gebhart/patrepeval huggingface dataset:
A Second Transport System for l -Arabinose in Escherichia coli B/r Controlled by the araC Gene (1972)

Escherichia coli B/r possesses two active transport systems for l-arabinose, both of which are regulated by araC, the regulatory gene for the l-arabinose operon. The system with the higher affinity for l-arabinose has a K(m) for initial uptake of l-arabinose of 8.3 x 10(-6)m; the system of lower affinity has a K(m) of 1.0 x 10(-4)m. The two systems can also be distinguished by differences in their response to analogues that act as competitive inhibitors of initial uptake. d-Galactose strongly inhibits l-arabinose uptake by the high affinity system but only weakly inhibits such uptake by the low affinity system. d-Fucose, d-xylose, and beta-methyl-l-arabinoside competitively inhibit the uptake of l-arabinose by both systems to approximately the same extent. d-Glucose and l-lyxose do not inhibit either system. On the basis of kinetic evidence and the properties of mutants lacking one or the other of the two systems, it has been concluded that the high affinity uptake system involves the l-arabinose binding protein. Kinetic studies have shown that the K(m) for l-arabinose uptake by the high affinity system resembles the K(m) for binding of l-arabinose by the binding protein, and both have similar K(i) values for the inhibitory substrates tested. A consideration of l-arabinose transport-deficient mutants has demonstrated that the previously described araE mutants lack the low affinity system but retain the high affinity system and have normal levels of the l-arabinose binding protein. Mutants described in this communication which lack only the high affinity system either contain no detectable l-arabinose binding protein or possess an immunologically cross-reacting material that is reduced in its ability to bind l-arabinose. These observations support a role for the binding protein in l-arabinose uptake.
Cloning of the complete gene for carcinoembryonic antigen: analysis of its promoter indicates a region conveying cell type-specific expression. (1990)

Carcinoembryonic antigen (CEA) is a widely used tumor marker, especially in the surveillance of colonic cancer patients. Although CEA is also present in some normal tissues, it is apparently expressed at higher levels in tumorous tissues than in corresponding normal tissues. As a first step toward analyzing the regulation of expression of CEA at the transcriptional level, we have isolated and characterized a cosmid clone (cosCEA1), which contains the entire coding region of the CEA gene. A close correlation exists between the exon and deduced immunoglobulin-like domain borders. We have determined a cluster of transcriptional starts for CEA and the closely related nonspecific cross-reacting antigen (NCA) gene and have sequenced their putative promoters. Regions of sequence homology are found as far as approximately 500 nucleotides upstream from the translational starts of these genes, but farther upstream they diverge completely. In both cases we were unable to find classic TATA or CAAT boxes at their expected positions. To characterize the CEA and NCA promoters, we carried out transient transfection assays with promoter-indicator gene constructs in the CEA-producing adenocarcinoma cell line SW403, as well as in nonproducing HeLa cells. A CEA gene promoter construct, containing approximately 400 nucleotides upstream from the translational start, showed nine times higher activity in the SW403 than in the HeLa cell line. This indicates that cis-acting sequences which convey cell type-specific expression of the CEA gene are contained within this region.
Laparoscopic-Assisted Pancreatic Necrosectomy (2006)

This is the largest reported study of laparoscopic debridement for pancreatic necrosis. The procedure is feasible and associated with a low morbidity and mortality. Pancreatic debridement with HALS may provide a new option for the surgical treatment of selected patients with severe necrotizing pancreatitis.
Combined single‐clade candidate HIV‐1 vaccines induce T cell responses limited by multiple forms of in vivo immune interference (2007)

We assessed in mice whether broad CD8+ T cell responses capable of efficient recognition of multiple HIV-1 clades could be induced using current single-clade vaccine constructs that were or will be used in clinical trials in Europe and Africa. We found that single-clade A, B and C vaccines applied alone induced only limited cross-clade reactivity and that the epitope hierarchy varied according to the immunizing clade. However, combining single-clade HIV-1 vaccines into multi-clade formulations resulted in multiple forms of in vivo immune interference such as original antigenic sin and antagonism, which dampened or even abrogated induction of responses to epitope variants and reduced the breadth of induced T cell responses. Simultaneous administration of individual clade-specific vaccines into anatomically separated sites on the body alleviated antagonism and increased the number of detectable epitope responses. Although cross-reactivity of murine CD8+ T cells does not directly translate to humans, the molecular interactions involved in triggering T cell responses are the same in mouse and man. Thus, these results have important ramifications for the design of both prophylactic and therapeutic vaccines against HIV-1 and other highly variable pathogens.
Synergistic effect of IFN-γ and human cytomegalovirus protein UL40 in the HLA-E-dependent protection from NK cell-mediated cytotoxicity (2001)

Human CMV (HCMV) has evolved several strategies to evade the immune system of the infected host. Here, we investigated the role of the HCMV-encoded protein UL40 in the modulation of NK cell lysis. UL40 carries in its leader sequence a nonameric peptide similar to that found in many HLA class I molecules leader sequences. This peptide up-regulates the expression of HLA-E, the ligand for the NK cell inhibitory receptor CD94/NKG2A. The UL40-encoded HLA-E-binding peptide was present in all HCMV clinical (4636, 13B, 109B, 3C) and laboratory (AD169) strains analyzed. However, transfection of UL40 in different cell lines (293T, 721.221, K562) did not consistently confer protection from NK lysis (as measured using NKL and the newly generated NK line Nishi), despite a moderate up-regulation of HLA-E. Interestingly, combined transfection and treatment with IFN-gamma increased the inhibitory effect, via an HLA-E- and CD94/NKG2A-dependent mechanism. Although cells transfected with UL40 derived from either AD169 or 3C showed protection from NK cell lysis, infection of fibroblasts with the viruses resulted in a strong inhibition only with the clinical strain 3C. Our results suggest that UL40 and IFN-gamma-dependent up-regulation of HLA-E is only one possible mechanism to avoid NK cell recognition of HCMV infected cells.
Generation of CD4+ or CD8+ regulatory T cells upon mesenchymal stem cell-lymphocyte interaction (2007)

These findings indicate that powerful regulatory CD4+ or CD8+ lymphocytes are generated in co-cultures of PBMC with MSC. This strongly suggests that these regulatory cells may amplify the reported MSC-mediated immunosuppressive effect.
Molecular cloning and expression of murine vascular endothelial- cadherin in early stage development of cardiovascular system (1996)

An early step in the formation of the extraembryonic and intraembryonic vasculature is endothelial cell differentiation and organization in blood islands and vascular structures. This involves the expression and function of specific adhesive molecules at cell-to-cell junctions. Previous work showed that endothelial cells express a cell-specific cadherin (vascular endothelial [VE]-cadherin, or 7B4/cadherin-5) that is organized at cell-to-cell contacts in cultured cells and is able to promote intercellular adhesion. In this study, we investigated whether VE-cadherin could be involved in early cardiovascular development in the mouse embryo. We first cloned and sequenced the mouse VE-cadherin cDNA. At the protein level, murine VE-cadherin presented 75% identity (90%, considering conservative amino acid substitutions) with the human homologue. Transfection of murine VE-cadherin cDNA in L cells induced Ca(++)-dependent cell-to-cell aggregation and reduced cell detachment from monolayers. In situ hybridization of adult tissues showed that the murine molecule is specifically expressed by endothelial cells. In mouse embryos, VE-cadherin transcripts were detected at the very earliest stages of vascular development (E7.5) in mesodermal cells of the yolk sac mesenchyme. At E9.5, expression of VE-cadherin was restricted to the peripheral cell layer of blood islands that gives rise to endothelial cells. Hematopoietic cells in the center of blood islands were not labeled. At later embryonic stages, VE-cadherin transcripts were detected in vascular structures of all organs examined, eg, in the ventricle of the heart, the inner cell lining of the atrium and the dorsal aorta, in intersomitic vessels, and in the capillaries of the developing brain. A comparison with flk-1 expression during brain angiogenesis revealed that brain capillaries expressed relatively low amounts of VE-cadherin. In the adult brain, the level of VE-cadherin transcript was further reduced. By immunohistochemistry, murine VE-cadherin protein was detected at cell-to-cell junctions of endothelial cells. Overall, these data demonstrate that VE-cadherin is an early, constitutive, and specific marker of endothelial cells. This distinguishes this molecule from other cadherins and suggests that its expression is associated with the early assembly of vascular structures.
Organozinc Chemistry Enabled by Micellar Catalysis. Palladium-Catalyzed Cross-Couplings between Alkyl and Aryl Bromides in Water at Room Temperature (2011)

Negishi-like cross-couplings between (functionalized) alkyl and aryl bromides are described. Despite the fact that organozinc reagents are intolerant of water, their formation as well as their use in an aqueous micellar environment is discussed herein. Each component of this complex series of events leading up to C-C bond formation has an important role which has been determined insofar as the type of zinc, amine ligand, surfactant, and palladium catalyst are concerned. In particular, the nature of the surfactant has been found to be crucial in order to obtain synthetically useful results involving highly reactive, moisture-sensitive organometallics. Neither organic solvent nor heat is required for these cross-couplings to occur; just add water.
Nutrition and Prostate Cancer (2002)

Despite intense efforts, little is known about the etiology of prostate cancer, and treatment of advanced forms of the disease has had limited success. Nonetheless, epidemiologic studies combined with animal model and in vitro experiments indicate that natural components of the diet, including n-3 PUFA, the carotenoid lycopene, and the trace element selenium, may serve as chemopreventive agents that suppress the growth and dissemination of neoplastic prostate cells. Until further study, however, soy isoflavones should be viewed with some caution, especially as adjuvant's to chemotherapy, in patients with hormone-refractory prostate cancer. Future studies, using different forms and doses of selenium and tomato carotenoids, may shed new light on the etiology and prevention of prostate cancer.
Induction of nitric oxide synthase protects against malaria in mice exposed to irradiated Plasmodium berghei infected mosquitoes: involvement of interferon gamma and CD8+ T cells. (1994)

Exposure of BALB/c mice to mosquitoes infected with irradiated Plasmodium berghei confers protective immunity against subsequent sporozoite challenge. Immunized mice challenged with viable sporozoites develop parasitemia when treated orally with substrate inhibitors of nitric oxide synthase (NOS). This suggests that the production of nitric oxide (NO) prevents the development of exoerythrocytic stages of malaria in liver. Liver tissue from immunized mice expressed maximal levels of mRNA for inducible NOS (iNOS) between 12 and 24 h after challenge with sporozoites. Intraperitoneal injection of neutralizing monoclonal antibody against interferon gamma (IFN-gamma) or in vivo depletion of CD8+ T cells, but not CD4+ T cells, at the time of challenge blocked expression of iNOS mRNA and ablated protection in immunized mice. These results show that both CD8+ T cells and IFN-gamma are important components in the regulation of iNOS in liver which contributes to the protective response of mice immunized with irradiated malaria sporozoites. IFN-gamma, likely provided by malaria-specific CD8+ T cells, induces liver cells, hepatocytes and/or Kupffer cells, to produce NO for the destruction of infected hepatocytes or the parasite within these cells.
Target Antigen Expression on a Professional Antigen-Presenting Cell Induces Superior Proliferative Antitumor T-Cell Responses via Chimeric T-Cell Receptors (2005)

Human T cells expressing tumor antigen-specific chimeric receptors fail to sustain their growth and activation in vivo, which greatly reduces their therapeutic value. The defective proliferative response to tumor cells in vitro can partly be overcome by concomitant CD28 costimulatory signaling. We investigated whether T-cell activation via chimeric receptors (chRec) can be further improved by ligand expression on antigen-presenting cells of B-cell origin. We generated Epstein-Barr virus (EBV)-specific cytotoxic T lymphocytes (CTLs) expressing a CD19-specific chRec. These CTLs are provided with native receptor stimulation by autologous EBV-transformed B-lymphoblastoid cell lines (LCLs) but exclusively with chRec (CD19-specific) stimulation by allogeneic, human leukocyte antigen (HLA)-mismatched CD19+ LCLs. CD19zeta-transduced EBV-specific CTLs specifically lysed both allogeneic EBV targets and CD19+ tumor cells through the chRec in a major histocompatibility complex-independent manner, while maintaining their ability to recognize autologous EBV targets through the native T-cell receptor. The transduced CTLs failed to proliferate in response to CD19+ tumor targets even in the presence of CD28 costimulatory signaling. By contrast, CD19 expressed on HLA-mismatched LCL-induced T-cell activation and long-term proliferation that essentially duplicated the result from native receptor stimulation with autologous LCLs, suggesting that a deficit of costimulatory molecules on target cells in addition to CD28 is indeed responsible for inadequate chRec-mediated T-cell function. Hence, effective tumor immunotherapy may be favored if engagement of the chRec on modified T cells is complemented by interaction with multiple costimulator molecules. The use of T cells with native specificity for EBV may be one means of attaining this objective.
Increased numbers of T lymphocytes with gamma delta-positive antigen receptors in a subgroup of individuals with pulmonary sarcoidosis. (1990)

Individuals with sarcoidosis were evaluated for preferential usage of T cells with the gamma delta-positive (+) type of T cell antigen receptor. Compared with normal subjects (n = 19), the group with sarcoidosis had increased numbers of CD3+ alpha beta-negative (-) T cells in the blood (normal, 58 +/- 12 cells/microliters; sarcoid, 192 +/- 45 cells/microliters, P less than 0.05) and in the epithelial lining fluid of the lung (normal, 78 14 cells/microliters; sarcoid, 240 +/- 60 cells/microliters, P less than 0.04) and a concomitant elevated number of blood and lung CD3+ gamma delta+ T cells, owing to a striking increase in the number of CD3+ gamma delta+ T cells in a subgroup (7 of 20) of sarcoid individuals. The elevated numbers of sarcoid blood gamma delta+ T lymphocytes were mostly Ti gamma A+ and delta TCS1-, a pattern also seen in normal individuals, consistent with the majority of gamma delta+ T cells expressing one gamma-chain variable region, V gamma 9. The observation of an increase in the total gamma delta+ T cell numbers in a sarcoid subgroup suggests that various specific stimuli may trigger the expansion of different T cell subpopulations within different groups of individuals with sarcoidosis.
Phosphorylation of the cytoplasmic domain of the MUC1 mucin correlates with changes in cell-cell adhesion (2000)

The MUC1 epithelial mucin is expressed by glandular epithelial cells and is often highly expressed and associated with poor prognosis in adenocarcinomas. Tyrosine phosphorylation of the highly conserved cytoplasmic tail of MUC1 (MUC1-CT) has been demonstrated in MUC1 transfected cells and in one breast cancer cell line. In addition, associations between MUC1 and secondary signalling molecules have been demonstrated in breast cancer cell lines. MUC1 clearly plays a role in intracellular signalling, since we were able to demonstrate tyrosine phosphorylation of the MUC1-CT in breast and ovarian cancer cell lines and in primary cultures of serous ovarian cancers. We were unable to modulate MUC1-CT phosphorylation using conditioned media from cell lines showing the highest levels of signalling. However, in several breast and ovarian cancer cell lines, we clearly showed the highest levels of MUC1-CT tyrosine phosphorylation occurred during recolonisation of culture dishes or in low-density adherent cultures. We now hypothesise that phosphorylation changes may reflect either involvement of MUC1 in cell motility or a redistribution of MUC1 in the membrane during the course of cell-cell adhesion.
Solution Synthesis of Germanium Nanocrystals:  Success and Open Challenges (2004)

We present a two-step synthesis route that yields nanometer-size crystalline germanium in the form of a black powder. It relies on high temperature decomposition of tetraethylgermane (TEG) in organic solvents. The presence of pure germanium with diamond structure is unambiguously attested by powder XRD measurements. Low-resolution TEM indicates that the particles are between ∼5 to 30 nm in size, depending on the synthesis conditions. The as-synthesized Ge powders can be stored in air for months and no oxidation occurs. The Ge powders are sparingly soluble in conventional solvents because Ge nanocrystals are likely embedded in a matrix composed mainly of CC, C−C, and C−H bonds. The presence of residual organic byproducts impedes probing of the optical properties of the dots. Also, we discuss drawbacks and open challenges in high-temperature solution synthesis of Ge nanocrystals that could also be faced in the synthesis of Si nanocrystals. Overall, our results call for a cautious interpretation of reported optical properties of Ge and Si nanocrystals obtained by high-temperature solution methods.
Improving the flavor of fresh fruits: genomics, biochemistry, and biotechnology (2010)

It is generally accepted that the flavor quality of many fruits has significantly declined over recent decades. While some of this decline can be linked to selection for certain traits, such as firmness and postharvest shelf life, that run counter to good flavor, a major contributing factor has been the challenge of breeding for such a complex quality trait. Flavor involves integration of sugars, acids and a set of 20 or more volatile chemicals. Together, these compounds involve a large number of primary and secondary metabolic pathways, many of which have only recently been established. This review describes recent advances in the understanding of the pathways and genes controlling synthesis of the volatile components of flavor. Because of tomato's unique role as a model for fruit development, the review emphasizes advances in this fruit. In the last decade we have literally advanced from a list of chemicals known to influence flavor to a detailed understanding of how and where they are made. However, our knowledge of the regulation of the critical metabolic pathways is still limited. Nonetheless, the pieces are in place for rapid advances to be made in the manipulation of flavor chemistry in the immediate future.
Chemoenzymatic Fc Glycosylation via Engineered Aldehyde Tags (2014)

Glycoproteins with chemically defined glycosylation sites and structures are important biopharmaceutical targets and critical tools for glycobiology. One approach toward constructing such molecules involves chemical glycosylation of aldehyde-tagged proteins. Here, we report the installation of a genetically encoded aldehyde tag at the internal glycosylation site of the crystallizable fragment (Fc) of IgG1. We replaced the natural Fc N-glycosylation sequon with a five amino-acid sequence that was efficiently converted by recombinant formylglycine generating enzyme in vitro, thereby introducing aldehyde groups for subsequent chemical elaboration. Oxime-linked glycoconjugates were synthesized by conjugating aminooxy N-acetylglucosamine to the modified Fc followed by enzymatic transfer of complex N-glycans from corresponding glycan oxazolines by an EndoS-derived glycosynthase. In this manner we generated specific Fc glycoforms without relying on natural protein glycosylation machineries.
Hard-sphere interactions between spherical domains in diblock copolymers (1984)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHard-sphere interactions between spherical domains in diblock copolymersDavid J. Kinning and Edwin L. ThomasCite this: Macromolecules 1984, 17, 9, 1712–1718Publication Date (Print):September 1, 1984Publication History Published online1 May 2002Published inissue 1 September 1984https://pubs.acs.org/doi/10.1021/ma00139a013https://doi.org/10.1021/ma00139a013research-articleACS PublicationsRequest reuse permissionsArticle Views2643Altmetric-Citations472LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts