189 research outputs found
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Function of B cells expressing a human immunoglobulin M rheumatoid factor autoantibody in transgenic mice.
We have generated transgenic mice that express the immunoglobulin (Ig)M heavy chain and kappa light chain genes coding for a human IgM rheumatoid factor (RF), Les. Transgenic B cells expressing human IgM RF show striking similarities to their counterparts in normal humans. They comprise a significant proportion of the adult B cell population, but secrete only low levels of RF into the serum. The RF transgene-expressing B cells localize to primary B cell follicles and the mantle zone regions of secondary follicles in the spleen. Using these mice we have been able to show that one of the central functions of normal RF-expressing B cells may be to act as highly efficient antigen-presenting cells for low concentrations of immune-complexed antigen. High levels of secretion of IgM RF can not be induced under normal circumstances, although RF-expressing B cells proliferate well in vitro to both aggregated human IgG and anti-human IgM antibodies. However, these mice are not intrinsically secretion deficient. By crossing the RF transgenic mice with the autoimmune MRL/lpr background, we find a dramatic increase, > 200-fold, in levels of serum RF. The results strongly suggest that a major function of normal resting RF B cells is unrelated to antibody secretion. Rather, the RF B cells in the follicles may play a role in antigen presentation and regulation of immune responses to antibody-bound nonself-, and possibly self-antigens. This physiologic role of RF B cells may be disrupted in RF-associated autoimmune disease
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Coordination of Geological and Engineering Research in Support of the Gulf Coast Co-Production Program
Shallow-marine sandstones in Northeast Hitchcock field having high porosities and
permeabilities contain abundant authigenic kaolinite and have acted as preferential conduits
for fluid migration. Authigenic clay creates fluid production problems because of
its delicate structure. Dislodged clay will obstruct pore throats at high production
rates. A maximum safe rate of fluid production will need to be determined for co-produced
wells.
Middle and lower Miocene barrier-island sands in Northeast Hitchcock field have the
potential for receiving large volumes of co-produced brines. These sands have permeabilities
in excess of 2,000 md, are internally homogeneous, and are laterally extensive in
the field area.
Detailed geologic analyses of two reservoirs in Seeligson field delineate heterogeneous, fluvial sandstones that probably contain isolated, undrained reservoir compartments.
Zone 15 can be subdivided into at least four genetic sandstones, and Zone 18-C can
be subdivided into two separate sandstones.
Two new pool discoveries (Miocene) in Tom O'Connor field developed during growth-fault
activity along the Vicksburg Fault Zone. Deposition of these sandstones, as part of an
offshore system during initial parasequence deposition, was confined between the Vicksburg
Fault Zone and the Tom O'Connor anticlinal crest.Bureau of Economic Geolog
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Coordination of Geological and Engineering Research in Support of the Gulf Coast Co-Production Program - Final Report
At Northeast Hitchcock field, the presence of the Skolithos assemblage and other structures has supported the interpretation of shallow-marine, tidal, distributary-mouth-bar, and channel depositional environments for most of the major reservoir sandstones. Several shaly horizons exhibit characteristics of interdistributary bays, and the Frio A is capped by a thin sequence of crevasse splays and washover sands that represent the initiation of the transgression that overlapped the Frio in Anahuac times.
The high-energy depositional environment of reworked distributary-mouth-bar sandstones is the major control of the high porosity (around 30 percent) and permeability (around 1,000 millidarcies) in Frio A sandstones at Northeast Hitchcock field. Well-winnowed sandstones with high porosities and permeabilities contain abundant authigenic kaolinite and have served as preferential conduits for migrating acid waters and major fluid flow during co-production. Authigenic clay can create fluid production problems due to its delicate structure. Dislodged clay may obstruct pore throats at high production rates, necessitating the determination of a maximum safe rate of fluid production for co-produced wells.
Middle and lower Miocene barrier island sands, buried at depths from 3,500 to 6,800 feet in Northeast Hitchcock field, have the potential to receive large volumes of co-produced brines from the Frio 1-A reservoir. These sands exhibit high permeabilities exceeding 2,000 millidarcies, are internally homogeneous, and are laterally extensive in the field area. The 6,150-foot sand (lower Miocene) was chosen for initial brine disposal in the H.D.S. Thompson No. 3 brine-disposal well based on these criteria. The 3,780-foot sand (middle Miocene) is recommended for future up-hole brine disposal in the H.D.S. Thompson No. 3 well because it is shallower, requiring less injection pressure and lower costs for brine disposal.Bureau of Economic Geolog
The Lysyl Oxidase Inhibitor, β-Aminopropionitrile, Diminishes the Metastatic Colonization Potential of Circulating Breast Cancer Cells
Lysyl oxidase (LOX), an extracellular matrix remodeling enzyme, appears to have a role in promoting breast cancer cell motility and invasiveness. In addition, increased LOX expression has been correlated with decreases in both metastases-free, and overall survival in breast cancer patients. With this background, we studied the ability of β-aminopropionitrile (BAPN), an irreversible inhibitor of LOX, to regulate the metastatic colonization potential of the human breast cancer cell line, MDA-MB-231. BAPN was administered daily to mice starting either 1 day prior, on the same day as, or 7 days after intracardiac injection of luciferase expressing MDA-MB-231-Luc2 cells. Development of metastases was monitored by in vivo bioluminescence imaging, and tumor-induced osteolysis was assessed by micro-computed tomography (μCT). We found that BAPN administration was able to reduce the frequency of metastases. Thus, when BAPN treatment was initiated the day before, or on the same day as the intra-cardiac injection of tumor cells, the number of metastases was decreased by 44%, and 27%, and whole-body photon emission rates (reflective of total tumor burden) were diminished by 78%, and 45%, respectively. In contrast, BAPN had no effect on the growth of established metastases. Our findings suggest that LOX activity is required during extravasation and/or initial tissue colonization by circulating MDA-MB-231 cells, lending support to the idea that LOX inhibition might be useful in metastasis prevention
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Secondary Natural Gas Recovery: Targeted Technology Applications for Infield Reserve Growth
Activities during the year comprised screening and selection of gas fields for detailed studies; integrated geological, petrophysical, geophysical, and engineering analyses of the fields selected; and data acquisition in cooperative wells. A comprehensive workplan was prepared, and a methodology for geological and engineering screening of sandstone reservoirs was developed and applied to leading candidate fields. Contacts made with field operators resulted in active participation of Mobil Exploration and Producing U.S., Inc., and Shell Western Exploration and Production Inc.
Lake Creek, Seeligson, McAllen Ranch, and Stratton-Agua Dulce fields were selected for study. These fields are representative of a spectrum of depositional systems and reservoir heterogeneities in highly productive gas reservoirs in the Texas coastal plain. Producing intervals are fluvial Frio reservoirs in Seeligson and Stratton-Agua Dulce fields, deltaic Vicksburg reservoirs in McAllen Ranch field, and deltaic Wilcox reservoirs in Lake Creek field.
New data, comprising cores, open- and cased-hole logs, vertical seismic profiles, and sequential formation-pressure tests, were acquired in two wells in Seeligson field and in one well in McAllen Ranch field. Results to date suggest that reservoir heterogeneity can be defined using integrated geologic, geophysical, and engineering data.Bureau of Economic Geolog
Ratiometric array of conjugated polymers–fluorescent protein provides a robust mammalian cell sensor
© 2016 American Chemical Society.Supramolecular complexes of a family of positively charged conjugated polymers (CPs) and green fluorescent protein (GFP) create a fluorescence resonance energy transfer (FRET)-based ratiometric biosensor array. Selective multivalent interactions of the CPs with mammalian cell surfaces caused differential change in FRET signals, providing a fingerprint signature for each cell type. The resulting fluorescence signatures allowed the identification of 16 different cell types and discrimination between healthy, cancerous, and metastatic cells, with the same genetic background. While the CP-GFP sensor array completely differentiated between the cell types, only partial classification was achieved for the CPs alone, validating the effectiveness of the ratiometric sensor. The utility of the biosensor was further demonstrated in the detection of blinded unknown samples, where 121 of 128 samples were correctly identified. Notably, this selectivity-based sensor stratified diverse cell types in minutes, using only 2000 cells, without requiring specific biomarkers or cell labeling
Cloning and chromosomal assignment of a widely expressed human receptor-like protein-tyrosine phosphatase
AbstractInsight into the regulation of the actions of the protein-tyrosine kinases will be greatly facilitated by the full characterization of the family of protein-tyrosine phosphatases. A search for novel phosphatases resulted in the isolation of a cDNA, termed HLPR, encoding a member of the family of human receptor-like protein-tyrosine phosphatases: its cDNA sequence predicts a protein of 793 amino acids (unglycosylated Mr, 87500) and includes a 121 residue extracellular domain, a single transmembrane segment, and two tandem intra-cytoplasmic catalytic domains. The HLPR gene is located on human chromosome 20, and the protein it encodes likely plays a fundamental role in the physiology of all cells as its expression appears to be ubiquitous
Prion protein attenuates excitotoxicity by inhibiting NMDA receptors
It is well established that misfolded forms of cellular prion protein (PrP [PrPC]) are crucial in the genesis and progression of transmissible spongiform encephalitis, whereas the function of native PrPC remains incompletely understood. To determine the physiological role of PrPC, we examine the neurophysiological properties of hippocampal neurons isolated from PrP-null mice. We show that PrP-null mouse neurons exhibit enhanced and drastically prolonged N-methyl-d-aspartate (NMDA)–evoked currents as a result of a functional upregulation of NMDA receptors (NMDARs) containing NR2D subunits. These effects are phenocopied by RNA interference and are rescued upon the overexpression of exogenous PrPC. The enhanced NMDAR activity results in an increase in neuronal excitability as well as enhanced glutamate excitotoxicity both in vitro and in vivo. Thus, native PrPC mediates an important neuroprotective role by virtue of its ability to inhibit NR2D subunits
MusMorph, a database of standardized mouse morphology data for morphometric meta-analyses
Complex morphological traits are the product of many genes with transient or lasting developmental effects that interact in anatomical context. Mouse models are a key resource for disentangling such effects, because they offer myriad tools for manipulating the genome in a controlled environment. Unfortunately, phenotypic data are often obtained using laboratory-specific protocols, resulting in self-contained datasets that are difficult to relate to one another for larger scale analyses. To enable meta-analyses of morphological variation, particularly in the craniofacial complex and brain, we created MusMorph, a database of standardized mouse morphology data spanning numerous genotypes and developmental stages, including E10.5, E11.5, E14.5, E15.5, E18.5, and adulthood. To standardize data collection, we implemented an atlas-based phenotyping pipeline that combines techniques from image registration, deep learning, and morphometrics. Alongside stage-specific atlases, we provide aligned micro-computed tomography images, dense anatomical landmarks, and segmentations (if available) for each specimen (N = 10,056). Our workflow is open-source to encourage transparency and reproducible data collection. The MusMorph data and scripts are available on FaceBase (www.facebase.org, https://doi.org/10.25550/3-HXMC) and GitHub (https://github.com/jaydevine/MusMorph)
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