Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01350 (gastrin)
 9,683 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Universal, polyclonal and monoclonal immunoperoxidase staining kits from BioGenex, Dako and Ortho were employed for the localization of antigens such as gastrin, prostate specific antigen, IgA, IgG, AFP and CEA in histological sections from formaldehyde fixed and paraffin embedded human specimens. The kit components were controlled by immunohistological and serological assays and were also compared with self-prepared reagents. In connection with specific primary antibodies, universal/basic kits gave reliable localization of defined antigens. The optimal concentration of the primary antibodies had to be established by dilution experiments. In the case of polyclonal kits, typical antigen localization was obtained in selected tissue sections with all the respective kits. CEA kits also stained strongly NCA molecules present in organs such as colon, stomach and liver. BioGenex polyclonal kits gave almost stronger stainings than kits from Dako and Ortho. Irrespective of which kit from different commercial sources is used, development of peroxidase activity with AEC/H2O2 often had to be stopped far below the recommended incubation time of 40 min or overstaining with color change from reddish to muddy green occurred. The latter was attributed to insufficiently balanced kit reagents, an interpretation which was supported by quantitative serological studies. Sensitivity of immunohistological reactivity was much enhanced by pretreatment of tissue sections with Pronase. Thus, stronger immunostainings and larger numbers of positive cells were detected than in conventionally rehydrated sections.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Commercial polyclonal and monoclonal histostaining PAP kits. Immunoperoxidase reagents and performance characteristics in comparison with self-prepared immunoreagents. 389 52

Transactivation of human immunodeficiency virus (HIV) gene expression depends upon the interaction of the viral regulatory protein Tat with the transactivation responsive region (TAR) RNA, a 59-base stem-loop structure located at the 5'-end of all mRNAs. We have used a site-directed RNA-cleaving strategy to determine the neighborhood of the core domain of a Tat fragment in the Tat-TAR complex. We synthesized a 35-amino acid fragment containing arginine-rich RNA-binding domain of Tat(38-72) and attached an EDTA analog to its amino terminus. A derivative of (p-aminobenzyl)-EDTA tetra-tert-butyl ester was synthesized and attached to the amino terminus of the Tat peptide by standard peptide coupling methods. Cleavage from the resin and deprotection of the peptide were carried out in trifluoroacetic acid which also generated unprotected metal binding EDTA moieties. We used this EDTA-Tat conjugate to form a specific complex with TAR RNA. This sequence-specific RNA-binding peptide was converted into a sequence-specific RNA-cleaving peptide by the addition of Fe(II) salt, ascorbate, and H2O2. Hydroxyl radicals generated from the tethered Fe(II) cleaved the TAR RNA backbone in two localized regions. Site-specific cleavage of TAR RNA was observed at the bulge residues (U23, C24, and U25), in the loop region (G34 and A35), and at the strand opposite the bulge (U40 and C41). These results demonstrate that, in the three-dimensional structure of the Tat-TAR complex, the Phe38 of Tat(38-72) is located in the proximity of the bulge region and two nucleotides from the loop sequence.
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PMID:Probing the proximity of the core domain of an HIV-1 Tat fragment in a Tat-TAR complex by affinity cleaving. 937 65

Oxidant stress is thought to play a role in the pathogenesis of many gastric disorders. We have recently reported that histidine decarboxylase (HDC) promoter activity is stimulated by gastrin through a protein kinase C- and extracellular signal-regulating kinase (ERK)-dependent pathway in gastric cancer (AGS-B) cells, and this transcriptional response is mediated by a downstream cis-acting element, the gastrin response element (GAS-RE). To study the mechanism through which oxidant stress affects gastric cells, we examined the effects of hydrogen peroxide (H2O2) on HDC promoter activity and intracellular signaling in AGS-B cells. H2O2 (10 mM) specifically activated the HDC promoter 10-12-fold, and this activation was blocked by both mannitol and N-acetylcysteine. Hydrogen peroxide treatment of AGS-B cells increased the phosphorylation and kinase activity of ERK-1 and ERK-2, but did not affect Jun kinase tyrosine phosphorylation or kinase activity. In addition, treatment of AGS-B cells with H2O2 resulted in increased c-fos/c-jun mRNA expression and AP-1 activity, and also led to increased phosphorylation of epidermal growth factor receptor (EGFR) and Shc. H2O2-dependent stimulation of HDC promoter activity was completely inhibited by kinase-deficient ERKs, dominant-negative (N17 and N15) Ras, and dominant-negative Raf, and partially blocked by a dominant-negative EGFR mutant. In contrast, protein kinase C blockade did not inhibit H2O2-dependent induction of the HDC promoter. Finally, deletion analysis demonstrated that the H2O2 response element could be mapped to the GAS-RE (nucleotides 2 to 24) of the basal HDC promoter. Overall, these studies suggest that oxidant stress activates the HDC promoter through the GAS-RE, and through an Ras-, Raf-, and ERK-dependent pathway at least partially involving the EGFR.
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PMID:Oxidative stress activates the human histidine decarboxylase promoter in AGS gastric cancer cells. 972 30

Resveratrol is a phytoalexin with several biological and pharmacological activities including the "French paradox". We investigated the effect of resveratrol on cytolytic activity by oxygen reactive species and on soluble and particulate tyrosine kinases from human placenta and human prostatic adenoma. These effects were compared with those of piceatannol, quercetin, catechin and epicatechin. Fifty percent of erythrocyte lysis due to H2O2-lactoperoxidase-KI incubation, in which I3-, OI- and oxygen singlet are produced, was obtained after 22 +/- 7 (SD) min in the absence of the tested compounds. The 50% lysis was obtained after 66 +/- 15, 129 +/- 35, 196 +/- 21, 240 +/- 63 and 420 +/- 80 min with 40 microM piceatannol, quercetin, resveratrol, epicatechin and catechin respectively. Protection was concentration dependent. The assay of tyrosine kinase activity was performed using two different substrates as follows: substrate A corresponded to the sequence 1-17 of gastrin, and substrate B to sequence 6-20 of cell division kinase p34cdc2. In all experiments, initial velocity was measured. When assayed with both substrates, tyrosine kinase activities from particulate and cytosolic fractions of placenta were more inhibited by piceatannol and quercetin. Resveratrol significantly inhibited the particulate fraction and the cytosolic fraction respectively when substrates A and B were employed: Catechin acted as an inhibitor with substrate A and particulate fraction while in the other experimental conditions it acted as an activator. Resveratrol inhibited the tyrosine kinase of particulate and cytosolic fractions of prostatic adenoma assayed with substrate A and B.
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PMID:Effect of resveratrol and some other natural compounds on tyrosine kinase activity and on cytolysis. 1037 Aug 68

High intensity interval training (HIIT) is characterized by vigorous exercise with short rest intervals. Hydrogen peroxide (H2O2) plays a key role in muscle adaptation. This study aimed to evaluate whether HIIT promotes similar H2O2 formation via O2 consumption (electron leakage) in three skeletal muscles with different twitch characteristics. Rats were assigned to two groups: sedentary (n=10) and HIIT (n=10, swimming training). We collected the tibialis anterior (TA-fast), gastrocnemius (GAST-fast/slow) and soleus (SOL-slow) muscles. The fibers were analyzed for mitochondrial respiration, H2O2 production and citrate synthase (CS) activity. A multi-substrate (glycerol phosphate (G3P), pyruvate, malate, glutamate and succinate) approach was used to analyze the mitochondria in permeabilized fibers. Compared to the control group, oxygen flow coupled to ATP synthesis, complex I and complex II was higher in the TA of the HIIT group by 1.5-, 3.0- and 2.7-fold, respectively. In contrast, oxygen consumed by mitochondrial glycerol phosphate dehydrogenase (mGPdH) was 30% lower. Surprisingly, the oxygen flow coupled to ATP synthesis was 42% lower after HIIT in the SOL. Moreover, oxygen flow coupled to ATP synthesis and complex II was higher by 1.4- and 2.7-fold in the GAST of the HIIT group. After HIIT, CS activity increased 1.3-fold in the TA, and H2O2 production was 1.3-fold higher in the TA at sites containing mGPdH. No significant differences in H2O2 production were detected in the SOL. Surprisingly, HIIT increased H2O2 production in the GAST via complex II, phosphorylation, oligomycin and antimycin by 1.6-, 1.8-, 2.2-, and 2.2-fold, respectively. Electron leakage was 3.3-fold higher in the TA with G3P and 1.8-fold higher in the GAST with multiple substrates. Unexpectedly, the HIIT protocol induced different respiration and electron leakage responses in different types of muscle.
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PMID:High Intensity Interval Training (HIIT) Induces Specific Changes in Respiration and Electron Leakage in the Mitochondria of Different Rat Skeletal Muscles. 2612 Dec 48