Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: DrugBank:APRD00080 (Leaf)
 21,685 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A chitinase purified from culture filtrates of Trichoderma resei KDR-11 efficiently catalyzed a transglycosylation reaction on tetra-N-acetylchitotetraoside in a buffer medium containing ammonium sulfate, converting the tetrasaccharide into hexa-N-acetylchitohexaose (39.6%) and di-N-acetylchitobiose (55.7%) as the major products. Sugar-chain elongation from di-N-acetylchitobiose as the initial substrate to hexa-N-acetyl-chitohexaose and hepta-N-acetylchitoheptaose was also efficiently induced through lysozyme catalysis in the presence of ammonium sulfate at high (30%) concentration. In this case, the addition of ammonium sulfate to the reaction system resulted in a remarkable increase of the hexamer and heptamer productions, which are desirable as biologically active oligosaccharides.
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PMID:Enzymic synthesis of useful chito-oligosaccharides utilizing transglycosylation by chitinolytic enzymes in a buffer containing ammonium sulfate. 222 4

The present study describes biochemical and morphological differences of pseudophakic bullous keratopathy (PBK) corneas as compared with normal corneas. At the ultrastructural level, all PBK corneas studied had abnormal fibrillar material posterior to the Descemet's membrane. In addition, two of the six PBK buttons had subepithelial fibrocellular materials disrupting the epithelial basement membrane and Bowman's layer. Aggregates of collagen fibrils with 110 nm periodicity were occasionally seen within the stroma of the PBK corneas. Isolation and purification of the collagen from the Descemet's membrane/posterior collagenous layer (DM/PCL) showed an increased amount of material with molecular weight in the range of 50-60K daltons (presumably type VIII collagen) and decreased amounts of higher molecular weight, disulfide-bonded collagenous materials (presumably type IV collagen) as compared with normals. Sugar-specific lectin studies showed an increased deposition of peanut agglutinin (PNA) and Ricinus communis agglutinin I (RCA120) in the DM/PCL of the PBK corneas. Our data suggest that the DM/PCL of PBK corneas have an increased accumulation of terminal B-galactose and B-D-galactose (1-3)-D-N-acetylgalactosamine residues and altered ratios of low and high molecular weight collagenous proteins.
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PMID:Abnormal extracellular matrix in corneas with pseudophakic bullous keratopathy. 232 80

The role of antigen concentration on the immunosuppressive effect of adrenocorticotropin (ACTH) was tested in 6-week-old White Rock chickens that were immunized i.v. with 1 ml of heat-treated Salmonella pullorum at packed cell volume concentrations of .06 to .00015%, At 16 and 10 hr before the antigen (Ag) injection, the birds received either 4 IU . 100 g body wt-1 of ACTH i.m., or the gelatin (Gel) vehicle. Total, 2-mercaptoethanol sensitive (2-MES), and 2-mercaptoethanol resistant (2-MER) agglutinin antibody titers were determined. The ACTH significantly suppressed total agglutinin titers with the lower Ag concentrations (.0015 and .00015%) but not with the higher Ag concentrations. The ACTH significantly suppressed 2-MES titers only when Ag concentrations were low but suppressed 2-MER titers regardless of Ag concentration. The results indicated that there may be critical Ag concentrations capable of inducing maximal humoral antibody responses in moderate environments but which allow these responses to be suppressed by environments that stimulate increased pituitary-adrenal activity.
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PMID:Concentration of Salmonella pullorum antigen and the immunosuppressive effect of adrenocorticotropin in growing chickens. 630 89

Concentrations of birch-pollen antigens were measured in 10 homes in southwestern Finland, four in urban and six in rural areas. Dust samples were collected once a week with a vacuum cleaner equipped with a special collection device (ALK, Copenhagen) combined with an exchangeable glass microfiber filter in a filter dish. Control samples were taken from horizontal surfaces outdoors. All samples were analyzed by a modification of the IgG-ELISA procedure. The birch-pollen antigenic activity in indoor settled dust was lower than that in dust outdoors. The mean concentration of antigenic activity indoors peaked 3 weeks later than outdoors. The lag indicates that the most important means whereby antigens are carried indoors is via footwear and clothes, rather than, for instance, ventilation. Antigenic activity was still detected 2 months after the peak pollen period. As a source of antigens, both indoor and outdoor dust may be an important cause of pollen-allergy symptoms after the season.
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PMID:Birch-pollen antigenic activity of settled dust in rural and urban homes. 757 12

IGF-I has been reported to increase hematopoietic progenitor cell cloning efficiency. To investigate this phenomenon, we studied the IGF-I responsiveness of human marrow cells expressing IGF-I receptor (IGF-IR), a direct strategy not used previously. IGF-IR+ and control CD34+ marrow cells were isolated using immunoaffinity methods. Then, the cells were cloned in methylcellulose containing variable amounts of serum- and lineage-appropriate growth factors supplemented with recombinant human IGF-I. In contrast to CD34+ cells, IGF-IR+ cells never gave rise to CFU-Blast, CFU-Mix, CFU-GM, BFU-E, or CFU-E. To substantiate the suggestion that CD34+ and IGF-IR+ cells were distinct populations, we used reverse transcription PCR to detect IGF-I, EpO, and KIT receptor mRNAs in these cells. The mRNA phenotype of CD34+ cells was EpO (+), KIT (+), and IGF-IR (-), while IGF-IR+ cells were IGF-IR (+), EpO (-), and KIT (-). These results suggested that IGF-IR is either not expressed or expressed at low levels on normal hematopoietic progenitor cells. Functional significance of the latter possibility was tested by exposing CD34+ cells to IGF-IR antisense oligodeoxynucleotides. Colony formation was unaffected by oligodeoxynucleotide disruption of IGF-IR, suggesting that, even if expressed at low level, the receptor's functional significance was doubtful. Nevertheless, when cultured in the presence of IGF-I, IGF-IR+ cells elaborated an activity with mild BFU-E stimulatory effects. Accordingly, if IGF-I plays a role in hematopoietic colony formation, it is probably and results from stimulation of IGF-IR-positive ancillary cells to secrete growth factors. Studies carried out with human leukemia cells yielded similar results.
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PMID:A reappraisal of the role of insulin-like growth factor I in the regulation of human hematopoiesis. 804 Feb 73

We assessed the relationship between the exposure to dust mite allergens and a bronchial response to exercise in 8-year-old schoolchildren. Dust was collected from the mattresses of 1,291 children and the concentration of mite allergens was estimated by a commercially available ELISA test using monoclonal antibodies (ALK, Copenhagen) against the major allergens of Dermatophagoides pteronyssinus (Der pt) and Dermatophagoides farinae (Der f). A positive bronchial response to exercise (decrease of peak expiratory flow > or = 15% after exercise) occurred in 21 (22.6%) of 101 children sensitized to mite allergens (wheal size > or = 4 mm) and in 51 (4.8%) of 1,070 nonsensitized children. In the highest exposure groups (> 10 micrograms allergen/g dust), 15% of children sensitized to Der f and 20% of children sensitized to Der pt were responsive to exercise. Corresponding figures for the lowest exposure groups (< 0.4 micrograms allergen/g dust) were 11 and 28%, respectively. This negative finding may indicate that measurement of allergen concentration in mattresses does not reflect true exposure or alternatively that at the age of 8 years high exposure to dust mite allergens does not affect bronchial response to exercise in sensitized children.
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PMID:Relationship between exposure to dust mite allergen and bronchial response to exercise in schoolchildren sensitized to dust mites. 805 30

Results obtained with RapiTest THC (One Step delta 9-Tetrahydrocannabinol Test), RapiTest MOP (One Step Morphine Test), RapiTest MET (One Step Methamphetamine Test), and RapiTest COC (One Step Cocaine Test) were compared with the results obtained with Emit d.a.u. and with gas chromatographic-mass spectrometric (GC-MS) methods. In all, 81 urine samples taken from specimens submitted for routine analysis in the Laboratory of Pharmacology and Toxicology were analyzed. Samples were screened with Emit, reanalyzed by RapiTests, and quantitated using GC-MS methods. Both positive and negative urine samples were tested. The results obtained with RapiTests correlated well with the Emit d.a.u. and GC-MS data when operating above the cutoff concentrations specified for these methods. RapiTest MOP was found to have crossreactivity with codeine and ethylmorphine, and RapiTest MET crossreacted with amphetamine.
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PMID:Comparison of RapiTest with Emit d.a.u. and GC-MS for the analysis of drugs in urine. 901 93

2H NMR spectroscopy and freeze-fracture electron microscopy were used to compare the transmembrane domains of two Class I protein receptor tyrosine kinases (the EGF receptor and Neu/erbB-2) regarding overall behaviour in fluid lipid bilayer membranes. The 34-residue peptide, EGFRtm, was synthesised to contain the 23 amino acid hydrophobic stretch (Ile622 to Met644) thought to span the membrane of the human EGF receptor, plus the first 10 amino acids (Arg645 to Thr654) of the cytoplasmic domain. Deuterium probes replaced selected 1H nuclei at sites corresponding to Ala623, Met644, and Val650. The 38-residue peptide, Neutm, was synthesised having the 21 residue hydrophobic stretch (Ile660 to Ile680) calculated to span the membrane in rat Neu/erbB-2, plus residues Lys681 to Thr691 of the contiguous cytoplasmic domain. Deuterium probes replaced selected 1H nuclei at Ala661, Leu667, and Val676. A third peptide, Neutm*, was also prepared, corresponding to the transmembrane domain of a constitutively-activating Neu/erbB-2 transformant in which Val664 is replaced by Glu: it was deuterated in a manner identical to Neutm. Peptides were studied by 2H NMR spectroscopy at 1 mol% and 6 mol% in unsonicated fluid bilayers of 1-palmitoyl-2-oleoylphosphatidylcholine (POPC) and in POPC containing 33 mol% cholesterol, over the range 12 degrees to 65 degreesC. Overall motion was found to be different for each of the three peptides under a given set of conditions. EGFRtm spectra were characteristic of axially symmetric motion in membranes of POPC alone, and in POPC/cholesterol at 35 degreesC and above. In contrast, spectra of the transmembrane peptides, Neutm and Neutm*, were characteristic of significantly axially asymmetric motion under all conditions studied (and regardless of sample preparation method). Addition of 33% cholesterol to membranes was accompanied by spectral changes consistent with increased formation of peptide dimers/oligomers in all cases. The transformant peptide, Neutm*, showed greater spectral evidence of immobilisation than did the wild type - probably reflecting a greater tendency to form large oligomers. Sequence-related details within the transmembrane domains of Class I receptor tyrosine kinases appear to exert important control over their associations within membranes. Freeze-fracture electron microscopy of the NMR samples demonstrated their liposomal nature. Peptide-related intramembranous particles (IMPs) were present which likely represent oligomers of the transmembrane peptide. IMP size and distribution were similar under a given set of conditions for all three peptides, suggesting that the differences seen by NMR spectroscopy reflect structures smaller than the 2 nm resolution limit of freeze-fracture EM and peptide relationships within its 20 nm accuracy of identifying lateral position.
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PMID:Sequence-related behaviour of transmembrane domains from class I receptor tyrosine kinases. 963 Jun 29

Allergic reactivity to house-dust mites (HDM) can be detected in patients with atopic eczema by prick and patch test challenge. To determine the clinical relevance of this reactivity, we performed a placebo-controlled, double-blind trial of anti-HDM measures. Active treatment comprised Gortex bags for all the bedding elements, a high-powered vacuum cleaner, and a spray containing benzyl alcohol and tannic acid to kill mites and denature allergens. Placebo treatment was light cotton bags, a cheap vacuum cleaner, and water spray. Forty-eight patients (28 active group) completed the trial, which lasted 6 months. Dust was sampled from the mattress surface and bedroom and living-room carpets before and at monthly intervals after institution of the measures. Dust was weighed and Der p 1 determined by ELISA (ALK). Patients were assessed for area and severity of eczema by a blinded observer. There was a highly significant reduction in bed surface dust - most beds yielded insufficient dust to extract and assay. Carpet Der p 1 levels were reduced to similar minimal levels by both active and placebo treatments (about 250 ng/m2). There were highly significant benefits on the eczema scores, the active treatment being greatly superior to placebo (P< or =0.0006; analysis of covariance). In conclusion, Gortex bed bags were highly effective at containing dust within the bed. This was associated with clinical improvement in most patients with atopic eczema - the biggest improvements were seen in the most severely affected subjects.
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PMID:Mite elimination--clinical effect on eczema. 1009 18

Glomerular hypertension and hyperglycemia are major determinants of diabetic nephropathy. We sought to identify the mechanisms whereby stretch-induced activation of mesangial cell extracellular signal-regulated kinase 1 and 2 (ERK1/ERK2) is enhanced in high glucose (HG). Mesangial cells cultured on fibronectin Flex I plates in normal glucose (NG; 5.6 mM) or HG (30 mM), were stretched by 15% elongation at 60 cycles/min for up to 60 min. In HG, a 5-min stretch increased ERK1/ERK2 phosphorylation by 6.4 +/- 0.4/4.3 +/- 0.3-fold (P < 0.05 vs. NG stretch). In contrast, p38 phosphorylation was increased identically by stretch in NG and HG. Unlike many effects of HG, augmentation of ERK activity by HG was not dependent on protein kinase C (PKC) as indicated by downregulation of PKC with 24-h phorbol ester or inhibition with bisindolylmaleimide IV. In both NG and HG, pretreatment with arginine-glycine-aspartic acid peptide (0.5 mg/ml) to inhibit integrin binding or with cytochalasin D (100 ng/ml) to disassemble filamentous (F) actin, significantly reduced phosphorylation of ERK1/ERK2 and p38. To determine whether the rate of mitogen-activated protein kinase dephosphorylation is affected by HG, cellular kinase activity was inhibited by depleting ATP. Post-ATP depletion, phosphorylation of ERK1/ERK2 was reduced to 36 +/- 9/51 +/- 14% vs. 9 +/- 5/7 +/- 6% in NG (P < 0.05, n = 5). Thus stretch-induced ERK1/ERK2 and p38 activation in both NG and HG is beta(1)-integrin and F-actin dependent. Stretch-induced ERK1/ERK2 is enhanced in high glucose by diminished dephosphorylation, suggesting reduced phosphatase activity in the diabetic milieu. Enhanced mesangial cell ERK1/ERK2 signaling in response to the combined effects of mechanical stretch and HG may contribute to the pathogenesis of diabetic nephropathy.
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PMID:Stretch-induced mesangial cell ERK1/ERK2 activation is enhanced in high glucose by decreased dephosphorylation. 1099 19


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