Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0267964 (PAA)
 2,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In conscious rats provided with appropriate indwelling catheters the kinetic period of adaptation (short-term adaptation) of digestive enzymes was investigated in response to a rapid change of diet and to intraduodenal infusions of different food components. Flow-rate and total protein concentration of pancreatic juice were measured. Enzyme-separation by PAA-Gel-Electrophoresis and quantitative analysis of amylases I and II, lipase, chymotrypsins I and II and trypsin were performed. The specific enzymatic activity was characterized by the enzyme fraction in percent of total protein. Rapid "change of diet" in rats, previously adapted for two weeks to a certain diet, caused increasing and decreasing concentrations of the corresponding enzymes respectively. The kinetic of this adaptation could well be described by exponential functions. Intraduodenal perfusion of starch, soy-bean oil or amino acids revealed similar changes in enzyme secretion as seen in the dietary experiments; i. e. intraduodenaL perfusion of starch caused mainly an increase in amylase secretion, soy-bean oil in lipase secretion and amino acids in the secretion of proteases. The kinetics could be described as a definite transfer function to a rectangular stimulus. The time lag between the duodenal "stimulation" and "response" in pancreatic enzyme secretion was only a few hours. After a period of rapid change in enzyme secretion during the initial 5 hours, the secretion rises more slowly to reach steady-state level after 18-22 hours. The results of this study allow a more detailed formal description of the kinetics of pancreatic short-term adaptation to nutritional stimuli without clarifying the involved mechanisms.
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PMID:Physiological studies of exocrine pancreatic secretion in conscious rats. 7th communication: short-term kinetics of adaptation of digestive enzymes to different nutritional stimuli. 241 22

In conscious rats provided with appropriate indwelling catheters the steady-state adaptation of digestive enzymes in pancreatic juice is investigated in relation to different food composition. Six isocaloric diets with different composition of carbohydrates (5-70%), proteins (10-57%) and fat (0-38%) are applied for two weeks before operation and also afterwards. The parameters determined are: flow-rate and total protein concentration of pancreatic juice, enzyme-separation by PAA-Gel-Electrophoresis and quantitative analysis of amylases I and II, lipase, chymotrypsins I and II and trypsin. The specific enzymatic activity, characterized by the enzyme fraction in per cent of total protein can be described best as a linear function of the corresponding nutrient portion (%) in the food. (Coefficient of linear regression mostly r = 0.98%). The regression lines for the sum of both amylases and all proteases are parallel to each other (y = 0.45x + b). Lipase activity is also linearly increasing with fat in food having a much smaller slope (y = 0.16x + b). The regression lines (y = ax + b) intersect with the ordinate at different points (section b), characterizing the "basal" secretion of pancreatic enzymes without any substrate in food. b (in %) for amylase I = 3.14, amylase II = 0.7 !, total proteases = 12.5 and lipase = 13.6. The regularity of inherent laws governing adaptation of pancreatic enzyme production and secretion to food composition allow to predict the prospective enzymatic secretion pattern for any given food composition.
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PMID:Physiological studies of exocrine pancreatic secretion in conscious rats. 6th communication: steady-state adaptation to different food composition. 620 64

A special class of hydrophobically modified polyelectrolytes was studied wherein poly(acrylic acid) (PAA) was conjugated with Pluronic F127 NF surfactant. The Pluronic-PAA copolymer solutions form gels at low concentrations when exposed to bodytemperature. Such gels possess enhanced retention in topical applications. Circular dichroism spectra indicate that tertiary structures of human insulin, haemoglobin, and albumin were stabilized in solutions of Pluronic-PAA. Aggregation of insulin in gelled solutions of Pluronic-PAA was impeded as demonstrated in shaking tests. The presence of Pluronic-PAA hindered the insulin degradation by alpha-chymotrypsin by at least 7-fold. Extraction of calcium ions from trypsin by Pluronic-PAA led to the dramatic changes in the tertiary structure and total loss of enzymatic activity, suggesting that Pluronic-PAA could inhibit tryptic degradation of proteins.
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PMID:Interactions among proteins and hydrophobically modified polyelectrolytes. 1134 72

A carboxyethylester-polyrotaxane was synthesized as a novel calcium chelating polymer in the field of oral drug delivery and characterized in terms of mechanism of trypsin inhibition. Here, carboxyethylester (CEE) groups are introduced to all the primary hydroxyl groups in alpha-cyclodextrins (alpha-CDs), which are threaded onto a poly(ethylene glycol) chain capped with bulky end-groups (polyrotaxane). The solubility of the CEE-polyrotaxane in physiological conditions increased with pH, indicating ionization-related solubility similar to conventional polyacrylates. The ability of calcium (Ca2+) chelation was found to increase in the order of poly(acrylic acid) (PAA)>CEE-polyrotaxanez.Gt;CEE-alpha-CD, suggesting that the increased density of carboxyl groups enhances the Ca2+ chelating ability. The activity of trypsin was inhibited by these compounds in the same order of the calcium chelation. However, the inhibitory effect of CEE-polyrotaxane was reduced by adding excess Ca2+ without precipitation that was observed in the presence of PAA. Such the reduced inhibition and precipitation by CEE-alpha-CD was not observed. Therefore, the inhibitory effect of CEE-polyrotaxane is due to Ca2+ chelation from trypsin without non-specific interaction.
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PMID:Carboxyethylester-polyrotaxanes as a new calcium chelating polymer: synthesis, calcium binding and mechanism of trypsin inhibition. 1217 24

The bacterial surfaces of enterococci are not uniform. This fact is confirmed by several studies and by our results when great differences between individual strains with regard to their cell surface hydrophobicity, binding of eight ECM (extracellular matrix) molecules immobilized on latex beads and four selected ECM molecules in microtiter plates were observed. The strains expressing high binding of ECM molecules (e.g., HJ 18, HJ 23, HJ 24, HJ 26, HJ 28, HJ 36, etc.) were found among Enterococcus faecalis and E. faecium by PAA (particle agglutination assay). On the other hand, weak ECM binders (e.g., HJ 21, HJ 32, HJ 34, HJ 38, HJ 39, HJ 42, HJ 43) were also found. A direct correlation was found between porcine mucin and fetuin binding ability of eight selected strains tested in microtiter plates and by PAA. Moreover, the influence of tunicamycin treatment was different because significant (P < 0.001) blocking effect of tunicamycin was observed with two selected strains (HJ 26 and HJ 36), whereas two strains (HJ 18 and HJ 22) were not significantly affected in their fetuin binding. The treatment of six enterococcal strains with proteolytic enzymes, pronase P, and trypsin, and with sodium metaperiodate also significantly (P < 0.001) decreased their fetuin binding. This suggests that both protein and carbohydrate moieties are involved in the binding of immobilized fetuin. However, the influence of these chemicals on the fetuin binding by individual strains was different.
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PMID:Binding of extracellular matrix molecules by enterococci. 1273 51

Pancreatic acinar atrophy (PAA) is by far the most common cause for the maldigestion signs of canine exocrine pancreatic insufficiency (EPI). The ability to diagnose PAA in the subclinical phase before the development of total acinar atrophy and manifestation of clinical signs has offered new possibilities to study the pathogenesis of the disease. Marked T-lymphocyte infiltration during the progression of acinar atrophy and the genetic susceptibility of the disease have been taken as a primary evidence of the autoimmune nature of the disease. The term autoimmune-mediated atrophic lymphocytic pancreatitis is preferred to describe pathologic findings. A single abnormally, low serum canine trypsin-like immunoreactivity (cTLI) concentration (< 2.5 mg/L), in dogs with typical maldigestion signs has been shown to be highly diagnostic for clinical EPI and is found in dogs with end-stage PAA. Repeatedly subnormal cTLI values (2.5-5.0 micrograms/L) in dogs with no clinical signs of EPI are valuable markers of subclinical EPI and highly suggestive for partial PAA. The primary treatment of EPI is supplementing each meal with pancreatic enzymes. The long-term treatment response for the nonenteric-coated enzyme supplements has been found to be good in half of these dogs, but the response varied considerably.
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PMID:Exocrine pancreatic insufficiency in dogs. 1455 66

The amidase activity of bovine pancreas trypsin in water-soluble complexes with poly(ethylene glycol)-block-poly(alpha,beta-aspartic acid) (PEG-PAA) was evaluated by a colorimetric assay using L-lysine p-nitroanilide as a substrate. The enzymatic reaction of trypsin was accelerated through the complexation with PEG-PAA. By determining the kinetic parameters of the enzymatic reaction of trypsin, it was confirmed that the catalytic rate constant of the complexed trypsin was 15 times higher than that of the native trypsin. From the evaluation of pH dependence of initial reaction rate, it was indicated that this acceleration was induced by a stabilization of the imidazolium ion of the His residue in the catalytic site, the Asp-His-Ser triad, of trypsin due to the Asp units of PEG-PAA. The hydrogen bonded Asp-His pairs are critical constituents in several key enzymatic reactions including serine protease and apurinic endonucleases, and it was expected that the acceleration of the catalytic reaction might occur for other enzymes by the formation of water-soluble complexes with PEG-PAA.
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PMID:Acceleration of enzymatic reaction of trypsin through the formation of water-soluble complexes with poly(ethylene glycol)-block-poly(alpha,beta-aspartic acid). 1576 22

The amidase reaction of trypsin, which is a member of the serine proteinase family, is accelerated by its complexation with block ionomers containing a polycarboxylate block, such as PEG-PAA, PEG-PGA, or PEG-PMA. PEG-PAA and PEG-PGA had similar effects, causing an increase in the k(cat) value and a shift in the pH profile to a lower pH region. On the other hand, PEG-PMA showed not only an increase in the k(cat) value, but also a decrease in the activation energy; however, there was no shift in the pH dependence of the initial reaction rate. Such differences might be induced by the difference in pK(a) values of the polycarboxylate block in block ionomers.
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PMID:Effect of polycarboxylate blocks on the amidase activity of trypsin through complexation with PEG/polycarboxylate block ionomers. 1737 Feb 72

Thermo-responsive poly(N-isopropylacrylamide-co-acrylamide)-block-polyallylamine-conjugated albumin nanospheres (PAN), new thermal targeting anti-cancer drug carrier, was developed by conjugating poly(N-isopropylacrylamide-co-acrylamide)-block-polyallylamine (PNIPAM-AAm-b-PAA) on the surface of albumin nanospheres (AN). PAN may selectively accumulate onto solid tumors that are maintained above physiological temperature due to local hyperthermia. PNIPAM-AAm-b-PAA was synthesized by radical polymerization, and AN was prepared by ultrasonic emulsification. AN with diameter below 200 nm and narrow size distribution was obtained by optimizing the preparative conditions. Rose Bengal (RB) was used as model drug for entrapment into the AN and PAN during the particle preparation. The release rate of RB from PAN compared with AN in trypsin solution was slower, and decreased with the increase of PNIPAM-AAm-b-PAA molecular weight, which suggested that the existence of a steric hydrophilic barrier on AN made digestion of AN more difficult. Moreover, the release of RB from PAN above the cloud-point temperature (T(cp)) of PNIPAM-AAm-b-PAA became faster. This was because the density of temperature-responsive polymers on AN was not so high, so that the interspace between the polymer chains increased after they shrunk due to the high temperature. As a result, the biodegradable AN was attacked more easily by trypsin. The design of PAN overcame the disadvantages of temperature-responsive polymeric micelles.
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PMID:Preparation and characterization of thermo-responsive albumin nanospheres. 1765 29

In this publication different detachment factors were tested for enhancing carrier to carrier transfer for scale-up of macroporous microcarrier based bioprocesses. Two Chinese hamster ovary cell lines, CHO-K1 and a genetically engineered CHO-K1 derived cell line (CHO-MPS), producing recombinant human Arylsulfatase B, were examined. The cells were grown on Cytoline 1microcarriers (Amersham Biosciences, Uppsala, Sweden) in protein-free and chemically defined medium respectively. Fully colonised microcarriers were used at passage ratios of approximately 1:10 for carrier to carrier transfer experiments. To accelerate the colonisation of the non-colonised, freshly added microcarriers the detachment reagents trypsin, papain, Accutasetrade mark (PAA, Linz, Austria), heparin and dextransulphate were used. Both cell lines showed good results with trypsin, Accutase and dextransulphate (Amersham Biosciences, Uppsala, Sweden), while papain failed to enhance carrier to carrier transfer in comparison to the non-treated reference. The maximum growth rate of cells on microcarriers with 2% dextransulphate in the medium was 0.25 +/- 0.02d(-1) and 0.27 +/- 0.03d(-1) for the CHO-MPS and CHO-K1, respectively. TheCHO-K1 grew best after detachment with trypsin (mu = 0.36 +/- 0.03d(-1)). This indicates, that one of the key parameters for carrier to carrier transfer is the uniform distribution of cells on the individual carriers during the initial phase. When this distribution can be improved, growth rate increases, resulting in a faster and more stable process.
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PMID:Detachment factors for enhanced carrier to carrier transfer of CHO cell lines on macroporous microcarriers. 1900 2


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