Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: T20B12 .5
956,342 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The authors studied the effect of propoxysilatran (POS) on the biosynthesis of the main connective tissue biopolymeres. The use of POS in the form of 0.5 and 2.0% ointments on lanolin-vaseline base caused stimulation of cellular proliferation in the granulation fibrous tissue developing in the open skin defects of albino rats. Stimulation of cellular proliferation in these animals was accompanied by increase of collagen biosynthesis and of noncollagen proteins. In concentrations of 10(-3)--10(-4) M POS caused intensification of collagen biosynthesis (formation of peptide-bound nondialyzed 14C-oxyproline) in vitro in the cartilage tissue of chick embryos. Thus, silatrans are biologically-active substances producing a regulating effect on the course of the reparative-proliferative processes in the connective tissue.
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PMID:[Effect of silicoorganic compounds on protein biosynthesis in granulation-fibrous tissue]. 42 Sep 36

Total protein, collagen (hydroxyproline) and glycoproteins (hexosamine) content of control and myelofibrosis (MF) bone marrow samples was determined using a sequential extraction procedure. MF marrow extracts contained higher amounts of collagen than control extracts. The collagen content appeared to increase with the duration of the disease. In more recent MF cases (less than 2 years) at least 60% of the total collagen was extracted in 0.5 M NaCl. this proportion decreases to 33% in older cases (greater than 4 years), indicating a progressive insolubilization (crosslinking) of collagen. The hexosamine content of the extracts decreased in MF as compared to controls reflecting a decrease in glycosaminoglycans (and possibly of structural glycoproteins). The reticulin content of the same bone marrows was estimated by a quantitative morphometric procedure. There was a positive correlation between the morphometrically estimated reticulin surface and the total hydroxyproline content of the marrow samples. The slopes of the least square lines correlating increase of reticulin surface to hydroxyproline content were, however, significantly different in control and MF marrows, indicating a 44% higher increase in histochemically detectable reticulin per unit increase in hydroxyproline content than in the control marrows. This result may indicate a more efficient fibrogenetic process in MF marrow than in normal bone marrow. The above results confirm the collagenous nature of the fibrous reticulin like material deposited in MR marrows and suggests a correlation between the progression of the disease and the rate of synthesis and deposition of collagen fibres.
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PMID:Biochemical and histological analysis of bone marrow collagen in myelofibrosis. 42 28

Clinical impression suggests that Adriamycin (ADR) interferes with wound healing. To examine the effects of ADR on wound healing, male Fischer rats were subjected to a dorsal, midline, full-thickness longitudinal incision (day 0). Wound clips were removed on day +7. Twenty animals per group were given intravenous ADR on day -7, day 0, day +3 and day +7. Twenty animals served as non-treated, wounded controls (C). Five animals/group were sacrificed on days +7, +14 and +21, at which time two 9.5 mm wide strips were taken from each animal perpendicular to the wound axis and submitted for wound breaking strength (WBS) measurements and load-extension curve analysis. WBS differed most markedly at Day 21 between C(1671 +/- 59g) and ADR day -7(1360 + 71 g) p less than 0.01; C and ADR day 0 (1051 +/- 108 g) p less than 0.001; C and ADR day + 3(1134 +/- 176 g) p less than 0.02. No difference existed between C and day +7 (1790 +/- 153 g). A point of inflection always occurred between 55-60% elongation in ADR treated animals only. This portion of the curve has been previously shown to represent collagen content. It is concluded that perioperative ADR administration (day -7 through day +3) significantly and substantially impairs skin wound healing in the rat. A form of collagen yielding underlies and may contribute to this defect.
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PMID:The quantitative and qualitative impairment of wound healing by adriamycin. 42 32

Platelets eluted from nylon fiber filters after filtration leukapheresis have been studied. The platelet yield from 61 routine donations was 1.25 +/- 0.18 x 10(11), (mean +/- SEM) corresponding to 1.78 x 10(10) per 500 ml blood processed. Filtered platelets labeled with radiochromate demonstrated reduced recovery in vivo 15 minutes after infusion (38.5 +/- 1.7%) when compared to the control value (68.5 +/- 6.8, p less than 0.001). The survival of those platelets remaining in the circulation after 15 minutes did not however differ from the control value. ADP (10 micrometer, 1 mM), adrenaline (100 micrometer) and collagen (7.25 mg/ml) added in vitro induced less aggregation of filtered platelets than normal control platelets and electron microscopy revealed structural abnormalities. It is concluded that recipients of granulocyte transfusions obtained by filtration leukapheresis are unlikely to be benefited by the platelets contained in these transfusions.
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PMID:Studies on platelets contained in eluates following filtration leukapheresis. 43 22

The diameter of collagen fibrils was studied in a patient with porphyria cutanea tarda in a specimen obtained from the sclerodermatous skin of the back. A bimodal distribution of the diameter of the fibrils was observed with maxima at 33.5 nm and 68.7 nm. The mean diameter was 67 nm with a standard deviation of 10.6 nm. These results are similar to those obtained previously in localized scleroderma (morphoea).
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PMID:Diameter of the collagen fibrils in the sclerodermatous skin of porphyria cutanea tarda. 44 30

Nickel sub-sulphide-induced leiomyosarcomas in rabbit white skeletal muscle were studied by both light and electron microscopy. Two types of tumor cells, small spindle cells and elongated smooth muscle cells, are revealed by light microscopy. Nevertheless, their ultrastructure displays the same general feature. The most differentiated cells have abundant cytoplasmic filaments 7 nm in diameter, kept together in bundles by dense bodies. There also exist many 10 nm filaments and a large number of microtubules. The nuclei have prominent nucleoli with an extensive nucleolonema which form an irregular tridimensional network. Distinct fibrillar nuclear bodies were observed. Sometimes there exist desmosomes or gap junctions. The Golgi apparatus produces coated vesicles with secretory function. In the tumors were generally found the Ni3S2 implantations surrounded by a capsule, the major component of which were collagen fibers, degenerated nuclei and rod-like structures with a transverse periodicity of 15.5 nm. From these observations, several characteristics should be pointed out: 1) Many tumor cells contain large nucleoli and distinct intranuclear inclusions of undetermined nature. 2) The coated vesicles represent a secretory activity of the tumor cells; the coat material is probably used during the formation of cell membranes. Another possible function of coated vesicles could be the sequestering of calcium ions. 3) The rod-like structures in the Ni3S2-including capsule are not of Z-line material. 4) The tumoral stem myoblast in heart and skeletal muscle arise from mesenchymal cells.
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PMID:Nickel sub-sulphide-induced leiomyosarcoma in rabbit white skeletal muscle: a light microscopical and ultrastructural study. 44 36

Because human platelets participate in the contact phase of intrinsic coagulation and contain a Factor XI-like coagulant activity, the nature of the Factor XI-like activity was examined and compared with purified plasma Factor XI. The platelet factor XI-like activity was sedimented with the particulate fraction of a platelet lysate, was inactivated by heat (t(1/2) 3.5 min, 56 degrees C), was not a nonspecific phospholipid activity, and was destroyed by treatment with Triton X-100. Isolated platelet membranes were four-fold enriched in Factor XI activity and similarly enriched in plasma membrane marker enzymes. The Factor XI-like activity of platelet membranes was detected only when assayed in the presence of kaolin, which suggests that it is present in an unactivated form and can participate in contact activation. Concanavalin A inhibited the Factor XI-like activity of platelet lysates and platelet membranes but not of plasma or purified Factor XI. A platelet membrane-Factor XI complex was isolated after incubation of membranes with purified Factor XI. The Factor XI activity of the platelet membrane-plasma Factor XI complex was inhibited by concanavalin A, whereas unbound plasma Factor XI retained activity. An antibody raised against plasma Factor XI inhibited the in vitro Factor XI activity of plasma and of the platelet membrane-plasma Factor XI complex but had no effect on the endogenous Factor XI-like activity of washed lysed platelets or isolated platelet membranes. Washed platelets and isolated platelet membranes obtained from a Factor XI-deficient donor without a history of excessive bleeding had normal quantities of platelet Factor XI-like activity and normal behavior in the contact phase of coagulation (collagen-induced coagulant activity). These results indicate that platelet membranes contain an endogenous Factor XI-like activity that is functionally distinct from plasma Factor XI.
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PMID:Human platelets and factor XI. Localization in platelet membranes of factor XI-like activity and its functional distinction from plasma factor XI. 44 22

Soluble 125I-labeled type I collagen binds to cultured fibroblasts but not to cultured epithelia. The binding of the ligand to fibroblasts is reversible, saturable and highly specific for sequences contained within the helical portions of the alpha1 and alpha2 chains. The amount of ligand bound is dependent upon cell number and ligand concentration. Binding is decreased but measurable at 4 degrees C. The steady state binding is greater at 26 degrees than at 37 degrees C due to a more rapid dissociation of the ligand-acceptor complex at 37 degrees C. The half-life of the complex is 46 min at 37 degrees C and approximately 2.5 hr at 26 degrees C. Scatchard plots of binding data indicate a single class of high affinity binding sites (KD = 1.2 X 10(-11) M) with each fibroblast binding approximately 500,000 molecules at saturation. Pretreatment of fibroblasts with bacterial collagenase, chondroitinase ABC or testicular hyaluronidase does not affect the binding reaction, whereas pretreatment of the cells with phospholipase C increases the amount of ligand bound. Ligand binding is decreased but not abolished after fibroblasts are treated with trypsin concentrations which remove surface fibronectin. Fibroblast monolayers treated with antiserum against fibronectin bind the radiolabeled ligand normally. In contrast to collagen, addition of excess fibronectin does not accelerate the dissociation of bound ligand from fibroblasts. Possible functions for surface-bound collagen are discussed.
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PMID:Binding of soluble type I collagen molecules to the fibroblast plasma membrane. 45 36

Fresh frozen, unfixed, chloroforme-acetone treated or freeze-dried cryostat sections or sections from aldehyde-fixed blocks of tissue were tried for the histochemical investigation of dipeptidylpeptidase IV (DPP IV) with L-glycyl-L-prolyl(gly-pro)-naphthylamides as substrates and stable or unstable diazonium salts for simultaneous coupling and various buffers, pH 5--7.5 in rats, mice, guinea-pigs, cats, rabbits, hamsters and human enterobiopsies. The best results are obtained with 1.7--3.4 mM gly-pro-4-methoxy-2-naphthylamide and 1 mg Fast Blue B/ml or (with some limitations) 0.025 ml hexazotized new fuchsine/ml in 0.1 M cacodylate or phosphate buffer, pH 7.5 and unfixed sections for the demonstration of the total activity of DPP IV and freeze-dried celloidin-mounted cryostat sections for the precise localization of the enzyme or the detection of lysosomes, Golgi apparatus and secretion granules sections from aldehyde fixed tissue blocks are only suitable to study the lysosomal hydrolysis of gly-pro-naphthylamides between pH 5 and 7 when hexazotized p-rosaniline or new fuchsine are employed. DPP IV is firmly bound to strutures and shows species- and organ-dependent differences. In general, the enzyme occurs in the capillary endothelium, sinusoidal cells, perineurium, epithelial cells of intercalated and striated ducts, microvillous zone of intestinal crypts and villi, uterus, Fallopian tubes, ductus epididymis and proximal renal tubules, hepatocyte and lymphocyte membrane, plasmalemma of pseudostratified and transient epithelia and in the capsules and interstitium of many organs. These sites of activity can be completely inhibited by diisopropyl fluorophosphate and partially by Pb2+; Mg2+, Mn2+, Co2+ EDTA are without any influence. Phenantrolin may activate DPP IV. The biochemical assay works with 10 mM gly-pro-2-naphthylamide in 0.1 M cacodylate buffer, pH 7; the enzyme activity is determined fluorometrically in guinea-pig and rat organs; the data confirm and enlarge the species- and organ-dependent differences revealed by histochemistry. Compared with other dipeptide as well as tripeptide and amino acid naphthylamides the results obtained for DPP IV suggest a peptidylpeptidase which seems to be involved in other metabolic processes beside the degradation of collagen.
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PMID:[Peptidases II. Localization of dipeptidylpeptidase IV (DPP IV). Histochemical and biochemical study]. 45 48

The main objective of this study was to produce primary acute ischemic injury to myocardium in a live animal. In vitro, guinea pig platelets were sensitive to perturbation and aggregation by a suspension of ultrafine fibrillary collagen material isolated from the aorta of an aged burro (Equus asinus). The platelets responded to the stimulatory action of this material down to 100 to 200 ng (dry weight) added to 0.45 ml of platelet-rich plasma, as determined by aggregometric technique. Aortic fibrillary collagen material injected IV into guinea pigs (350 to 1900 microgram protein/kg of weight) produced a transitory disappearance of virtually all circulating platelets within 5 minutes. In animals in which blood samples were taken 2.5 hours after injection, 50 to 75% of the average base-line platelets in the circulation of controls returned to the circulation. In other experiments, 3 anesthetized animals were injected by jugular vein with an amount of active fibrillary collagen material (300 microgram as protein/kg of animal weight) estimated to produce reversible platelet aggregation in vivo. Two control animals were injected with the same dose of the material that had been inactivated (15 minutes at 100 C) to abolish platelet aggregation. Treated and control animals were maintained under general anesthesia for 2.5 hours. Intraventricular pressures and electrocardiographs (ECG) were monitored continuously for the first 30 minutes. The injection of the active fibrillary collagen material caused a large ventricular pressure elevation (170/10, 180/10, and 150/10 mm of Hg) in approximately 40 s. Preinfusion ventricular pressures in the 3 animals were 65/0, 85/5, and 88/0 mm of Hg, respectively. Within 60 s, there was a reduction in the absolute platelet number in the peripheral circulation. The elevation of ventricular pressure persisted for approximately 5 minutes and was followed within 30 minutes by a set of ECG events suggestive of acute myocardial ischemic injury, which included premature ventricular contractions, transient S-T segment depression concurrent with ventricular hypertension, and S-T segment elevation with reversed tall upright T-waves in association with a decrease to the preinfusion ventricular base line. Other ECG changes included prolongation of the P-R segment, missed ventricular contractions, and arrhythmia. The ECG changes seemed to be subsequent to platelet microthrombus formation in the pulmonary arterial microcirculation. By 2.5 hours after the treatment, platelets "rebounded" into the circulation in 2 surviving guinea pigs, and left ventricular pressures and ECG profiles returned to the preinfusion base lines. Guinea pigs IV infused with similar amounts of inactivated (15 minutes at 100 C) fibrillary collagen material did not show changes.
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PMID:A proposed mechanism(s) of transitory ischemic injury to myocardium. 46 53


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