Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two patients with rheumatoid arthritis and peripheral corneal ulcerations were successfully treated by conjunctival resection. The tissues removed were assayed by a variation of the radial diffusion method for tissue collagenases. We used an agarose matrix containing lathyritic rat skin collagen. Wells 3 mm deep were punched in the agarose-collagen and surgical specimens were placed in the wells. Spaces remaining in the wells were filled with balanced salt solution. The assay dishes were incubated for four days at 32 degrees C near 100% humidity. Under these conditions release of collagenase was detected by the clearing of diffuse zones in the gel surrounding the well. Conjunctiva proximal to the ulcer produced definite zones of lysis, whereas control specimens taken remote to the ulceration produced no lysis. This direct evidence for collagenase involvement offers an exploration for the beneficial effects of conjunctival resection.
 ...
PMID:Peripheral rheumatoid ulceration and evidence for conjunctival collagenase production. 22 Aug 78

This study tried to improve the number of viable islets isolated from a pancreas because a sufficient number cannot be obtained when the organ is preserved in the manner used for pancreas transplantation. The mechanism involved in the decrease in islet yield during preservation was studied to try to develop a better method for islet preparation. First, the integrity of the ductal system was compared between fresh and 6-hr simply preserved (in Hanks' balanced salt solution) rat pancreases. The ductal pressure after ductal injection of HBSS reached a plateau earlier and was significantly lower for the preserved pancreases (0.073 +/- 0.026 min, 410 +/- 17 mmHg, n = 5) than for the fresh ones (0.176 +/- 0.086 min, 561 +/- 103 mmHg, n = 7, P less than 0.05). Second, the extent of pancreatic distention was examined following ductal injection of barium gelatin solution. Solution leakage occurred earlier and distention was less in the preserved pancreas. In addition, the gelatin was found in the capillaries within some islets of the preserved pancreas. These results indicated that the preservation led to a rapid loss of integrity of the ductal system before collagenase injection. We therefore tested the efficacy of ductal collagenase injection at the time of harvesting: 15 ml of 1.0 mg/ml collagenase HBSS was intraductally injected and the pancreas was preserved at 4 degrees C for 2, 4, 6, and 24 hr. The isolation procedure was similar to that used for the fresh pancreas. The yield was significantly better than that of the simply preserved pancreas at 4 hr (241 +/- 22, n = 3, vs. 140 +/- 58, n = 3, P less than 0.05) and at 6 hr (171 +/- 58, n = 14, vs. 32 +/- 33, n = 6, P less than 0.01). These isolated islets were spherical-oval and their viability was confirmed by the ability to reverse STZ-induced diabetes in mice. These results indicated that the integrity of the ductal system, which is necessary for distention of the whole pancreas, was lost during preservation. To solve this problem, ductal collagenase injection should be done at the time of pancreas harvesting and then followed by simple preservation. This method is recommended to obtain viable islets from a preserved pancreas.
 ...
PMID:Improvement in islet yield from a cold-preserved pancreas by pancreatic ductal collagenase distention at the time of harvesting. 184 29

To evaluate the potential of utilizing porcine islet tissue as an alternative to human islet tissue for transplantation, we developed a method for the isolation of large amounts of highly purified porcine islets, and assessed the in vitro and in vivo function of the isolated islets after 1, 4, and 7 days of culture. The pancreatic duct of the splenic lobe was cannulated and distended by injection of Hanks' balanced salt solution containing 1.5 mg/ml collagenase. The pancreas was then processed by a modification of the automated digestion-filtration method developed in this laboratory, and with purification accomplished by Euro-Ficoll gradients (dialyzed Ficoll in Eurocollins solution), consisting of two layers of 1.108 and 1.091 g/cm3 density, topped with a layer of HBSS. The postpurification yield was 5203 +/- 645 (mean +/- SEM) islets per gram of pancreas with a number of islet equivalents (IE) per gram pancreas (islet equivalence: 150-microns-sized islets) of 3551 +/- 305, and a volume of 6.27 +/- 1.7 mm3 islet tissue per gram of pancreas. The islet purity exceeded 90%. Overnight-cultured, perifused porcine islets released 53.1 +/- 8.2 pM insulin/200 IE at 3.3 mM glucose, and 114.9 +/- 25.4 pM insulin/200 IE at 16.7 mM glucose (P less than 0.001 vs. basal output). When theophylline was added, insulin secretion increased to 264.2 +/- 63.2 pM/200 IE (P less than 0.001 vs. basal secretion and P less than 0.005 vs. secretion at 16.7 mM glucose). After 4 days of culture, the islets still responded to secretagogues. The functional integrity of the isolated islets was confirmed by reversal of diabetes in aL3T4 antibody-treated C57B/B6 diabetic mice: normoglycemia was promptly restored by transplanting 1000 overnight- or 7-day-cultured (24 degrees C) islets under the kidney capsule. These results suggest that continued improvements of porcine islet isolation and culture could permit the use of porcine islets in immunoalteration and immunoisolation studies that may lead to eventual human transplantation.
 ...
PMID:Automated large-scale isolation, in vitro function and xenotransplantation of porcine islets of Langerhans. 187 91

The mechanical and electrical properties of cochlear outer hair cells (OHCs) are suggested to modulate transduction by inner hair cells. These properties of OHCs are presumably regulated by efferent neurons which use several transmitters including acetylcholine (Ach) and gamma aminobutyric acid (GABA). Since it had been suggested that Ach causes isolated OHCs to shorten visibly, this study was designed to investigate whether GABA also alters the length of OHCs. OHCs were isolated from the guinea pig cochlea by mechanical dispersion after collagenase treatment. Cells were initially selected by strict morphological criteria. In addition they were only included in further studies if they attained a constant length during 10 min of superfusion with buffer solution. Neither GABA (20 microM: 100 microM), Ach (5 mM; 10 microM with 10 microM eserine) or carbachol (10 microM; 100 microM) altered OHC length when applied in iso-osmotic Hank's balanced salt solution (total number of cells tested, 72). If a change in length occurred it must have been smaller than 0.3 microns, our detection ability. In contrast, high potassium and variations in osmolarity changed hair cell length by 3-10% in agreement with other reports.
 ...
PMID:Acetylcholine, carbachol, and GABA induce no detectable change in the length of isolated outer hair cells. 222 97

Seventy-nine mongrel dogs underwent total pancreatectomy. Fifteen dogs served as apancreatic controls and died 7.0 +/- 4.2 days later (mean +/- SD). The pancreases of 44 dogs (group 1) were intraductally distended by manual injection of Hanks' balanced salt solution (HBSS). Thereafter each organ was mechanically disrupted and subjected to collagenase digestion as described by Mirkovitch et al. The pancreases of 20 dogs (group 2) were intraductally distended and subsequently perfused with collagenase by a roller pump. The organs were then mechanically disrupted and filtered through screens as described by Horaguchi et al. The resulting tissue suspensions were injected into the spleens of the dogs as autotransplants in both groups, by direct punction of the splenic capsule in group 1 and by retrograde infusion via a splenic vein tributary in group 2. The functional outcome was better in group 2 than in group 1, as assessed by the number of animals that became normoglycemic after transplantation [15/20 (75%) vs. 13/44 (30%); P = .0025]. The degree of islet purification, as measured by an increase in the tissue insulin/amylase ratio, was higher in group 2, and in both groups it was higher in normoglycemic than in hyperglycemic animals. The percent engraftment [i.e., amount of insulin recovered from spleen as percent of tissue transplanted (mean, 15.4% in group 1 and 14.5% in group 2) or as percent of original pancreas (mean, 4.9% in group 1 and 4.4% in group 2)] was low in both groups but again was higher in normoglycemic than in hyperglycemic animals within each group. In conclusion, both the degree of engraftment and purification and the route of implantation influenced the functional outcome after dispersed pancreatic islet autotransplantation to the spleen of totally pancreatectomized dogs, with purified tissue injected retrogradely functioning better than unpurified tissue injected directly.
 ...
PMID:Comparison of two methods of islet preparation and transplantation in dogs. 242 88

The inhibitory effect of chloramphenicol (CAP) on the DNA repair synthesis were studied on a primary cell culture of fetal liver tissue of rats. The fetuses were taken out with the umbilical cords and the placenta: then, the fetal livers were injected with a balanced salt solution and Type I collagenase through the umbilical vein. At the same time, the blood of the fetal livers were drained through the umbilical artery. The cells were detached at 10 degrees C with a steel mesh. Chloramphenicol 1.6-403.8 mmol/L did not show significant increase in DNA repair synthesis. The unscheduled DNA synthesis (UDS) was active when the positive control 7,12-dimethylbenzanthrancene(DMBA) was added alone to the culture in autoradiographic assay, but it was inactive when DMBA was added together with CAP. Therefore, it may be assumed that CAP has an inhibitory effect on the DNA repair synthesis.
 ...
PMID:[Effect of chloramphenicol on DNA repair synthesis in fetal liver cells of rats]. 264 54

A new method for preparation of viable islet cells from the normal pancreas is introduced. After total pancreatectomy, the pancreatic duct is cannulated and perfused with Hanks' balanced salt solution (HBSS) containing 0.2% collagenase at 37 degrees C for 30-45 minutes. The gland is then chopped and dissociated by shaking in a water bath. The cell suspension is filtered through steel mesh and washed with cold HBSS by centrifugation. By this method, collagenase is applied preferentially into the acinar tissue and the islet yield is greatly enhanced with decreased acinar contamination. Estimation of insulin and amylase in pancreatic tissue and islet rich cell suspension (graft) indicates a 57% islet recovery and a six-fold enrichment in islet concentration. Graft prepared by this method is autotransplanted into totally pancreatectomised dogs and normoglycemia is achieved in ten of 13 animals.
 ...
PMID:[A new method for preparation of islet cells from dogs]. 298 34

Certain in vitro culture conditions were determined for equine endothelial cells obtained from the aorta and pulmonary arteries. Cells were enzymatically isolated from the vessel lumen, using clostridial collagenase (2.5 mg/ml of Hanks's balanced salt solution) incubated at 37 C for 30 minutes. Cells were cultured in alpha minimum essential medium supplemented with plasma-derived and nonplasma-derived bovine fetal sera, endothelial cell-growth supplement, heparin, and antibiotics. Smooth muscle cell growth was not inhibited with nonplasma-derived animal sera, plasma-derived equine serum, or heparin. Heparin and a serum replacement were toxic to the cells used in the present study. Statistically significant differences were not found between the various media supplements.
 ...
PMID:Equine endothelial cells in vitro. 300 14

A simple and rapid method has been described to isolate the epithelial cells of cauda epididymidis of adult bull. Perfusion of the lumen of the cauda epididymidis with 1 mg/ml collagenase in calcium- and magnesium-free Hank's balanced salt solution and incubation of the tissue at 37 degrees C for 90 min releases the principal and basal cells into the lumen. Several individual epithelial cells and cell aggregates without the contamination of stromal or smooth muscle cells can be flushed out at the end of incubation. The isolated epithelial cells, suspended in Dulbecco's medium with 10% horse serum, attach to plastic dishes within 3 h after seeding the cells and proliferate to form a monolayer in approximately 8-12 days. The electron microscopic study and immunostaining of the cultured epithelial cells indicate that the cultured cells are principal cells. The basal cells of the intact cauda epididymidis of bull show within their cytoplasm the presence of varying amounts of "lipid-like" material often closely associated with whorls of membrane.
 ...
PMID:Isolation and cell culture of the epithelial cells of cauda epididymidis of the bull. 406 39

Canine pancreases were excised, minced, mechanically chopped, and incubated with collagenase in a manner similar to that used routinely in the preparation of mixed-cell pancreatic autografts. The resultant pancreatic fragments were studied by light and electron microscopy after various periods of collagenase incubation. As a control, pancreatic tissue was studied immediately after organ excision, immediately before addition of collagenase, and after various periods of incubation in balanced salt solution without collagenase. The mincing and chopping procedures alone induced a large population of highly aberrant, severely vacuolated acinar cells within the fragments. This vacuolation was caused by massive dilation of the cisternae of the rough endoplasmic reticulum. Subsequent incubation in collagenase solution, which appeared to destroy the aberrant cells in a selective manner, led to a remnant population with much improved acinar cell morphology. Incubation in balanced salt solution without collagenase resulted in a progressive increase in vacuolated cell incidence until abnormal pancreatic acinar cells dominated the tissue. The findings suggest that collagenase treatment may facilitate mixed-cell pancreatic transplantation by culling degenerative acinar cells from the grafted cell population, thereby reducing the likelihood of autodigestion at the transplant site. The extensive acinar cell destruction mediated by the collagenase may also be responsible for the release of a previously described hypotensive factor (pancreatic shock factor) into the graft infusion.
 ...
PMID:Morphological changes in pancreatic fragments prepared for transplantation by collagenase treatment. 608 89


1 2 3 4 Next >>