tbuckley/cabot-search huggingface dataset:
Characterization of the cell surface receptor for human granulocyte/macrophage colony-stimulating factor.
Authors: L S Park, D Friend, S Gillis, D L Urdal
Journal: The Journal of Experimental Medicine (1986)

125I-labeled recombinant human GM-CSF was used to identify and characterize receptors specific for this lymphokine on both a mature primary cell, human neutrophils, and on the undifferentiated promyelomonocytic leukemia cell line, HL-60. Human GM-CSF also bound to primary human monocytes and to the myelogenous leukemia cell line, KG-1, but not to any of the murine cells known to express the murine GM-CSF receptor. In addition, although some murine T lymphomas can express the GM-CSF receptor, none of the human cell lines of T cell lineage that we examined bound iodinated human GM-CSF. Binding to all cell types was specific and saturable. Equilibrium binding studies revealed that on all cell types examined, GM-CSF bound to a single class of high affinity receptor (100-500 receptors per cell) with a Ka of 10(9)-10(10)/M. More extensive characterization with neutrophils and HL-60 cells showed that in both cases, binding of GM-CSF was rapid at 37 degrees C with a slow subsequent dissociation rate that exhibited marked biphasic kinetics. Among a panel of lymphokines and growth hormones, only human GM-CSF could compete for binding of human 125I-GM-CSF to these cells. GM-CSF can not only stimulate the proliferation and differentiation of granulocyte/macrophage precursor cells, but can modulate the functional activity of mature granulocytes and macrophages as well. No significant differences in the kinetic parameters of receptor binding were seen between mature neutrophils and the undifferentiated promyelocytic leukemia cell line HL-60, indicating that maturation-specific responses to GM-CSF are not mediated by overt changes in the binding characteristics of the hormone for its receptor.
Urinary Excretion of Aquaporin-2 in Rat Is Mediated by a Vasopressin-Dependent Apical Pathway
Authors: HUAJIE WEN, JØRGEN FRØKIÆR, TAE-HWAN KWON, SØREN NIELSEN
Journal: Journal of the American Society of Nephrology (1999)

Abstract. Clinical studies have shown that aquaporin-2 (AQP2), the vasopressin-regulated water channel, is excreted in the urine, and that the excretion increases in response to vasopressin. However, the cellular mechanisms involved in AQP2 excretion are unknown, and it is unknown whether the excretion correlates with AQP2 levels in kidney or levels in the apical plasma membrane. The present study was undertaken to clarify these issues. Immunoblotting of rat urine samples revealed significant excretion of AQP2, whereas AQP3, being a basolateral aquaporin in the same cells, was undetectable. Thus, there was a nonproportional excretion of AQP2 and AQP3 (compared with kidney levels), indicating that AQP2 is excreted predominantly via a selective apical pathway and not by whole cell shedding. Urinary AQP2 was associated with small vesicles, membrane fragments, and multivesicular bodies as determined by immunoelectron microscopy and negative staining techniques. In rats with normal water supply, daily urinary excretion of AQP2 was 3.9 ± 0.9% ( n = 6) of total kidney expression. Treatment with desmopressin acetate subcutaneously caused a fourfold increase in urinary excretion of AQP2 during 8 h. Forty-eight hours of thirsting, known to increase endogenous vasopressin secretion, resulted in a three-fold increase in kidney AQP2 levels but urinary excretion increased ninefold to 15 ± 3% ( n = 6) of AQP2 in kidney of thirsted rats. Moreover, rats that were thirsted for 48 h and subsequently allowed free access to water for 24 h produced a decrease in urinary AQP2 excretion to 38 ± 15% ( n = 6) of that during thirsting. In Brattleboro rats or lithium-treated normal rats completely lacking vasopressin action, and hence having extremely low levels of AQP2 in the apical plasma membrane, AQP2 was undetectable in urine. Thus, conditions with known altered vasopressin levels and altered levels of AQP2 in the apical plasma membrane were associated with corresponding major changes in AQP2 urine excretion. In contrast, in such conditions, kidney AQP2 levels and urinary AQP2 excretion did not show a proportional relationship.
von Willebrand factor: a marker of endothelial dysfunction in vascular disorders?
Authors: G Lip
Journal: Cardiovascular Research (1997)

The vascular endothelium is involved in the production of many important substances which are involved in cardiovascular pathophysiology. One such substance which is synthesised by, and stored in, endothelial cells is von Willebrand factor (vWf). When released, vWf appears to mediate platelet aggregation and adhesion. Numerous clinical and experimental reports suggest that high vWf levels reflect damage to the endothelium or endothelial dysfunction. The close association between vWf and the processes of thrombus formation (thrombogenesis) or atherogenesis also suggests that high vWf levels may be a useful indirect indicator of atherosclerosis and/or thrombosis. The availability of a useful marker of endothelial dysfunction may have potential clinical value. The measurement of such a marker can perhaps be a non-invasive way of assisting in clinical diagnosis or as an indicator of disease progression. High vWf levels have also been shown to have prognostic value in patients with ischaemic heart disease, peripheral vascular disease and inflammatory vascular disease. However, there is limited information that increased vWf is actually causal in the progression of vascular disease and that measures aimed at reducing vWf levels will be beneficial. In addition, interpretation of raised plasma vWf levels is complicated by the fact that vWf may be an acute phase reactant. Further research is indicated to explore the predictive value of this marker in population studies and, perhaps, therapeutic approaches in (and the value of) modulating vWf levels or function.
Combination of an Allosteric Akt Inhibitor MK-2206 with Etoposide or Rapamycin Enhances the Antitumor Growth Effect in Neuroblastoma
Authors: Zhijie Li, Shuang Yan, Navid Attayan, Sridevi Ramalingam, Carol J. Thiele
Journal: Clinical Cancer Research (2012)

Abstract Purpose: Activation of Akt is a marker of decreased event-free or overall survival in neuroblastoma patients. MK-2206, a novel allosteric Akt inhibitor, is now tested in clinical trials in adult cancers. In this study, effect of MK-2206 on tumor growth and murine survival, alone or in combination, with etoposide or rapamycin was evaluated. Experimental Design: The anticell proliferation effect of MK-2206 was tested in eight neuroblastoma cell lines by MTS assay. Caspase-3/7 activity, cell-cycle analysis, and reactive oxygen species (ROS) production were determined. Effect of MK-2206 combined with etoposide or rapamycin was evaluated in vitro and in vivo. Akt phosphorylation was measured by Western blotting in neuroblastoma cells and tumors. Results: In vitro, MK-2206 treatment inhibited neuroblastoma cell proliferation, which was accompanied by a cell line selective G1 arrest of cell cycle or production of ROS. A synergistic effect between MK-2206 and etoposide was detected in four tested neuroblastoma cell lines via caspase-dependent apoptosis, whereas increased inhibition of cell growth induced by combination of MK-2206 and rapamycin was mediated by ROS production. In vivo, MK-2206 alone decreased tumor growth and increased murine survival at dose that inhibited Akt phosphorylation in tumors. MK-2206, in combination with etoposide or rapamycin, caused a significant decrease in tumor growth and increase of murine survival compared with MK-2206 alone. Conclusion: Akt inhibition by MK-2206 increased the efficacy of etoposide or rapamycin. Our study supports future clinical evaluation of MK-2206 in combination with conventional cytotoxic therapy or with rapamycin in high-risk neuroblastoma patients. Clin Cancer Res; 18(13); 3603–15. ©2012 AACR.
Retinoic Acid Inhibits HIV-1–Induced Podocyte Proliferation through the cAMP Pathway
Authors: John Cijiang He, Ting-Chi Lu, Margaret Fleet, Masaaki Sunamoto, Mohammad Husain, Wei Fang, Susana Neves, Yibang Chen, Stuart Shankland, Ravi Iyengar, Paul E. Klotman
Journal: Journal of the American Society of Nephrology (2006)

HIV-associated nephropathy is characterized by renal podocyte proliferation and dedifferentiation. This study found that all-trans retinoic acid (atRA) reverses the effects of HIV-1 infection in podocytes. Treatment with atRA reduced cell proliferation rate by causing G1 arrest and restored the expression of the differentiation markers (synaptopodin, nephrin, podocin, and WT-1) in HIV-1-infected podocytes. It is interesting that both atRA and 9-cis RA increased intracellular cAMP levels in podocytes. Podocytes expressed most isoforms of retinoic acid receptors (RAR) and retinoid X receptors (RXR) with the exception of RXRgamma. RARalpha antagonists blocked atRA-induced cAMP production and its antiproliferative and prodifferentiation effects on podocytes, suggesting that RARalpha is required. For determination of the effect of increased intracellular cAMP on HIV-infected podocytes, cells were stimulated with either forskolin or 8-bromo-cAMP. Both compounds inhibited cell proliferation significantly and restored synaptopodin expression in HIV-infected podocytes. The effects of atRA were abolished by Rp-cAMP, an inhibitor of the cAMP/protein kinase A pathway and were enhanced by rolipram, an inhibitor of phosphodiesterase 4, suggesting that the antiproliferative and prodifferentiation effects of atRA on HIV-infected podocytes are cAMP dependent. Furthermore, both atRA and forskolin suppressed HIV-induced mitogen-activated protein kinase 1 and 2 and Stat3 phosphorylation. In vivo, atRA reduced proteinuria, cell proliferation, and glomerulosclerosis in HIV-1-transgenic mice. These findings suggest that atRA reverses the abnormal phenotype in HIV-1-infected podocytes by stimulating RARalpha-mediated intracellular cAMP production. These results demonstrate the mechanism by which atRA reverses the proliferation of podocytes that is induced by HIV-1.
CYTOCHROME P450: Nature's Most Versatile Biological Catalyst
Authors: Minor J. Coon
Journal: The Annual Review of Pharmacology and Toxicology (2004)

The author describes studies that led to the resolution and reconstitution of the cytochrome P450 enzyme system in microsomal membranes. The review indicates how purification and characterization of the cytochromes led to rigorous evidence for multiple isoforms of the oxygenases with distinct chemical and physical properties and different but somewhat overlapping substrate specificities. Present knowledge of the individual steps in the P450 and reductase reaction cycles is summarized, including evidence for the generation of multiple functional oxidants that may contribute to the exceptional diversity of the reactions catalyzed.
Agenesis of the right lung: an unusual presentation
Authors: W. Pallie, S. M. A. Alhady, O. B. Din
Journal: Thorax (1967)

A case of agenesis or aplasia of the right lung, in a cyanosed neonate, exceptionally associated with a `vascular ring9 abnormality produced by a right aortic arch, an aberrant left subclavian artery, and a patent ductus arteriosus, is reported. The presence of an abnormal lobe of the liver, projecting together with small gut and a subhepatic caecum into the right hemithorax, caused mediastinal displacement to the left side and produced the illusion of a diaphragmatic hernia, thereby obscuring the correct preoperative diagnosis.
A RICKETTSIAL INFECTION IN CANADIAN VOLES
Authors: James A. Baker
Journal: The Journal of Experimental Medicine (1946)

From apparently normal voles captured on Grosse Isle, Province of Quebec, Canada, an infective agent has been grown in embryonated eggs, and by inoculation an inapparent infection was established in voles, mice, guinea pigs, hamsters, and rats. No growth of the agent was obtained in the absence of living cells, and the manner of its development in the yolk sac of embryonated eggs, as well as morphological, epidemiological, and pathogenic features, indicates a rickettsial nature. The inability to transmit infection by either cage or intrauterine contact points to a vector, and mites are shown to have a probable part in the epidemiology. Mice infected with the vole agent resist lethal doses of the Karp strain of scrub typhus, and certain epidemiological, morphological, and immunological features support the relationship indicated by the mouse tests. It is therefore concluded that voles on this island have an inapparent infection due to a rickettsia that may be related to the rickettsia of scrub typhus.
Phase II Trial of Pemetrexed and Bevacizumab in Patients With Recurrent or Metastatic Head and Neck Cancer
Authors: Athanassios Argiris, Michalis V. Karamouzis, William E. Gooding, Barton F. Branstetter, Shilong Zhong, Luis E. Raez, Panayiotis Savvides, Marjorie Romkes
Journal: Journal of Clinical Oncology (2011)

We hypothesized that bevacizumab, a monoclonal antibody against vascular endothelial growth factor (VEGF), will potentiate the activity of pemetrexed, a multitargeted antifolate, in squamous cell carcinoma of the head and neck (SCCHN).Patients with previously untreated, recurrent, or metastatic SCCHN were treated with pemetrexed 500 mg/m(2) and bevacizumab 15 mg/kg given intravenously every 21 days with folic acid and B(12) supplementation until disease progression. Primary end point was time-to-progression (TTP). DNA was isolated from whole blood samples for the detection of polymorphisms in thymidylate synthase, methylenetetrahydrofolate reductase (MTHFR), and VEGF.Forty patients were enrolled. The median TTP was 5 months, and the median overall survival (OS) was 11.3 months. In 37 evaluable patients, the overall response rate was 30%, including a complete response rate of 5%, and the disease control rate was 86%. Grade 3 to 5 bleeding events occurred in six patients (15%): four were grade 3, and two were fatal. Other serious toxicities in 10% or more of patients included neutropenia (10%) and infection (12.5%). One patient died of sepsis after receiving eight cycles of therapy. For the MTHFR A1298C (rs1801131) single nucleotide polymorphisms, homozygote patients with AA had worse OS (P = .034).The addition of bevacizumab to pemetrexed resulted in promising efficacy outcomes in SCCHN. Bleeding events were frequent but some may have been due to natural history of disease. Polymorphisms in MTHFR may offer potential for treatment individualization.
Hemarthrosis From Heparin Therapy
Authors: William B. Hale
Journal: JAMA (1980)

<h3>To the Editor.—</h3> Bleeding is a potential risk in patients with chronic renal failure who are receiving maintenance hemodialysis with intermittent heparinization. Biggers et al,<sup>1</sup>in a recent study during a seven-year period, observed nine cases of bleeding complications attributable to heparin anticoagulation in patients receiving hemodialysis. We report here the occurrence of spontaneous hemarthrosis in the hip joint of a patient while he was undergoing intermittent hemodialysis for chronic renal failure. <h3>Report of a Case.—</h3> A 64-year-old, retired professional golfer with chronic renal failure secondary to glomerulonephritis experienced sudden-onset, left-hip pain during maintenance hemodialysis with systemic heparinization. He had been playing golf regularly but had no history of hip injury. He had no previous history of bleeding problems. On admission, after a day of steadily worsening pain, the hip was tender, with movement aggravating the pain. A roentgenogram of the hip revealed distension of the joint space with
Redox Regulation of Vascular Smooth Muscle Cell Differentiation
Authors: B. Su, S. Mitra, H. Gregg, S. Flavahan, M. A. Chotani, K. R. Clark, P. J. Goldschmidt-Clermont, N. A. Flavahan
Journal: Circulation Research (2001)

Experiments were performed to determine the role of reactive oxygen species (ROS) in regulating vascular smooth muscle cell (VSMC) phenotype. After quiescence, cultured human VSMCs increased their expression of differentiation proteins (alpha-actin, calponin, and SM1 and SM2 myosin), but not beta-actin. ROS activity, determined using the H(2)O(2)-sensitive probe dichlorodihydrofluorescein (DCF), remained high in quiescent cells and was inhibited by catalase (3000 U/mL) or by N-acetylcysteine (NAC, 2 to 20 mmol/L). A superoxide dismutase mimic (SOD; MnTMPyP, 25 micromol/L) or SOD plus low concentrations of NAC (SODNAC2, 2 mmol/L) increased DCF fluorescence, which was inhibited by catalase or by NAC (10 to 20 mmol/L). Inhibition of ROS activity (by catalase or NAC) decreased the baseline expression of differentiation proteins, whereas elevation of ROS (by SOD or SODNAC2) increased expression of the differentiation markers. The latter effect was blocked by catalase or by NAC (10 to 20 mmol/L). None of the treatments altered beta-actin expression. SODNAC2-treated cells demonstrated contractions to endothelin that were absent in proliferating cells. p38 Mitogen-activated protein kinase (MAPK) activity was decreased when ROS activity was reduced (NAC, 10 mmol/L) and was augmented when ROS activity was increased (SODNAC2). Inhibition of p38 MAPK with pyridyl imidazole compound (SB202190, 2 to 10 micromol/L) reduced expression of differentiation proteins occurring under basal conditions and in response to SODNAC2. Transduction of VSMCs with an adenovirus encoding constitutively active MKK6, an activator of p38 MAPK, increased expression of differentiation proteins, whereas transduction with an adenovirus encoding dominant-negative p38 MAPK decreased expression of the differentiation proteins. These findings demonstrate that ROS can increase VSMC differentiation through a p38 MAPK-dependent pathway.
Expression of the smoothelin gene is mediated by alternative promoters
Authors: S Rensen
Journal: Cardiovascular Research (2002)

Objective: Two major isoforms of smoothelin have been reported, a 59-kDa smoothelin-A in visceral smooth muscle cells and a 110-kDa smoothelin-B in vascular smooth muscle cells. The present study was undertaken to investigate the expression of these smoothelin isoforms in different smooth muscle tissues and to determine how they are generated. Methods: Western blotting with a new, well-defined, smoothelin antibody was used to confirm the existence of two major smoothelin isoforms. Northern blotting, RT-PCR, primer extension and 5′RACE were applied to analyse the expression of these isoforms in human and mouse. Promoter reporter assays were carried out to establish the existence of a dual promoter system governing the expression pattern of the gene. Results: Antibody C6G confirmed the existence of two smoothelin proteins. Northern blotting showed that in vascular tissues a larger smoothelin transcript is generated than in visceral tissue. The cDNA of this larger smoothelin-B was cloned. Computer analysis of the open reading frame suggests an α-helical structure of 130 amino acids at the amino terminus of smoothelin-B. The smoothelin gene was cloned and sequenced. It comprises about 25 kb and contains 21 exons. The translational start of smoothelin-B is located in exon 2, whereas transcription and translation of the previously described smoothelin-A starts inside exon 10. Smoothelin-A and -B were demonstrated to be generated by two physically separated promoters. Splice variants within the calponin homology domain at the 3′ end of the gene were found for both isoforms. Conclusions: Two major smoothelin isoforms are generated from a single gene by a dual promoter system in a tissue specific manner. Further variation in the smoothelin proteins is achieved by alternative splicing in the calponin homology domain.
Molecular screening of patients with long standing extensive ulcerative colitis: detection of p53 and Ki-<i>ras</i> mutations by single strand conformation polymorphism analysis and differential hybridisation in colonic lavage fluid
Authors: S M Lang, D F Stratakis, M Heinzlmann, W Heldwein, B Wiebecke, K Loeschke
Journal: Gut (1999)

BACKGROUND In patients with long standing ulcerative colitis at risk of developing malignancy, mutations of the p53 and Ki- ras gene were investigated in lavage solution obtained at surveillance colonoscopy. METHODS DNA was isolated from 31 consecutive patients with total or subtotal ulcerative colitis and a disease duration of between seven and 26 years. Twenty seven control patients showed no macroscopic or microscopic inflammation on colonoscopy. Exons 5–8 of the p53 gene and exon 1 of the Ki- ras gene were amplified by polymerase chain reaction. Mutations of the p53 gene were detected by single strand conformation polymorphism analysis. Point mutations of the Ki- ras gene were hybridised on dot blots with oligonucleotides marked with digoxigenin. RESULTS In all cases of ulcerative colitis and in all of the 27 control patients, wild type p53 and wild type Ki- ras could be detected. In four patients with ulcerative colitis, a mutation in exon 5 to 7 of the p53 gene was found, and two patients had a mutation of the Ki- ras gene (Gly to Asp-12, Gly to Val-12). None of these patients had dysplasia in serial biopsy specimens, and all but one had had the disease for more than 10 years. One control patient had a mutation. CONCLUSIONS Mutations were more frequent in patients with long standing ulcerative colitis (19%) than in control patients (3%, p = 0.07). The technique may be useful for screening for early malignancy in ulcerative colitis.
Estrogen Rescues Preexisting Severe Pulmonary Hypertension in Rats
Authors: Soban Umar, Andrea Iorga, Humann Matori, Rangarajan D. Nadadur, Jingyuan Li, Federica Maltese, Arnoud van der Laarse, Mansoureh Eghbali
Journal: American Journal of Respiratory and Critical Care Medicine (2011)

Pulmonary hypertension (PH) is characterized by progressive increase in pulmonary artery pressure leading to right ventricular (RV) hypertrophy, RV failure, and death. Current treatments only temporarily reduce severity of the disease, and an ideal therapy is still lacking.Estrogen pretreatment has been shown to attenuate development of PH. Because PH is not often diagnosed early, we examined if estrogen can rescue preexisting advanced PH.PH was induced in male rats with monocrotaline (60 mg/kg). At Day 21, rats were either treated with 17-β estradiol or estrogen (E2, 42.5 μg/kg/d), estrogen receptor-β agonist (diarylpropionitrile, 850 μg/kg/d), or estrogen receptor α-agonist (4,4',4"-[4-Propyl-(1H)-pyrazole-1,3,5-triyl] trisphenol, 850 μg/kg/d) for 10 days or left untreated to develop RV failure. Serial echocardiography, cardiac catheterization, immunohistochemistry, Western blot, and real-time polymerase chain reaction were performed.Estrogen therapy prevented progression of PH to RV failure and restored lung and RV structure and function. This restoration was maintained even after removal of estrogen at Day 30, resulting in 100% survival at Day 42. Estradiol treatment restored the loss of blood vessels in the lungs and RV. In the presence of angiogenesis inhibitor TNP-470 (30 mg/kg) or estrogen receptor-β antagonist (PHTPP, 850 μg/kg/d), estrogen failed to rescue PH. Estrogen receptor-β selective agonist was as effective as estrogen in rescuing PH.Estrogen rescues preexisting severe PH in rats by restoring lung and RV structure and function that are maintained even after removal of estrogen. Estrogen-induced rescue of PH is associated with stimulation of cardiopulmonary neoangiogenesis, suppression of inflammation, fibrosis, and RV hypertrophy. Furthermore, estrogen rescue is likely mediated through estrogen receptor-β.