bluuebunny/crossref_metadata_2025_split huggingface dataset:
Secondary Sjögren’s Syndrome in Systemic Lupus Erythematosus Defines a Distinct Disease Subset
Authors: BAER ALAN N. , MAYNARD JANET W. , SHAIKH FASIL , MAGDER LAURENCE S. , PETRI MICHELLE 
Published: April 2010

Objective.Sjögren’s syndrome (SS) may occur in patients with systemic lupus erythematosus (SLE). We sought to determine whether the presence of SS in a large cohort of patients with SLE defines a subset with distinctive sociodemographic, clinical, and laboratory features.Methods.The Johns Hopkins Lupus Cohort was divided into 2 groups, based on the presence or absence of SS, defined by the presence of an objective measure of sicca or an abnormal minor salivary gland biopsy in a patient with sicca symptoms. These groups were compared with regard to sociodemographic, clinical, and laboratory features. Multivariable logistic regression was then performed to adjust the findings for potential sociodemographic, clinical, and laboratory confounders.Results.The 259 patients with SS (14% of the cohort), when compared with the 1531 patients without SS, were older at the time of SLE diagnosis and were more commonly women and white. Photosensitivity, oral ulcers, Raynaud’s phenomenon, anti-Ro antibodies, and anti-La antibodies had a significant positive association while renal disease, anti-ribonucleoprotein (RNP) antibodies, and anti-dsDNA antibodies had a negative association with the presence of SS after adjustment for age (at last cohort visit), gender, ethnicity, and anti-Ro antibodies. The older age at diagnosis of SLE among the patients with SS did not remain a significant finding after adjustment for the age of the patient at last cohort visit.Conclusion.The subset of patients with SLE and SS has a distinct clinical and laboratory phenotype, with a higher frequency of older white women with photosensitivity, oral ulcers, Raynaud’s phenomenon, anti-Ro antibodies, and anti-La antibodies and a lower frequency of renal disease, anti-dsDNA antibodies, and anti-RNP antibodies.
Production of Vascular Endothelial Growth Factors from Human Lung Macrophages Induced by Group IIA and Group X Secreted Phospholipases A2
Authors: Granata Francescopaolo , Frattini Annunziata , Loffredo Stefania , Staiano Rosaria I. , Petraroli Angelica , Ribatti Domenico , Oslund Rob , Gelb Michael H. , Lambeau Gerard , Marone Gianni , Triggiani Massimo 
Published: April 2010

Abstract
Angiogenesis and lymphangiogenesis mediated by vascular endothelial growth factors (VEGFs) are main features of chronic inflammation and tumors. Secreted phospholipases A2 (sPLA2s) are overexpressed in inflammatory lung diseases and cancer and they activate inflammatory cells by enzymatic and receptor-mediated mechanisms. We investigated the effect of sPLA2s on the production of VEGFs from human macrophages purified from the lung tissue of patients undergoing thoracic surgery. Primary macrophages express VEGF-A, VEGF-B, VEGF-C, and VEGF-D at both mRNA and protein level. Two human sPLA2s (group IIA and group X) induced the expression and release of VEGF-A and VEGF-C from macrophages. Enzymatically-inactive sPLA2s were as effective as the active enzymes in inducing VEGF production. Me-Indoxam and RO092906A, two compounds that block receptor-mediated effects of sPLA2s, inhibited group X-induced release of VEGF-A. Inhibition of the MAPK p38 by SB203580 also reduced sPLA2-induced release of VEGF-A. Supernatants of group X-activated macrophages induced an angiogenic response in chorioallantoic membranes that was inhibited by Me-Indoxam. Stimulation of macrophages with group X sPLA2 in the presence of adenosine analogs induced a synergistic increase of VEGF-A release and inhibited TNF-α production through a cooperation between A2A and A3 receptors. These results demonstrate that sPLA2s induce production of VEGF-A and VEGF-C in human macrophages by a receptor-mediated mechanism independent from sPLA2 catalytic activity. Thus, sPLA2s may play an important role in inflammatory and/or neoplastic angiogenesis and lymphangiogenesis.
B Cells Have Distinct Roles in Host Protection against Different Nematode Parasites
Authors: Liu Qian , Kreider Timothy , Bowdridge Scott , Liu Zhugong , Song Youngmia , Gaydo Andrew G. , Urban Joseph F. , Gause William C. 
Published: April 2010

Abstract
B cells can mediate protective responses against nematode parasites by supporting Th2 cell development and/or by producing Abs. To examine this, B cell-deficient mice were inoculated with Nippostrongylus brasiliensis or Heligmosomoides polygyrus. B cell-deficient and wild type mice showed similar elevations in Th2 cytokines and worm expulsion after N. brasiliensis inoculation. Worm expulsion was inhibited in H. polygyrus-inoculated B cell-deficient mice, although Th2 cytokine elevations in mucosal tissues were unaffected. Impaired larval migration and development was compromised as early as day 4 after H. polygyrus challenge, and administration of immune serum restored protective immunity in B cell-deficient mice, indicating a primary role for Ab. Immune serum even mediated protective effects when administered to naive mice prior to inoculation. This study suggests variability in the importance of B cells in mediating protection against intestinal nematode parasites, and it indicates an important role for Ab in resistance to tissue-dwelling parasites.
Intragraft Th17 Infiltrate Promotes Lymphoid Neogenesis and Hastens Clinical Chronic Rejection
Authors: Deteix Clémence , Attuil-Audenis Valérie , Duthey Aurélie , Patey Natacha , McGregor Brigitte , Dubois Valérie , Caligiuri Giuseppina , Graff-Dubois Stéphanie , Morelon Emmanuel , Thaunat Olivier 
Published: April 2010

Abstract
To evaluate the influence of intragraft inflammatory infiltrate on the course of chronic rejection, 11 human renal grafts, detransplanted for terminal failure, were analyzed. Samples were divided into two groups according to their graft survival (&gt; or ≤8 y). In both groups, the main cell population infiltrating the graft interstitia was T lymphocytes. The extent of the lymphocytic infiltration and the distribution of naive and memory, CD4+ and CD8+ T cells, were similar in both groups. Although all types of Th polarization profiles can lead to terminal chronic rejection, a correlation between shorter graft survival and the presence of Th17 cells that produce IL-17 and IL-21 was observed. In contrast, grafts infiltrated by regulatory T cells survived significantly longer. The correlation between the expressions of activation-induced cytidine deaminase (the key enzyme of the germinal center reaction) and IL-21 suggests that Th17 could exert their deleterious effect by promoting lymphoid neogenesis, namely, the organization of inflammatory effectors into ectopic germinal centers in which a local humoral immune response is elicited. Further studies will determine whether Th17 infiltration can be used as a prognosis tool and whether theTh17 subset constitutes a therapeutic target for slowing down chronic rejection.
Environmental correlates of hermatypic coral (Montastrea annularis) growth on the East Flower Gardens Bank, northwest Gulf of Mexico1
Authors: Dodge Richard E. , Lang Judith C. 
Published: April 2010

Time series of annual linear growth increments from 12 Montastrea annularis (E. and S.) collected at the East Flower Gardens Bank reef in the northwestern Gulf of Mexico have a common pattern. This is best expressed in an index master chronology (average by year of the annual percentage deviations from the mean of each coral).Comparisons with time series of environmental data indicate that coral extension rates vary positively with seasonal (February through May—4 months) surface water temperature and negatively with annual discharge of the Atchafalaya River. We propose that secular variations of water temperature and other parameters are the major long term controls of coral growth in the area. Our data do not support the view that sinking of the Flower Gardens reef, caused by catastrophic collapse of the underlying substrate, has been a prime influence on the corals.
Population dynamics of food‐limited rotifers in two‐stage chemostat culture1,2
Authors: Boraas Martin E. 
Published: April 2010

The population dynamics of Brachionus calyciflorus were studied in two‐stage chemostat cultures. Chlorella pyrenoidosa was supplied continuously from a steady state culture growing with constantillumination onlimiting nitrate. Rotifer growth in the second stage (in the dark) was limited by the rate of supply of algae. The algal supply rate and rotifer specific growth rate, µ, were determined by the second‐stage dilution rate, D(µ = D in the steady state). Population densities and size‐age structures were determined with an electronic particle counter. Small body size and obligate amictic females apparently were selected in these chemostats. The growth rates observed were the highest yet recorded for any species of Brachionus.The chemostat system facilitated unambiguous determinations of rotifer growth and fecundity, since food was supplied and wastes were removed at continuous, controlled rates. Specific ingestion and loss rates, yield (netrotifers produced/algae ingested), production (rotifers produced·h−1), and rotifer standing crop increased directly with µ. Although most observations are qualitatively similar to data from heterotrophic microbial chemostat studies, a close fit to the rotifer steady state observations was obtained only when K was assumed to be variable (an inverse function of µ) rather than constant. Numerical simulations of the same model only approximately reproduced transient data. Microbial growth models may be useful to represent rotifer growth at or near steady state but are inadequate to explain moderate to large transient fluctuations of populations.
Silicon‐32 as a tool for studying silicon behavior in estuaries
Authors: Nijampurkar V. N. , Martin J. M. , Maybeck M. 
Published: April 2010

Cosmogenic 32Si has been used as a tracer to study the behavior of stable silicon in the Gironde estuary, southwest France, particularly to identify the source of excess stable silicon observed in low salinity areas.The results indicate that the dissolved 32Si behaves conservatively in mixing in the estuary and that the excess stable silicon found in the low salinity zone is likely to be anthropogenic.
The effect of the Asiatic clam, Corbicula fluminea, on phytoplankton of the Potomac River, Maryland
Authors: Cohen Ronald R. H. , Dresler Paul V. , Phillips Elizabeth J. P. , Cory Robert L. 
Published: April 2010

In the summers of the 1960s and 1970s, phytoplankton in the fresh, tidal Potomac River showed a downstream gradient of low to high abundance. Phytoplankton abundance in a 6–8‐km segment of the river, in summer 1980 and 1981, was 40–60% below that upstream and downstream, forming a “sag.”In 1980, the highest densities of the Asiatic clam Corbicula fluminea were in the same reach as the phytoplankton sag. Filtration rates indicate that the volume of the sag reach could be pumped through the Corbicula population in 3–4 days. Corbicula removed 30% of the phytoplankton chlorophyll a from a river water sample in 2 h. Pheophytin a in surficial sediments correlated well with clam biomass as a consequence of phytoplankton excreted in pseudofeces.The hypotheses that peak discharges, zooplankton, toxic substances, and nutrient limitation induced the sag were not supported.
Chaoborus predation on typical and spined morphs of Daphnia pulex: Behavioral observations1
Authors: Havel John E. , Dodson Stanley I. 
Published: April 2010

Behavioral observations of Chaoborus americanus predation on juvenile instars of typical and spined forms of Daphnia pulex were used to answer two questions: Does the spined morph (SM) have a higher escape efficiency than the typical morph (TM)? Is handling time of ingested SM longer than that of TM?Results indicate that SM was clearly superior to TM in escaping the grasp of both third and fourth instar Chaoborus larvae and visible injuries to escapees were rare. The escape efficiency of larger Daphnia was higher than that of smaller Daphnia when tested with fourth instar Chaoborus. Differences in handling time for the two morphs could not be demonstrated. Handling times were short but highly variable, being partly dependent on Chaoborus length and orientation of the prey item. Within the range of 0.8–1.3 mm, Daphnia body length had no discernible influence on handling time.
The growth of heterotrophic bacteria in the surface waters of warm core rings1
Authors: Ducklow Hugh W. , Hill Suzanne M. 
Published: April 2010

The “seawater culture” approach is evaluated as a means of observing changes in cell numbers over time to estimate specific growth rates and production of heterotrophic bacterioplankton in oligotrophic open ocean waters. We use models of exponential growth limited by grazers, and of logistic growth limited by substrate availability, to estimate the specific growth rates of natural bacterial populations in warm core Gulf Stream rings. The two models yielded somewhat different rate estimates, but in general the results suggest that in situ specific growth rates for bacterial populations in oligotrophic ocean waters are as fast as rates in rich coastal waters and lakes (1–2 d−1). Estimates of hourly bacterial production averaged 10% of hourly primary production. Since bacteria grew at night, up to 40% of the daytime primary production was estimated to pass through the bacteria every 24 h. Estimates of removal rates by grazers are about the same as bacterial growth rates. However we estimate that only 3–7% of primary production was converted to protozoan biomass via ingestion of bacteria.Our data suggest that simple dilution of natural samples with cell‐free water is a useful, valid method for estimation of bacterial specific growth rates.
A remote‐sensing reflectance model of a red‐tide dinoflagellate off west Florida1
Authors: Carder K. L. , Steward R. G. 
Published: April 2010

A mathematical model that simulates the spectral curves of remote‐sensing reflectance of blooms of the red‐tide dinoflagellate Ptychodiscus brevis is developed. The model is compared to measurements obtained from a low‐flying helicopter for P. brevis populations with chlorophyll‐like pigment concentrations from 7 to 77 mg m−3 found in the case 2 waters along the west Florida shelf in October 1983.The model simulates the effects of backscattering from water, phytoplankton, and detritus, and the effects of absorption due to water, phytoplankton, detritus, and yellow dissolved matter (“Gelb‐stoff”) for case 1 and case 2 waters. It can be easily modified to simulate the spectral reflectance of phytoplankton from other pigment color groups. Matching the model spectral curves to measured remote‐sensing reflectance curves provides accurate estimates of chlorophyll a plus pheophytin a and also estimates of Gelbstoff and detritus concentrations. Comparison of remote‐sensing reflectance data to model reflectance data allows calculation of the quantum efficiency of fluorescence for a given phytoplankton population, which provides a remote measurement of a factor that has been found to increase with the nutrient stress of the population.
An analysis of the feeding behavior of Daphnia pulex1
Authors: Meise Carol J. , Munns Wayne R. , Hairston Nelson G. 
Published: April 2010

The feeding abilities of Daphnia pulex were investigated by offering it suspensions of the small alga Chlamydomonas minutissima and its larger congener Chlamydomonas capensis. The suspensions differed in the relative abundance of the two algae and in th e presence or absence of intermediately sized latex spheres. The experiments were designed to distinguish between mechanistic and behavioral modes of feeding.Daphnia showed marked flexibility in its feeding patterns, consistent with the behavioral hypothesis. It preferred to feed on C. minutissima. Significant feeding on C. capensis occurred only when C. capensis‐conditioned animals were presented suspensions relatively low in C. minutissima or in the presence of latex spheres. Analysis of gut contents revealed a reduction in the ingestion of latex spheres over time. Total carbon and life history analyses suggest that the preferred food, C. minutissima, is the superior food as well.
Shipboard comparison of micro‐ and minielectrodes for measuring oxygen distribution in marine sediments
Authors: Helder Willem , Bakker Joop F. 
Published: April 2010

We have compared the shipboardperformance of laboratory‐made microelectrodes (o.d., 5–10 µm; Pt‐electrode tip, 2–8 µm) with a commercially available minielectrode (o.d., 700 µm; Pt‐electrode tip, 35–40 µm) for measuring oxygen distributions in marine sediment. The performance of the two types of electrodes was similar. The general availability, the relative ease of modifications necessary for work on marine sediment, the rugged construction, and the high current output (∼ 5,000 pA) make the minielectrodes satisfactory for measuring O2 distributions in marine sediments.
Dependence of the rate of release of phosphorus by zooplankton on the P: C ratio in the food supply, as calculated by a recycling model1
Authors: Olsen Yngvar , Jensen Arne , Reinertsen Helge , BØrsheim Knut Yngve , Heldal Mikal , Langeland Arnfinn 
Published: April 2010

In two enclosure experiments, Daphnia pulex ingested cryptophytes, bacteria, and probably detritus particles. The specific clearance rate of the zooplankton increased when the concentration of food decreased. The P : C ratio of the food also increased. More than 92% of the particulate phosphorus was located in the living cells (algae and bacteria); the detritus was practically phosphorus‐free. The specific release rate of phosphorus estimated for the daphnids by use of the recycling model increased as the P : C ratio of the food increased and became zero at a critical low P : C ratio, Q, of 6–8 µg P mg−1 C. At this concentration, all the ingested phosphorus is needed for growth and reproduction, and no release of the element can be expected. This indicates that Daphnia may experience P limitation in nature, since the P : C ratio of P‐starved algae and detritus may be considerably <6–8 µg P mg−1 C.The use of mass balance also appears to be suitable for modeling phosphorus and carbon fluxes through zooplankton in pelagic ecosystems.
Compositions and fluxes of particulate organic material in the Amazon River1
Authors: Hedges John I. , Clark Wayne A. , Quay Paul D. , Richey Jeffrey E. , Devol Allan H. , Santos M. 
Published: April 2010

Lignin, elemental, and stable carbon isotope compositions are reported for local plants and for coarse (>63 µm) and fine (<63 µm) suspended particulate materials collected along a 1,950‐km reach of the lower Amazon River during four contrasting stages of the 1982–1983 hydrograph. Fluxes of chemically recognizable lignin in the two size classes generally parallel each other along the mainstem with the fine fraction usually predominating. Particulate organic matter transported in the coarse size fraction of the mainstem and its major tributaries is composed of recently formed and well preserved tree leaf debris along with some wood. Organic matter in the fine size fraction is comparatively old, degraded, and rich in immobilized nitrogen and derives primarily from soils. C‐4 grasses, which are abundant in the mainstem floodplain (várzea), are not major components of either the coarse or fine particulate material in the river.Particulate organic matter in both size fractions is introduced largely from upstream sources within the Rio Solimões and Rio Madeira drainage basins. Most of this organic matter is unreactive and is transported conservatively with mineral particles along the Amazon mainstem. However, some downstream compositional trends are seen in both size fractions which reflect the addition or exchange of highly degraded, 13C‐depleted, and lignin‐poor organic materials from lower basin sources.
Characterization of uranium(VI) in seawater1
Authors: Djogić Renata , Sipos Laszlo , Branica Marko 
Published: April 2010

The physicochemical characterization of uranium(VI) in seawater is described on the basis of species distribution calculations and experiments using polarography and spectrophotometry in artificial seawater at elevated uranium concentrations. Various dissolved uranium(VI) species are identified under different conditions of pH and carbonate concentration. Below pH 4, the hydrated uranyl ion is present in the “free” state (forming “labile” complexes). Above pH 4, a stepwise coordination of uranyl by the carbonate ion occurs. The monocarbonate complex is formed in the pH range 4–5, the bicarbonate uranyl complex between 5 and 6. Above pH 8, uranium is present predominately as the tricarbonate and to a smaller extent as a trihydroxide complex. There is satisfactory agreement between our experiments and the theoretically computed distribution of uranium(VI) in seawater based on published stability constants.The experiments done at higher concentrations are justified by theoretical distributions showing that there is no great difference in species distribution between the uranium at concentrations of 10−4 and 10−8 mol dm−3.
The role of sulfate reduction in long term accumulation of organic and inorganic sulfur in lake sediments1
Authors: Rudd John W. M. , Kelly C. A. , Furutani Akira 
Published: April 2010

Sulfate reduction and the accumulation of reduced sulfur in epilimnetic sediments were studied in lakes in southern Norway, the Adirondack Mountains, and at the Experimental Lakes Area (ELA) of northwestern Ontario. In all of the lakes, in addition to the previously known formation of acid volatile sulfur, sulfate reduction also produced substantial quantities of pyrite and organic sulfur compounds. In 9‐month in situ experiments at ELA using 35S, there was a large loss (55%) with time of the S initially reduced and deposited in the sediments and a preferential loss of inorganic S compounds which led to a predominance of organic 35S accumulation in the sediments. An intensive study of long term accumulation of sulfur in the epilimnetic sediments of four Adirondack lakes also showed that the most important long term end product of sulfate reduction was organic S and that sulfate reduction was the major source of S to the sediments.Because of the high concentrations of iron in all of the sediments we sampled and because of the long term storage of sulfur in sediments, mostly as organic S, iron did not limit iron sulfide accumulation in these sediments. Iron limitation is unlikely to occur except in unusual circumstances.This study indicates that formation of organic S in epilimnetic sediments is primarily responsible for H consumption via sulfate reduction in acidified lakes.