. The delta14C values of microbial PLFA in all sediment horizons (contaminated and noncontaminated) matched the delta14C of the total sedimentary organic carbon after petroleum removal, indicating that no measurable metabolism of petroleum residues was occurring. This result agrees with ancillary data such as the delta13C content and distribution of PLFA, and the residual hydrocarbon composition determined by comprehensive two-dimensional gas chromatography (GCxGC) analysis. We hypothesize that microbes have chosen to respire the natural organic matter rather than the residual petroleum hydrocarbons because the former is more labile. Future efforts directed at determining indices of microbial degradation of petroleum hydrocarbons should consider competition with natural organic matter.

Background: Pericardial involvement with Coccidioides immitis is an infrequent occurrence with a relatively unfavorable prognosis., Methods: A case of coccidioidal pericarditis is presented along with a review of the medical literature on coccidioidal pericarditis to give the clinician a better understanding of the various presentations, complications and outcomes of this disease. Medline (National Library of Medicine, Bethesda) was electronically searched covering the years 1966-2003 using search words coccidioidomycosis and pericarditis., Results: Sixteen patients were identified from the literature review and one new patient was added. All the patients were males with a mean age of 37.5 years. Chest pain, dyspnea and cough were the most common presenting symptoms. Five patients had evidence of pericardial tamponade, pulsus paradoxus was noted in three patients and three patients presented with pericardial constriction. One patient had Kussmaul's sign, one patient had pericardial frictional rub and another had pericardial knock. Cardiomegaly on chest x-ray was present in ten patients; EKG was noted to have low voltage in five and ST segment elevation in four patients. Delayed hypersensitivity to coccidioidal antigen was reported in nine patients and positive in eight patients. Complement fixation titers were positive in all 11 patients in whom it was assayed. Fifty-three percent of the patients with coccidioidal pericarditis died., Conclusion: Coccidioidal pericarditis is a rare disease entity that has a relatively unfavorable prognosis, yet many patients present with diagnostic clues to this disorder. An enhanced understanding of the clinical features of coccidioidal pericarditis may lead to improved outcomes.

Sixty-two patients with coccidioidal meningitis underwent neuroimaging. Magnetic resonance imaging detected neuroimaging abnormalities in 76% of patients, and computed tomography scanning detected neuroimaging abnormalities in 41.6%. The most common abnormal neuroimaging findings were hydrocephalus (51.6%), basilar meningitis (46.8%), and cerebral infarction (38.7%). Significantly elevated mortality rates were associated with hydrocephalus and hydrocephalus coexisting with infarction. Basilar meningitis did not influence outcome. Patients without neuroimaging abnormalities had a mortality rate of 7.7%.

Methoxylated polybrominated diphenyl ethers (MeO-PBDEs) have been found bioaccumulated in the tissues of a variety of aquatic animals and at concentrations comparable to those of anthropogenic halogenated organic compounds, including polychlorinated biphenyls (PCBs). The origin of the MeO-PBDEs has been uncertain; circumstantial evidence supports a natural and/or an industrial source. By analyzing the natural abundance radiocarbon content of two MeO-PBDEs isolated from a True's beaked whale (Mesoplodon mirus), we show that these compounds were naturally produced.

Basic physical-chemical properties of five bromine and chlorine containing mixed halogenated dimethyl bipyrroles (HDBPs) were determined using established methods. Subcooled liquid vapour pressures (P(o)(L,25)), aqueous solubilities (S(w,25)), and octanol/water partition coefficients (K(ow)) were determined using the gas chromatography-retention time, generator column, and slow-stirring methods, respectively. Henry's Law constants (H25) were estimated using experimentally-derived P(o)(L) and S(w,25) data. Values of all four properties were generally similar to those reported for other polyhalogenated aromatic compounds [P(o)(L,25) = (7.55-191) x 10(-6) Pa; S(w,25) = (1.0-1.9) x 10(-5) g/l; log K(ow) = 6.4-6.7; H25 = 0.0020-0.14 Pa m3/mol]. The effect of replacing a chlorine with a bromine atom significantly decreased P(o)(L,25) (log P(o)(L,25) = -0.4197 (# bromine atoms) - 2.643, p<0.01) and H25 (log H25 = -0.508 (# bromine atoms) + 0.394, p<0.02). There were no significant effects of bromine/chlorine substitution on S(w,25) or K(ow). A simple Level I equilibrium partitioning model predicted the environmental behaviour of HDBPs to be similar to a tetrabrominated diphenyl ether. Only slight differences in behaviour amongst HDBP congeners were predicted since substitution of a bromine for a chlorine (Cl/Br substitution) atom had less effect than H/Cl or H/Br substitution on P(o)(L,25), S(w,25), H25, and K(ow).

Source-diagnostic markers and the isotopic composition of polycyclic aromatic hydrocarbons (PAHs) were examined in surface sediments from the greater Stockholm waterways to deduce the contribution from biomass sources to the environmental PAH load. The summed concentration of 20 PAHs ranged from 0.8 to 45.1 microg/g (dry weight) and exhibited a steep decline with increasing distance from the city center evidencing that sources within the metropolitan area of Stockholm dominate its PAH burden. Several diagnostic PAH ratios indicated an overwhelming predominance of pyrogenic sources over the petrogenic ones, while retene and 1,7-dimethylphenanthrene were unable to correctly evaluate the contribution from biomass combustion. The stable carbon isotope composition (delta13C) of individual PAHs ranged from -24.8 to -27.0% but also was proved inefficient to discriminate between different types of fuels due to the overlapping signals in various sources. The delta14C values of PAHs ranged between -550.4 and -934.1%, indicating a clear predominance of fossil fuel sources. By using an isotopic mass balance approach, we estimated that on average 17+/-9% of PAHs derived from biomass combustion. This radiocarbon apportionment, in conjunction with detailed energy statistics for the Stockholm region, revealed that the ambient PAH burden is roughly similar, per unit energy produced, from fossil fuels and biofuels. Societies' shifting energy policies toward a larger reliance on biofuels may thus not lead to further deterioration of air quality and respiratory ailments for the urban population.

The crystal structure of the title compound, alternatively called 1,2,3-triiodo-5-(triphenylmethyl)benzene, C(25)H(17)I(3), is analysed in terms of I.I and I.pi interactions and the herring-bone T motif between phenyl groups. There are two molecules in the asymmetric unit, denoted A and B. Inversion-related A molecules are connected via an I.pi interaction (3.641 A, to a C-C bond mid-point) to form an I.pi dimer, and these dimers are connected through symmetry-independent B molecules via I.I [3.5571 (15) A] and I.pi (3.561 A, to a C-C bond mid-point) interactions.

Halogenated organic compounds (HOCs) such as 1,1'-dimethyl-3,3',4,4'-tetrabromo-5,5'-dichloro-2,2'-bipyrrole (DBP-Br4Cl2) and heptachloro-1'-methyl-1,2'-bipyrrole (Q1) have been detected worldwide, sometimes at high levels in Antarctic air, seabird eggs, the blubber of marine mammals, and, most notably, even human milk. To date, it has been difficult to determine whether these compounds are natural products or derived from industrial synthesis. Molecular-level 14C analysis of these compounds is particularly appealing because most industrial compounds are manufactured from petrochemicals (14C-free) and natural compounds should have "modern" or "contemporary" 14C levels. To investigate the source of DBP-Br4Cl2, we isolated 600 microg of this compound (150 microg of carbon) from marine animal extracts by employing gel permeation chromatography, Florisil column chromatography, and two-dimensional preparative capillary gas chromatography. The purified DBP-Br4Cl2 was split into two samples (75 microg of carbon each) and analyzed by accelerator mass spectrometry for 14C content. The delta14C values were -449 percent per thousand and -467 percent per thousand, corresponding to conventional 14C ages of 4740 and 5000 years before present (BP), respectively. The presence of detectable 14C in the DBP-Br4Cl2 strongly points to at least a natural or biogenic source. However, these delta14C values for DBP-Br4Cl2 are more depleted than expected for a recently synthesized natural product. Several explanations are discussed, but additional samples

Objective: Granulomatous disorders may be associated with hypercalcemia. In sarcoidosis, the pathogenesis of hypercalcemia has been clarified, whereas in other granulomatous disorders, such as coccidioidomycosis, the mechanism is unclear. We present 13 patients with coccidioidomycosis and hypercalcemia to illustrate the clinical course and the mechanism of hypercalcemia., Methods: We retrospectively reviewed all patients admitted to Kern Medical Center, a 270-bed public hospital, from 1990 through 1997 with coccidioidomycosis and a serum calcium level of greater than 10.5 mg/dL on at least 3 occasions. In addition, no other causes for hypercalcemia were identified., Results: The mean highest serum calcium level was 12.7 +/- 1.8 mg/dL. All patients had disseminated disease. Six patients were nonambulatory and 4 had bone involvement. Of the 9 patients in whom parathyroid hormone was measured, it was normal in 6 and suppressed in 3. Of the 9 patients in whom 25-hydroxyvitamin D was measured, it was normal in 6, suppressed in 2, and elevated in 1. Of the 7 patients in whom 1,25-dihydroxyvitamin D was measured, it was normal in 3 and suppressed in 4. Urinary calcium was elevated in 2 patients, both of whom were ambulatory. Nonambulatory patients had significantly higher serum calcium levels (14.3 +/- 1.0 mg/dL) than ambulatory patients (11.3 +/- 0.46 mg/dL) (P<0.001)., Conclusions: The mechanism of hypercalcemia in coccidioidomycosis is unrelated to increased production of 1,25-dihydroxyvitamin D. Nonambulatory status is associated with higher mean serum calcium.

In order to develop more robust insight into the natural attenuation of polychlorinated biphenyls (PCBs), the chlorine isotopic composition of residual 2,3,4,5-tetrachlorobiphenyl (2,3,4,5-CB) was monitored as it underwent microbial reductive dechlorination to 2,3,5-trichlorobiphenyl (2,3,5-CB) in laboratory cultures. Reverse-phase high performance liquid chromatography (HPLC) was employed to isolate the former compound from the experimental matrix for delta37Cl measurement. No detectable isotopic fractionation was observed over the 90 day incubation with sterile control, standard, and inoculated samples all exhibiting delta37Cl values with a range of approximately 0.5 per thousand. These results show that this type of biological activity can be discriminated from other transformations by the absence of a measurable isotope effect during microbial reductive dechlorination. The utility of HPLC isolation for compound-specific delta37Cl analyses of environmentally relevant species is also demonstrated.

VCRC B426, 0.09% emulsifiable concentrate (EC) formulation developed from a metabolite of Pseudomonas fluorescens was tested for efficacy against Culex quinquefasciatus larvae and pupae. At application rates of 100, 200, 300 ml/m2, the formulation caused 100% elimination of larvae and pupae at day 1 after treatments and >80% reduction in pupal density for periods of 7, 12 and 11 days in cesspits and 5, 9 and 10 days in U-shaped drains. In both the habitats, the efficacy of the formulation against pupae was 1.7 times more at 200 ml/m2 than at 100 ml/m2. An increase in dosage to 300 ml/m2 did not improve the efficacy in cesspits but a marginal increase was observed in drains.

Halogenated dimethyl bipyrroles (HDBPs) recently have been identified as a group of environmentally persistent naturally produced bioaccumulative organohalogens. The ability of these compounds to activate the aryl hydrocarbon receptor (AhR) signaling pathway in vitro was examined. Induction of cytochrome P4501A (CYP1A), measured as ethoxyresorufin-O-deethylase (EROD) activity, and porphyrin accumulation were monitored after exposure of chick embryo hepatocytes to three individual HDBP congeners and two HDBP mixtures. All HDBP congeners and mixtures tested caused induction of EROD activity. Induction equivalency factors, calculated as the ratio of the effective concentration of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to induce 10 and 50% of the maximal EROD induction to that of the HDBP congener or mixture ranged from 0.0004 to 0.05. Halogenated dimethyl bipyrroles also caused porphyrin accumulation, which increased with exposure time of the hepatocytes and molar bromine content of the HDBP congener or mixture. Heptacarboxylporphyrin III and corproporphyrinogen III were the most abundant porphyrins observed after an exposure period of 48 h. The individual HDBP congeners and mixtures also inhibited binding of [3H]TCDD to chicken and mouse AhR. Binding of [3H]TCDD to chicken AhR was inhibited approximately 20% by tetra- to hexabrominated congeners at concentrations of 20 to 40 microM; binding to mouse AhR was inhibited 40 to 50% by tri- and tetrabrominated dimethyl bipyrroles (DBPs) at 10 microM. The relative affinity of the hexabrominated DBP congener (vs TCDD) for binding to chicken AhR was estimated to be 0.000017. The results of this work illustrate that HDBPs act as agonist ligands for the AhR in the same manner as many anthropogenic organohalogens.

Comprehensive two-dimensional gas chromatography (GC x GC) was used to investigate the chemical composition of the unresolved complex mixture (UCM) of hydrocarbons in petroleum-contaminated marine sediments. The UCM hydrocarbons were extracted and separated with silica and silver-impregnated silica gel chromatography to yield four fractions (branched alkanes and cycloalkanes, monoaromatics, naphthalenes, and multi-ring PAHs) prior to GC x GC analysis. GC x GC separations used a poly-(dimethylsiloxane) stationary phase for volatility selectivity on the first dimension and a 14% cyanopropylphenyl polysiloxane phase for polarity selectivity on the second dimension to fully resolve monoaromatic, naphthalene, and multi-ring PAH compounds from the UCM. A chiral gamma-cyclodextrin phase was used for shape selectivity on the second GC x GC dimension to resolve individual branched alkanes and cycloalkanes in the saturates fraction of the UCM. The ability of GC x GC to resolve thousands of individual chemical components from the UCM will facilitate an understanding of the sources, weathering, and toxicity of UCM hydrocarbons.

A high-resolution record of polycyclic aromatic hydrocarbon (PAH) deposition in Rhode Island over the past approximately 180 years was constructed using a sediment core from the anoxic Pettaquamscutt River basin. The record showed significantly more structure than has hitherto been reported and revealed four distinct maxima in PAH flux. The characteristic increase in PAH flux at the turn of the 20th century was captured in detail, leading to an initial maximum prior to the Great Depression. The overall peak in PAH flux in the 1950s was followed by a maximum that immediately preceded the 1973 Organization of Petroleum Exporting Countries (OPEC) oil embargo. During the most recent portion of the record, an abrupt increase in PAH flux between 1996 and 1999 has been found to follow a period of near constant fluxes. Because source-diagnostic ratios indicate that petrogenic inputs are minor throughout the record, these trends are interpreted in terms of past variations in the magnitude and type of combustion processes. For the most recent PAH maximum, energy consumption data suggest that diesel fuel combustion, and hence traffic of heavier vehicles, is the most probable cause for the increase in PAH flux. Systematic variations in the relative abundance of individual PAHs in conjunction with the above changes in flux are interpreted in relation to the evolution of combustion processes. Coronene, retene, and perylene are notable exceptions, exhibiting unique down-core profiles.

Several chlorinated organic compounds (COCs) that have been detected in a wide range of human, animal, and environmental samples may be derived from natural or anthropogenic sources. To determine whether the Cl isotope ratios of these compounds could be used to differentiate sources, we investigated the chlorine isotope effect for enzyme-catalyzed chlorination. Two aromatic substrates, 1,3,5-trimethylbenzene (TMB) and 3,5-dimethylphenol (DMP), were treated with a chloroperoxidase isolated from the fungus Caldariomyces fumago. A kinetic isotope effect (KIE) (in terms of k35/k37) was calculated to be 1.012 for TMB and 1.011 for DMP. A similar reaction, but not catalyzed, with hypochlorite yielded a much smaller KIE. These results indicate that a substantial KIE exists for this process. Furthermore, natural COCs synthesized by this enzymatic pathway may have Cl isotope ratios that will be easily distinguished from anthropogenic COCs.

The long-term fate of petroleum hydrocarbons in marsh sediments (West Falmouth, MA) contaminated in 1969 by the spill of the barge Florida was investigated. A 36-cm-long sediment core was collected in August 2000, and sediment extracts were analyzed by gas chromatography (GC) and comprehensive two-dimensional gas chromatography (GC x GC). The latter technique is capable of separating 1 order of magnitude more compounds than the former and was used to observe whether any compositional changes in the unresolved complex mixture (UCM) occurred. No evidence of petroleum residues was detected in the top 6 cm (0-6 cm) and the lower 8 cm (28-36 cm) of the core. However, the central sections 16-28 cm) were dominated by a UCM in the boiling range of n-C13-n-C25 alkanes, consistent with a No. 2 fuel oil source. The 12-14- and 14-16-cm sections had the highest concentrations of UCM approximately 8 mg g(-1)). These values are similar to concentrations observed shortly after the spill. Initial GC x GC analysis revealed that only the n-alkanes were completely degraded, and contrary to previous studies, pristane and phytane as well as numerous other branched alkanes are still present in the sediments. These results suggestthatatthis site hydrocarbon contamination will persist indefinitely in the sedimentary record.

To determine the relative inputs of polycyclic aromatic hydrocarbons (PAHs) and black carbon (BC) in environmental samples from the combustion of fossil fuels and biomass, we have developed two independent analytical methods for determining the 14C abundance of PAHs and BC. The 5730 yr half-life of 14C makes it an ideal tracer for identifying combustion products derived from fossil fuels (14C-free) versus those stemming from modern biomass (contemporary 14C). The 14C abundance of PAHs in several environmental Standard Reference Materials was measured by accelerator mass spectrometry after extraction and then purification by high-performance liquid chromatography and preparative capillary gas chromatography. This method yields pure compounds that allow for a high degree of confidence in the 14C results. The PAHs data were then used to compare and evaluate results from an operationally defined thermal oxidation method used to isolate a BC fraction. The 14C compositions of PAHs and BC were very similar and suggest that the thermal oxidation method employed for isolating BC is robust and free from interferences by non-BC components. In addition, these data indicate that both the PAHs and the BC species derive mostly from fossil fuels and/or their combustion products.

Some halogenated organic compounds, such as polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polybrominated diphenyl ethers (PBDEs), have been suggested to have natural sources but separating these compounds from their commercially synthesized counterparts is difficult. Molecular-level 14C analysis may be beneficial since most synthetic compounds are manufactured from petrochemicals (14C-free) and natural compounds should have "modern" or "contemporary" 14C levels. As a baseline study, we measured, for the first time, the 14C abundance in commercial PCB and PBDE mixtures, a number of organochlorine pesticides, as well as one natural product 2-(3',5'-dibromo-2'-methoxyphenoxy)-3,5-dibromoanisole. The latter compound was isolated from a marine sponge and is similar in structure to a PBDE. All of the synthetic compounds were 14C-free except for the pesticide toxaphene. which had a modern 14C abundance, as did the brominated natural compound. The result for toxaphene was not surprising since it was commercially synthesized by the chlorination of camphene derived from pine trees. These results suggest that measuring the 14C content of halogenated organic compounds may be quite useful in establishing whether organic compounds encountered in the environment have natural or synthetic origins (or both) provided that any synthetic counterparts derive from petrochemical feedstock.

Intention, Goal, Scope, Background: Identifying different sources and following reaction pathways of chlorinated organic contaminants in the environment can be challenging, especially when only their concentrations are available. Compound-specific stable chlorine measurements of some contaminants have recently been shown to provide additional information and an increased understanding of their biogeochemistry. These studies, however, have been generally limited to volatile molecules., Objective: Here, the stable chlorine isotope ratios of the semi-volatile pesticide, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) were investigated. Specifically, the intramolecular stable chlorine isotopic compositions of DDT and the kinetic isotope effect (KIE) for the abiotic dehydrochlorination of DDT to 2,2-bis(p-chlorophenyl)-1,1-dichloroethene (DDE) were determined., Methods: Selective chemical oxidation of DDT to dichlorobenzophenone (DCBP) and analysis of each compound was used to calculate the stable chlorine isotope ratios of the alkyl and aromatic chlorines in DDT. To determine the KIE for dehydrochlorination, DDT was reacted in a basic solution to yield DDE at 52 degrees C, 60 degrees C, and 72 degrees C for 3, 5, and 5 days, respectively., Results and Discussion: Significant intramolecular stable chlorine isotopic differences were observed in one sample of DDT where the alkyl and aromatic delta 37Cl values were -5.76 +/- 0.45 and -2.21 +/- 0.24%@1000, respectively. Dehydrochlorination of DDT to DDE in basic solutions at 52, 60, and 70 degrees C resulted in a substantial intramolecular KIE where the alkyl chlorines of DDE shifted by approximately 3%@1000 relative to the alkyl chlorines in DDT. However, no temperature dependence was observed. The KIE, calculated by an iterative program, was 1.009., Conclusions: Intramolecular differences in the stable chlorine isotope ratios were observed in DDT and this is the first such finding. Dehydrochlorination of DDT yields a measurable and distinct intramolecular stable chlorine KIE., Recommendation and Outlook: The results of this study demonstrate the existence of significant intramolecular differences in chlorinated organic compounds. Many other chlorinated semi-volatile and volatile organic contaminants are synthesized from multiple sources of chlorine, and we recommend that similar studies be performed on many such molecules in order to attain a clear understanding of their intramolecular chlorine isotopic differences. The existence of a measurable KIE for the dehydrochlorination of DDT to DDE shows the potential strength of using isotopic measurements to investigate the biogeochemistry of these important compounds. For example, the isotopically depleted aqueous chloride produced by dehydrochlorination of DDT to DDE may be a useful tracer of these reactions in freshwater environments.

On 19 January 1996, the North Cape oil barge ran aground near Moonstone Beach, RI, and spilled over 2700 metric tons of No. 2 fuel oil during a severe winter storm. High winds and rough seas drove the oil into the water column, and the oil spread throughout Block Island Sound and into several coastal salt ponds. Over 50 water samples were collected from Point Judith Pond (PJP) and the southern coast of Rhode Island for four months after the spill and analyzed for polycyclic aromatic hydrocarbons (PAHs) and total petroleum hydrocarbons (TPHs). These analyses revealed that at least 60 km2 of coastal waters were impacted from the spill. Maximum concentrations of sigmaPAHs and TPHs were 115 and 3940 microg l(-1), respectively. The percentage of sigmaPAHs relative to the TPHs for all samples varied from 0.2 to 43%, showing that there was no clear relationship between sigmaPAHs and TPHs for the whole dataset and likely resulting from spatial and temporal partitioning over the course of the spill. However, within the dataset, there were stronger correlations for distinct samples collected at similar locations and times. In PJP, water column concentrations of individual PAHs decreased at rates of 0.08-0.24 day(-1) and lower-molecular weight PAHs were removed faster than higher-molecular weight PAHs.

A bacterial enrichment culture (specific to doubly flanked chlorine removal) reductively dechlorinated 2,3,4,5-tetrachlorobiphenyl (2,3,4,5-CB) to 2,3,5-trichlorobiphenyl (2,3,5-CB) in aqueous media. Approximately 90% conversion to 2,3,5-CB occurred after 90 days, with no other products formed. The delta13C values of 2,3,4,5-CB and 2,3,5-CB were relatively constant over the course of the reaction, indicating a very small or no isotope effect. In addition, compound-specific delta13C analysis performed for every congener in three different lots of Aroclor 1268 showed an intrinsic isotopic trend of decreasing 13C abundance with increasing chlorine content, similar to observations in other commercial mixtures of polychlorinated biphenyls (PCBs). The results of this laboratory study suggest that microbial reductive dechlorination of PCBs in contaminated sediments will create congeners with more depleted delta13C values than native PCBs of similar chlorination. Such information may provide additional evidence for the occurrence of this process and aid in further understanding the biogeochemistry of these compounds.

We report data from two related assay systems (isolated enzyme assays and whole blood assays) that C-phycocyanin a biliprotein from Spirulina platensis is a selective inhibitor of cyclooxygenase-2 (COX-2) with a very low IC(50) COX-2/IC(50) COX-1 ratio (0.04). The extent of inhibition depends on the period of preincubation of phycocyanin with COX-2, but without any effect on the period of preincubation with COX-1. The IC(50) value obtained for the inhibition of COX-2 by phycocyanin is much lower (180 nM) as compared to those of celecoxib (255 nM) and rofecoxib (401 nM), the well-known selective COX-2 inhibitors. In the human whole blood assay, phycocyanin very efficiently inhibited COX-2 with an IC(50) value of 80 nM. Reduced phycocyanin and phycocyanobilin, the chromophore of phycocyanin are poor inhibitors of COX-2 without COX-2 selectivity. This suggests that apoprotein in phycocyanin plays a key role in the selective inhibition of COX-2. The present study points out that the hepatoprotective, anti-inflammatory, and anti-arthritic properties of phycocyanin reported in the literature may be due, in part, to its selective COX-2 inhibitory property, although its ability to efficiently scavenge free radicals and effectively inhibit lipid peroxidation may also be involved., (Copyright 2000 Academic Press.)

Spicbiomoss, an aqueous suspension formulation of Bacillus sphaericus was evaluated for its efficacy against immatures of Culex quinquefasciatus at the application rate of 120 l/ha in cement tanks, cesspits and drains in Pondicherry and in drains in Kochi, Kerala. The formulation was also tested against anophelines (Anopheles fluviatilis and An. culicifacies) breeding in stream pools in Malkangiri district, Orissa. In cement tanks and cesspits more than 80 per cent reduction in immature density was observed for a period of 6-13 days (mean 9.8 +/- 1.25 days) and 3-8 days (mean 5.2 +/- 0.7 days) respectively. The same level of reduction was found to last for 1-4 days (mean 2.2 +/- 0.52 days) in drains in Pondicherry and 2-9 days (mean 4.8 +/- 1.17 days) in Kochi. In bunded stream pools 40-79 per cent reduction in immature density of Anopheles was obtained for an average period of 1-7 (mean 3.83 +/- 0.98) days. There was no improvement in the efficacy of the formulation against anophelines even at the higher application rate (240 l/ha). Thus, Spicbiomoss can be used against Cx. quinquefasciatus in an integrated vector management programme.

Novel compounds having a dual pharmacophore were synthesised and evaluated for their insulin sensitiser and anti-inflammatory properties in different animal models.

The benzene chloroform and alcoholic extracts of the flowers of H.r.sinensis were administered (i.p.) at two different dose levels of 125 and 250 mg/kg body weight to adult male albino mice for 20 days. The results have shown decrease in the spermatogenic elements of testis and epididymal sperm count. High content of testicular cholesterol may be due to lowered androgen synthesis. The increase in the weight of accessory reproductive organs indicates the androgenicity of the plant extract itself, which is proved in the present study by testing the benzene extract in immature mice.

The benzene extract of Hibiscus rosa sinensis flowers was administered intraperitoneally at the dose levels of 125 and 250 mg/kg body weight to adult mice and resulted in an irregular estrous cycle with prolonged estrus and metestrus. An increase in the atretic follicles and the absence of corpora lutea indicate the antiovulatory effect of the extract. The extract also showed estrogenic activity in immature mice by early opening of the vagina, premature cornification of the vaginal epithelium and an increase in uterine weight. Therefore the antiovulatory effect may be due to an imbalance in the hormonal environment, as there may be an increase in the endogenous secretion of estrogen by atretic follicles, and also to the estrogenicity of the flower extract.

A preliminary study has shown that the marshy terrain and brackish water bodies associated with mangrove forests contributed profuse breeding of mosquitos in Vypeen island, causing a severe menace to the island population. A total of 14 species belonging to four genera viz, Aedes, Anopheles, Armigeres and Culex was recorded from different habitats. Culex sitiens was found to be the predominant mosquito in all the perennial breeding habitats. The extent of different habitats in the production of mosquitos, and its possible abatement, using environmental and/or biocontrol methods are discussed.

The Committee on Infectious Diseases of the American Academy of Pediatrics, and the Advisory Committee on Immunization Practices of the Center for Disease Control for many years have recommended the routine use of influenza vaccine in various hemoglobinopathies including sickle cell disease. This recommendation, however, has not been included in the patient care protocols of the Comprehensive Sickle Cell Centers program of NIHLB. Most clinicians have not used yearly influenza vaccine for their patients with sickle cell disease. This article reports a case of a 5-year-old boy with sickle cell disease who had not received influenza vaccine. He developed pneumonitis and acute myositis during a serologically confirmed influenza B virus infection. The incapacitating and protracted course of his illness presented diagnostic and management problems. His case strongly supports the recommendation of the two infectious disease committees.

Three different formulations of Bacillus sphaericus viz, Spherimos, Vectobac and Spherifix, were evaluated for their efficacy and residual activity against Culex quinquefasciatus breeding in polluted disused wells. Spherimos, a flowable concentrate formulation, exerted 96-100% control when treated at the dosage of 10 l/ha for 17 days, whereas the effective residual activity lasted up to 67 days at 15 l/ha. In the case of Vectolex, a granular formulation, the residual activity lasted up to 56 days with the dosage of 30 l/ha and up to 66-77 days with higher dosages of 45 and 60 l/ha. The residual activity of Spherifix, a floating controlled release formulation, lasted up to 67 days with a dosage of 10 kg/ha.

Enterobacter species, in recent years, have been divided into E aerogenes, E hafniae, E liquefaciens, and E cloacae. Early reviews of neonatal meningitis include some cases due to Klebsiella-Aerobacter,(1) and recent reviews(2,3) include Enterobacter which did not divide them into species of Enterobacter. Reported here is a case of neonatal meningitis due to a gram-negative organism, Enterobacter cloacae.

A 10½-year-old boy with an IQ of 71, short stature, and isolated growth hormone deficiency was found to have diploid/tetraploid mosaicism. He was born to a 46xx/47xxx mosaic mother. The mother was found to be moderately mentally retarded but showed no other abnormalities. A review of literature pertinent to this case is presented.

A 10-year-old girl initially presented with clinical features and thyroid function tests consistent with hyperthyroidism. She was treated with propylthiouracil, 100 mg, three times a day. She developed jaundice and hepatitis following treatment with propylthiouracil for 40 days. Clinical features of hepatitis improved after the discontinuation of propylthiouracil and she became euthyroid. At this time, an immunofluorescent technique revealed antibodies consistent with autoimmune thyroiditis. From this report, it appears that hepatitis is one of the infrequent complications of treatment with propylthiouracil and transient hyperthyroidism may be associated with autoimmune thyroiditis.