tbuckley/cabot-search huggingface dataset:
Characterization and Signaling of the AT4 Receptor in Human Proximal Tubule Epithelial (HK-2) Cells
Authors: RAJASH K. HANDA
Journal: Journal of the American Society of Nephrology (2001)

Abstract. 125 I-divalinal-angiotensin IV (metabolically resistant analog of angiotensin IV) was used as a receptor ligand to identify the expression and properties of the angiotensin AT 4 receptor in epithelial HK-2 cells (an immortalized cell line derived from adult human proximal tubules). Saturation binding isotherms revealed that HK-2 cells contain a saturable 125 I-divalinal-angiotensin IV binding site with an affinity of 3 nmol/L and a density of 508 fmol/mg protein. An analysis of ligand specificity showed that only angiotensin AT 4 receptor ligands (angiotensin IV and divalinal-angiotensin IV) competed with both a high- and low-affinity binding site. GTPγS and dithiothreitol did not affect 125 I-Ang IV or 125 I-divalinal-Ang IV binding, suggesting that the AT 4 receptor was not G-protein coupled and did not require sulfhydryl bonds for receptor affinity. Activation of the AT 4 receptor caused a complex concentration-dependent rise in [Ca 2+ ] i , an elevation in [Na + ] i , and increased mitogen-activated protein kinase activity. These results suggest that human proximal tubule epithelial cells contain functional AT 4 receptors that are pharmacologically similar to the AT 4 receptor described in more distal segments of the nephron. Furthermore, the AT 4 receptor uses several intracellular signaling pathways to convey information.
Honokiol, a Constituent of Oriental Medicinal Herb <i>Magnolia officinalis</i>, Inhibits Growth of PC-3 Xenografts <i>In vivo</i> in Association with Apoptosis Induction
Authors: Eun-Ryeong Hahm, Julie A. Arlotti, Stanley W. Marynowski, Shivendra V. Singh
Journal: Clinical Cancer Research (2008)

Abstract Purpose: This study was undertaken to determine the efficacy of honokiol, a constituent of oriental medicinal herb Magnolia officinalis, against human prostate cancer cells in culture and in vivo. Experimental Design: Honokiol-mediated apoptosis was assessed by analysis of cytoplasmic histone-associated DNA fragmentation. Knockdown of Bax and Bak proteins was achieved by transient transfection using siRNA. Honokiol was administered by oral gavage to male nude mice s.c. implanted with PC-3 cells. Tumor sections from control and honokiol-treated mice were examined for apoptotic bodies (terminal deoxyribonucleotidyl transferase–mediated dUTP nick end labeling assay), proliferation index (proliferating cell nuclear antigen staining), and neovascularization (CD31 staining). Levels of Bcl-2 family proteins in cell lysates and tumor supernatants were determined by immunoblotting. Results: Exposure of human prostate cancer cells (PC-3, LNCaP, and C4-2) to honokiol resulted in apoptotic DNA fragmentation in a concentration- and time-dependent manner irrespective of their androgen responsiveness or p53 status. Honokiol-induced apoptosis correlated with induction of Bax, Bak, and Bad and a decrease in Bcl-xL and Mcl-1 protein levels. Transient transfection of PC-3 cells with Bak- and Bax-targeted siRNAs and Bcl-xL plasmid conferred partial yet significant protection against honokiol-induced apoptosis. Oral gavage of 2 mg honokiol/mouse (thrice a week) significantly retarded growth of PC-3 xenografts without causing weight loss. Tumors from honokiol-treated mice exhibited markedly higher count of apoptotic bodies and reduced proliferation index and neovascularization compared with control tumors. Conclusion: Our data suggest that honokiol, which is used in traditional oriental medicine for the treatment of various ailments, may be an attractive agent for treatment and/or prevention of human prostate cancers.
Effects of guanidine derivatives on mitochondrial function
Authors: Frank Davidoff
Journal: Journal of Clinical Investigation (1968)

Derivatives of guanidine, such as phenethylbiguanide, are potent inhibitors of mitochondrial respiration in vitro, but the relevance of this inhibition to their in vivo blood sugar-lowering action is not clear. We have studied the metabolism of pyruvate and long chain fatty acids by mitochondria from several tissues of guinea pigs and rats and observed the effects of phenethylbiguanide on these processes. The rate of pyruvate decarboxylation and of beta-oxidation of long chain fatty acyl-CoA derivatives by guinea pig heart mitochondria in vitro has been found to exceed the flux of substrate through the citric acid cycle, both in the presence and absence of phosphate acceptor. When serum albumin is included in the incubation medium, the respiration of guinea pig heart, skeletal muscle, and liver mitochondria is inhibited by concentrations of phenethylbiguanide which approximate the levels achieved in those tissues in vivo. In the absence of albumin, the mitochondria are several fold less sensitive to phenethylbiguanide inhibition. Mitochondria from rat tissues are less sensitive than those of guinea pig to in vitro inhibition by phenethylbiguanide, but serum albumin alters sensitivity to inhibition in similar fashion in both species. During the breakdown of pyruvate or long chain fatty acyl-CoA, phenethylbiguanide demonstrates no specificity of inhibition toward the oxidative reactions before the citric acid cycle versus those of the cycle itself. However, oxidation of free fatty acids is relatively resistant to inhibition.
Therapeutic Footwear in Diabetes
Authors: Andrew J.M. Boulton, Edward B. Jude
Journal: Diabetes Care (2004)

In recent years, it has generally been accepted by the diabetes community that “good” footwear prevents foot ulceration. Indeed, it is virtually an axiom of diabetes care that a patient with a history of foot ulcer is a footwear patient for life (1). Similarly, most health care professionals believe that “bad” footwear is a major cause of ulceration in diabetes and that in the past, the fact that most therapeutic footwear was perceived as “ugly” resulted in poor compliance when such footwear was prescribed (2). Where is the evidence to support these beliefs? The last two points are easier dealt with than the first.

There are studies that support the belief that bad or inappropriate footwear causes ulceration. Apelqvist et al. (3) identified shoes as the precipitating cause in the majority of toe ulcers and a significant minority of lesions elsewhere on the foot. In another European study (4), footwear was implicated as being contributory to 21% of all ulcers in a large …
Suppression of Mammary Carcinoma Growth by Retinoic Acid: Proapoptotic Genes Are Targets for Retinoic Acid Receptor and Cellular Retinoic Acid–Binding Protein II Signaling
Authors: Leslie J. Donato, Noa Noy
Journal: Cancer Research (2005)

Retinoic acid (RA) displays pronounced anticarcinogenic activities in several types of cancer. Whereas the mechanisms that underlie this activity remain incompletely understood, tumor suppression by RA is believed to emanate primarily from its ability to regulate transcription of multiple target genes. Here, we investigated molecular events through which RA inhibits the growth of MCF-7 mammary carcinoma cells, focusing on the involvement of the two proteins that mediate transcriptional activation by RA, the nuclear hormone receptor retinoic acid receptor (RAR) and the cellular retinoic acid-binding protein (CRABP) II, in this process. RA treatment of MCF-7 cells did not affect cell cycle distribution but triggered pronounced apoptosis. Accordingly, expression array analyses revealed that RA induces the expression of several proapoptotic genes, including caspase 7 and caspase 9. Whereas caspase 7 is an indirect responder to RA signaling, caspase 9 is a novel direct target for RAR, and it harbors a functional retinoic acid response element in its second intron. In agreement with the known role of CRABP-II in enhancing the transcriptional activity of RAR, the binding protein augmented RA-induced up-regulation of caspase 9, cooperated with RA in activating both caspase 7 and 9, and amplified the ability of RA to trigger apoptosis. Surprisingly, the data indicate that CRABP-II also displays proapoptotic activities on its own. Specifically, overexpression of CRABP-II, in the absence of RA, up-regulated the expression of Apaf1 and triggered caspase 7 and caspase 9 cleavage. These observations suggest that, in addition to its known role in direct delivery of RA to RAR, CRABP-II may have an additional, RA-independent, function.
Presentation of newly synthesized glycoproteins to CD4+ T lymphocytes. An analysis using influenza hemagglutinin transport mutants.
Authors: D J Kittlesen, L R Brown, V L Braciale, J P Sambrook, M J Gething, T J Braciale
Journal: The Journal of Experimental Medicine (1993)

Human lymphoblastoid cells transiently expressing the hemagglutinin (HA) glycoprotein of influenza virus are rapidly and efficiently recognized by CD4+ HA-specific T lymphocytes. This endogenous presentation pathway is sensitive to chloroquine and is therefore likely related to the classical class II major histocompatibility complex (MHC) exogenous pathway of antigen presentation. In this study we have examined a series of transport-defective HA mutants. We correlate the intracellular fate of the native antigen with its presentation characteristics. We have found that the native antigen must enter the secretory pathway since a cytosolic form is not presented. However, surface expression and normal trafficking through the Golgi apparatus are not required for efficient presentation. Instead, escape of native antigen from the endoplasmic reticulum appears to be both necessary and sufficient for gaining access to a compartment where antigen is processed and binds class II MHC molecules.
THE EFFECT OF ACTH, RENIN, ANGIOTENSIN II, AND VARIOUS PRECURSORS ON BIOSYNTHESIS OF ALDOSTERONE BY ADRENAL SLICES
Authors: Norman M. Kaplan, Frederic C. Bartter
Journal: Journal of Clinical Investigation (1962)

both of a considerable amount of zona glomerulosa in the inner slices and of functionally inactive fibrous cap- sule in the outer slice.The slices were minced with scissors and weighed.Specimens weighing about 500 mg were placed in 5 ml of Krebs-Ringer bicarbonate medium containing glucose in a concentration of 200 mg per 100 ml.At least 4 vessels were incubated and analyzed separately for each portion of each experiment.Thus, there were at least 4 control vessels and at least 4 with each precursor or stimulating agent studied in each experiment.The tissues were kept chilled until incubation, which was started between 3 and 5 hours after the death of the cattle.Tissues were preincubated for 1 hour at 37°C under 5 per cent CO2-95 per cent 02 on the Dubnoff metabolic shaker.The preincubation medium was removed, and 5 ml of fresh medium was used to transfer the slices to vessels to which the appropriate precursor had been added with or with- out ACTH, renin, or angiotensin II.Incubation was for 2 hours.
CANCER DIAGNOSIS WITH POSITRON COMPUTED TOMOGRAPHY AND CARBON-11-LABELLED L-METHIONINE
Authors: K Kubota, M Ito, Y Abe, T Fujiwara, J Hatazawa, R Iwata, K Ishiwata, H Fukuda, K Ito, S Yoshioka, T Matsuzawa, S Watanuki, T Ido
Journal: The Lancet (1983)
Mass Spectrometric Analysis of Surfactant Metabolism in Human Volunteers Using Deuteriated Choline
Authors: Wolfgang Bernhard, Christopher J. Pynn, Andreas Jaworski, Gunnar A. Rau, Jens M. Hohlfeld, Joachim Freihorst, Christian F. Poets, Dieter Stoll, Anthony D. Postle
Journal: American Journal of Respiratory and Critical Care Medicine (2004)

Surfactant reduces surface tension at pulmonary air-liquid interfaces. Although its major component is dipalmitoyl-phosphatidylcholine (PC16:0/16:0), other PC species, principally palmitoylmyristoyl-PC, palmitoylpalmitoleoyl-PC, and palmitoyloleoyl-PC, are integral components of surfactant. The composition and metabolism of PC species depend on pulmonary development, respiratory rate, and pathologic alterations, which have largely been investigated in animals using radiolabeled precursors. Recent advances in mass spectrometry and availability of precursors carrying stable isotopes make metabolic experiments in human subjects ethically feasible. We introduce a technique to quantify surfactant PC synthesis in vivo using deuteriated choline coupled with electrospray ionization tandem mass spectrometry. Endogenous PC from induced sputa of healthy volunteers comprised 54.0 +/- 1.5% PC16:0/16:0, 9.7 +/- 0.7% palmitoylmyristoyl-PC, 10.0 +/- 1.0% palmitoylpalmitoleoyl-PC, and 13.1 +/- 0.3% palmitoyloleoyl-PC. Infusion of deuteriated choline chloride (3.6 mg/kg body weight) over 3 hours resulted in linear incorporation into PC over 30 hours. After a plateau of 0.61 +/- 0.04% labeled PC between 30 and 48 hours, incorporation decreased to 0.30 +/- 0.02% within 7 days. Compared with native PC, fractional label was initially lower for PC16:0/16:0 (31.9 +/- 8.3%) but was higher for palmitoyloleoyl-PC (21.0 +/- 1.2%), and equilibrium was achieved after only 48 hours. We conclude that infusion of deuteriated choline and electrospray ionization tandem mass spectrometry is useful to investigate surfactant metabolism in humans in vivo.
Formation of soluble amyloid oligomers and amyloid fibrils by the multifunctional protein vitronectin
Authors: Thuzar M Shin, J Mario Isas, Chia-Ling Hsieh, Rakez Kayed, Charles G Glabe, Ralf Langen, Jeannie Chen
Journal: Molecular Neurodegeneration (2008)

Abstract Background The multifunctional protein vitronectin is present within the deposits associated with Alzheimer disease (AD), age-related macular degeneration (AMD), atherosclerosis, systemic amyloidoses, and glomerulonephritis. The extent to which vitronectin contributes to amyloid formation within these plaques, which contain misfolded, amyloidogenic proteins, and the role of vitronectin in the pathophysiology of the aforementioned diseases is currently unknown. The investigation of vitronectin aggregation is significant since the formation of oligomeric and fibrillar structures are common features of amyloid proteins. Results We observed vitronectin immunoreactivity in senile plaques of AD brain, which exhibited overlap with the amyloid fibril-specific OC antibody, suggesting that vitronectin is deposited at sites of amyloid formation. Of particular interest is the growing body of evidence indicating that soluble nonfibrillar oligomers may be responsible for the development and progression of amyloid diseases. In this study we demonstrate that both plasma-purified and recombinant human vitronectin readily form spherical oligomers and typical amyloid fibrils. Vitronectin oligomers are toxic to cultured neuroblastoma and retinal pigment epithelium (RPE) cells, possibly via a membrane-dependent mechanism, as they cause leakage of synthetic vesicles. Oligomer toxicity was attenuated in RPE cells by the anti-oligomer A11 antibody. Vitronectin fibrils contain a C-terminal protease-resistant fragment, which may approximate the core region of residues essential to amyloid formation. Conclusion These data reveal the propensity of vitronectin to behave as an amyloid protein and put forth the possibilities that accumulation of misfolded vitronectin may contribute to aggregate formation seen in age-related amyloid diseases.
Chromatin Central: towards the comparative proteome by accurate mapping of the yeast proteomic environment
Authors: Anna Shevchenko, Assen Roguev, Daniel Schaft, Luke Buchanan, Bianca Habermann, Cagri Sakalar, Henrik Thomas, Nevan J Krogan, Andrej Shevchenko, A Francis Stewart
Journal: Genome biology (2008)

Understanding the design logic of living systems requires the understanding and comparison of proteomes. Proteomes define the commonalities between organisms more precisely than genomic sequences. Because uncertainties remain regarding the accuracy of proteomic data, several issues need to be resolved before comparative proteomics can be fruitful.The Saccharomyces cerevisiae proteome presents the highest quality proteomic data available. To evaluate the accuracy of these data, we intensively mapped a proteomic environment, termed 'Chromatin Central', which encompasses eight protein complexes, including the major histone acetyltransferases and deacetylases, interconnected by twelve proteomic hyperlinks. Using sequential tagging and a new method to eliminate background, we confirmed existing data but also uncovered new subunits and three new complexes, including ASTRA, which we suggest is a widely conserved aspect of telomeric maintenance, and two new variations of Rpd3 histone deacetylase complexes. We also examined the same environment in fission yeast and found a very similar architecture based on a scaffold of orthologues comprising about two-thirds of all proteins involved, whereas the remaining one-third is less constrained. Notably, most of the divergent hyperlinks were found to be due to gene duplications, hence providing a mechanism for the fixation of gene duplications in evolution.We define several prerequisites for comparative proteomics and apply them to examine a proteomic environment in unprecedented detail. We suggest that high resolution mapping of proteomic environments will deliver the highest quality data for comparative proteomics.
Chemotherapy As an Alternative to Radiotherapy in the Treatment of Stage IIA and IIB Testicular Seminoma: A Spanish Germ Cell Cancer Group Study
Authors: Xavier Garcia-del-Muro, Pablo Maroto, Josep Gumà, Javier Sastre, Marta López Brea, José A. Arranz, Nuria Lainez, Diego Soto de Prado, Jorge Aparicio, José M. Piulats, Xavier Pérez, Josep R. Germá-Lluch
Journal: Journal of Clinical Oncology (2008)

To assess the long-term efficacy and toxicity of front-line cisplatin-based chemotherapy in patients with stage IIA or IIB testicular seminoma.Untreated patients with pure seminoma of the testis after orchiectomy, with clinical stage IIA or IIB, were considered eligible for this prospective observational study. Chemotherapy consisted of either four cycles of cisplatin and etoposide or three cycles of cisplatin, etoposide, and bleomycin.Between April 1994 and March 2003, 72 patients were entered onto the study at 26 participating centers. Eighteen patients had stage IIA disease, and 54 patients had stage IIB disease. Eighty-three percent of patients achieved complete response, and 17% achieved partial response with residual mass. After a median follow-up time of 71.5 months, six patients with stage IIB disease experienced relapse, and one of these patients died as a result of seminoma. Three patients experienced non-seminoma-related deaths (two died from a further esophageal carcinoma, and one died from an upper digestive hemorrhage). The estimated 5-year progression-free survival rates for patients with stage IIA or IIB disease were 100% and 87% (95% CI, 77.5% to 97%), respectively. Five-year progression-free and overall survival rates for the whole group were 90% (95% CI, 82% to 98%) and 95% (95% CI, 89% to 100%), respectively. Severe granulocytopenia and thrombocytopenia were observed in eight and two patients, respectively. Mild to moderate emesis, stomatitis, and diarrhea were the most common nonhematologic effects.Chemotherapy is a highly effective and well-tolerated treatment for patients with stage IIA or IIB seminoma and represents an available alternative that could avoid some of the serious late effects associated with radiotherapy. Further studies focusing on long-term toxicities of different treatment modalities are needed.
Addition of Pioglitazone and Ramipril to Intensive Insulin Therapy in Type 2 Diabetic Patients Improves Vascular Dysfunction by Different Mechanisms
Authors: Marianella Fernandez, Curtis Triplitt, Estela Wajcberg, Apiradee A. Sriwijilkamol, Nicholas Musi, Kenneth Cusi, Ralph DeFronzo, Eugenio Cersosimo
Journal: Diabetes Care (2007)

OBJECTIVE—We examined the relationship between glycemic control, vascular reactivity, and inflammation in type 2 diabetic subjects. RESEARCH DESIGN AND METHODS—Thirty subjects with type 2 diabetes were initiated on intensive insulin therapy (continuous subcutaneous insulin infusion [n = 12] or multiple daily injections [n = 18]) and then randomized to either pioglitazone (PIO group;45 mg/day), ramipril (RAM group; 10 mg/day), or placebo (PLC group) for 36 weeks. Euglycemic-hyperinsulinemic clamp was used to quantify insulin resistance, and plethysmography was used to assess changes in forearm blood flow (FBF) after 1) 5 min of reactive hyperemia and 2) brachial artery infusion of acetylcholine (7.5, 15, and 30 μg/min) and sodium nitroprusside (3 and 10 μg/min). RESULTS—The decreases in A1C (∼9.0–7.0%) and fasting plasma glucose (∼190–128 mg/dl) were equal in all groups. In the PIO group, glucose disposal increased from 3.1 to 4.7 mg · kg−1 · min−1, and there was a greater decrease in plasma triglycerides (∼148 vs. 123 mg/dl) and free fatty acids (∼838 vs. 595 mEq/l) compared with the RAM or PLC groups (P &amp;lt; 0.05). Plasma adiponectin doubled with pioglitazone treatment (6.2 ± 0.7 to 13.1 ± 1.8 μg/ml), while endothelin-1 decreased only with ramipril treatment (2.5 ± 0.2 to 1.1 ± 0.2 pg/ml) (P &amp;lt; 001). The increase in FBF during reactive hyperemia (215%) and acetylcholine (from 132 to 205%, 216 to 262%, and 222 to 323%) was greater in the PIO versus RAM or PLC groups. In contrast, FBF during sodium nitroprusside treatment was greater in the RAM group (141–221% and 218–336%) compared with the PIO or PLC groups (all P &amp;lt; 0.05). CONCLUSIONS—Addition of pioglitazone or ramipril to intensive insulin therapy in type 2 diabetes further improves vascular dysfunction. Pioglitazone enhances endothelial-mediated vasodilation, whereas ACE inhibition enhances endothelial-independent vasodilation. These different vascular effects, combined with the observation that pioglitazone decreases free fatty acids and triglycerides and increases adiponectin, while ramipril reduces endothelin-1, suggest that different mechanisms underlie the vascular responses.
Eosinophils and eosinophil-derived proteins in children with moderate asthma
Authors: MO Hoekstra, H Hovenga, J Gerritsen, HF Kauffman
Journal: European Respiratory Journal (1996)

Laboratory parameters can contribute to the diagnosis of asthma, which is often a difficult procedure in paediatric patients. The aim of this study was to investigate the value of eosinophil cationic protein (ECP) and eosinophil-derived neurotoxin (EDN) in the diagnosis of paediatric asthma. The number of eosinophils, serum ECP and EDN, and urinary EDN were determined in 22 children with stable, allergic asthma, aged 4-14 yrs, and in 17 age-matched healthy controls. Symptoms were monitored, the peak expiratory flow rate (PEFR) was recorded in the younger children, and lung function tests (forced expiratory volume in one second (FEV1) and the provocative concentration of histamine causing a 20% fall in FEV1 (PC20)) were performed in the older children. None of the asthmatic children had respiratory symptoms. PEFR was not significantly different in asthmatic children compared to controls. The FEV1 % predicted was significantly lower compared to controls. The number of eosinophils, serum ECP and EDN, and urinary EDN were significantly higher in asthmatic children compared with controls. After correction of serum ECP and EDN, and urinary EDN for the number of eosinophils, the differences between patients and controls disappeared. The nocturnal PEFR and the FEV1 were significantly related to urinary EDN. The results suggest that serum and urinary concentration of eosinophil-derived proteins can be determined instead of the number of eosinophils to support the diagnosis of asthma in childhood. The urinary concentration of eosinophil-derived neurotoxin can be especially valuable in young children, because in this age group quantification of lung function cannot be performed and blood sampling can be difficulty.