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PubMed2005

[Changes of serum soluble P-selectin and tumor necrotic factor-alpha in patients with CMV induced acute coronary syndrome].

OBJECTIVE: To explore the changes and relationship between serum soluble P-selectin, tumor necrosis factor-alpha (TNF-alpha) in coronary heart disease patients with acute coronary syndrome (ACS) and human cytomegalovirus (HCMV) infection. METHODS: The levels of circulating soluble P-selectin, TNF-alpha, HCMV-IgM and HCMV-IgG were determined by enzyme-linked immunosorbent assay (ELISA) in 79 cases for ACS group, 30 cases for stable angina (SA) group and 30 healthy control cases. RESULTS: (1) The serum positive rate of HCMV-IgM and HCMV-IgG in the ACS, SA and healthy control groups were 30.4% (24/79), 10.0% (3/30) and 6.7% (2/30); 86.1% (68/79), 80.0% (24/30) and 53.3% (16/30), respectively. Positive rate of HCMV-IgM in the ACS was higher than those in SA and healthy control groups (P < 0.01), positive rate of HCMV-IgG in the ACS and SA groups were higher than that of the healthy control group (P < 0.01). (2) Compared with the SA group and healthy control group, the levels of the serum soluble P-selectin and TNF-alpha were significantly higher in patients with ACS [(6437.3 +/- 666.9) pg/ml vs. (1520.0 +/- 112.7) pg/ml and (1481.0 +/- 109.1) pg/ml, (56.2 +/- 18.4) pg/ml vs. (27.3 +/- 13.7) pg/ml and (28.1 +/- 11.3) pg/ml], respectively, P < 0.01). The AMI group, compared with the UA group in the ACS group, had significantly higher levels of the serum soluble P-selectin and TNF-alpha (P < 0.01). Compared with the SA group, the levels of the serum soluble P-selectin and TNF-alpha were not significantly different in healthy control group. (3) The levels of the serum soluble P-selectin and TNF-alpha in HCMV-IgM positive patients were significantly higher than the HCMV-IgM negative patients in the ACS group (P < 0.01). CONCLUSION: The chronic infection with HCMV might injure endothelial cells that subsequently contribute to the formation and progression of atherosclerosis, the acute infection with HCMV may induce increased serum levels of soluble P-selectin and TNF-alpha that might participate in acute coronary events.

Acute Coronary Syndrome↗

PubMed1991

Soluble interleukin-2 receptor in sera of patients with Graves' disease.

Recently, in vitro production of interleukin-2 receptor induced by mitogens have been shown to be impaired in autoimmune disorders including organo-specific autoimmune diseases. The aim of this study was to investigate serum levels of soluble interleukin-2 receptor in 20 untreated patients with Graves' disease and to follow up their changes in relation to clinical picture and TSH-receptor-, anti-thyroglobulin-, anti-microsomal as well as anti-eye muscle antibodies. Soluble interleukin-2 receptor level was significantly increased in newly-diagnosed Graves' patients compared to controls (667 +/- 270 vs. 205 +/- 45 U/ml) (P less than 0.001). Among the patients sera those with active infiltrative ophthalmopathy had higher soluble interleukin-2 receptor levels than those without eye symptoms (810 +/- 313 vs. 525 +/- 180 U/ml). Soluble interleukin-2 receptor level was normalized in Methimazole-treatment-induced remission in the majority of patients except those with ophthalopathy. In five patients the soluble interleukin-2 receptor levels were studied after interruption of thyrostatic therapy; an increase was observed in three patients; thereafter hyperthyrosis relapsed in two cases. Furthermore, a correlation was found between soluble interleukin-2 receptor levels and TSH-receptor antibodies, however, the association with other immune parameters examined was not significant. In conclusion, an enhanced level of soluble interleukin-2 receptor was detected in patients with untreated Graves' disease. This finding might play a significant role in regulation of impaired cell-mediated immune mechanism and has a prognostic value for relapse of autoreactive processes.

Adult↗

PubMed1990

Comparative anticalculus effect of dentifrices containing 1.30% soluble pyrophosphate with and without a copolymer.

A six-month, double blind, clinical study was conducted to determine the effect on supragingival calculus formation of a dentifrice containing 1.30% soluble pyrophosphate (from 2.0% tetrasodium pyrophosphate) and 1.50% of a copolymer of methoxyethylene and maleic acid, as compared to a dentifrice containing the same amount of soluble pyrophosphate but without the copolymer. This pyrophosphate/copolymer dentifrice contained the optimal ratio of pyrophosphate anion to copolymer required for obtaining a comparable anticalculus effect to a clinically proven anticalculus dentifrice containing 3.3% soluble pyrophosphate and 1.0% of a copolymer. The optimal pyrophosphate/copolymer ratio was determined by a series of in vitro laboratory and in vivo animal studies. Male and female adult subjects were stratified into three balanced groups according to baseline calculus scores. They received an oral prophylaxis and were assigned to the use of either the dentifrice containing soluble pyrophosphate and the copolymer, or to the dentifrice containing soluble pyrophosphate but without the copolymer, or to a placebo dentifrice that did not contain an anticalculus ingredient. The results of the three-month calculus examination indicated that the dentifrice containing soluble pyrophosphate and the copolymer provided a 33.66% reduction in supragingival calculus formation after an oral prophylaxis as compared to the placebo dentifrice. This reduction was statistically significant at the 99 percent level of confidence. The results of the six-month calculus examination indicated that the dentifrice containing the soluble pyrophosphate and the copolymer provided a 36.10% reduction in supragingival calculus formation after an oral prophylaxis, as compared to the placebo dentifrice. This reduction was also statistically significant at the 99% level of confidence.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1989

A soluble form of bovine rod photoreceptor phosphodiesterase has a novel 15-kDa subunit.

A substantial fraction (20-30%) of the bovine rod outer segment phosphodiesterase (PDE) activity is not associated with outer segment membranes prepared with buffers of moderate ionic strength; this PDE activity appears to represent a distinct, soluble isozyme. Although this PDE isozyme can be demonstrated to be present in sealed rod outer segments, it is discarded from most standard rod outer segment preparations. A method was developed that allowed the rapid purification of the soluble rod PDE by 2600-fold, to apparent homogeneity, using a monoclonal antibody column (ROS-1a). The soluble rod PDE isozyme has a novel Mr = 15,000 subunit (delta) in addition to subunits of Mr = 88,000 (alpha sol), 84,000 (beta sol), and 11,000 (gamma sol). The delta subunit comigrates with and may be identical to the cone PDE 15-kDa subunit. The small subunits of the soluble rod PDE and the membrane-associated rod PDE were isolated by reverse-phase chromatography. The gamma sol subunit was a potent inhibitor of trypsin-activated rod PDE, inhibiting 50% of 1 pM PDE activity at a concentration of 11 pM. This concentration was similar to that observed for the gamma subunit of the membrane-associated rod PDE. The purified delta subunit did not appear to affect PDE activity; this subunit was, however, unusually difficult to keep in solution. All of the kinetic and physical properties of the soluble rod PDE tested thus far are similar to those of the membrane-associated form, except for the presence of the delta subunit, suggesting that this unique subunit could mediate the solubility of the soluble rod PDE and the cone PDE in the intact photoreceptor.

Animals↗

PubMed1987

Comparison of cell-associated and soluble galactosyltransferase isoenzymes from a human bladder transitional cell carcinoma line.

We investigated the asialo-agalactofetuin galactosyltransferase solubilized by Triton X-100 from a human bladder transitional cell carcinoma line (cell-associated form). The specific activity of this enzyme was dependent on cell population density, being about 50% higher in cells from confluent than from sparse cultures. We compared the properties of this enzyme with those of a galactosyltransferase isoenzyme present in the culture medium (soluble form). Electrophoresis on nondenaturing polyacrylamide gels showed the two forms to be isoenzymes, in that the mobility of the soluble enzyme was greater than that of the cell-associated enzyme. The isoenzymes differed in that the Km for UDP-galactose of the cell-associated enzyme (1 X 10(-5) M) was one-half that of the soluble isoenzyme. The isoenzymes differed by 1 order of magnitude in their affinity for a fetuin-derived acceptor with a Km of 16 X 10(-5) M for the cell-associated and 1.2 X 10(-5) M for the soluble form, although the Km for ovalbumin and asialomucin as acceptor was similar for both. Both enzymes were active over a broad pH range and their response to divalent cations was the same: the most efficient cation was Mn2+; but modest activity was detected in the presence of either Cd2+ or Co2+. As determined by gel filtration on Sepharose 6B, the cell-associated galactosyltransferase showed a molecular weight of 66,000, whereas that of the soluble form was 51,000. Limited proteolysis of the cell-associated enzyme with thermolysin and subsequent analysis by nondenaturing polyacrylamide gel electrophoresis demonstrated that the cell-associated enzyme could be converted to an isoenzyme showing the same electrophoretic mobility as the soluble enzyme present in the culture medium, presumably by removal of a portion of the peptide chain. The same result was obtained by treating the cell-associated enzyme with a cell extract. This suggests but does not prove that the soluble enzyme secreted or shed into the medium is produced from the cell-associated form by an endogenous protease.

Carcinoma, Transitional Cell↗

PubMed1987

Relative and absolute changes in soluble and insoluble collagen pool size in skin during normal growth and with dietary protein restriction in rats.

Absolute and relative changes in 0.5M acetic acid soluble and insoluble collagen were followed in the whole skins of young rats fed an adequate diet (18% lactalbumin) for 495 days (n = 92) and a low-protein (3% lactalbumin) diet for 210 days (n = 94). In well-nourished rats, the soluble collagen pool size reached a maximum at approximately 100-140 days of age whereas the insoluble pool tended to increase throughout the period of observation. Thus, the percent soluble collagen increased to a maximum of approximately 80% of total collagen at 40-50 days, thereafter declining progressively to about 20% by 495 days. In contrast, the size of the soluble collagen pool remained constant in protein-restricted rats, but with insoluble collagen increasing linearly throughout, although achieving only a level of about 1/6th of that reached in well-nourished rats. In the restricted rats, percent soluble collagen decreased rapidly and remained at about 25% of total between 80 and 210 days. These data were used to develop prediction equations for the size (mumoles hydroxyproline) of the soluble and insoluble collagen pools in healthy and protein-restricted rats. Hence, where A = days of age, the equations were, respectively: 0.414 X 10(-3) A - 0.390 A2 + 86.9 A - 1800; 0.262 X 10(-2) A3 + 0.793 A2 - 26.5 A + 272; 0.236 A + 155; and 5.07 A - 38.5. These findings are discussed with reference to possible mechanisms responsible for conversion of soluble to insoluble collagens in skin of well-nourished and growth-retarded rats.

Aging↗

PubMed1981

A sensitive equilibrium binding assay for soluble beta-adrenergic receptors.

An equilibrium binding assay has been developed for digitonin-solubilized beta-adrenergic receptors using 125 I-pindolol (IPIN) as a radioligand. Up to 50% of the beta-adrenergic receptors from rat lung membranes could be solubilized using 1% digitonin. Following incubation of soluble fractions with IPIN at 25 degree, protein associated radioactivity was identified by column chromatography using Sephadex G-50. The solubilized receptors bound IPIN with properties similar but not identical to those of the membrane bound receptor. The Kd determined for IPIN binding to soluble receptors was 113 pM while the Kd for membrane associated receptors was 36 pM. The rate constant for association (k1) of IPIN was 0.15x10(9) M-1 for soluble receptors and 2.2x10(9) M-1 min-1 for lung membrane receptors. The rate constant for dissociation (k2) was 0.025 min-1 for soluble receptors and 0.048 min-1 for membrane receptors. Agonists and antagonist of beta-adrenergic receptors inhibited in a stereoselective manner the binding of IPIN to both soluble and membrane bound receptors. The affinities of individual drugs determined for soluble receptors were similar to those determined for membrane receptors. Not only could digitonin-solubilized receptors be identified in soluble preparations from rat lung, but also from rat cerebral cortex and liver, and from L6 muscle, C6 rat glioma, and 1321N1 astrocytoma cell membranes.

Animals↗

PubMed1984

Specific blockers of myoblast fusion inhibit a soluble and not the membrane-associated metalloendoprotease in myoblasts.

We previously reported that the cell fusion that occurs during muscle development, when mononucleated myoblasts fuse to form multinucleated myotubes, requires endogenous metalloendoprotease activity at the time of fusion. We report here that myoblasts contain both soluble and membrane-associated metalloendoproteases, and that these proteases have different inhibitor specificities. Several inhibitors, previously shown to block myoblast fusion, inhibit only soluble and not membrane-associated metalloendoprotease activity in myoblasts. Another metalloendoprotease inhibitor, phosphoramidon, which had no effect on fusion, inhibits only the membrane-associated metalloendoprotease. These observations implicate a soluble metalloendoprotease in myoblast fusion. Two soluble metalloendoproteases can be demonstrated by column chromatofocusing, with pI values at pH 5.9 and 4.8. The soluble metalloendoprotease eluted at pH 5.9 is not inhibited by an inhibitor which blocks fusion, while the soluble metalloendoprotease eluted at pH 4.8 is inhibited. Of the three metalloendoprotease activities identified in myoblasts, the metalloendoprotease required in myoblast fusion appears to be the soluble metalloendoprotease with a pI of 4.8.

Animals↗

PubMed1980

[Conformation and thermal stability of soluble and liposomal forms of cytochrome P-450].

This secondary structure of soluble cytochrome P-450 and the one incorporated into liposomes from egg lecithin and microsomal lipids has been studied. Using circular dichroism and infrared spectroscopy, it was shown that about 60% of alpha-helices are presented in the structure of haemoprotein and the rest 40% have the structure of statistical coil. The binding of haemoprotein with the type II substrates--octylamine and diaminooctan, slightly increases alpha-helices in soluble cytochrome P-450. The type I non-polar substrates--hexane and cyclohexane--do not change the conformation of isolated enzyme. Cytochrome P-450 incorporated into the artificial membranes of phosphatidyl choline and microsomal phospholipid has almost identical secondary structure as does the soluble one. Data from circular dichroism suggest that the binding of the types I and II substrates to cytochrome P-450 incorporated into lecithin liposomes and microsomal lipid liposomes does not change the conformation of the polypeptide chain. The reduction of cytochrome P-450 haem increases the degree of alpha-spiralization by 10% for soluble haemoprotein and by 5% for the membrane-bound enzyme. The thermal stability of soluble and liposomal forms of cytochrome P-450 was investigated by circular dichroism technique. The effective values of enthalpy and the temperature transition of soluble cytochrome P-450 at pH 6.9, 7,6 and 7,9 are 78, 80 and 78 kcal/mol and 47,7 degrees, 45,2 degrees and 42,4 degrees, respectively. The enzyme incorporated into the phospholipid vesicles is much more stable. The cooperative transition of soluble cytochrome is clearly expressed in contrast to the one of the membrane-bound enzyme.

Circular Dichroism↗

PubMed1993

Mechanism of release of soluble forms of tumor necrosis factor/lymphotoxin receptors by phorbol myristate acetate-stimulated human THP-1 cells in vitro.

The mechanism involved in the release of the soluble forms of 55 and 75 kDa TNF and lymphotoxin (LT) membrane receptors was studied in a continuous human monocytic cell line, THP-1, in vitro. THP-1 cells were found to spontaneously release soluble forms of both 55 and 75 kDa TNF/LT receptors. Release was up-regulated by PMA, and optimal release was achieved at 10(-8) M PMA. Serine protease inhibitors such as PMSF,3,4 dichloroisocoumarin, N alpha-p-tosyl-L-lysine chloromethyl ketone (TLCK), and N-tosyl-L-phenylalanine chloromethyl ketone (TPCK) were found to inhibit the production of both soluble TNF/LT receptors. PMSF (2 mM) also blocked receptors shedding from paraformaldehyde-fixed THP-1 cells coincubated with conditioned media from PMA-stimulated THP-1 cells. Colchicine at 1 and 10 microM stimulated the production of both soluble TNF/LT receptors, but the PMA-induced release of both soluble TNF/LT receptors was inhibited. It appears that the PMA-induced release of soluble TNF/LT receptors involves serine proteases in the extracellular space where the soluble parts of the TNF/LT receptors are cleaved directly off the cell membrane.

Cell Line↗

PubMed1996

Reduced serum levels of a soluble form of the human adhesion receptor CD58 (LFA-3) in patients with inflammatory bowel disease.

The activation of monocytes, neutrophils, and B cells by T-lymphocytes appears to play a pivotal role in the pathophysiology of inflammatory bowel disease. The pan T cell marker CD2 and its ligand CD58 mediate these immune function. We asked whether serum levels of a soluble form of CD58 is altered in patients with inflammatory bowel disease. Soluble CD58 was measured in sera from 41 patients with Crohn's disease, 19 patients with ulcerative colitis, and 24 normal controls. Soluble CD58 levels were significantly decreased in sera from patients with ulcerative colitis and even more with Crohn's disease when compared to controls (p = 0.025 and p < 0.0001, respectively). Reduction of soluble CD58 serum levels correlated significantly with various humoral (e.g. erythrocyte sedimentation rate: r = -0.48, p = 0.0002) and clinical parameters of disease activity (e.g. CDAI: r = -0.44, p = 0.005). In conclusion, serum levels of soluble CD58 are reduced in patients with inflammatory bowel disease. Since soluble CD58 can block the CD2/CD58 interaction further studies have to show whether the reduction of soluble CD58 in patients with inflammatory bowel disease contributes to T cell adhesiveness in the mucosa.

Adolescent↗

PubMed1996

Soluble P-selectin as parameter for platelet activation during storage.

Platelet concentrates stored at room temperature deteriorate. The so-called storage lesion is characterised by morphological changes and a loss of functionality. To find an assay for early platelet activation in platelet concentrates the morphological score, beta-TG release and P-selectin expression were determined, and compared with the amount of soluble P-selectin. An ELISA was used to quantify soluble P-selectin in the storage medium. We found a significant correlation between the amount of soluble P-selectin and the percentage of P-selectin positive platelets (flow-cytometric analysis) (r = 0.7449; p < 0.0001) or the amount of beta-TG release (r = 0.6837; p < 0.0001). The morphological score also correlated significantly (negative) with the amount of soluble P-selectin (r = -0.7669; p = 0.0002). From day 0 till day 8, the amount of soluble P-selectin increased constantly from 219 +/- 49.2 ng/ml to 556 +/- 102.3 ng/ml. The detection of soluble P-selectin can be used to quantify activation of platelets during storage. The immuno-assay for soluble P-selectin is more sensitive than flow-cytometric analysis of the percentage of P-selectin-positive cells and allows earlier detection of platelet activation.

Biomarkers↗

PubMed1997

[Serum soluble adhesion molecules in patients with sarcoidosis].

We measured serum soluble adhesion molecules levels in patients with sarcoidosis. The serum levels of soluble ICAM-land L-, E-, and P-selectin were significantly elevated in patients with sarcoidosis compared with healthy volunteers. However, there was no significant difference in serum soluble VCAM-1 levels between the patients and healthy volunteers. A significant correlation was observed between serum soluble L-selectin levels and the number of lymphocytes in the bronchoalveolar lavage fluid of patients with sarcoidosis. Although higher levels of serum soluble adhesion molecules were present in accordance with the clinical stage of sarcoidosis, the differences were not statistically significant. There was a significant correlation between serum ACE and soluble ICAM-1 or VCAM-1 levels. These findings suggest that soluble adhesion molecules may play an important role in the pathogenesis of sarcoidosis.

Adult↗

PubMed1998

Serum-soluble interleukin-2 receptor concentrations in patients with breast cancer: a preliminary report.

BACKGROUND: The serum-soluble interleukin-2 receptor has been claimed to be a marker of host biological response in patients with solid malignancies. This study was designed to evaluate the biological significance of the preoperative serum-soluble interleukin-2 receptor concentration in patients with invasive breast cancer. MATERIALS AND METHODS: Venous blood samples were collected from 66 patients with invasive breast carcinoma and the serum concentrations of soluble interleukin-2 receptor were measured with an enzyme immunoassay method. Data regarding maximum tumor diameter, age, estrogen receptor status, lymph node status, distant metastasis status, histologic grade, ploidy pattern and S-phase fraction were also collected and evaluated simultaneously with the serum concentration levels of soluble interleukin-2 receptor. Fifteen age-matched healthy subjects were used as a control group. RESULTS: The mean value of serum-soluble interleukin-2 receptor in patients with invasive breast cancer was 621 +/- 145 units/ml and that of the control group was 308 +/- 59 units/ml; and the difference was significant (p = 0.000). With multivariate analysis, lymph node status (p = 0.000), distant metastasis status (p = 0.000) and maximum tumor diameter (p = 0.000) appeared as independent factors in regards to the significantly, higher serum concentrations of soluble interleukin-2 receptor. CONCLUSION: Based on our preliminary results, the preoperative serum-soluble interleukin-2 receptor concentration is closely related to lymph node status, distant metastasis status and tumor diameter in invasive breast carcinoma. This may be an additional valuable predictive factor for the diagnosis of invasive breast cancer.

Adult↗

PubMed1998

Effect of cilostazol on soluble adhesion molecules and platelet-derived microparticles in patients with diabetes.

We evaluated the plasma concentrations of soluble adhesion molecules and platelet-derived microparticles (PMP) in patients with non-insulin dependent diabetes mellitus (NIDDM) and studied the effect of cilostazol on PMP generation. There were differences in the levels of soluble adhesion molecules between NIDDM patients (N = 43) and the control subjects (N = 30) (soluble thrombomodulin: 11.5+/-5.3 vs. 7.0+/-1.2 TU/ml, p<0.0001; soluble vascular cell adhesion molecule-1: 708+/-203 vs. 492+/-113 ng/dl, p<0.0001; soluble intercellular cell adhesion molecules- 1: 274+/-65 vs. 206+/-48 ng/dl, p<0.0001; soluble P-selectin: 194+/-85 vs. 125+/-43 ng/dl, p<0.0001). There were also differences in the levels of PMP and platelet activation markers between NIDDM patients and the controls (PMP: 943+/-504 vs. 488+/-219/10(4) plt, p<0.0001; platelet CD62P: 9.2+/-4.6 vs. 4.4+/-4.3%, p<0.001; platelet CD63: 10.2+/-4.5 vs. 4.5+/-3.3%, p<0.0001; platelet annexin V: 9.1+/-3.9 vs. 5.3+/-3.8%, p<0.001). To study the release of PMP into plasma, a modified cone-and-plate viscometer was used. Increased release of PMP from platelets was observed in diabetic plasma compared to normal plasma under high shear stress conditions (2,672+/-645 vs. 1,498+/-386/10(4) plt, p<0.05). Therefore, one cause of PMP elevation in NIDDM may be high shear stress. The levels of PMP, activated platelets, and soluble adhesion molecules all decreased significantly after treatment with cilostazol. These results suggest that cilostazol may be useful for the inhibition of both PMP-dependent and -independent vascular damage in NIDDM.

Adult↗

PubMed2001

The membrane-bound but not the soluble form of human Fas ligand is responsible for its inflammatory activity.

The ectopic expression of Fas ligand (FasL/CD95L) in tissues or tumors induces neutrophil infiltration and the destruction of the tissues or the rejection of tumors. It has been suggested that the infiltrated neutrophils are responsible for the latter phenomena. FasL is synthesized as a type II transmembrane protein, and soluble FasL is produced by a proteolytic mechanism from the membrane-bound form. We previously demonstrated that uncleavable membrane-bound FasL of mice induces IL-1 beta release from inflammatory cells, and suggested that the IL-1 beta enhances neutrophil infiltration. However, recent papers reported that human soluble FasL is directly chemoattractive to neutrophils in vitro and proposed that the soluble form of FasL is responsible for its inflammatory activity. Therefore, in this report, we investigated which form is responsible for the inflammatory activities of human FasL. We produced tumor cell lines expressing one or both forms of human FasL. Cells expressing both forms or only the membrane-bound form of FasL induced neutrophil infiltration when transplanted into the peritoneal cavity of syngeneic mice, while cells expressing only the soluble form did not. Purified soluble FasL failed to induce neutrophil infiltration in vivo. IL-1 beta release from inflammatory peritoneal exudate and acceleration of tumor rejection were also mediated by membrane-bound but not soluble FasL. These results indicate that the membrane-bound form of FasL is primarily responsible for its inflammatory activity.

Animals↗

PubMed2004

Solubility of endotoxins from Escherichia coli and Pseudomonas aeruginosa.

BACKGROUND: The Limulus amebocyte lysate (LAL) assay may underestimate endotoxins because only soluble endotoxins are determined. The solubility of endotoxins was, therefore, studied in two species of Gram-negative bacteria. METHODS: Cultures were grown in serum broth, cells were harvested by centrifugation and washed in physiological saline. Bacterial suspensions were either filtered through PTFE filters and air dried at room temperature, dried in polypropylene tubes at room temperature in a desiccator, or freeze dried. Samples were extracted with aqueous Tween 20. The soluble and insoluble fractions were dried, methanolysed, and hydroxy-fatty acid methyl esters were determined by gas chromatography (GC) as markers of endotoxins. RESULTS: The solubility of the endotoxins from Escherichia coli and Pseudomonas aeruginosa ranged from 9% to 83%. Species and drying conditions had substantial influence on the solubility. CONCLUSIONS: Endotoxin exposure may be underestimated in environmental samples by the LAL test because a substantial fraction can be non-soluble and is not detected.

Bacterial Toxins↗

PubMed1994

Serum levels of soluble adhesion molecules intercellular adhesion molecule 1, vascular cell adhesion molecule 1, and E-selectin in patients with Wegener's granulomatosis. Relationship to disease activity and relevance during followup.

OBJECTIVE: To assess the value of measuring serum levels of soluble intercellular adhesion molecule 1 (sICAM-1), soluble vascular cell adhesion molecule 1 (sVCAMP-1), and soluble E-selectin for monitoring disease activity in Wegener's granulomatosis (WG). METHODS: A sandwich enzyme-linked immunosorbent assay was used to measure levels of soluble adhesion molecules at the time of diagnosis in 22 consecutive patients with WG, in 12 WG patients studied serially prior to disease relapse, at the time of upper airways infection in 18 patients with inactive WG, and in 57 controls. Disease activity was assessed by disease activity score and C-reactive protein levels. RESULTS: At diagnosis of WG, sICAM-1 and sVCAM-1 levels were significantly elevated and correlated with disease activity. At the time of relapse, a significant increase in all 3 soluble adhesion molecules was found compared with levels at 6 months prior to relapse, but only sVCAM-1 levels were significantly elevated compared with those in controls. Levels of soluble adhesion molecules at the time of relapse did not differ from those measured during an upper airways infection without disease activity. CONCLUSION: Elevated serum levels of sICAM-1 and sVCAM-1 can be found in active WG and correlate with disease activity. However, their clinical relevance for followup is limited due to lack of sensitivity and specificity for WG disease activity.

Adolescent↗