Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Regional distribution of prolactin-releasing peptide (PrRP) in the human brain was studied by radioimmunoassay. The antiserum raised against human PrRP-31 in a rabbit was used in the assay, which showed 100% cross reaction with PrRP-20 and no significant cross reaction with other peptides. The highest concentrations of immunoreactive-PrRP were found in hypothalamus (912 +/- 519 fmol/g wet weight, n = 6, mean +/- SEM), followed by medulla oblongata (496 +/- 136 fmol/g wet weight) and thalamus (307 +/- 117 fmol/g wet weight). On the other hand, immunoreactive-PrRP was not detected in frontal lobe or temporal lobe (<50 fmol/g wet weight). Sephadex G50 column chromatography of the immunoreactive-PrRP in the hypothalamus and medulla oblongata showed three immunoreactive peaks; one peak eluting in the position of PrRP-20, one eluting in the position of PrRP-31 and one eluting earlier. Reverse phase high-performance liquid chromatography (HPLC) of these brain tissue extracts showed a peak eluting in the position of PrRP-20 and PrRP-31. The present study has shown for the first time the presence of immunoreactive-PrRP in the human brain. The immunoreactive-PrRP levels in the human hypothalamus were, however, lower than the levels of other neuropeptides with prolactin-releasing activity, such as thyrotropin-releasing hormone and vasoactive intestinal polypeptide.
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PMID:Regional distribution of immunoreactive prolactin-releasing peptide in the human brain. 1106 3

The aim of this study was to compare immunoreactivities for substance P with other enteric neuropeptides and GAP-43, a general marker for enteric nerves, in normal human colon and in different stages of ulcerative colitis. Tissue samples from normal colon and regions of ulcerative colitis colon were obtained at surgery and immunostained for substance P, vasoactive intestinal polypeptide (VIP), somatostatin, calcitonin gene-related peptide (CGRP), enkephalin, galanin, GAP-43, and neuron-specific enolase (NSE). Visual examination and semiquantitative analysis revealed a clear increase in the immunoreactivity for substance P in ulcerative colitis, whereas no differences were observed in the distribution of the other peptides. Therefore, quantitative analysis was performed only for substance P immunoreactivity in the lamina propria, circular muscle layer, and myenteric ganglia. In the lamina propria, the score of total intensity of substance P immunoreactivity was 0.55 +/- 0.15 (mean +/- SEM) in normal colon, 1.30 +/- 0.35 (p = 0.087) in least affected colon, and 2.22 +/- 0.28 (p < 0.001) in moderately affected colon, whereas no significant differences were observed in immunoreactivities for GAP-43. Similar results were obtained for the mean substance P- or GAP-43-immunoreactive area. In the circular muscle layer, the number, density, total intensity, and perimeter of substance P- and GAP-43-immunoreactive fibers were essentially similar in normal colon, and in mild or moderately affected colon. We conclude that ulcerative colitis does not change the density of gut innervation as a whole. However, the density of substance P-containing nerves is specifically increased, probably due to increased peptide synthesis leading to better visibility of the fibers.
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PMID:Quantitative comparison of growth-associated protein-43 and substance P in ulcerative colitis. 1137 21

A protein capable of inducing neuromuscular blockade in avian preparations and of depolarizing mouse diaphragm muscle was isolated from Bothrops lanceolatus venom using gel filtration and ion-exchange chromatography. The purified protein was a single chain polypeptide with an estimated molecular mass of 27.5 kDa by SDS-PAGE and had caseinolytic activity (13.3 units/mg), but no phospholipase A(2). B.lanceolatus venom (50 micro g/ml) and the caseinolytic protein (20 micro g/ml) produced contracture and progressive irreversible blockade (50% in 25+/-5 min (SEM) and 45+/-15 min, respectively), in indirectly stimulated chick biventer cervicis preparations. The contractile responses to acetylcholine (ACh; 37 and 74 micro M, n=6) were inhibited by venom and the caseinolytic protein, whereas those to potassium (13.4mM, n=6) were not. Membrane resting potential measurements in mouse hemidiaphragm preparations showed that B.lanceolatus venom and the purified protein caused depolarization which was prevented by D-tubocurarine (14.6mM). The venom produced a slight increase in the amplitude and frequency of miniature end-plate potentials, but this effect was not seen with the purified fraction. These results suggest that the purified protein acts exclusively post-synaptically.
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PMID:Neuromuscular action of Bothrops lanceolatus (Fer de lance) venom and a caseinolytic fraction. 1222 Jul 13

The mode of appearance and assembly of cyst wall filaments on the surface of Giardia duodenalis trophozoites committed to encyst was analysed by scanning and transmission electron microscopy (SEM and TEM) and by fluorescence microscopy (FM). SEM showed a progressive appearance of fibril patches, predominantly on the anterior area of ventral and dorsal surfaces, which then spread and coalesced. By TEM, ruthenium red (RR) displayed staining in encysting cells as rodlike spots of variable diameter (3-25 nm), possibly microfibril tips with polyanionic moieties, that displayed tangential associations and random orientations over the cell membrane. In FM assays, the 1,10-phenanthroline derivative of ruthenium red (RR/oPHE) was a specific ligand for these assembling fibrils and this staining was significantly blocked by N-acetylgalactosamine (GalNac) and galactosamine (GalN). Interestingly, RR staining was lost when the cyst wall was completely assembled and thickened as observed by TEM and FM. Kinetic FM assays, in which a mAb specific for a 26 kDa Giardia cyst wall polypeptide was used concomitantly with RR/oPHE staining, showed a differential pattern for the appearance and reactivity of polypeptide and assembling GalN/GalNac-rich moieties of Giardia cyst wall.
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PMID:Sequential exposure and assembly of cyst wall filaments on the surface of encysting Giardia duodenalis. 1235 18

Amylin is a polypeptide hormone produced in pancreatic beta-cells that belongs to the family of calcitonin gene-related peptides. There is a 20% sequence homology between amylin and calcitonin and 44% homology with calcitonin gene-related peptide. Amylin and its fragments stimulate the proliferation of osteoblasts, inhibit bone resorption, and increase bone density and the amount of bone mass. We measured amylin total and unreduced amylin fasting plasma levels in patients with osteoporosis ( n=28; 3 men, 25 women; mean age 65 years), type 2 diabetes mellitus ( n=10; 5 men, 5 women; 64 years), and in the control group ( n=24; 11 men, 13 women; 53 years) using an ELISA kit with immunofluorescent detection (Linco). Amylin total plasma levels in patients with osteoporosis were 3.33+/-0.46 pmol/l (mean+/-SEM), in patients with type 2 diabetes 6.29+/-1.47 pmol/l (mean+/-SEM), and in the control group 8.48+/-3.12 pmol/l (mean+/-SEM). Mean plasma levels were lower in patients with osteoporosis than in patients with type 2 diabetes and in the control group. Unreduced amylin plasma levels in patients with osteoporosis ( n=28) were 2.51+/-0.87 pmol/l (mean+/-SEM), in patients with type 2 diabetes ( n=10) 4.15+/-0.95 pmol/l (mean+/-SEM) and in the control group ( n=5) 13.50+/-3.94 pmol/l (mean+/-SEM). Plasma levels were significantly lower in patients with osteoporosis than in patients with type 2 diabetes ( P<0.01) and in the control group ( P<0.001). Amylin plasma levels are decreased in patients with osteoporosis. Amylin deficiency in these patients may contribute to the development of osteoporosis. Amylin should be investigated in relation to the pharmacological treatment of osteoporosis.
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PMID:Amylin fasting plasma levels are decreased in patients with osteoporosis. 1460 1

In clinical practice it is important to differentiate pseudocysts from cystic pancreatic tumors, especially potentially malignant mucinous cystic tumors. We investigated three new markers-tumor-associated trypsin inhibitor (TATI) and the free alpha and beta subunits of human choriogonadotropin (hCGalpha and hCGbeta, respectively)-in the cyst fluid of patients with cystic pancreatic lesions and compared the concentrations of these markers to those of carcinoembryonic antigen (CEA), CA 19-9, CA 242, CA 125, CA 15-3, alpha-fetoprotein, and tissue polypeptide antigen in order to distinguish benign cysts from malignant cysts. Between 1995 and 2001, a total of 34 patients operated on for cystic pancreatic lesions at Tampere University Hospital were included. Cyst fluid was aspirated at operation and stored at -70 C. The histologic diagnosis was pseudocyst in 23 patients, serous cystadenoma (SCA) in four patients, benign mucinous cystadenoma (MCA) in four patients, cystic papillary neoplasm (CPN) in one patient, glucagonoma in one patient, and malignant endocrine islet cell carcinoma (EC) in one patient. Significantly higher concentrations of TATI were found in patients with MCA and EC (2239 +/- 149 microg/L [mean +/- SEM]) than in patients with pseudocyst (55 +/- 29 microg/L; P=0.001) and in patients with SCA (36 +/- 23 microg/L; P=0.01). The patient with CPN and the patient with glucagonoma had relatively low levels of TATI (30.7 and 46.5 microg/L). Mean CEA was higher in patients with MCA compared to those with pseudocysts (19,993 +/- 9418 vs. 53 +/- 20 microg/L, P=0.002) and SCA (0.4 +/- 0.1 microg/L; P=0.02), but in the patient with malignant EC, the patient with CPN, and the patient with glucagonoma, CEA was normal. HCGalpha, hCGbeta, CA 19-9, CA 242, CA 125, CA 15-3, alpha fetoprotein, and tissue polypeptide antigen could not distinguish between MCA vs. pseudocyst or SCA, because both normal and elevated values were seen in all groups. To our knowledge, this is the first time that TATI has been quantitated in the cyst fluid of patients with cystic pancreatic lesions. It appears to be a potential marker in the differential diagnosis of benign from malignant cystic pancreatic lesions.
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PMID:Cyst fluid tumor-associated trypsin inhibitor may be helpful in the differentiation of cystic pancreatic lesions. 1523 93

A high swelling resin, CLPSER has been developed and utilized for the solid phase synthesis of Pardaxin, which is an 18-residue peptide. The resin was characterized by gel phase (13)C NMR, IR and SEM. The utility of the new polymer support in polypeptide synthesis was further established by the comparative synthesis of pardaxin with commercially available Merrifield resin. The MALDI TOF MS, amino acid analysis and the HPLC revealed the superior quality of CLPSER.
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PMID:Synthesis of a shark repellent peptide toxin, Pardaxin (16-33) on a highly flexible polymer support: CLPSER. 1557 24

A new protein engineering strategy was utilized to synthesize an elastin-mimetic polypeptide. The primary structure represents an elastic motif composed of thirty amino acids with one lysine and one glutamic acid per repeat unit EMM = (VPGVG VPGKG VGPVG VPGVG VPGEG VPGIG). The gene was constructed using a Seamless Cloning method by generating three DNA cassettes which all encoded the EMM repeat unit, but with different flanking restriction recognition sites. The DNA cassettes were assembled to yield a gene that could be directly cloned into the multiple cloning site of pBluescript II SK+. The resulting gene (EMM)(7) with approximately 650 base pairs in length was further cloned into the expression vector pET-28b. Protein biosynthesis in E. coli strain BLR(DE3) resulted in the 21.5 kDa repeating polypeptide His(6)-(EMM)(7) yielding up to 50 mg . L(-1) of cell culture. Secondary structure analysis by far UV circular dichroism revealed a minimum at 197 nm and a shoulder at 218 nm indicative for a random coil with some type II beta-turn conformation content. Lower critical solution temperature (LCST) behavior strongly depends on salt and polypeptide concentration. Importantly, first cross-linking experiments indicate successful hydrogel formation with a surface structure reminiscent to natural elastin as visualized by SEM micrographs.
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PMID:Biosynthesis of an elastin-mimetic polypeptide with two different chemical functional groups within the repetitive elastin fragment. 1594 26

The diphenylalanine peptide, the core recognition motif of the beta-amyloid polypeptide, efficiently self-assembles into discrete, well-ordered nanotubes. Here, we describe the notable thermal and chemical stability of these tubular structures both in aqueous solution and under dry conditions. Scanning and transmission electron microscopy (SEM and TEM) as well as atomic force microscopy (AFM) revealed the stability of the nanotubes in aqueous solution at temperatures above the boiling point of water upon autoclave treatment. The nanotubes preserved their secondary structure at temperatures up to 90 degrees C, as shown by circular dichroism (CD) spectra. Cold field emission gun (CFEG) high-resolution scanning electron microscope (HRSEM) and thermogravimetric analysis (TGA) of the peptide nanotubes after dry heat revealed durability at higher temperature. It was shown that the thermal stability of diphenylalanine peptide nanotubes is significantly higher than that of a nonassembling dipeptide, dialanine. In addition to thermal stability, the peptide nanotubes were chemically stable in organic solvents such as ethanol, methanol, 2-propanol, acetone, and acetonitrile, as shown by SEM analysis. Moreover, the acetone environment enabled AFM imaging of the nanotubes in solution. The significant thermal and chemical stability of the peptide nanotubes demonstrated here points toward their possible use in conventional microelectronic and microelectromechanics processes and fabrication into functional nanotechnological devices.
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PMID:Thermal and chemical stability of diphenylalanine peptide nanotubes: implications for nanotechnological applications. 1643 Feb 99

In orthopaedics and cardiovascular surgery, titanium has become the metal of choice, due to its excellent mechanical properties and biocompatibility. In many surgical operations, chemicals and/or biomolecules (such as antibiotics or growth factors) are used in conjunction with prostheses, so as to avoid or stimulate targeted biological events. Often, immobilization instead of release of such molecules is preferred to optimize their effects, thus avoiding ectopic transformations. A versatile method for the functionalization of pure Ti is shown here, which allows the covalent immobilization of polypeptides. In order to avoid the hydrolysable Ti-O-Si bond found in directly silanized Ti, we use organic/inorganic silica colloids, derived from commercially available 25 nm Ludox silica nanoparticles. Prior to deposition onto Ti-Cp, the silica nanoparticles are functionalized by a propylsemicarbazide moiety by silanization. After spin-coating onto the Ti substrates, the colloids were shown by SEM to form a uniform layer, and to be very strongly adsorbed; the reactivity of the supported semicarbazide (Sc) functionalities being maintained. Chemoselective reaction of semicarbazide groups on the surface with aldehyde moieties present on the polypeptide of interest was chosen in this work due to its efficiency, to its compatibility with the proteinogenic amino acids and in particular cystein and to the use of mild experimental conditions. Aldehyde groups are also easily introduced onto polypeptides by synthesis, oxidation of N-terminal Ser residue or polysaccharide moieties of glycoproteins. Biological assays with MC3T3-E1 osteoblasts revealed an excellent cytocompatibility as shown by the assessment of cell viability, vitality and morphology.
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PMID:Ti-Cp functionalization by deposition of organic/inorganic silica nanoparticles. 1786 78


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