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)

Sarcoidosis affecting the lungs may cause obstructive and/or restrictive lung function impairment. The bronchial reactivity is related to the release of histamine from the mast cells. Upon activation mast cells also release tryptase. This enzyme may activate latent collagenase and thus possibly contribute to the fibrosis formation observed in sarcoidosis. We analyzed the bronchoalveolar lavage fluid (BALF) from 13 nonsmoking and untreated patients with sarcoidosis and from 30 healthy volunteers (18 smokers) with regard to the number of mast cells and the tryptase concentration. Concomitantly albumin, fibronectin and hyaluronan were measured as markers of the inflammatory reaction in the alveoli and interstitium. The number of mast cells was higher (p < 0.001) in patients with sarcoidosis than in controls. Also, the concentration of tryptase was significantly higher in patients (225.3 +/- 83.9 [SEM] mU/L) compared to nonsmoking and smoking controls (34.7 +/- 7.8 and 44.7 +/- 13.0 mU/L, respectively; p < 0.01 for both). In addition, the concentrations of albumin, fibronectin and hyaluronan were higher in patients with sarcoidosis compared to the nonsmoking controls (p < 0.001 for all). However, there was no relationship between either the mast cell number or the tryptase concentration and the lung function parameters (VC, TLC, FEV1, FEV%, DLCO). As our patients did not show any functional signs of bronchial obstruction (FEV1 91.7% +/- 13.3 [SD] and FEV% 99.5% +/- 6.4 of predicted) the lack of correlation is not surprising. The high concentrations observed in the BALF of the noncellular components may just reflect an ongoing inflammatory process that may resolve or, if exaggerated, lead to fibrosis.
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PMID:Elevated levels of tryptase in bronchoalveolar lavage fluid from patients with sarcoidosis. 813 9

Clinical human islet transplantation programmes are considerably hampered by the variability of islet isolation outcome. The effects of the islet content of the pancreas and other donor-related variables on isolation outcome have not been evaluated systematically so far--either in large animals, or in man. We studied the impact of interindividual differences in age, body weight and pancreatic islet content on the outcome of collagenase isolation of islets from the splenic pancreas of beagle dogs (n = 31). The islet volume of the splenic pancreas amounted to a mean (+/- SEM) 15.7 +/- 0.9 microliters per gramme pancreas, and varied three-fold (from 8.4 to 27.3 microliters). Isolated islet yield was 7.6 +/- 0.7 microliters/g and varied nine-fold (1.8-16.3 microliters). Animals also varied in age eight-fold (8-67 months) and body weight two-fold (8.6-18.3 kg). Differences in body weight and age explained 60% of variance in the fractional islet volume of the pancreas and 50% of the variance in islet yield (p < 0.001). Fractional islet volume of the splenic pancreas also explained 50% of the variance in islet yield (p < 0.001). We conclude that the outcome of islet isolation may be predictable after controlling for the variable islet content of pancreases, and other donor-related variables, and suggest that similar studies should be done in man.
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PMID:Impact of donor-related variables on islet isolation outcome in dogs. 815 Feb 23

Although it is generally accepted that polyurethane-covered breast implants have decreased the incidence of clinical capsular contracture, there remain many unanswered questions regarding the physical and chemical degradation of the polyurethane foam covering itself. We have systematically studied the fibrous capsule and polyurethane foam recovered from human breast "explants" in an effort to characterize more precisely the biodegradation of polyurethane foam in the human body. Seventy-five freshly retrieved polyurethane-covered implants and surrounding capsule from 47 patients have been analyzed. Capsular tissue from several sampling sites around the surface of the implants was digested in a collagenase solution until foam was recovered or all tissue was digested. Additional samples were fixed in 10% formalin. Scanning electron microscopy was used to look for structural changes in the recovered intact foam and to determine the foam strut widths. Fourier transform IR spectroscopy and x-ray photoelectron spectroscopy were used to analyze the chemical composition of the polyurethane. The formalin-preserved capsule samples were examined histologically for further evidence of foam degradation. Of the 75 prostheses analyzed, 36 (48 percent) were removed because of capsular contracture and 10 (13 percent) because of infection or exposure of the prosthesis. The remaining 29 (39 percent) implants were removed for various other reasons. Visibly intact foam was recovered from 36 (48 percent) prostheses after enzymatic digestion of capsule tissue. There was a progressive decline in the ability to recover intact foam as the total implantation time increased. Scanning electron microscopy revealed fractures and fissures in the foam structure and thinning of the polyurethane struts. The mean strut width of control, unimplanted foam was 49 +/- 1.5 microns (+/- SEM). Retrieved foam from implants which developed capsular contracture and the infected implants had strut widths of 30 +/- 3.1 and 32 +/- 3.1 microns, respectively. In implants removed for other reasons, the polyurethane foam strut width was 41.2 +/- 2.3 microns. Despite an inability to recover visibly intact foam from 39 specimens, standard light microscopy of 37 of these same specimens showed residual polyurethane still present in the capsule. Various degrees of scalloping and fracturing of the foam were seen in the histologic sections. There is convincing evidence by scanning electron microscopy and histology that polyurethane is degrading. It was not possible to quantitate accurately the rate of degradation, but factors such as capsular contracture, infection, and time appear to have a role in the biodegradation of polyurethane in the human body. These relationships require further study.
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PMID:Biodegradation of the polyurethane foam covering of breast implants. 823 96

Other investigators have shown that exogenously administered transforming growth factor-beta (TGF-beta) inhibits lymphocyte adherence to vascular endothelial cells (VEC). We examined the role of TGF-beta 1 as an autocrine mediator of lymphocyte adhesion to adult human VECs. VECs were harvested from eight saphenous or cadaveric iliac veins using 0.2% collagenase. Low-passage VECs in MCDB + 0.1% BSA were pretreated for 24 hr with monoclonal anti-TGF-beta 1 antibody (5 micrograms/ml), LPS (5 micrograms/ml), or IL-1 (10 U/ml). Adherence of fluorescently labeled lymphocytes to pretreated VECs was quantitated and results were expressed as relative adhesion compared to untreated control. Total mRNA from LPS- or IL-1-treated VECs was subjected to Northern analysis to determine relative TGF-beta 1 expression. Total TGF-beta 1 protein concentration in supernatants from LPS- or IL-1-treated VECs was determined by ELISA. Data (means +/- SEM) were analyzed by ANOVA with a Newman-Keuls posttest. Neutralizing endogenous TGF-beta 1 with anti-TGF-beta 1 antibody significantly increased adhesion of lymphocytes to VEC monolayers compared to control (125 +/- 3 vs 101 +/- 2%, P < 0.01, n = 8). The level of adhesion was equivalent to that seen with IL-1 stimulation (131 +/- 6%). Spearman correlation of lymphocyte adherence to IL-1- or LPS-treated VECs vs TGF-beta 1 mRNA expression or vs relative TGF-beta 1 protein concentration showed significant inverse relationships (r = -0.82, P < 0.001, and r = -0.87, P < 0.001, respectively). Endogenous TGF-beta 1's inhibitory effect on lymphocyte adhesion was blocked by a specific neutralizing antibody. VEC TGF-beta 1 mRNA expression and TGF-beta 1 production were inversely proportional to lymphocyte adhesion, suggesting down-regulation of TGF-beta 1 in response to proinflammatory cytokines. Together, these observations support the hypothesis that TGF-beta 1 has an autocrine inhibitory role in regulation of lymphocyte adhesion to VECs.
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PMID:Transforming growth factor-beta 1 serves as an autocrine inhibitor of human endothelial cell/lymphocyte adhesion. 853 71

Microcapsules composed of collagen and chondroitin sulfate were obtained by complex coacervation and characterized by DSC, optical microscopy, SEM, and UV-Vis spectroscopy. Composition of the microcapsules could be adjusted by the feed ratio and the pH of the solution. Prepared under low temperature and aqueous solution, the process is most suitable for encapsulating delicate bioactive agents. Albumin as a model protein was encapsulated with a loading level of up to 95% by weight. Degradation rate of the microcapsules decreased with the concentration of the crosslinking agent glutaraldehyde and increased with the bacterial collagenase level. Correspondingly the release of albumin could also be varied by the cross-linking degree of the microcapsules.
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PMID:Microcapsules obtained from complex coacervation of collagen and chondroitin sulfate. 856 17

Fibroblast growth factors (FGF) are osteoblast mitogens, but their effects on bone formation are not clearly understood. Most in vitro studies examining the effects of FGFs on osteoblasts have been performed only during the initial proliferative stage of osteoblast culture. In these studies, we examined the consequential effect of acidic FGF in cultures of rat fetal diploid osteoblasts that undergo a developmental differentiation program producing a mineralized bone-like matrix. During the initial growth period (days 1-10), addition of acidic FGF (100 micrograms/ml) to actively proliferating cells increased (P < 0.05) 3H-thymidine uptake (2,515 +/- 137, mean +/- SEM vs. 5,884 +/- 818 cpm/10(4) cells). During the second stage of maturation (days 10-15), osteoblasts form multilayered nodules of cells and accumulate matrix, followed by mineralization (stage 3, days 16-29). Addition of acidic FGF to the osteoblast cultures from days 7 to 15 completely blocked nodule formation. Furthermore, addition of acidic FGF after nodule formation (days 14-29) inhibited matrix mineralization, which was associated with a marked increase in collagenase gene expression, and resulted in a progressive change in the morphology of the nodules, with only a few remnants of nonmineralized nodules present by day 29. Histochemical and biochemical analyses revealed a decrease in alkaline phosphatase and mineral content, confirming the acidic FGF-induced inhibition of nodule and matrix formation. To identify mechanisms contributing to these changes, we examined expression of cell growth and bone phenotypic markers. Addition of acidic FGF during the proliferative phase (days 7-8) enhanced histone H4, osteopontin, type I collagen, and TGF-beta mRNA levels, which are coupled to proliferating osteoblasts, and blocked the normal developmental increase in alkaline phosphatase and osteocalcin gene expression and calcium accumulation. Addition of acidic FGF to the cultures during matrix maturation (days 14-15) reactivated H4, osteopontin, type I collagen, and TGF-beta gene expression, and decreased alkaline phosphatase and osteocalcin gene expression. In an in vivo experiment, rats were treated with up to 60 micrograms/kg/day acidic FGF intravenously for 30 days. Proliferation of osteoblasts and deposition of bone occurred in the marrow space of the diaphysis of the femur in a dose-related fashion. The metaphyseal areas were unaffected by treatment. In conclusion, our data suggest that acidic FGF is a potent mitogen for early stage osteoblasts which leads to modifications in the formation of the extracellular matrix; increases in TGF-beta and collagenase are functionally implicated in abrogating competency for nodule formation. Persistence of proliferation prevented expression of alkaline phosphatase and osteocalcin, also contributing to the block in the progression of the osteoblast developmental sequence.
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PMID:Acidic fibroblast growth factor inhibits osteoblast differentiation in vitro: altered expression of collagenase, cell growth-related, and mineralization-associated genes. 872 64

A lack of a sufficient number of human donor pancreases has stimulated interest in isolation and cryopreservation techniques for islets from the porcine pancreas. But because of a poorly developed outer membrane porcine islets are particularly susceptible to damage during cryopreservation. The aims of this study were two-fold: 1) to develop a method for isolation and storage of islets from neonatal porcine pancreas and, 2) to examine effects of Sertoli cells on islet yield and function in Sertoli cell-islet cell cocultures. A total of 170 neonatal porcine pancreases were processed by means of a short period of digestion with collagenase and culture of the tissues at 32 degrees C for periods up to 7 days following isolation. Results were: The mean +/- SEM, number of viable islets, and percentage loss of cells following 7 days of culture were 29,442 +/- 1,119 and 22.2 +/- 1.2, respectively, Cryopreservation had a marked impact on recovery of viable islets: In absence of Sertoli cells an average of only 64% of islets remained viable; by contrast, when cryopreserved islets were cocultured with Sertoli cells, a mean of 82% was recovered. Glucose at 16.7 mmol/L had the capacity to elicit insulin release from 3-day-old cultured islets. The concentration in absence of Sertoli cells was 57.3 +/- 3.8 uU/mL/10 islets; in the presence of Sertoli cells the level increased to a mean +/- SEM of 112.8 +/- 17.7, uU/mL/10 islets. Similar results were obtained following cryopreservation: glucose at 16.7 mmol/L stimulated a mean +/- SEM of 27.9 +/- 6.6, uU/mL/10 islets, of insulin in absence of, and 44.9 +/- 9.9, uU/mL/10 islets, in presence of, Sertoli cells. Our results show that isolation and cryopreservation of neonatal porcine islets can be successfully accomplished. In addition, coculture with Sertoli cells significantly improves both the yield and functional capacity of islets following cryopreservation.
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PMID:Sertoli cell-induced defects on functional and structural characteristics of isolated neonatal porcine islets. 888 11

Intraductal distention of the pancreas with collagenase followed by stationary warm incubation improves the recovery of islets of Langerhans in the rat, but controlled studies are needed for valid comparison with standard isolation methods. We have modified Gotoh's technique of stationary digestion for high-yield isolation in the rat (Stationary). The method is subjected herein to rigorous blinded comparison with the standard chopped tissue (Chopped) technique, based on Lacy et al., as performed in our laboratory for over 10 yr. Islet recovery was determined by a single observe 'blinded' to the method of isolation used, and only intact islets of diameter > or = 100 microns were included. Stationary gave 719 +/- 114 islets per pancreas (mean +/- SD, n = 21 isolations) vs. 487.5 +/- 69 for Chopped (n = 36 isolations), a 47.5% increment in yield (p < 0.0001). In vitro islet perifusion showed no statistical difference in stimulation index (SI) or stimulated area under the curve (SAUC) between the two methods, but Stationary showed a trend towards improved phase II insulin release. In vivo function was assessed by isogeneic transplantation of 2,000 islets beneath the renal capsule of streptozotocin diabetic recipients (65 mg/kg Sigma); Stationary recipients (n = 7) became normoglycemic (< or = 8 mmol/L) by 3.3 +/- 4.8 days vs. 1.6 +/- 1.5 days for Chopped recipients (p = 0.4 ns, mean +/- SEM). IVGTT performed at 1 mo posttransplant gave K-values for Stationary of 2.64 +/- 0.8 vs. 2.62 +/- 0.8 for Chopped (mean +/- SD, p = 0.9 ns, n = 6, unpaired t-test), which were not distinguishable from normal control rats (2.59 +/- 0.8) (p = 0.9 ns, n = 10). Graft function remained stable until graft bearing nephrectomy induced hyperglycemia uniformly within 1 day. Graft histology showed a healthy well-preserved structure on light microscopy, with well-granulated beta cells on EM. Economic costs of rat, collagenase, and Ficoll were 26% ($50.82) lower per recipient for Stationary. We conclude that modified stationary digestion significantly improves islet recovery with excellent in vitro and in vivo function, and is cost effective.
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PMID:High yield of rodent islets with intraductal collagenase and stationary digestion--a comparison with standard technique. 895 Dec 21

Before clinical islet transplantation can become an effective and reliable treatment for type 1 diabetic patients, there must be significant improvements in the methods employed for the isolation of islets of Langerhans. We have developed an automated cell extraction system (ACES), which allows computer control of the isolation process. As well, it incorporates a novel method of recombining dissociated pancreatic tissue. Following initial system design and testing to determine the optimal system configuration, a series of 12 consecutive canine islet isolations were performed. Pancreases were perfused with collagenase via the duct and dissociated and recombined using either the standard Ricordi-based protocol (group 1, n = 6) or dissociated and recombined using the ACES system (group 2, n = 6). A total of 90.8 +/- 21 x 10(3) islet equivalents (IE) (mean +/- SEM) were recovered in group 1 vs. 99 +/- 14 x 10(3) IE in group 2 (p = NS, student unpaired t-test). Following Ficoll purification the recovery was 56.2 +/- 14 x 10(3) IE for group 1 vs. 54.7 +/- 11 x 10(3) IE for group 2 (p = NS). Viability was equivalent with an 8.6-fold increase in insulin secretion for group 1 and an 8.8-fold increase for group 2 when the islets were exposed to high glucose solution supplemented with IBMX (3-isobutyl-1-methylxanthine) during static incubation. In vivo function was equivalent following transplantation of 2000 IE under the kidney capsule of alloxan-induced diabetic nude mice with five of six and five of seven mice surviving long-term (> 50 days posttransplant) (groups 1 and 2, respectively). This data shows that an entirely automated pancreatic islet extraction system can result in effective canine islet recovery without compromising islet yields and viability. The ACES system has several advantages over the standard isolation protocol. These include: 1) computer control and monitoring over all phases of the isolation, 2) a single-use sterile disposable tubing set, and 3) a novel method of tissue recombination.
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PMID:Development of an automated computer-controlled islet isolation system. 904 Sep 55

This study was conducted to determine whether interferon-alpha-2b (IFN-alpha-2b) can be encapsulated in liposomes without compromising its anti-fibrogenic effects on human dermal fibroblasts. The rationale for this approach is that systemic administration of IFN-alpha-2b by injection for treatment of dermal fibrosis is uncomfortable, requires a large quantity of the cytokine, and cannot be easily used in children. Liposomes are potentially useful as vehicles for the topical delivery of drugs if they can be encapsulated without loss of biologic activity. Empty sonicated vesicles composed of dioleoyl-phosphatidylcholine:dioleoyl-phosphatidylglycerol at a molar ratio of 7:3 were mixed with various concentrations of IFN-alpha-2b and then dried and rehydrated. An enzyme-linked immunosorbent assay (ELISA) was used to determine the efficiency of encapsulation and the stability of the preparation under experimental conditions. Greater than 80% of added IFN-alpha-2b became associated with the liposomes and remained encapsulated for up to 5 d at 4 degrees C. The rate of release increased markedly at 37 degrees C. Liposome-encapsulated IFN-alpha-2b (2000 units per ml) significantly reduced the proliferation of dermal fibroblasts (60 +/- 8.8 vs. 100 +/- 8, mean +/- SEM, p < 0.05, n = 8) and the levels of mRNA for type I (41.5 +/- 8.7% vs 100 +/- 18, p < 0.05, n = 4) and type III (68 +/- 8.4% vs 100 +/- 4.9%, p < 0.05, n = 3) procollagen, as analyzed on northern blots. This was consistent with the reduction found in collagen in conditioned medium from treated fibroblasts. In contrast, treatment increased levels of mRNA for collagenase (241 +/- 42% vs 100 +/- 3.4, p < 0.05, n = 3) and collagenase activity (289 +/- 5.8% vs 100 +/- 10.9%, p < 0.05, n = 9) in conditioned medium. This last effect was probably not due to a reduction in TIMP-1 (tissue inhibitor of metalloproteinase-1) because levels of mRNA for this inhibitor were not lower in treated cells. The efficacy of liposome-associated IFN-alpha-2b in vitro supports the concept of the topical use of this anti-fibrogenic agent for treatment of fibroproliferative disorders.
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PMID:Liposome-associated interferon-alpha-2b functions as an anti-fibrogenic factor for human dermal fibroblasts. 920 55


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