Acute management of dengue shock syndrome: a randomized double-blind comparison of 4 intravenous fluid regimens in the first hour.
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Dengue hemorrhagic fever is an important cause of morbidity among Asian children, and the more severe dengue shock syndrome (DSS) causes a significant number of childhood deaths. DSS is characterized by a massive increase in systemic capillary permeability with consequent hypovolemia. Fluid resuscitation is critical, but as yet there have been no large trials to determine the optimal fluid regimen. We undertook a randomized blinded comparison of 4 fluids (dextran, gelatin, lactated Ringer's, and "normal" saline) for initial resuscitation of 230 Vietnamese children with DSS. All the children survived, and there was no clear advantage to using any of the 4 fluids, but the longest recovery times occurred in the lactated Ringer's group. The most significant factor determining clinical response was the pulse pressure at presentation. A comparison of the colloid and crystalloid groups suggested benefits in children presenting with lower pulse pressures who received one of the colloids. Further large-scale studies, stratified for admission pulse pressure, are indicated. (+info)
Permeability characteristics of human endothelial monolayers seeded on different extracellular matrix proteins.
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OBJECTIVE: To investigate whether endothelial monolayer permeability changes induced by inflammatory mediators are affected by the extracellular matrix protein used for cell seeding. METHODS: Human umbilical venular endothelial cells (HUVEC) were grown to confluent monolayers on membranes coated with either collagen, fibronectin or gelatin. The permeability to albumin and dextran was then assessed, both under normal conditions and after treatment with tumor necrosis factor-alpha (TNF-alpha) and bacterial lipopolysaccharide (LPS). RESULTS: With any of the three protein coatings, tight junctions were formed all over the monolayers. The permeability of the coated membranes to albumin and dextran was reduced strongly by confluent monolayers; the relative reduction was similar for the three matrix proteins used. Pre-incubation of the monolayers with either TNF-alpha or LPS increased permeability dose dependently. However, the relative increase due to either treatment was independent of the protein used for membrane coating. CONCLUSION: The extracellular matrix protein used for initial seeding of endothelial cultures plays a minor role in determining the permeability changes induced in HUVEC monolayers by inflammatory mediators. (+info)
Novel method for producing hypoallergenic wheat flour by enzymatic fragmentation of the constituent allergens and its application to food processing.
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A novel method is proposed to produce hypoallergenic wheat flour suitable for patients allergic to wheat. Wheat flour was mixed with a cellulase solution, and the mixture was incubated at 50 degrees C for 1 h to hydrolyze the carbohydrate allergens. The hydrolysate was further incubated with actinase at 40 degrees C for 1 h while gently stirring to decompose the proteinaceous allergens. The product was evaluated for its allergenicity by an enzyme-linked immunosorbent assay, the results of which suggested negative allergenicity in most cases. The product changed to a batter state that was difficult to process by the usual methods. Gelatinization of the starch in the product and the addition of a surfactant were beneficial for food processing. (+info)
Measurement of cartilage oligomeric matrix protein (COMP) in normal and diseased equine synovial fluids.
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OBJECTIVE: This study was designed to assay cartilage oligomeric matrix protein (COMP) in equine synovial fluids and to compare the concentration in synovial fluids from normal horses with joint diseased horses. The relationship between the COMP degradation and the matrix metalloproteinase activity in synovial fluids was also investigated. DESIGN: Using COMP antigen prepared from equine articular cartilage and murine monoclonal antibody (12C4) raised against human COMP, an inhibition ELISA was developed. COMP in equine synovial fluids from normal and diseased joints was quantified. Metalloproteinase activities were evaluated in the same synovial fluids by a gelatin degradation ELISA. COMP fragments were evaluated qualitatively by Western blotting. RESULTS: The COMP inhibition ELISA was reliable at concentrations of equine COMP between 62.5 and 2000 ng/ml. COMP values in joint fluids in both aseptic and septic joint disease (19.7+/-15.3 and 16.1+/-11.2 microg/ml, respectively) were significantly (P < 0.001) lower than normal (53.2+/-29.0 microg/ml). The molecular sizes of COMP on immunoblots were different between normal and diseased synovial fluids; more fragments were seen in diseased fluids. The aseptic (26.6 +/- 20.6%) and septic joint disease synovial fluids (36.1 +/- 37.5%) had significantly higher (P < 0.02 and 0.002, respectively) gelatinolytic activities than normal (13.6 +/- 13.7%). There was a negative correlation (R = -0.31, P < 0.002) between COMP level and gelatinase activity. Conclusions We conclude that the fragment pattern and the absolute COMP concentration maybe useful for monitoring joint disease, and that COMP degradation in synovial fluids from progressed joint disease may be due to MMP gelatinolytic activity. (+info)
Free amino acids in crocodilians fed proteins of different biological value.
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Changes in plasma levels of amino acids derived from fed protein were determined by feeding crocodilians (Caiman crocodilus crocodilus and Alligator mississipiensis) 7.5 g protein/kg body weight and by monitoring the plasma free amino acids for several days. Zein and several other vegetable proteins produced no rise in plasma amino acids and were excreted intact in the feces. Casein and fish muscle were rapidly digested but produced little rise in plasma amino acids, and the increases showed no relationship to the composition of the protein fed. Gelatin feeding led to large increases in plasma amino acids that persisted for more than a week, and the resulting pattern was nearly identical to the composition of gelatin with the exception of aspartic and glutamic acids, and several animals died. Equivalent quantities of fish muscle protein were assimilated without difficulty by the crocodilians. Endogenous protein secreted into the gut apparently contributed little to the amino acid mixture absorbed. (+info)
Production of a biologically active epidermal growth factor fusion protein with high collagen affinity.
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Collagen is generally incapable of capturing polypeptides such as growth factors in a specific manner. In this study, we established a collagen-binding growth factor (FNCBD-EGF) consisting of epidermal growth factor (EGF) and the fibronectin collagen-binding domain. A typical yield of FNCBD-EGF was approximately 200 microg/ml culture in an Escherichia coli expression system. This fusion protein bound to gelatin and fibrillar collagen sponges, and the bound protein was not effectively eluted even with 2 M NaCl. In addition, FNCBD-EGF bound to type I, II, III, or IV collagen-coated plates, and the specificity of binding was confirmed by competitive inhibition using fibronectin. FNCBD-EGF substantially stimulated cell growth after binding to collagen-coated culture plates, whereas EGF had no effect, indicating that this fusion protein acted as a collagen-associated growth factor. In an animal model of impaired wound healing, FNCBD-EGF, but not EGF, was retained with collagen sponges at wound sites 4 d after implantation, and repair of epidermis was observed underneath the sponges. These results suggested that our fusion protein with high collagen affinity would be useful for wound healing. (+info)
Melanoma chondroitin sulfate proteoglycan regulates matrix metalloproteinase-dependent human melanoma invasion into type I collagen.
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Tumor cell adhesion and proteolysis of the extracellular matrix proteins surrounding the cells are tightly linked processes in tumor invasion. In this study, we sought to identify components of the cell surface of a vertical growth phase melanoma cell line, WM1341D, that mediate invasive cellular behavior. We determined by antisense inhibition that melanoma chondroitin sulfate proteoglycan (MCSP) and membrane-type 3 matrix metalloproteinase (MT3-MMP) expressed on WM1341D are required for invasion of type I collagen and degradation of type I gelatin. MT3-MMP co-immunoprecipitated with MCSP in WM1341D melanoma cells cultured on type I collagen or laminin. The association between MT3-MMP and MCSP was largely disrupted by removing chondroitin sulfate glycosaminoglycan (CS) from the cell surface, suggesting CS could mediate the association between the two cell surface core proteins. Recombinant MT3-MMP and MT3-MMP from whole cell lysates of WM1341D cells were specifically eluted from CS- conjugated affinity columns. The results indicate that MT3-MMP possesses the potential to promote melanoma invasion and proteolysis and that the formation of a complex between MT3-MMP and MCSP may be a crucial step in activating these processes. (+info)
The hairpin structure of the (6)F1(1)F2(2)F2 fragment from human fibronectin enhances gelatin binding.
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The solution structure of the (6)F1(1)F2(2)F2 fragment from the gelatin-binding region of fibronectin has been determined (Protein Data Bank entry codes 1e88 and 1e8b). The structure reveals an extensive hydrophobic interface between the non-contiguous (6)F1 and (2)F2 modules. The buried surface area between (6)F1 and (2)F2 ( approximately 870 A(2)) is the largest intermodule interface seen in fibronectin to date. The dissection of (6)F1(1)F2(2)F2 into the (6)F1(1)F2 pair and (2)F2 results in near-complete loss of gelatin-binding activity. The hairpin topology of (6)F1(1)F2(2)F2 may facilitate intramolecular contact between the matrix assembly regions flanking the gelatin-binding domain. This is the first high-resolution study to reveal a compact, globular arrangement of modules in fibronectin. This arrangement is not consistent with the view that fibronectin is simply a linear 'string of beads'. (+info)