gebhart/patrepeval huggingface dataset:
Increased expression of basement membrane components in human endothelial cells cultured in high glucose. (1988)

Although the degree of hyperglycemia is a powerful and independent risk factor for diabetic microvascular disease, it has not been established if and how high glucose per se can induce the typical lesions of microangiopathy. We have investigated in human vascular endothelial cells the expression of messenger RNA (mRNA) for collagen type IV and fibronectin, the two glycoproteins characteristically increased in diabetic basement membranes. In 12 confluent primary cultures exposed for 11 +/- 1 d (mean +/- SD) to 30 mM glucose and exhibiting cell number and thymidine incorporation similar to control cultures, the levels of collagen IV and fibronectin mRNA were, respectively, 238 +/- 140 and 221 +/- 231 percent of control (P less than 0.01). The effects of high glucose were selective (the levels of collagen I and c-myc mRNA remained unchanged), independent of the proliferative activity of the cultures and of the plating substratum, and maintained throughout multiple passages. However, several days of exposure to high glucose were required before their appearance. These observations establish that high glucose is a perturbation sufficient to mimic the effects of diabetes on the regulation of basement membrane components and propose that modifications in gene expression may pertain to the chain of events leading to diabetic angiopathy.
Regulation and drug resistance mechanisms of mammalian ribonucleotide reductase, and the significance to DNA synthesis (1990)

Mammalian ribonucleotide reductase, which occupies a key position in the synthesis of DNA, is a highly controlled enzyme activity, because it is solely responsible for the de novo reduction of ribonucleoside diphosphates to their corresponding deoxyribonucleoside diphosphate forms, required for DNA synthesis. Ribonucleotide reductase consists of two dissimilar protein components often called M1 and M2, which are independently regulated during cell proliferation. The M1 component contains multiple effector binding sites and is responsible for the complex allosteric regulation of the enzyme, whereas the M2 protein contains nonheme iron and a unique tyrosyl-free radical required for ribonucleotide reduction. Since the reaction is rate limiting for DNA synthesis, ribonucleotide reductase plays an important role in regulating cell division, and hence, cell proliferation. There are many inhibitors of ribonucleotide reductase and perhaps the most valuable one from a cell biology, biochemistry, and clinical point of view is the hydroxamic acid, hydroxyurea. This drug has also been very useful as a selective agent for isolating a variety of mammalian mutant cell lines altered in ribonucleotide reductase gene expression. Regulatory, structural, and biological characteristics of ribonucleotide reductase are reviewed, including evidence that ribonucleotide reductase, particularly the M2 protein, has an important early role to play in tumor promotion. In addition, modifications in the expressions of genes altered in hydroxyurea-resistant mutants and cultured in the absence or presence of hydroxyurea are discussed, with emphasis on changes in M2 protein, M1 protein, and the iron-storage protein ferritin.(ABSTRACT TRUNCATED AT 250 WORDS)
A tryptophan derivative, ITE, enhances liver cell metabolic functions in vitro (2016)

Cell encapsulation provides a three-dimensional support by incorporating isolated cells into microcapsules with the goal of simultaneously maintaining cell survival and function, as well as providing active transport for a bioreactor in vitro similarly to that observed in vivo. However, the biotra-nsformation and metabolic functions of the encapsulated cells are not satisfactory for clinical applications. For this purpose, in this study, hepatoma-derived Huh7 cells/C3A cells were treated with 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE), an endogenous non-toxic ligand for aryl hydrocarbon receptor, in monolayer cultures and on microspheres. The mRNA and protein levels, as well as the metabolic activities of drug metabolizing enzymes, albumin secretion and urea synthesis were determined. When the Huh7 and C3A cells cultured in a monolayer on two‑dimensional surfaces, ITE enhanced the protein levels and the metabolic activities of the major cytochrome P450 (CYP450) enzymes, CYP1A1, CYP1A2, CYP3A4 and CYP1B1, and slightly increased albumin secretion and urea synthesis. Moreover, when cultured on microspheres, ITE also substantially increased the protein levels and metabolic activities of CYP1A1, CYP1A2, CYP3A4 and CYP1B1 in both liver cell lines. On the whole, our findings indicate that ITE enhances the enzymatic activities of major CYP450 enzymes and the metabolic functions of liver cells cultured in monolayer or on microspheres, indicating that it may be utilized to improve the functions of hepatocytes. Thus, it may be used in the future for the treatment of liver diseases.
Successful Long-Term Treatment of Refractory Cushing’s Disease with High-Dose Mifepristone (RU 486) (2001)

An extremely ill patient, with Cushing's syndrome caused by an ACTH-secreting pituitary macroadenoma, experienced complications of end-stage cardiomyopathy, profound psychosis, and multiple metabolic disturbances. Initially treated unsuccessfully by a combination of conventional surgical, medical, and radiotherapeutic approaches, he responded dramatically to high-dose long-term mifepristone therapy (up to 25 mg/kg x d). Treatment efficacy was confirmed by the normalization of all biochemical glucocorticoid-sensitive measurements, as well as by the significant reversal of the patient's heart failure, the resolution of his psychotic depression, and the eventual unusual return of his adrenal axis to normal. His 18-month-long mifepristone treatment course was notable for development of severe hypokalemia that was attributed to excessive cortisol activation of the mineralocorticoid receptor, which responded to spironolactone administration. This case illustrates the efficacy of high-dose long-term treatment with mifepristone in refractory Cushing's syndrome. The case also demonstrates the potential need for concomitant mineralocorticoid receptor blockade in mifepristone-treated Cushing's disease, because cortisol levels may rise markedly, reflecting corticotroph disinhibition, to cause manifestations of mineralocorticoid excess.
Measurement of Cdk4 Kinase Activity Using an Affinity Peptide-Tagging Technology (2000)

Cyclin-dependent kinases such as Cdk4 are involved in the control of cell cycle progression, and misregulation of Cdk4 has been implicated in many types of cancers. In the present study, we report the development of a novel homogeneous assay using an affinity peptide-tagging technology for rapidly discovering Cdk4 inhibitors. The DNA sequence encoding a streptavidin recognition motif, or StrepTag (AWRHPQFGG), was cloned and expressed at the C-terminus of a fusion protein of a 152-amino acid hyperphosphorylation domain (Rb152) of the retinoblastoma protein (Rb) linked to GST at the N-terminus. This affinity peptide-tagged protein (GST-Rb152-StrepTag), which contains the two known phosphorylation sites of Rb, specifically phosphorylated by Cdk4 in vivo, was used as a substrate in the current in vitro kinase assay. After phosphorylation, scintillation proximity assay (SPA) scintillant beads coated with streptavidin were added. Radiolabeled GST-Rb152-StrepTag was brought in close proximity to the SPA scintillant beads through the interaction between StrepTag and streptavidin, resulting in the emission of light from beads. By applying the affinity peptide-tagging technology, we have eliminated the separation and wash steps which are normally required in a radioactive filtration assay. Therefore, this homogeneous method is simple, robust, and highly amenable to high-throughput screening of Cdk4-specific inhibitors. Furthermore, the affinity peptide tagging technique reported here is a simple, generic method that can be applied to many recombinant proteins for the development of kinase and protein-protein interaction assays.
Cancer Stem Cell Immunology: Key to Understanding Tumorigenesis and Tumor Immune Escape? (2014)

Cancer stem cell (CSC) biology and tumor immunology have shaped our understanding of tumorigenesis. However, we still do not fully understand why tumors can be contained but not eliminated by the immune system and whether rare CSCs are required for tumor propagation. Long latency or recurrence periods have been described for most tumors. Conceptually, this requires a subset of malignant cells which is capable of initiating tumors, but is neither eliminated by immune cells nor able to grow straight into overt tumors. These criteria would be fulfilled by CSCs. Stem cells are pluripotent, immune-privileged, and long-living, but depend on specialized niches. Thus, latent tumors may be maintained by a niche-constrained reservoir of long-living CSCs that are exempt from immunosurveillance while niche-independent and more immunogenic daughter cells are constantly eliminated. The small subpopulation of CSCs is often held responsible for tumor initiation, metastasis, and recurrence. Experimentally, this hypothesis was supported by the observation that only this subset can propagate tumors in non-obese diabetic/scid mice, which lack T and B cells. Yet, the concept was challenged when an unexpectedly large proportion of melanoma cells were found to be capable of seeding complex tumors in mice which further lack NK cells. Moreover, the link between stem cell-like properties and tumorigenicity was not sustained in these highly immunodeficient animals. In humans, however, tumor-propagating cells must also escape from immune-mediated destruction. The ability to persist and to initiate neoplastic growth in the presence of immunosurveillance - which would be lost in a maximally immunodeficient animal model - could hence be a decisive criterion for CSCs. Consequently, integrating scientific insight from stem cell biology and tumor immunology to build a new concept of "CSC immunology" may help to reconcile the outlined contradictions and to improve our understanding of tumorigenesis.
Organ-Selective Homing Defines Engraftment Kinetics of Murine Hematopoietic Stem Cells and Is Compromised by Ex Vivo Expansion (1999)

Hematopoietic reconstitution of ablated recipients requires that intravenously (IV) transplanted stem and progenitor cells “home” to organs that support their proliferation and differentiation. To examine the possible relationship between homing properties and subsequent engraftment potential, murine bone marrow (BM) cells were labeled with fluorescent PKH26 dye and injected into lethally irradiated hosts. PKH26+ cells homing to marrow or spleen were then isolated by fluorescence-activated cell sorting and assayed for in vitro colony-forming cells (CFCs). Progenitors accumulated rapidly in the spleen, but declined to only 6% of input numbers after 24 hours. Although egress from this organ was accompanied by a simultaneous accumulation of CFCs in the BM (plateauing at 6% to 8% of input after 3 hours), spleen cells remained enriched in donor CFCs compared with marrow during this time. To determine whether this differential homing of clonogenic cells to the marrow and spleen influenced their contribution to short-term or long-term hematopoiesis in vivo, PKH26+ cells were sorted from each organ 3 hours after transplantation and injected into lethally irradiated Ly-5 congenic mice. Cells that had homed initially to the spleen regenerated circulating leukocytes (20% of normal counts) approximately 2 weeks faster than cells that had homed to the marrow, or PKH26-labeled cells that had not been selected by a prior homing step. Both primary (17 weeks) and secondary (10 weeks) recipients of “spleen-homed” cells also contained approximately 50% higher numbers of CFCs per femur than recipients of “BM-homed” cells. To examine whether progenitor homing was altered upon ex vivo expansion, highly enriched Sca-1+c-kit+Lin−cells were cultured for 9 days in serum-free medium containing interleukin (IL)-6, IL-11, granulocyte colony-stimulating factor, stem cell factor, flk-2/flt3 ligand, and thrombopoietin. Expanded cells were then stained with PKH26 and assayed as above. Strikingly, CFCs generated in vitro exhibited a 10-fold reduction in homing capacity compared with fresh progenitors. These studies demonstrate that clonogenic cells with differential homing properties contribute variably to early and late hematopoiesis in vivo. The dramatic decline in the homing capacity of progenitors generated in vitro underscores critical qualitative changes that may compromise their biologic function and potential clinical utility, despite their efficient numerical expansion.
Development and characterization of 89Zr-labeled panitumumab for immuno-positron emission tomographic imaging of the epidermal growth factor receptor. (2013)

The epidermal growth factor receptor (EGFR) is overexpressed in the majority of malignancies and has been associated with poor outcomes. Panitumumab, an anti-EGFR monoclonal antibody that binds to the extracellular binding domain of EGFR, is increasingly used with radiotherapy and chemotherapy but has associated toxicities. The purpose of this study was to develop and characterize a novel targeted imaging agent for the EGFR using radiolabeled panitumumab. Flow cytometry studies were performed to evaluate EGFR expression in several cell lines. Desferrioxamine-Bz-NCS (DFO) was conjugated to panitumumab and labeled with (89)Zr. Cell uptake studies were performed in four cell lines. For biodistribution studies and micro-positron emission tomography/computed tomography (PET/CT), mouse xenograft models were generated using the same cell lines. PET was performed, and tumors and select organs were harvested for biodistribution studies. Panitumumab was radiolabeled with (89)Zr with high radiochemical purity and specific activity and was found to be stable in serum. Cell binding studies demonstrated that radiotracer uptake in cells correlated with the degree of EGFR expression. MicroPET/CT imaging studies demonstrated a high intensity of (89)Zr-panitumumab in A431 and HCT 116 tumors in comparison with the EGFR-negative tumors. Biodistribution studies confirmed the results from the imaging studies. (89)Zr-panitumumab imaging of EGFR-positive tumors demonstrated levels of radiotracer uptake associated with EGFR expression.
An All-d Amino Acid Peptide Model of α1(IV)531−543 from Type IV Collagen Binds the α3β1 Integrin and Mediates Tumor Cell Adhesion, Spreading, and Motility (1997)

Type IV collagen promotes integrin-mediated cell adhesion, spreading, and motility. Several regions within the triple-helical domain of type IV collagen have been identified as tumor cellular recognition sites. Among these regions, the α1(IV)531−543 sequence, designated l-Hep-III, promotes integrin-mediated tumor cell adhesion and directly binds to the α3β1 integrin [Miles, A. J., et al. (1994) J. Biol. Chem. 269, 30939−30945; Miles, A. J., et al. (1995) J. Biol. Chem. 270, 29047−29050]. We have presently compared the activities of the all-d enantiomeric peptide model of α1(IV)531−543, designated d-Hep-III, with l-Hep-III, for promoting the adhesion, spreading, and motility of metastatic melanoma and breast carcinoma cells. d-Hep-III was found to support melanoma and breast carcinoma cell adhesion, spreading, and motility in a dose-dependent fashion similar to that of l-Hep-III. The adhesions of melanoma and breast carcinoma cells to both type IV collagen and fibronectin were effectively inhibited by l-Hep-III and d-Hep-III. Melanoma cell invasion of the basement membrane was also inhibited by d-Hep-III. Characterization of the cell surface receptor for d-Hep-III was acheived via cell adhesion assays and affinity chromatography using monoclonal antibodies against integrin subunits. Immunoprecipitation analysis following EDTA elution from a d-Hep-III affinity column indicated that d-Hep-III binds to the α3β1 integrin but not to the α2 or α6 integrin subunits. In summary, these studies demonstrate that an all-d model of the α1(IV)531−543 sequence mimics the biological activities of the all-l peptide. d-Hep-III is the first all-d peptide that has been shown to promote tumor cell adhesion, spreading, and migration, inhibit tumor cell adhesion and migration on type IV collagen and invasion of the basement membrane, and bind directly to an integrin. Due to the resistance to proteolysis, all-d receptor-binding peptides such as d-Hep-III have great potential for in vivo studies and as therapeutic agents.
A common bicyclic protein kinase cascade inactivates the regulatory enzymes of fatty acid and cholesterol biosynthesis (1987)

A highly purified rat liver protein kinase phosphorylates and inactivates acetyl-CoA carboxylase, and causes rapid inactivation of microsomal HMG-CoA reductase in the presence of MgATP. Both effects are stimulated in an identical manner by AMP, and are greatly reduced by prior treatment of the kinase with purified protein phosphatase. The dephosphorylated kinase can be reactivated in the presence of MgATP, apparently due to a distinct kinase kinase, and this reactivation is stimulated by nanomolar concentrations of palmitoyl-CoA. These results show that a common, bicyclic protein kinase cascade can potently inactivate the regulatory enzymes of both fatty acid and cholesterol biosynthesis.
Design and implementation of TCP data probes for reliable and metric-rich network path monitoring (2009)

Monitoring network services and diagnosing their prob-lems often require active probing methods. Current prob-ing methods, however, are becoming unreliable, because of interferences from various middleboxes, and inad-equate due to their limited path metrics support. In this paper, we present the design and implementation of OneProbe, a new TCP probing method for reliable and metric-rich path monitoring. We have implemented HTTP/OneProbe (i.e., OneProbe for HTTP) which sends TCP data probes containing legitimate HTTP requests to induce HTTP responses for path measurement. Since the probing method is based on TCP’s basic data transmis-sion mechanisms, OneProbe works correctly on all major operating systems and web server software, and on 93% of the 37,874 websites randomly selected from the Inter-net. We also successfully deployed HTTP/OneProbe to monitor a number of network paths for over a month and obtained interesting and useful measurement results. 1
Primary respiratory syncytial virus infection in mice (1988)

A mouse model of respiratory syncytial virus (RSV) infection is described. A high-titered, large-volume inoculum results in replication of RSV to a high titer in lungs of BALB/c mice. Mice older than 15 weeks of age are more susceptible to RSV infection. Titers up to 10(6.9) plaque-forming units (pfu)/gram lung can be attained in 32-week-old mice. Older mice experience a clinical illness manifested by ruffled fur, reduced activity, and weight loss. Lung histology of older mice infected with RSV shows bronchiolitis and increased number of lymphocytes and macrophages in alveolar spaces compared with that of mice less than 8 weeks old. This model will serve as the basis for investigating immunodeterminants of recovery and protection from RSV infection.
Cotinine, a Neuroactive Metabolite of Nicotine: Potential for Treating Disorders of Impaired Cognition (2005)

The pharmacological effects of the tobacco-derived alkaloid nicotine have been widely studied in humans and animals for decades. However, relatively little attention has been given to the potential actions of its major metabolite, cotinine. After nicotine consumption the duration of cotinine's presence in blood and brain greatly exceeds that of nicotine. Therefore, cotinine could mediate the more protracted pharmacological effects of nicotine. The studies described in this report were thus designed to further investigate certain neuropharmacological actions of cotinine. Behavioral tests (e.g., delayed matching-to-sample) were conducted in aged rhesus monkeys to assess the effects of cotinine on working memory and attention. In rats a prepulse inhibition (PPI) procedure was used to assess the effects of the compound on auditory gating - a method for predicting the potential antipsychotic properties of drugs. Cotinine exhibited significant effectiveness in these tasks. The drug was also cytoprotective in differentiated PC-12 cells with a potency equivalent to that of nicotine. The effects of chronic cotinine treatment on the expression of nicotinic and muscarinic acetylcholine receptors in rat brain were measured by [125I]epibatidine, [125I]alpha-bungarotoxin ([125I]BTX), [3H]pirenzepine ([3H]PRZ), and [3H]AFDX-384 ([3H]AFX) autoradiography. Unlike nicotine, cotinine failed to upregulate the expression of brain nicotinic receptors. Based on its relative safety in man, cotinine should prove useful in the treatment of diseases of impaired cognition and behavior without exhibiting the toxicity usually attributed to nicotine.
Conformation and dynamics of heparin and heparan sulfate (2000)

The glycosaminoglycans heparin and heparan sulfate contain similar structural units in varying proportions providing considerable diversity in sequence and biological function. Both compounds are alternating copolymers of glucosamine with both iduronate- and glucuronate-containing sequences bearing N-sulfate, N-acetyl, and O-sulfate substitution. Protein recognition of these structurally-diverse compounds depends upon substitution pattern, overall molecular shape, and on internal mobility. In this review particular attention is paid to the dynamic aspects of heparin/heparan sulfate conformation. The iduronate residue possesses an unusually flexible pyranose ring conformation. This extra source of internal mobility creates special problems in rationalization of experimental data for these compounds. We present herein the solution-state NMR parameters, fiber diffraction data, crystallographic data, and molecular modeling methods employed in the investigation of heparin and heparan sulfate. Heparin is a useful model compound for the sulfated, protein-binding regions of heparan sulfate. The literature contains a number of solution and solid-state studies of heparin oligo- and polysaccharides for both isolated heparin species and those bound to protein receptors. These studies indicate a diversity of iduronate ring conformations, but a limited range of glycosidic linkage geometries in the repeating disaccharides. In this sense, heparin exhibits a well-defined overall shape within which iduronate ring forms can freely interconvert. Recent work suggests that computational modeling could potentially identify heparin binding sites on protein surfaces.
[Lewis Acid]+[Co(CO)4] Complexes: A Versatile Class of Catalysts for Carbonylative Ring Expansion of Epoxides and Aziridines (2002)

Efficient carbonyl insertion into CO and CN bonds using [Lewis acid]+[Co(CO)4]− complexes 1 and 2 gives regio- and stereoselective carbonylation of a variety of epoxides and aziridines to yield β-lactones and β-lactams, respectively. Both transformations are proposed to occur by the same mechanism, yielding products with inversion of configuration at the site of CO insertion. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2002/z18813_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.