Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0848332 (Spots)
 453 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The resolution of (+/-)-atenolol, (+/-)-propranolol and (+/-)-metoprolol into their enantiomers was achieved by TLC on silica-gel plates impregnated with optically pure L-lysine (0.5%) and L-arginine (0.5%) as the chiral selectors. In all cases, different combinations of acetonitrile-methanol solvent systems were found to be successful in resolving these compounds. Spots were detected using iodine vapour. The detection limit for both (+/-)-atenolol and (+/-)-propranolol was 2.6 microg and for (+/-)-metoprolol, it was 0.26 microg.
 ...
PMID:Direct enantioseparation of some beta-adrenergic blocking agents using impregnated thin-layer chromatography. 965 83

The therapy of advanced cancer using chemotherapy alone or in combination with radiation or hyperthermia yields an overall response rate of about 20-50%. This success is often marred by the development of resistance to cytostatic drugs. Our aim was to study the global analysis of protein expression in the development of chemoresistance in vitro. We therefore used a cell culture model derived from the gastric carcinoma cell line EPG 85-257P. A classical multidrug-resistant subline EPG85-257RDB selected to daunorubicin and an atypical multidrug-resistant cell variant EPG85-257RNOV selected to mitoxantrone, were analysed using two-dimensional electrophoresis in immobilized pH-gradients (pH 4.0-8.0) in the first dimension and linear polyacrylamide gels (12%) in the second dimension. After staining with coomassie brilliant blue, image analysis was performed using the PDQuest system. Spots of interest were isolated using preparative two-dimensional electrophoresis and subjected to microsequencing. A total of 241 spots from the EPG85-257RDB-standard and 289 spots from the EPG85-257RNOV-standard could be matched to the EPG85-257P-standard. Microsequencing after enzymatic hydrolysis in gel, mass spectrometric data and sequencing of the peptides after their fractionation using microbore HPLC identified that two proteins annexin I and thioredoxin were overexpressed in chemoresistant cell lines. Annexin I was present in both the classical and the atypical multidrug-resistant cells. Thioredoxin was found to be overexpressed only in the atypical multidrug-resistant cell line.
 ...
PMID:Increased expression of annexin I and thioredoxin detected by two-dimensional gel electrophoresis of drug resistant human stomach cancer cells. 987 Jan 85

Surveys during the rainy season of 1996 showed that Septoria lycopersici developed two different types of leaf spots on tomatoes grown in kitchen gardens at the University of Zambia Campus and in nearby gardens. The two types of spots could be easily distinguished on the basis of their external morphology. One type, designated as T1, began as dark brown spots of less than 1 mm diameter. Upon increase in size, the spots differentiated into a dark brown outer ring and a grey centre, reaching a maximum diameter of 5 mm. Spots of this type are common and have been described in reports on Septoria leaf spot disease. A second type of spot found in our survey was designated as T2. This Septoria spot was greyish brown with several concentric rings of shrunken leaf tissue. The type T2 spots were larger and did not differentiate into two parts as in T1. The T2 spot diameter was 4-12 mm. The conidia showed differences in curvature, and significantly length, between T1 and T2. The study has shown that S. lycopersici in Zambia is variable.
 ...
PMID:Rare symptoms and conidial variation in Septoria lycopersici in Zambia. 992 22

Salicylic acid (SA), produced by plants as a signal in defense against pathogens, induces metabolic heating mediated by alternative respiration in flowers of thermogenic plants, and, when exogenously applied, increases leaf temperature in nonthermogenic plants. We have postulated that the latter phenomenon would be detectable when SA is synthesized locally in plant leaves. Here, resistance to tobacco mosaic virus (TMV) was monitored thermographically before any disease symptoms became visible on tobacco leaves. Spots of elevated temperature that were confined to the place of infection increased in intensity from 8 h before the onset of visible cell death, and remained detectable as a halo around the ongoing necrosis. Salicylic acid accumulates during the prenecrotic phase in TMV-infected tobacco and is known to induce stomatal closure in certain species. We show that the time course of SA accumulation correlates with the evolution of both localized thermal effect and stomatal closure. Since the contribution of leaf respiration is marginal, we concluded that the thermal effect results predominantly from localized, SA-induced stomatal closure. The presymptomatic temperature increase could be of general significance in incompatible plant-pathogen interactions.
 ...
PMID:Presymptomatic visualization of plant-virus interactions by thermography. 1042 50

Macular edema is a common feature of posterior segment diseases. It is an expression of abnormal permeability in either retinal vessels (inner blood-retinal barrier) or in the retinal pigment epithelium (outer blood-retinal barrier). It occurs in either a diffuse pattern where the macula appears generally thickened or, in more severe cases, as cystoid edema with the typical petaloid appearance. Grid laser treatment may be useful to reduce macular edema. Spots of 100-250 micrometers in diameter are applied to the whole posterior pole, one to two groups apart. The foveal avascular zone remains untouched. In patients treated bilaterally, areas temporal and nasal to the macula must be spared to prevent the development of deep scotomas. The mechanism yielding positive results with the grid technique is still debated. Among the most reliable hypotheses are: Proliferation of pigment epithelial cells, followed by and improved efficiency of the outer blood-retinal barrier; proliferation of endothelial cells in retinal capillaries followed by an improved efficiency of the inner blood-retinal barrier; improvement of the retinochoroidal exchanges, and finally, release by coagulative necrosis of a factor able to improve the efficiency of the blood-retinal barriers. Lasers with long wavelengths, such as krypton red and diode, are the most appropriate ones to perform grid treatment.
 ...
PMID:When and how to do a grid laser for diabetic macular edema. 1089 58

We report a novel method to identify protein kinase C (PKC) substrates. Tissue lysates were fractionated by ion exchange chromatography and used as substrates in in vitro kinase reactions. The phosphorylated proteins were separated using two-dimensional gel electrophoresis. Spots that contained isolated phosphoproteins were excised and digested with trypsin. The tryptic peptides were analyzed using mass spectrometry. While several of the proteins identified using this technique represent known PKC substrates, we identified a new PKC substrate in the initial screen. This protein, sm22, is expressed in smooth muscle cells and served well as a substrate for PKC in vitro. Sm22 is predominantly associated with the actin cytoskeleton. Upon activation of PKC in vivo, sm22 dissociates from the actin cytoskeleton and is distributed diffusely in the cytoplasm. Our data strongly suggest that phosphorylation by PKC controls the intracellular localization of sm22. This demonstrates that our approach, using a complex mixture of proteins as in vitro kinase substrates and subsequently identifying the newly phosphorylated proteins by mass spectrometry, is a powerful method to identify new kinase substrates.
 ...
PMID:Identification of the smooth muscle-specific protein, sm22, as a novel protein kinase C substrate using two-dimensional gel electrophoresis and mass spectrometry. 1093 58

We describe the identification and initial characterization of neurobeachin, a neuron-specific multidomain protein of 327 kDa with a high-affinity binding site (K(d), 10 nm) for the type II regulatory subunit of protein kinase A (PKA RII). Neurobeachin is peripherally associated with pleomorphic tubulovesicular endomembranes near the trans sides of Golgi stacks and throughout the cell body and cell processes. It is also found in a subpopulation of synapses, where it is concentrated at the postsynaptic plasma membrane. In live cells, perinuclear neurobeachin is dispersed by brefeldin A (BFA) within 1 min, and in permeabilized cells a recruitment of neurobeachin from cytosol to Golgi-near membranes is stimulated by GTPgammaS and prevented by brefeldin A. Spots of neurobeachin recruitment are close to but distinct from recruitment sites of COP-I, AP-1, and AP-3 coat proteins involved in vesicle budding. These observations indicate that neurobeachin binding to membranes close to the trans-Golgi requires an ADP-ribosylation factor-like GTPase, possibly in association with a novel type of protein coat. A neurobeachin isoform that does not bind RII, beige-like protein (BGL), is expressed in many tissues. Neurobeachin, BGL, and approximately 10 other mammalian gene products share a characteristic C-terminal BEACH-WD40 sequence module, which is also present in gene products of invertebrates, plants, protozoans, and yeasts, thus defining a new protein family. The prototype member of this family of BEACH domain proteins, lysosomal trafficking regulator (LYST), is deficient in genetic defects of protein sorting in lysosome biogenesis (the beige mouse and Chediak-Higashi syndrome). Neurobeachin's subcellular localization, its coat protein-like membrane recruitment, and its sequence similarity to LYST suggest an involvement in neuronal post-Golgi membrane traffic, one of its functions being to recruit protein kinase A to the membranes with which it associates.
 ...
PMID:Neurobeachin: A protein kinase A-anchoring, beige/Chediak-higashi protein homolog implicated in neuronal membrane traffic. 1110 58

Beach pea (Lathyrus maritimus L.) cotyledons and hulls were air-classified into different fractions. The crude protein content (%N x 6.25) of samples ranged from 32.8 to 35.3% in cotyledons and 14.7 to 16.8% in hulls. Crude fiber content was higher in hulls fraction 1 (37.13%) and fraction 2 (36.85%) than in cotyledons (2.83, 2.99, and 3.08% in fractions 1, 2, and 3, respectively). Condensed tannins of cotyledons ranged from 5.76 to 6.90% and of hulls ranged from 52.49 to 57.24%, expressed as catechin equivalents. Minerals, namely P, K, and Zn, were higher in cotyledons, but Ca and Mn were more prevalent in hulls. Nonprotein nitrogen was concentrated in hulls, whereas phytic acid was more abundant in the cotyledons. The UV absorption pattern showed that flavonoids were present in fractions (I-III) from hulls separated on Sephadex LH-20. Fraction III from hulls had the highest content of total phenolics and condensed tannins, but no condensed tannins were detected in fractions I and II from hulls. The antioxidant activity of fractions separated on Sephadex LH-20 from hulls and crude extracts in a beta-carotene-linoleate model system was in the order of fraction III > crude extract > fraction II > fraction I. Spots on silica gel TLC plates, sprayed with a solution of beta-carotene and linoleic acid, indicated that many of the individual compounds were antioxidative in nature. Further, separation of fraction III from hulls on a semipreparative HPLC showed the presence of (+) catechin and (-) epicatechin as the main low-molecular-weight phenolic compounds present.
 ...
PMID:Nutrient distribution and phenolic antioxidants in air-classified fractions of beach pea (Lathyrus maritimus L.). 1126 51

Obstruction of the male reproductive tract commonly results in generation of antisperm autoantibodies. However, only a few of the sperm autoantigens recognized by these antibodies have been characterized. To identify postobstruction rat sperm autoantigens, sperm proteins were separated by two-dimensional(2-D) gel electrophoresis. Spots corresponding to proteins that were stained by at least 50% of postvasectomy rat sera on 2-D Western blots were removed from polyacrylamide gels and microsequenced by tandem mass spectrometry. From a total of 21 spots, 12 contained peptides that matched solely to either of two outer dense fiber proteins, odf1 or odf2. Six additional spots contained peptides comprising odf1 or odf2 and were accompanied by peptides representing other proteins. Only three spots lacked outer dense fiber peptides but did contain sequences of other known proteins. The results indicate that the outer dense fiber proteins odf1 and odf2 are dominant postobstruction autoantigens because they were detected in the majority of the immunoreactive protein spots examined. Possible explanations for this observation include the abundance of outer dense fiber proteins in spermatozoa, slow solubility, which may provide a sustained supply of antigen, and testis-specific expression during spermiogenesis.
 ...
PMID:Outer dense fiber proteins are dominant postobstruction autoantigens in adult Lewis rats. 1131 51

Identification of proteins binding specifically to peculiar nucleic acid structures can lead to comprehension of their role in vivo and contribute to the discovery of structure-related gene regulation. This work was devoted to establishing a reliable procedure to select proteins on the basis of their interaction with a nucleic acid probe chosen to fold into a given structure. 2D-electrophoresis and mass spectrometry were combined for protein identification. We applied this procedure to select and identify triplex-binding activities in HeLa nuclear extracts. To achieve this, we used a panel of deoxyribonucleic probes adopting intramolecular triple-helices, varying in their primary sequence, structure or triple-helix motif. A limited number of spots was reproducibly revealed by South-western blotting. Spots of interest were localised among a complex population of (35)S-labelled proteins according to their (32)P-specific emission. Position of the same spots was extrapolated on a preparative gel coloured with Coomassie blue, allowing excision and purification of the corresponding proteins. The material was subjected to mass spectrometry upon trypsin digestion and MALDI-TOF peptide fingerprinting was used for research in databases: five of them were identified and found to belong to the hnRNP family (K, L, A2/B1, E1 and I). The identities of several of them were confirmed by comparing western and South-western blots on the same membrane using specific antibodies. The recognition specificity of most of these proteins is large, according to previous reports and our own experiments. It includes pyrimidine-rich DNA sequences in different contexts: single strand to a small extent, triplex and possibly other higher-order structures.
 ...
PMID:Selection and identification of proteins bound to DNA triple-helical structures by combination of 2D-electrophoresis and MALDI-TOF mass spectrometry. 1137 62


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>