Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00790 (PGA)
 2,475 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pepsin treatment of ascitic fluid from patients with neoplasia generated a cysteine (thiol) proteinase activity which resembles cathepsin B (EC 3.4.22.1) in its requirements for thiol activators, susceptibility to inhibitors and specificity for synthetic substrates. As judged by gel filtration, pepsin reduced the molecular size of the latent enzyme from an Mr of 41,000 to 33,000 after activation. Both forms are larger than human liver cathepsin B. In addition to its presence in ascitic fluid, the pepsin-activated species was found in the medium of ascites cells maintained in culture. The latent enzyme may be an enzyme-inhibitor complex or an inactive precursor of a cathepsin B-like proteinase.
Biochim Biophys Acta 1981 Dec 15
PMID:A latent thiol proteinase from ascitic fluid of patients with neoplasia. 703 99

Suspensions of aggregated chondrocytes display active prostaglandin (PG) production. Radioimmunoassay of culture media and thin layer chromatographic analysis suggests that PGE2 is the primary PG synthesized. In order of decreasing concentration, the following PG were tentatively identified; PGE greater than PGI greater than PGA + PGB greater than or equal to PGF1+2 greater than TxB. An inverse logarithmic relationship was identified between PG synthesis and cells cultured at densities of 1.5 to 7.5 x 10(6) cells/ml. Little or no change in the PG distribution profile was seen at these high cell densities. Maximum PG synthesis was attained after 36 hours of incubation with persistence of high synthetic levels up to 48 hours. PGE2 production measured at various post-isolation intervals indicated an initial high rate of synthesis during the first 4 hours which decreased with time up to 24 hours. Cartilage explant organ cultures demonstrated a similar level of PG synthesis suggesting minimal effect of matrix on cellular PG production. Indomethacin (5 microgram/ml) inhibited PG synthesis by 70% within 4 hours and 85% after 24 hours of exposure. Arachidonic acid supplementation (10 microM) stimulated PG synthesis by 300%.
Prostaglandins 1980 Dec
PMID:The prostaglandins of articular cartilage. I. Correlates of prostaglandin activity in a chondrocyte culture system. 720 51

Epithelial and mesenchymal dental cells were grown in primary monolayer culture and the ability of both cell types to synthesize interstitial collagens was investigated. Pepsin-solubilized collagens were analyzed by CM-cellulose chromatography and both cell types were found to synthesize collagen type I, type III and type I trimer. The collagen phenotype of mesenchymal cells (type I: 82.4%, type III: 8.5%, type I trimer: 9.1%) was different from that of epithelial cells (type I: 71.8%, type III: 9.5%, type I trimer: 18.7%). The radioactivity incorporated into collagen molecules by mesenchymal cells was 34-times greater than the radioactivity incorporated by epithelial cells. This result agreed with previous observations obtained from tissue culture experiments (Lesot, H. and Ruch, J.V. (1979) Biol. Cell. 34, 23--37) which indicated a low synthesis of interstitial collagens by isolated dental epithelia when compared to isolated dental mesenchymes.
Biochim Biophys Acta 1981 Dec 28
PMID:Synthesis of collagen type I, type I trimer and type III by embryonic mouse dental epithelial and mesenchymal cells in vitro. 731 33

Styrene is rapidly metabolized in humans to mandelic () and phenylglyoxylic acids (P) which are excreted in urine. The present study investigates a gas chromatographic technique for measuring urinary concentrations of MA and PGA of workers exposed to styrene, compares the urinary concentrations of metabolites with time-weighted average air exposures to styrene and determines the levels of these metabolites in a population of workers not exposed to styrene. Post-shift urine specimens were obtained from a group of workers exposed to styrene in the reinforced plastic industry and from a control group. High positive correlation was found between post-shift urinary concentrations of metabolites and 8-hour TWA styrene exposure. Both MA and total metabolites (MA + PGA) gave correlation coefficient values of 0.96, p less than 0.0001. The mean MA excretion for the control groups was 6 mg/L. Determination of the concentration of these metabolites in a post-shift urine provides an effective means of estimating and monitoring human exposure to styrene.
Am Ind Hyg Assoc J 1980 Dec
PMID:Determination of urinary mandelic and phenylglyoxylic acids in styrene exposed workers and a control population. 746 63

The inhibitory specificity and stability of ovomucoid from Japanese quail egg white (OMJPQ) were examined to understand its nutritional significance. OMJPQ showed strong inhibitory activities toward trypsins from various origins including human, and the trypsin inhibitions occurred at molar ratios of enzyme to inhibitor between 1/1 and 2/1. On the other hand, an equimolar mixture of the second and third domains of OMJPQ inhibited bovine trypsin more strongly than the corresponding native OMJPQ did. This distinction was partly explained by the presence of steric hindrance on the formation of a 2:1 trypsin-OMJPQ complex. OMJPQ retained about 100% of its original activity over a pH range from 1 to 12 after a 24-h incubation at 37 degrees C. The inhibitor was most thermostable between pH 2 and 5, where more than 70% of its original activity was maintained after a 1-h incubation at 100 degrees C and about 25% of the activity even after a 30-min incubation at 121 degrees C. OMJPQ was also considerably resistant to pepsin attack. Pepsin digestion of the protein resulted in only about 40% loss of the original trypsin-inhibitory activity even after a 24-h digestion. Furthermore, the addition of bovine serum albumin to the digestion mixture brought about rapid elevation in the trypsin-inhibitory activity during an initial 30-min digestion. SDS-PAGE and immunoblot suggested that this was due to the liberation of active inhibitory domains from the native molecule by inter-domain proteolysis.
J Nutr Sci Vitaminol (Tokyo) 1994 Dec
PMID:Inhibitory specificity against various trypsins and stability of ovomucoid from Japanese quail egg white. 775 77

Rat osteoblasts were cultured on films of biodegradable poly(L-lactic acid) (PLLA), 75:25 poly(DL-lactic-co-glycolic acid) (PLGA), 50:50 PLGA, and poly(glycolic acid) (PGA) for up to 14 days. Osteoblasts attached equally well to all the polymer substrates after 8 h in culture. By day 4 in culture, osteoblasts had exceeded confluency numbers, and their proliferation leveled off by day 7. An increase in alkaline phosphatase (ALP) activity from 1.92 (+/- 0.47) x 10(-7) for day 7 to 5.75 (+/- 0.12) x 10(-7) mumol/cell per min for day 14 was reported for osteoblasts cultured on 75:25 PLGA, which was comparable to that observed for tissue culture polystyrene (TCPS) controls. The ALP activities expressed by osteoblasts cultured on PLLA, 50:50 PLGA, and PGA films did not significantly increase over time. Collagen synthesis for osteoblasts cultured on all polymer substrates was similar to that of TCPS and did not vary with time. The morphology of cultured osteoblasts was not affected by the continuous degradation of the polymer substrates. These results demonstrate that poly(alpha-hydroxy esters) can provide a suitable substrate for osteoblast culture and hold promise in bone regeneration by osteoblast transplantation.
J Biomed Mater Res 1994 Dec
PMID:Osteoblast function on synthetic biodegradable polymers. 787 84

Food-cobalamin absorption depends on the initial release of cobalamin from its binders in food. Therefore, the characterization of patients' gastric juices and their behavior in this process was undertaken. Pentagastrin-stimulated gastric juice specimens from three patients with severe food-cobalamin malabsorption, six patients with mild malabsorption, and five patients with normal absorption were tested for pH, pepsin, intrinsic factor content, and an in vitro method that quantitates transfer of cobalamin from egg yolk to gastric R binder. Transfer of cobalamin correlated best with in vivo egg yolk-cobalamin absorption test results in the 14 patients (r = 0.731, P < 0.005). Transfer also correlated inversely with gastric juice pH (r = -0.619, P < 0.02). Basal gastric juice specimens, with their higher pH, from the same subjects failed to promote cobalamin transfer until their pH was lowered to 1.0-1.3. Pepsin levels did not correlate with in vitro transfer or with absorption in vivo; nevertheless, raising the low pepsin concentration of one stimulated gastric juice improved transfer, while inhibiting pepsin activity with pepstatin A inhibited transfer. Mixing experiments with selected stimulated gastric juices demonstrated that poor in vitro transfer, which in a few cases seemed unrelated to pH or pepsin levels, was not due to any inhibitory activity of such gastric juices. These studies confirm that gastric acid and pepsin play a central role in releasing food-bound cobalamin and transferring it to R binder, but suggest that other, still unidentified gastric defects occasionally contribute to impaired transfer; the latter defects are not inhibitory in nature but seem to involve the absence of a permissive activity.(ABSTRACT TRUNCATED AT 250 WORDS)
Dig Dis Sci 1994 Dec
PMID:In vitro studies of gastric juice in patients with food-cobalamin malabsorption. 799 73

Gastric pepsin efflux, a putative aggressive factor because of its proteolytic activity, was examined to determine if it displays circadian rhythmicity as has been shown for other factors such as acid, bicarbonate, mucus, blood flow, potential difference, and tissue prostacyclin activity. Ninety-six fasted Sprague-Dawley male rats, 6-7 weeks of age were acclimated in sound-attenuating, light-proof chambers on a 12/12 light/dark schedule. They were studied in groups of 12 at 3-h intervals. After anesthesia and minor surgery, the stomach was cannulated and filled with 2 ml of saline for two sequential periods of 30 min. The samples were tested for pepsin according to the modified hemoglobin substrate colorimetric method. The data were analyzed with cosinor rhythmometric techniques. Pepsin efflux displayed significant (p < 0.05) circadian rhythmicity with an acrophase value or peak time at 06:49 h after lights on, during the lights-on resting phase. In contrast, the acrophase for acid secretion in the same model occurs during the dark period, when the rats are normally active. We postulate that differences in the circadian patterns of acid and pepsin may be protective.
Chronobiol Int 1993 Dec
PMID:Circadian rhythm of pepsin efflux in the fasting rat stomach. 811 65

Normal human esophageal mucosa exhibits biphasic secretory responses to intraluminal stimuli in terms of PGE2 release with a decline under the impact of HCl and an increase in PGE2 release during mucosal exposure to HCl/Pepsin. PGE2 secretory patterns in patients with reflux esophagitis (RE) remain unknown. We have studied, therefore, luminal release of PGE2 in 28 patients with nonhealed and healed RE, and compared the obtained results with corresponding values recorded in controls. The rate of luminal release of PGE2 in nonhealed RE exhibited a monophasic patterns, i.e., significantly decreased both during mucosal exposure to HCl (2,273 +/- 444, vs. 3,655 +/- 600 pg/min, p = 0.025) and HCl/pepsin (1,271 +/- 244, vs. 3,655 +/- 600 pg/min. p = 0.003) as compared to its basal value. However, the rate of luminal PGE2 release in patients with nonhealed RE in basal conditions and during mucosal exposure to HCl was significantly higher than corresponding values in controls. Luminal release of PGE2 in patients with healed endoscopic esophagitis was significantly lower as compared to corresponding values recorded in patients with nonhealed endoscopic changes and in controls. In conclusion, (a) monophasic inhibitory responses of the esophageal mucosa to intraluminal HCl and HCl/pepsin solutions in patients with RE indicate a different pattern of mucosal secretory response to intraluminal stimuli; (b) inhibition of the rate of luminal release of PGE2 under the impact of HCl/pepsin may play a role in the development and/or progression of mucosal damage; and (c) the decline in the rate of luminal PGE2 release in healed RE indicates that its elevated value in active esophageal disease should be considered as an implication of mucosal damage induced by HCl/pepsin.
J Clin Gastroenterol 1995 Dec
PMID:Monophasic luminal release of prostaglandin E2 in patients with reflux esophagitis under the impact of acid and acid/pepsin solutions. Its potential pathogenetic significance. 858 96

Neocartilage was engineered by culturing bovine chondrocytes on poly(glycolic acid) (PGA) fibrous nonwoven scaffolds. The biomechanical properties and morphologies of the PGA-chondrocyte constructs were studied over 12 weeks of in vitro culture. PGA scaffolds without cells lost their mechanical strength and structural integrity between week 2 and week 3 in culture. The thickness of the PGA-chondrocyte constructs decreased by 35% during the first 3 weeks, but the thickness increased from week 3 to week 9 to a thickness 42% higher than that of the starting scaffolds, which was then maintained. Safranin O staining of PGA-chondrocyte constructs revealed increasing proteoglycan formation over time. The compressive modules of PGA-chondrocyte constructs increased with in vitro culture time, and reached the same order of magnitude as that of normal bovine cartilage at week 9. The aggregate modulus of the PGA-chondrocyte constructs decreased by 57% over the first 2 weeks but then increased, reaching the same order of magnitude as normal bovine cartilage at week 12. The apparent permeability of the PGA-chondrocyte constructs, which was initially four orders of magnitude above that of normal cartilage, decreased between weeks 1 and 3 and thereafter remained the same order of magnitude as that measured for normal cartilage.
J Biomed Mater Res 1995 Dec
PMID:Development of biomechanical properties and morphogenesis of in vitro tissue engineered cartilage. 860 Jan 49


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