Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0009443 (cold)
 92,137 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of surface roughness on osteoblast proliferation, differentiation, and protein synthesis was examined. Human osteoblast-like cells (MG63) were cultured on titanium (Ti) disks that had been prepared by one of five different treatment regimens. All disks were pretreated with hydrofluroic acid-nitric acid and washed (PT). PT disks were also: washed, and then electropolished (EP); fine sandblasted, etched with HCl and H2SO4, and washed (FA); coarse sandblasted, etched with HCl and H2SO4, and washed (CA); or Ti plasma-sprayed (TPS). Standard tissue culture plastic was used as a control. Surface topography and profile were evaluated by brightfield and darkfield microscopy, cold field emission scanning electron microscopy, and laser confocal microscopy, while chemical composition was mapped using energy dispersion X-ray analysis and elemental distribution determined using Auger electron spectroscopy. The effect of surface roughness on the cells was evaluated by measuring cell number, [3H]thymidine incorporation into DNA, alkaline phosphatase specific activity, [3H]uridine incorporation into RNA, [3H]proline incorporation into collagenase digestible protein (CDP) and noncollagenase-digestible protein (NCP), and [35S]sulfate incorporation into proteoglycan. Based on surface analysis, the five different Ti surfaces were ranked in order of smoothest to roughest: EP, PT, FA, CA, and TPS. A TiO2 layer was found on all surfaces that ranged in thickness from 100 A in the smoothest group to 300 A in the roughest. When compared to confluent cultures of cells on plastic, the number of cells was reduced on the TPS surfaces and increased on the EP surfaces, while the number of cells on the other surfaces was equivalent to plastic. [3H]Thymidine incorporation was inversely related to surface roughness. Alkaline phosphatase specific activity in isolated cells was found to decrease with increasing surface roughness, except for those cells cultured on CA. In contrast, enzyme activity in the cell layer was only decreased in cultures grown on FA- and TPS-treated surfaces. A direct correlation between surface roughness and RNA and CDP production was found. Surface roughness had no apparent effect on NCP production. Proteoglycan synthesis by the cells was inhibited on all the surfaces studied, with the largest inhibition observed in the CA and EP groups. These results demonstrate that surface roughness alters osteoblast proliferation, differentiation, and matrix production in vitro. The results also suggest that implant surface roughness may play a role in determining phenotypic expression of cells in vivo.
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PMID:Effect of titanium surface roughness on proliferation, differentiation, and protein synthesis of human osteoblast-like cells (MG63). 754 45

Intestinal ischemia/reperfusion injury (I/R) results from reactive oxygen metabolites generated by the xanthine oxidase system and activated neutrophils (PMN). In animal models, removing PMN from initial reperfusate has consistently decreased tissue injury. This experiment was designed to test this potential clinical treatment in human bowel subjected to I/R. The extent of reperfusion injury was assessed by measuring the activity of mucosal alkaline phosphatase (A phi), which is a specific marker of reperfusion injury. Human small intestine (n = 13) obtained at the time of organ harvest for transplantation was perfused for 60 min on an ex vivo perfusion circuit. Reperfusate consisted of autologous blood passed through a leukocyte filter (n = 6) or unfiltered blood (n = 7). Control intestine was sampled at harvest, after transport to the lab on ice (cold ischemia), and after 60 min warm ischemia. Mucosa was homogenized and assayed for A phi activity by cleavage of p-nitrophenyl phosphate. A phi activity (nmole/mg/min) was not decreased after either cold (774 +/- 37) or warm (753 +/- 40) ischemia compared to freshly harvested bowel (770 +/- 51). Both reperfused segments showed a significant decrease in A phi activity compared to controls (P < 0.05); however, reperfusion with leukocyte-filtered blood attenuated the decrease in enzyme activity compared to unfiltered blood (327 +/- 30 vs 506 +/- 25, P < 0.05), constituting an apparent reduction in injury of 35%. The observation that the severity of reperfusion injury was decreased by removal of PMN from the reperfusate demonstrates the efficacy of this strategy in human intestine for the first time.
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PMID:Neutrophil depletion attenuates human intestinal reperfusion injury. 804 Nov 37

Mild to moderate protein energy malnutrition (PEM) was induced in young developing rhesus monkeys by giving them half of the casein-based synthetic diet which was given to control animals. After a body weight reduction of 30-40%, the PEM animals were sacrificed. The small intestine was removed, flushed with ice-cold saline, everted and divided into equal proximal, middle and distal segments. Brush border membrane vesicles (BBMV) were prepared from all three segments and assayed for marker enzymes, e.g. sucrase and alkaline phosphatase, to assess their purity. Sucrase was found to be purified 23-fold and alkaline phosphatase 12-fold compared to the respective homogenates in all three parts. In PEM animals, uptake of [U-14C]L-leucine into the BBMV was diminished in all three segments and cholesterol and phospholipid levels also decreased significantly. As a result there was an elevation in the molar ratio of cholesterol to phospholipid, and the sphingomyelin: phosphatidylcholine molar ratio also increased. This signified a decrease in lipid fluidity and amino acid uptake in PEM in the small intestine. Histologically, a mild to moderate grade of partial villus atrophy was observed in the intestine. The diminished uptake and lipid fluidity of the membrane and the histological changes returned to their control values after nutritional rehabilitation.
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PMID:Effect of protein energy malnutrition on the lipid composition and leucine uptake of small intestinal brush border vesicles of growing rhesus monkeys. 806 90

Tau protein was evaluated as a substrate for a proline-directed protein kinase (p34cdc2/p58cyclin A) which recognizes the phosphorylation site motif X-Ser/Thr-Pro-X. The shortest human tau isoform, expressed as a recombinant protein, was phosphorylated to a stoichiometry of 2 mol phosphate/mol tau. Phosphoamino acid analysis revealed phosphorylation of both serine and threonine residues. Phosphorylation of recombinant tau resulted in a decreased ability to induce microtubule assembly but had no effect on the final extent of microtubule formation or on the rate of cold-induced microtubule disassembly. Phosphorylation of tau by the proline-directed protein kinase completely blocked immunoreactivity with antibody SMI33. Phosphorylation did not create the epitopes for the phosphate-dependent antibodies SMI31 or SMI34. Antibody SMI33 recognizes neurofibrillary tangles after treatment with alkaline phosphatase, suggesting that the proline-directed protein kinase may phosphorylate tau at sites that are phosphorylated in Alzheimer's disease.
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PMID:Phosphorylation of tau by proline-directed protein kinase (p34cdc2/p58cyclin A) decreases tau-induced microtubule assembly and antibody SMI33 reactivity. 833 17

Urinary tract infection occurs more commonly, is more virulent and proves more difficult to eradicate in spinal cord injury persons than in the neurologically intact. In order to find out the peculiarities of the neuropathic bladder which make it vulnerable to recurrent cystitis, we studied the proliferation status of the urothelium in spinal cord injured persons. Eleven consecutive, unselected male spinal cord injury patients (aged 18-73 years) were included in the study. Those with, or undergoing treatment for acute urinary tract infection were excluded. All patients underwent cystoscopy and cold cup bladder biopsy from the trigone and bladder dome. Immunocytochemical analysis was performed using defined, commercially available antibodies for PCNA (PCNA 10, DAKO) and MIB-1 (raised against recombinant DNA defined segment of Ki-67 antigen DAKO) streptavidin/biotin and alkaline phosphatase immunocytochemistry (for MIB-1 with microwave-enhanced antigen retrieval) were used to demonstrate the presence of cell cycling-associated nuclear proteins. Foci of lymphocytic aggregations present in the sections served as in-section controls for antigen preservation. Ten patients showed labelling of 20-70% of cells for PCNA in basal cell layers of dome lining. Higher urothelial layers showed a variable, but generally reduced degree of labelling. Of these 10 patients, three showed complete absence of MIB-1 activity in the basal and other layers of dome urothelium and two demonstrated only a very occasional positive nucleus. MIB-1 labelling was < 5% in four others and it was between 5% and 10% in one.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Vesical urothelium proliferation in spinal cord injured persons: an immunohistochemical study of PCNA and MIB.1 labelling. 852 5

The activity of olpadronate labelled with technetium-99m(99mTc) was monitored in plasma and urine samples after single oral (925 MBq 99mTc/10 mg, coadministered with 50 mg cold drug) and intravenous (925 MBq 99mTc/5 mg) administrations to two groups of patients with different rates of bone turnover. The first group comprised high bone turnover (HBTO) patients suffering from Paget's bone disease; the second group comprised patients with normal to low bone turnover (NBTO) having the diagnosis of rheumatoid arthritis and secondary osteoporosis. Kinetic variables were correlated with anthropomorphometric variables, biological markers of bone metabolism and plasma proteins. Data were also obtained after repeatedly dosing the HBTO patients. Additionally, Paget's bone and healthy bone (PB/HB) uptake before and after low-dose oral treatment were assessed by means of scintigraphy. Results showed that most of the kinetic variables did not differ between the two groups of patients, except for a greater Vss and smaller blood area under the curve AUC in the patients with HBTO. After a repeated-dose administration period, the blood AUC activity and Whole Body Retention (WBR) of the HBTO patients tended to be similar to those of the NBTO patients. In both groups, after oral dosing, the Cmax was 20 times lower than the C0.5 after i.v. injection, and the oral bioavailability ranged from 3% to 4%. Finally, the plasma t1/2 beta ranged from 9 to 14 h. Correlation coefficients were obtained from multiple regression analysis; kinetic variables showed very low correlations with anthropomorphometric measurements. In contrast the Vss and WBR were significantly correlated with serum alkaline phosphatase levels and the Vss also with urine hydroxyproline levels. Plasma protein concentration was also correlated with excretion parameters such as CLP and plasma t1/2 beta after an oral dose. Scintigraphic studies in the HBTO group allowed bone selectivity to be seen through skeletal drug uptake. The 15 Pagetic lesions analysed in the HBTO group showed a decrease in PB/HB ratio from 3.8 in the basal study to 2.7 after olpadronate administration for 30 days at the rate of 50 mg/day. In conclusion, the kinetic profile of 99mTc-labelled olpadronate, mainly AUC and WBR, showed a dependence upon bone metabolism and seemed unrelated to body size variables. HBTO patients showed a lower blood AUC but a higher Vss. Both variables may have been reflecting the fact that the drug binds selectively with calcified tissues and, in turn, with the target compartment. Scintigraphy confirmed the labelled-compound bone selectivity as a desirable feature for a bone-scanning agent.
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PMID:Serum kinetics, bioavailability and bone scanning of 99mTc-labelled sodium olpadronate in patients with different rates of bone turnover. 858 68

A new sensitive method for the measurement of 1-beta-D-arabinofuranosyl-CTP (ara-CTP), an intracellular active metabolite of 1-beta-D-arabinofuranosylcytosine (ara-C), in human materials in vivo has been established. An acid-soluble fraction containing ara-CTP was extracted from blastic cells by ara-C treatment with trichloroacetic acid (final concentration, 0.3 M) neutralized with an equal volume of cold freon containing 0.5 M tri-n-octylamine. The ara-CTP fraction was separated from the acid -soluble fraction by high-performance liquid chromatography (TSK gel diethylaminoethyl-2 SW column) eluted with 0.05 M phosphate buffer (pH 6.9) and 20% acetonitrile. ara-CTP was lyophilized, dephosphorylated to ara-C by incubation with 10 units alkaline phosphatase for 12 h at 55 degrees C, and measured by RIA using anti-ara-C serum. Recovery through the whole procedure was 92%. In the human chronic myelogenous leukemia cell line K562, the intracellular ara-CTP levels produced when the cells were incubated with ara-c were assayed as above, and they showed a linear increase depending on Ara-C concentrations from 0.01 to 10 microns, demonstrating a very close correlation with the labeled ara CTP levels yielded by cells on incubation with radiolabeled ara-C (r2 = 0.99). The detection limit was 0.1 pmol/5 x 10(6) cells, and a sample amount of only 5 x 10(6) cells was enough for each assay. In the clinical applications, our method proved capable of detecting a wide concentration range of ara-CTP produced when patients were treated with ara-C or its derivatives from very low to intermediate doses. No radiolabeled drug was necessary. The method was very useful for in vivo pharmacodynamic studies of ara-C therapy.
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PMID:A new sensitive method for determination of intracellular 1-beta-D-arabinofuranosylcytosine 5'-triphosphate content in human materials in vivo. 862 Apr 96

Purified chloroplast ATP synthase (CF1) contains 1.2-2 mol of tightly bound ADP/mol of enzyme that resists removal by gel filtration or dialysis. CF1 was depleted of its endogenous nucleotide by treatment with alkaline phosphatase. Tightly bound nucleotide was demonstrated not to have an essential structural role. CF1 depleted of endogenous nucleotide retains its ability to catalyze Ca2+- and Mg2+-dependent ATPase activity and is not more sensitive to cold inactivation than untreated CF1. 2'(3')-O-Trinitrophenyladenosine 5'-diphosphate (TNP-ADP) binds tightly to two sites on nucleotide-depleted CF1, binding to either site at a faster rate than that of exchange of bound nucleotide for medium nucleotide. The nucleotide-depleted enzyme binds about one additional mol of TNP-ADP/mol of CF1, indicating that there is a tight TNP-ADP binding site that does not exchange readily with medium nucleotide. It is MgADP in this nonexchanging site, not the easily exchanging ADP binding site, that is responsible for the MgADP-induced inhibition of the ATPase activity. The rate of exchange of tightly bound ADP from CF1 matches the rate at which the Mg2+ATPase activity of CF1 is activated but is not itself responsible for the activation.
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PMID:Differences between two tight ADP binding sites of the chloroplast coupling factor 1 and their effects on ATPase activity. 870 14

A protein kinase which phosphorylates in vitro the biosynthetic ornithine decarboxylase (ODC) was partially purified from Escherichia coli. In vivo phosphorylation of ODC occurs after incubation of E. coli with [32P]orthophosphate. When the recombinant ODC was incubated with calf intestine alkaline phosphatase it was inactivated and this inactive ODC could be reversibly activated allosterically only by guanyl or uracyl phosphate analogues at a concentration of 10(-4) or 10(-3) M. The pH optimum of the [8-3H]GTP binding was determined and it was shown that the GTP binding is proportional to the amount of ODC. The [8-3H]GTP binds specifically to ODC as was proved by the addition of cold GTP or ATP. High concentration of GTP can dissociate the ODC-antizyme complex and either reactivate or liberate the ODC. Therefore, a working hypothesis is suggested describing the regulation of ODC by phosphorylation-dephosphorylation reaction or by antizyme and nucleotide analogues interaction.
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PMID:Regulation of the Escherichia coli biosynthetic ornithine decarboxylase activity by phosphorylation and nucleotides. 891 26

The cardiac capillarity in adult rats reared at 5 degrees C for 68 generations was studied with a double staining method of alkaline phosphatase and dipeptidylpeptidase IV. Capillary density, proportions of arteriolar, intermediate and venular capillary portions and capillary domain area were measured in the left ventricular wall. Compared with the control rats which had been brought back from the low temperature at the 12th generation and reared at 25 degrees C since then, the heart and the cardiac cells were hypertrophied, total capillary density increased and the capillary domain areas were reduced along the capillary path from the arteriolar to venular capillary portions. The number of the venular capillary portions showed no significant change but the arteriolar and intermediate capillary portions significantly increased. All these changes suggest that the cardiac capillary network was better developed in the cold-reared rats than in control rats. In the cold-adapted rats the hypertrophic changes in cardiac cells are thus accompanied by improvements in the oxygen delivery capacity. This adaptation provides a basis for the maintenance of increased thermogenesis in many organs. The changes cannot be established by several weeks exposure to low temperature, but only after rats have been bred in a cold room for generations.
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PMID:The capillarity of the subendocardium of left ventricle in rats reared at a low temperature for many generations. 917 12


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