Leukocyte surface origin of human alpha1-acid glycoprotein (orosomucoid)

Analytical performance of a canine ELISA monocyte chemoattractant protein-1 assay for use in cats and evaluation of circulating levels in normal weight and obese cats

BACKGROUND

In human and murine obesity, adipose tissue dwelling macrophages and adipocytes produce monocyte chemoattractant protein-1 (MCP-1) leading to systemic low-grade inflammation. The aim of the study was to validate a canine MCP-1 ELISA assay for use in cats and to investigate whether a difference in MCP-1 concentrations could be detected between: a) cats having normal or elevated circulating serum amyloid A (SAA) levels and b) normal weight and obese cats. Serum obtained from 36 client-owned cats of various breed, age and sex with normal (n = 20) to elevated SAA (n = 16) was used for the validation of the canine MCP-1 ELISA assay. As no golden standard exists for measurement of inflammation, circulating MCP-1 concentrations were compared to SAA measurements, as an indicator of systemic inflammation. Analytical precision, dilution recovery and detection limit were calculated. A possible correlation between MCP-1 concentrations and obesity related measures (body fat percentage (BF%), insulin sensitivity and cytokine expression) were investigated in another population of 73 healthy, lean to obese, neutered domestic short-haired cats.

RESULTS

Intra- (2.7-4.1%) and inter-assay (2.2-3.6%) coefficient of variation and dilution recovery were acceptable, and the detection limit was 27.1 pg/mL. MCP-1 did not correlate with SAA, and there was no difference between the inflammatory (SAA > 20 mg/L) and non-inflammatory group, due to a marked overlap in MCP-1 concentrations. Circulating MCP-1 concentrations were unaffected by BF% (r2 = 2.7 × 10-6, P = 0.21) and other obesity-related markers.

CONCLUSIONS

The present canine ELISA assay seems to be able to measure circulating feline MCP-1. However, further studies are needed to determine its possible use for detecting inflammation in relation to disease processes or obesity-related low-grade inflammation in cats.

Localisation of clozapine during experimental autoimmune encephalomyelitis and its impact on dopamine and its receptors

Multiple sclerosis is a disease characterised by axonal demyelination in the central nervous system (CNS). The atypical antipsychotic drug clozapine attenuates experimental autoimmune encephalomyelitis (EAE), a mouse model used to study multiple sclerosis, but the precise mechanism is unknown and could include both peripheral and CNS-mediated effects. To better understand where clozapine exerts its protective effects, we investigated the tissue distribution and localisation of clozapine using matrix-assisted laser desorption ionization imaging mass spectrometry and liquid chromatography-mass spectrometry. We found that clozapine was detectable in the brain and enriched in specific brain regions (cortex, thalamus and olfactory bulb), but the distribution was not altered by EAE. Furthermore, although not altered in other organs, clozapine levels were significantly elevated in serum during EAE. Because clozapine antagonises dopamine receptors, we analysed dopamine levels in serum and brain as well as dopamine receptor expression on brain-resident and infiltrating immune cells. While neither clozapine nor EAE significantly affected dopamine levels, we observed a significant downregulation of dopamine receptors 1 and 5 and up-regulation of dopamine receptor 2 on microglia and CD4+-infiltrating T cells during EAE. Together these findings provide insight into how neuroinflammation, as modelled by EAE, alters the distribution and downstream effects of clozapine.

Characterization of the signature of peripheral innate immunity in women with later-life major depressive disorder

The prevalence of depression in later life is higher in women than in men. However, the sex difference in the pathophysiology of depression in elderly patients is not fully understood. Here, we performed gene expression profiling in leukocytes of middle-aged and elderly patients with major depressive disorder, termed later-life depression (LLD) in this context, and we characterized the sex-dependent pathophysiology of LLD. A microarray dataset obtained from leukocytes of patients (aged ≥50 years) with LLD (32 males and 39 females) and age-matched healthy individuals (20 males and 24 females) was used. Differentially expressed probes were determined by comparing the expression levels between patients and healthy individuals, and then functional annotation analyses (Ingenuity Pathway Analysis, Reactome pathway analysis, and cell-type enrichment analysis) were performed. A total of 1656 probes were differentially expressed in LLD females, but only 3 genes were differentially expressed in LLD males. The differentially expressed genes in LLD females were relevant to leukocyte extravasation signaling, Tec kinase signaling and the innate immune response. The upregulated genes were relevant to myeloid lineage cells such as CD14⁺ monocytes. In contrast, the downregulated genes were relevant to CD4⁺ and CD8⁺ T cells. Remarkable innate immune signatures are present in the leukocytes of LLD females but not males. Because inflammation is involved in the pathophysiology of depression, the altered inflammatory activity may be involved in the pathophysiology of LLD in women. In contrast, abnormal inflammation may be an uncommon feature in LLD males.

The Immune Functions of α1 Acid Glycoprotein

α1-acid glycoprotein (orosomucoid, AGP) is an Acute Phase Protein produced by liver and peripheral tissues in response to systemic reaction to inflammation. AGP functions have been studied mostly in human, cattle and fish, although the protein has been also found in many mammalian species and birds. AGP fulfils at least two set of functions, which are apparently different from each other but in fact intimately linked. On one hand, AGP is an immunomodulatory protein. On the other hand, AGP is one of the most important binding proteins in plasma and, beside modulating pharmacokinetics and pharmacodynamics of many drugs, it is also able to bind and transport several endogen ligands related to inflammation. The focus of this review is the immunomodulatory activity of AGP. This protein regulates every single event related to inflammation, including binding of pathogens and modulating white blood cells activity throughout the entire leukocyte attacking sequence. The regulation of AGP activity is complex: the inflammation induces not only an increase in AGP serum concentration, but also a qualitative change in its carbohydrate moiety, generating a multitude of glycoforms, each of them with different, and sometimes opposite and contradictory, activities. We also present the most recent findings about the relationship between AGP and adipose tissue: AGP interacts with leptin receptor and, given its immunomodulatory function, it may be included among the potential players in the field of immunometabolism.

Utility of C-reactive protein and serum amyloid A in the diagnosis of equine protozoal myeloencephalitis

BACKGROUND

Accurate antemortem EPM diagnosis requires evidence of intrathecal antibody production. Some advocate the use of acute phase proteins in addition to serology, which alone results in substantial false positives.

HYPOTHESIS/OBJECTIVES

The purpose of this study was to determine if serum C-reactive protein (CRP) or serum amyloid A (SAA) concentrations were elevated in cases of equine protozoal myeloencephalitis (EPM) compared to other neurological diseases.

ANIMALS

25 clinical cases of equine neurological disease: EPM (10), cervical vertebral stenotic myelopathy (CVSM) (10), neuroborreliosis (2), equine motor neuron disease (1), degenerative myelopathy (1), and leukoencephalomalacia (1).

METHODS

Serum and CSF CRP and SAA were measured. Selection criteria included neurologic disease, antemortem diagnosis of EPM or CVSM, or postmortem diagnosis of EPM, CVSM, or other neurologic disease, and availability of serological results and archived samples for testing.

RESULTS

Serum SAA and serum CRP levels were generally undetectable or low in horses with EPM (median CRP ≤0.1 mg/L, ≤0.1-14.4 mg/L; median SAA ≤0.1 mg/L, ≤0.1-6.11 mg/L) and CVSM (median CRP ≤0.1, ≤0.1-2.41 mg/L; median SAA ≤0.1mg/L, ≤0.1-13.88 mg/L). CSF CRP and SAA for horses with EPM (median CRP 3.35 mg/l, 0.19-13.43 mg/l; median SAA ≤0.1 mg/L, ≤0.1-2.4 mg/L) and CVSM (median CRP 4.015 mg/L, 0.16-9.62 mg/L; median SAA 0.62 mg/L, ≤0.1-2.91 mg/L) were also undetectable or low. Kruskal-Wallis test showed no statistically significant differences between serum CRP (P = .14), serum SAA (P = .79), spinal fluid CRP (P = .65), or spinal fluid SAA between horses with EPM and CVSM (P = .52).

CONCLUSION

Neither SAA nor CRP in serum or CSF aid diagnosis of EPM.

Urinary biomarkers in childhood lupus nephritis

Juvenile-onset systemic lupus erythematosus (JSLE) is a rare, severe multisystem autoimmune disease affecting the kidney (Lupus Nephritis, LN) in up to 80% of children. LN is more severe in children than adults, with potential for irreversible kidney damage requiring dialysis or transplant. Renal biopsy is currently the gold standard for diagnosing and monitoring LN, however, it is invasive and associated with complications. Urine biomarkers have been shown to be better than serum biomarkers in differentiating renal disease from other organ manifestations. Over the past decade, there have been an increasing number of studies investigating specific candidate biomarkers implicated in the pathogenesis of LN or screening for urinary biomarkers using hypothesis free methods. In this review, developments in urine biomarkers for LN will be reviewed, highlighting those that are of relevance to children and have gone through validation in independent international patient cohorts, bringing them close to clinical translation.

The increased excretion of urinary orosomucoid 1 as a useful biomarker for bladder cancer

Improving the early detection rate and prediction of bladder cancer remains a great challenge in management of this disease. To examine the value of urinary orosomucoid 1 (ORM1) for the early detection and surveillance of bladder cancer, two-dimensional differential gel electrophoresis (2-DE) and matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-TOF/TOFMS) were applied to identify the differently expressed proteins in urine between bladder cancer and healthy controls. Thirteen different proteins including ORM1 were identified. After verification by western blotting, the ORM1 expressions were quantified in 186 urine samples by enzyme-linked immunosorbent assay (ELISA) correcting for creatinine expression. ELISA quantification showed the urinary ORM1-Cr was found to be higher in bladder cancer patients compared to controls and benign cases (7172.23±3049.67 versus 2243.16±969.01, 2493.48±830.37 ng/ml, respectively, P<0.0001). Furthermore, the pearson correlation analysis indicated that urinary ORM1 had high positive correlation with the pathology classification of bladder cancer. Receiver operating characteristic (ROC) analysis was used to calculate the cut-off value for early diagnosis of bladder cancer, and rendered an optimum cut-off value of 3912.97 ng/mg corresponding to 91.96% sensitivity and 94.34% specificity. Moreover, a cut-off value with 7351.28 ng/mg was utilized to distinguish infiltrating urothelial carcinoma from bladder cancer patients corresponding to 91.89% sensitivity and 90.67% specificity. In conclusion, our findings suggested the elevated urinary ORM1 could be a useful biomarker for bladder cancer. Further research is warranted to elucidate the pathogenic mechanisms of elevated ORM1.

α1-acid glycoprotein disrupts capillary-like tube formation of human lung microvascular endothelia

PURPOSE

The acute phase protein, α1-acid glycoprotein, is expressed in the lung, and influences endothelial cell function. We asked whether it might regulate angiogenesis in human lung microvascular endothelia.

MATERIALS AND METHODS

α1-acid glycoprotein was isolated from human serum by HPLC ion exchange chromatography. Its effects on endothelial cell functions including capillary-like tube formation on Matrigel, migration in a wounding assay, chemotaxis in a modified Boyden chamber, adhesion, and transendothelial flux of the permeability tracer, (14)C-albumin, were tested.

RESULTS

α1-acid glycoprotein dose-dependently inhibited capillary-like tube formation without loss of cell viability. At ≥0.50 mg/mL, it inhibited tube formation >70%, and at 0.75 mg/mL, >97%. α1-acid glycoprotein dose- and time-dependently restrained EC migration into a wound as early as 2 hours, and in washout studies, did so reversibly. It was inhibitory against vascular endothelial growth factor-A and fibroblast growth factor-2-driven migration but failed to inhibit chemotactic responsiveness. When α1-acid glycoprotein was added to preformed tubes, it provoked their almost immediate disassembly. As early as 15 minutes, it induced tube network collapse without endothelial cell-cell disruption. It exerted a biphasic effect on cell adhesion to the Matrigel substrate. At lower concentrations (0.05-0.25 mg/mL), it increased cell adhesion, whereas at higher concentrations (≥0.75 mg/mL) decreased adhesion. In contrast, it had no effect on transendothelial (14)C-albumin flux.

CONCLUSION

α1-acid glycoprotein, at concentrations found under physiological conditions, rapidly inhibits endothelial cell capillary-like tube formation that may be explained through diminished cell adhesion to the underlying matrix and/or reversibly decreased cell migration.

Excretion of urinary orosomucoid 1 protein is elevated in patients with chronic heart failure

Easily screening markers for early detection of chronic heart failure (CHF) are lacking. We identified twenty differently expressed proteins including orosomucoid 1(ORM1) in urine between patients with CHF and normal controls by proteomic methods. Bioinformatics analyses suggested ORM1 could be used for further analysis. After verification by western blotting, the urinary levels of ORM1 were quantified with enzyme-linked immunosorbent assay (ELISA) by correcting for creatinine expression. The ORM1-Cr was significantly elevated in CHF patients than normal controls (6498.83±4300.21 versus 2102.26±1069.24 ng/mg). Furthermore, a Spearman analysis indicated that the urinary ORM1 levels had a high positive correlation with the classification of CHF, and the multivariate analysis suggested that the urinary ORM1 content was associated with the plasma amino-terminal pro- brain natriuretic peptide (NT-proBNP) (OR: 2.106, 95% CI: 1.213–3.524, P = 0.002) and the New York Heart Association (NYHA) classification (OR: 3.019, 95% CI: 1.329–4.721, P<0.001). In addition, receiving operating curve (ROC) analyses suggested that an optimum cut-off value of 2484.98 ng/mg with 90.91% sensitivity and 85.48% specificity, respectively, could be used for the diagnosis of CHF. To sum up, our findings indicate that ORM1 could be a potential novel urinary biomarker for the early detection of CHF.

The orosomucoid 1 protein (α1 acid glycoprotein) is overexpressed in odontogenic myxoma

BACKGROUND

Odontogenic myxoma (OM) is a benign, but locally invasive, neoplasm occurring in the jaws. However, the molecules implicated in its development are unknown. OM as well as Dental Follicle (DF), an odontogenic tissue surrounding the enamel organ, is derived from ectomesenchymal/mesencyhmal elements. To identify some protein that could participate in the development of this neoplasm, total proteins from OM were separated by two-dimensional electrophoresis and the profiles were compared with those obtained from DF, used as a control.

RESULTS

We identified eight proteins with differential expression; two of them were downregulated and six upregulated in OM. A spot consistently overexpressed in odontogenic myxoma, with a molecular weight of 44-kDa and a pI of 3.5 was identified as the orosomucoid 1 protein. Western blot experiments confirmed the overexpression of this protein in odontogenic myxoma and immunohistochemical assays showed that this protein was mainly located in the cytoplasm of stellate and spindle-shaped cells of this neoplasm.

CONCLUSION

Orosomucoid 1, which belongs to a group of acute-phase proteins, may play a role in the modulation of the immune system and possibly it influences the development of OM.

Identification of Potential Glycoprotein Biomarkers in Estrogen Receptor Positive (ER+) and Negative (ER-) Human Breast Cancer Tissues by LC-LTQ/FT-ICR Mass Spectrometry

Breast cancer is the second most fatal cancer in American women. To increase the life expectancy of patients with breast cancer new diagnostic and prognostic biomarkers and drug targets must be identified. A change in the glycosylation on a glycoprotein often causes a change in the function of that glycoprotein; such a phenomenon is correlated with cancerous transformation. Thus, glycoproteins in human breast cancer estrogen receptor positive (ER+) tissues and those in the more advanced stage of breast cancer, estrogen receptor negative (ER-) tissues, were compared. Glycoproteins showing differences in glycosylation were examined by 2-dimensional gel electrophoresis with double staining (glyco- and total protein staining) and identified by reversed-phase nano-liquid chromatography coupled with a hybrid linear quadrupole ion trap/ Fourier transform ion cyclotron resonance mass spectrometer. Among the identified glycosylated proteins are alpha 1 acid glycoprotein, alpha-1-antitrypsin, calmodulin, and superoxide dismutase mitochondrial precursor that were further verified by Western blotting for both ER+ and ER- human breast tissues. Results show the presence of a possible glycosylation difference in alpha-1-antitrypsin, a potential tumor-derived biomarker for breast cancer progression, which was expressed highest in the ER- samples.

Flow cytometric detection of alpha-1-acid glycoprotein on feline circulating leucocytes

OBJECTIVE

To assess whether alpha-1-acid glycoprotein (AGP) can be detected on the membrane of feline circulating leucocytes.

DESIGN

The presence of AGP on circulating leucocytes was investigated in both clinically healthy cats and cats with different diseases. A group of feline coronavirus (FCoV)-positive cats, comprising cats with feline infectious peritonitis (FIP) and cats not affected by FIP but seropositive for FCoV, were included in this study because the serum concentration of AGP increases during FCoV infection.

PROCEDURE

Flow cytometry (using an anti-feline AGP antibody), serum protein electrophoresis, routine haematology and measurement of the serum AGP concentration were performed using blood samples from 32 healthy cats (19 FCoV-seropositive), 13 cats with FIP and 12 with other diseases (6 FCoV-seropositive). The proportion of cats with AGP-positive leucocytes in the different groups (e.g. controls vs sick; FIP vs other diseases, etc.) or in cats with different intensities of inflammatory response was compared using a Chi-square test.

RESULTS

AGP-positive leucocytes were found in 23% of cats. Compared with controls, the proportion of patients with positive granulocytes and monocytes was higher among sick cats (especially cats with diseases other than FIP) and cats with high serum AGP concentration, but not in cats with leucocytosis or that were FCoV-seropositive.

CONCLUSION

AGP-positive leucocytes can be found in feline blood, especially during inflammation. Conversely, no association between AGP-positive leucocytes and FIP was found. Further studies are needed to elucidate the mechanism responsible for this finding and its diagnostic role in cats with inflammation.

Changes in acute-phase proteins and cytokines in serum and milk whey from dairy cows with naturally occurring peracute mastitis caused by Klebsiella pneumoniae and the relationship to clinical outcome

This study was conducted to evaluate the changes in acute-phase proteins and cytokine concentrations in dairy cows with naturally occurring peracute Klebsiella pneumoniae (K. pneumoniae) mastitis and their association with the outcome of the disease. Seventeen Holstein cows with K. pneumoniae mastitis from 8 dairy farms were divided on the basis of outcome after local and systemic therapy into 2 groups comprising 8 euthanized cows and 9 that recovered. Changes in acute-phase proteins and cytokine concentrations in cows with K. pneumoniae mastitis were evaluated at the onset of the disease (day 0) and at days 3, 7 and 14 after therapy and compared with those of 13 healthy dairy cows. The concentrations of haptoglobin (Hp) and interleukin (IL)-6 in serum and α(1)-acid glycoprotein and IL-1β in serum and whey on day 0 were significantly (P<0.05) higher in the euthanized cows than in those that recovered and the healthy cows. A correlation (r=0.90, P<0.01, n=17) was found between IL-6 and Hp concentrations in sera from recovered and euthanized cows at day 0. This indicated that serum concentrations of Hp and IL-6 at the initial examination were prognostic factors for survival, and the cutoff values were 2,020 µg/ml and 32 ng/ml, respectively. These results suggest that IL-6 and Hp concentrations are involved in the manifestation of K. pneumoniae mastitis and may be possible indicators of the prognosis of peracute K. pneumoniae mastitis.

Verification of measurement of the feline serum amyloid A (SAA) concentration by human SAA turbidimetric immunoassay and its clinical application

Serum amyloid A (SAA) is one of the major acute phase proteins in cats that has potential to be used as an inflammatory marker. A previous study showed that the human SAA turbidimetric immunoassay (hSAA-TIA) could be used to measure the SAA concentration in cats. The objectives of the present study were to assess use of hSAA-TIA for determining the feline SAA concentration and to evaluate its clinical application. Recombinant feline SAA protein (rfSAA) was expressed in Escherichia coli and purified for SDS-PAGE and immunoblot analysis with anti-human SAA antibodies. The concentration of rfSAA was determined by ELISA and hSAA-TIA. Plasma SAA concentrations were measured in healthy and diseased cats by hSAA-TIA. The time-courses changes in the SAA and alpha1-acid glycoprotein (AGP) concentrations in the cats after ovariohysterectomy were investigated. In SDS-PAGE, rfSAA was detected as a clear band that reacted with anti-human SAA antibodies. There was significant correlation between the SAA concentration measured by ELISA and hSAA-TIA. The SAA concentration of the diseased cats (n=263) was significantly increased (P<0.01; 0.0-88.9 mg/l, mean: 7.52 mg/l) compared with that in the healthy cats (n=26; 0.0-0.9 mg/l, mean: 0.14 mg/l). No correlation was observed between SAA and WBC in the diseased cats. The SAA concentration changed more rapidly and remarkably than the AGP concentration after ovariohysterectomy. The present study revealed that hSAA-TIA is useful for determination of the feline SAA concentration. Measurement of the SAA concentration, in addition to the WBC count, would be clinically valuable as a routine test to detect inflammation.

Serum immunosuppressive acidic protein reflects systemic deterioration of colorectal cancer patient condition

AIMS

Immunosuppressive acidic protein (IAP) is a potent biological marker for immunological surveillance in patients with malignant tumors. This study aimed to investigate the significance of serum IAP as an index of disease status, clinicopathological findings and prognosis in colorectal cancer.

METHODS

A total of 101 patients with colorectal cancer and 80 normal volunteers were included in this retrospective trial. Preoperative serum IAP was assayed using a commercially available enzyme-linked immunosorbent assay kit.

RESULTS

The serum IAP level in the patients, which was not associated with clinicopathological features except for tumor size, was significantly higher than that in controls. The serum IAP level was closely correlated with percent body weight loss, serum albumin and cholinesterase, and percentage of circulating lymphocytes reflecting the host's nutritional and immunological conditions. Interestingly, these parameters were not associated with factors reflecting disease progression except for tumor size. The prognosis of patients with higher IAP levels was significantly worse than that of patients with lower IAP levels. Furthermore, an elevated serum IAP level was an independent prognostic marker in all patients.

CONCLUSION

The preoperative serum IAP level may reflect the general condition of colorectal cancer patients, and thus may predict long-term survival independently of stage progression.

Prognostic role of immunosuppressive acidic protein in patients with esophageal cancer

Immunosuppressive acidic protein (IAP) suppresses several immune responses in vivo and in vitro , and high preoperative IAP levels could predict the impairment of the host's immunity. In this study prognostic significance of preoperative IAP levels was investigated in 68 esophageal cancer patients with curative resection and eight with non-curative resection. The curative group had significantly lower levels than the non-curative group (432 +/- 183 mg/mL vs. 739 +/- 235 mg/mL, P < 0.0001). The IAP levels were associated with T-status (P < 0.0001), lymphatic invasion (P < 0.05), and p-stages (P < 0.0001). When 5-year survival rate of patients with curative resection was compared by setting various cutoff values of IAP between high and low IAP groups, several cutoff points (400-580 mg/mL) were revealed to be significantly associated with survival. Setting cutoff value of IAP to 560 mg/mL resulted in a most significant difference of 5-year survival rate of patients between the high and low IAP groups (13.9% and 61.5%, P < 0.0001). These data indicate that pre-operative IAP level is a useful parameter to predict the prognosis of esophageal cancer patients after curative resection.

Neutrophil elastase inhibitor (sivelestat) preserves antitumor immunity and reduces the inflammatory mediators associated with major surgery

PURPOSE

To examine the effects of the administration of perioperative sivelestat, a selective neutrophil elastase inhibitor, on tumor immunity and inflammatory mediators in patients who undergo major surgery.

METHODS

Thirteen patients admitted to the hospital for elective surgery were equally randomized into one of two groups: the Sivelestat group (n = 6) and the control group (n = 7). Thereafter, the immunosuppressive acidic protein (IAP), serum interleukin-6 (IL-6), and type 1/type 2 T-helper cell balance were all assessed at several time points before and after surgical intervention.

RESULTS

The serum IL-6 values at 1 and 12 h after surgery and on postoperative days 1 and 3 were all significantly lower in the sivelestat group than in the control group. The IAP values at postoperative days 7 and 28 in the sivelestat group were also significantly lower than those in the control group. There was a significant correlation between the IL-6 level at 1 h after surgery and the IAP level at postoperative days 7 and 28.

CONCLUSIONS

In this preliminary study, the perioperative administration of sivelestat was thus suggested to reduce surgical stress by decreasing the cytokine release and preserving the antitumor immunity.

Identification of alpha-1 acid glycoprotein as a lysophospholipid binding protein: a complementary role to albumin in the scavenging of lysophosphatidylcholine

Alpha-1 acid glycoprotein (AGP, orosomucoid), a major acute phase protein in plasma, displays potent cytoprotective and anti-inflammatory activities whose molecular mechanisms are largely unknown. Because AGP binds various exogenous drugs, we have searched for endogenous ligands for AGP. We found that AGP binds lysophospholipids in a manner discernible from albumin in several ways. First, mass spectrometric analyses showed that AGP isolated from plasma and serum contained lysophosphatidylcholine (LPC) enriched in mono and polysaturated acyl chains, whereas albumin contained mostly saturated LPC. Second, AGP bound LPC in a 1:1 molar ratio and with a higher affinity than free fatty acids, whereas albumin bound LPC in a 3:1 ratio but with a lower affinity than that of free fatty acids. Consequently, free fatty acids displaced LPC more avidly from albumin than from AGP. Competitive ligand displacement indicated the highest affinity for AGP to LPC20:4, 18:3, 18:1, and 16:0 (150-180 nM), lysophosphatidylserine (Kd 190 nM), and platelet activating factor (PAF) (Kd 235 nM). The high affinity of AGP to LPC in equilibrium was verified by stopped-flow kinetics, which implicated slow dissociation after fast initial binding, being consistent with an induced-fit mechanism. AGP also bound pyrene-labeled phospholipids directly from vesicles and more efficiently than albumin. AGP prevented LPC-induced priming and PAF-induced activation of human granulocytes, thus indicating scavenging of the cellular effects of the lipid ligands. The results suggest that AGP complements albumin as a lysophospholipid scavenging protein, particularly in inflammatory conditions when the capacity of albumin to sequester LPC becomes impaired.

Measurement of resiniferatoxin in serum samples by high-performance liquid chromatography

A novel and simple method of extraction, separation, identification and quantification of resiniferatoxin (RTX) in serum samples is reported. Human serum and whole blood were treated with acetonitrile to denature proteins, such as orosomucoid, and the soluble fraction was passed through a reversed-phase C18 cartridge. RTX eluted from the cartridge was quantified by high-performance liquid chromatography (HPLC) using a reversed-phase C18 column. Reproducible recovery of RTX and tinyatoxin, an internal standard, from serum was achieved. Isocratic elution with 62% acetonitrile provided a suitable retention time without interfering peaks eluting near the analyte. Therefore, the procedure described provides a useful assay for determination of serum RTX pharmacokinetic parameters.

Activated human PMN synthesize and release a strongly fucosylated glycoform of α1-acid glycoprotein, which is transiently deposited in human myocardial infarction

Alpha1-acid glycoprotein (AGP) is a major acute-phase protein present in human plasma as well as in polymorphonuclear leukocytes (PMN). In this report, we show that PMN synthesize a specific glycoform of AGP, which is stored in the specific and azurophilic granules. Activation of PMN results in the rapid release of soluble AGP. PMN AGP exhibits a substantially higher apparent molecular weight than plasma AGP (50-60 kD vs. 40-43 kD), owing to the presence of strongly fucosylated and sialylated polylactosamine units on its five N-linked glycans. PMN AGP is also released in vivo from activated PMN, as appeared from studies using well-characterized myocard slices of patients that had died within 2 weeks after an acute myocardial infarction. AGP was found deposited transiently on damaged cardiomyocytes in areas with infiltrating PMN only. It is interesting that this was inversely related to the deposition of activated complement C3. Strongly fucosylated and sialylated AGP glycoforms have the ability to bind to E-selectin and to inhibit complement activation. We suggest that AGP glycoforms in PMN provide an endogenous feedback-inhibitory response to excessive inflammation.

Inflammatory and autoimmune diseases of the nervous system; possibilities of laboratory diagnostic methods in cerebrospinal fluid

Contemporary aspects of cerebrospinal fluid analysis are discussed, including the relationship to neuro-infective, autoimmune and other neurological diseases. The actual state of cerebrospinal fluid microbiological and cytological investigation and analysis of cerebrospinal fluid protein fractions are described in detail.

Serum immunosuppressive acidic protein as an interleukin-6 related index of deteriorating condition in gastric cancer patients

BACKGROUND/AIMS

Immunosuppressive acidic protein (IAP) is an acute-phase reactant which has a close correlation with the impairment of the host's immunity. The present study aims to investigate the significance of serum IAP as an index of cytokine-related disease status in gastric cancer patients.

METHODS

Serum IAP levels were determined in 76 gastric cancer patients and 20 healthy subjects. In a subgroup of 39 patients, tissue interleukin-6 (IL-6) concentrations and expression of IL-6 protein in tumor tissues were also examined.

RESULTS

The mean serum IAP level in the patients was significantly higher than that in the normal controls. The serum IAP level in the patients was associated with clinicopathological features, such as tumor size and serosal invasion. The prognosis of patients with high IAP levels was significantly worse than that of those with low IAP levels. Moreover, the serum IAP level was closely correlated with various parameters reflecting the host's nutritional and immunological conditions. Immunohistochemically, IL-6 was overexpressed in the cytoplasm of tumor cells. The IL-6 concentration and immunoreactivity of IL-6 protein in tumor tissue was significantly correlated with the serum IAP level.

CONCLUSIONS

Elevated serum IAP, which may be upregulated by an activated IL-6 network in tumor tissue, may reflect not only tumor progression, but also a deteriorated condition that is associated with malnutrition and immunosuppression in gastric cancer patients.

Inhibition of cell proliferation and induction of apoptosis by ExFABP gene targeting

Ex-FABP, an extracellular fatty acid binding lipocalin, is physiologically expressed by differentiating chicken chondrocytes and myoblasts. Its expression is enhanced after cell treatment with inflammatory stimuli and repressed by anti-inflammatory agents, behaving as an acute phase protein. Chicken liver fragments in culture show enhanced protein expression after bacterial endotoxin treatment. To investigate the biological role of Ex-FABP, we stably transfected proliferating chondrocytes with an expression vector carrying antisense oriented Ex-FABP cDNA. We observed a dramatic loss of cell viability and a strong inhibition of cell proliferation and differentiation. When chondrocytes were transfected with the antisense oriented Ex-FABP cDNA we observed that Ex-FABP down-modulation increased apoptotic cell number. Myoblasts transfected with the same expression vector showed extensive cell death and impaired myotube formation. We suggest that Ex-FABP acts as a constitutive survival protein and that its expression and activation are fundamental to protect chondrocytes from cell death.

CSF and serum orosomucoid (alpha-1-acid glycoprotein) in patients with multiple sclerosis: a comparison among particular subgroups of MS patients

INTRODUCTION

To compare cerebrospinal fluid (CSF) and serum orosomucoid (alpha-1-acid glycoprotein-AAG) concentrations in various subgroups of patients with multiple sclerosis (MS).

MATERIALS AND METHODS

CSF and serum AAG concentrations, AAG quotient (i.e., CSF AAG/serum AAGx10(3)) and index were determined in a group of 59 patients with clinically definite or probable MS. Patients were subdivided according to the disease form, disease severity according to an expanded disability status scale (EDSS), its treatment, disease duration and sex.

RESULTS

CSF AAG was increased in 52.5% of the patients and AAG quotient even in 64.4%. An increase in the CSF AAG concentration, as well as in AAG quotient and index, appear only after several years of disease duration, while no significant correlation with age has been found. This suggests that CSF AAG changes in MS represent a secondary, unspecific phenomenon and that this protein is not relevant for the aethiopathogenesis of the disease. Nevertheless, the finding of subnormal CSF AAG levels in some MS patients in remission (never observed in those in the attack) implies the possibility that CSF AAG may be used as a "state marker" in MS. Serum AAG levels were significantly lower in secondary progressive form and in severely disabled patients. This observation suggest that serum AAG values determination might have some prognostic significance. Further studies are, however, needed. Serum AAG should be investigated in parallel with other CSF and serum protein fractions in order to establish a pannel of examinations enabling multiple statistical analyses. This approach may lead to the finding of a "complex state marker" enabling thus to evaluate more precisely disease course in individual patients and to accept appropriate therapeutic measures.

The peripheral benzodiazepine receptor ligand PK11195 binds with high affinity to the acute phase reactant alpha1-acid glycoprotein: implications for the use of the ligand as a CNS inflammatory marker

The peripheral benzodiazepine receptor ligand PK11195 has been used as an in vivo marker of neuroinflammation in positron emission tomography studies in man. One of the methodological issues surrounding the use of the ligand in these studies is the highly variable kinetic behavior of [(11)C]PK11195 in plasma. We therefore undertook a study to measure the binding of [(3)H]PK11195 to whole human blood and found a low level of binding to blood cells but extensive binding to plasma proteins. Binding assays using [(3)H]PK11195 and purified human plasma proteins demonstrated a strong binding to alpha1-acid glycoprotein (AGP) and a much weaker interaction with albumin. Immunodepletion of AGP from plasma resulted in the loss of plasma [(3)H]PK11195 binding demonstrating: (i) the specificity of the interaction and (ii) that AGP is the major plasma protein to which PK11195 binds with high affinity. PK11195 was able to displace fluorescein-dexamethasone from AGP with IC(50) of <1.2 microM, consistent with a high affinity interaction. These findings are important for understanding the behavior of the ligand in positron emission tomography studies for three reasons. Firstly, AGP is an acute phase protein and its levels will vary during infection and pathological inflammatory diseases such as multiple sclerosis. This could significantly alter the free plasma concentrations of the ligand and contribute to its variable kinetic behavior. Secondly, AGP and AGP-bound ligand may contribute to the access of [(11)C]PK11195 to the brain parenchyma in diseases with blood brain barrier breakdown. Finally, local synthesis of AGP at the site of brain injury may contribute the pattern of [(11)C]PK11195 binding observed in neuroinflammatory diseases.

Alpha(1)-acid glycoprotein: an acute phase protein with inflammatory and immunomodulating properties

alpha(1)-Acid glycoprotein (AGP) is a protein with a molecular weight of 41-43 kDa and is heavily glycosylated (45%). Due to the presence of sialic acids, it is negatively charged (pI=2.7-3.2). AGP is an acute phase protein in all mammals investigated to date. The serum concentration of AGP rises several fold during an acute phase response, the systemic answer to a local inflammatory stimulus. Also, its glycosylation pattern can change depending on the type of inflammation. The biological function of this protein is not clear. A number of activities on different type of blood cells have been described. In vivo, AGP clearly has protective effects in several models of inflammation. Here we review the data supporting an anti-inflammatory and immunomodulating role of AGP.

Overexpression of alpha(1)-acid glycoprotein in transgenic mice leads to sensitisation to acute colitis

BACKGROUND

alpha(1)-Acid glycoprotein (alpha(1)-AGP) is an acute phase protein in most mammalian species whose concentration rises 2-5-fold during an acute phase reaction. Its serum concentration has often been used as a marker of disease, including inflammatory bowel disease (IBD). High alpha(1)-AGP levels were found to have a prognostic value for an increased risk of relapse in IBD.

AIMS

To investigate a possible role for increased serum levels of alpha(1)-AGP in the development of IBD.

METHODS

Dextran sodium sulphate (DSS) 2% was added to the drinking water of transgenic mice, overexpressing the rat alpha(1)-AGP gene, to induce acute colitis, thus mimicking the conditions of relapse. Clinical parameters, inflammatory parameters, and histological analyses on colon sections were performed.

RESULTS

Homozygous alpha(1)-AGP-transgenic mice started losing weight and showed rectal bleeding significantly earlier than heterozygous transgenic or wild-type mice. Survival time of homozygous transgenic mice was significantly shorter compared with heterozygous and wild-type mice. The higher susceptibility of homozygous alpha(1)-AGP-transgenic mice to DSS induced acute colitis was also reflected in higher local myeloperoxidase levels, higher inflammation scores of the colon, and higher systemic levels of interleukin 6 and serum amyloid P component. Local inflammatory parameters were also significantly different in heterozygous transgenic mice compared with wild-type mice, indicating a local dosage effect. In homozygous transgenic mice, significantly higher amounts of bacteria were found in organs but IgA levels were only slightly lower than those of control mice.

CONCLUSION

Sufficiently high serum levels of alpha(1)-AGP result in a more aggressive development of acute colitis.

Preliminary observations on the influence of rheumatoid alpha-1-acid glycoprotein on collagen fibril formation

This study investigates the effect of alpha(1)-acid glycoprotein (AGP) isolated from both normal and rheumatoid plasma on type II collagen fibril formation. Rheumatoid samples were obtained over 2 years from two patients with early arthritis. The glycosylation of each sample was analysed to establish any correlation with fibrillogenesis. Rheumatoid AGP displays increased fucosylation compared to normal AGP. In both patients the fucosylation dipped after 1 year, then rose again over year 2. It is proposed that year 1 corresponds to the acute phase of the disease and the onset of chronic inflammation after this time produces a subsequent increase in fucosylation. Rheumatoid AGP influences type II collagen fibrillogenesis. Native fibrils were produced but with differences in the rate and extent of fibrillogenesis depending on AGP concentration and fucosylation. Low concentrations produced a decrease in fibrillogenesis rate and fibril diameter. High concentrations produced fibrils at a rate and diameter dependent on fucosylation. Highly fucosylated AGP produced narrow fibrils slowly, whereas poorly fucosylated AGP produced thicker fibrils more quickly. We propose that differences in glycosylation (especially fucosylation) of AGP are responsible for differences in collagen fibrillogenesis and this phenomenon may contribute to the exacerbation of cartilage destruction in rheumatoid arthritis.

Determination of alpha-1 acid glycoprotein in patients with Ph+ chronic myeloid leukemia during the first 13 weeks of therapy with STI571

The tyrosine kinase activity of the BCR/ABL fusion protein is required for the transformation in patients with chronic myeloid leukemia. The tyrosine kinase inhibitor STI571 inhibits the BCR/ABL and ABL kinase activity and consequently inhibits growth of BCR/ABL-positive cells. However, resistance to STI571 has been demonstrated in Ph+ cell lines and in CML patients and can be explained in some cases by point mutations within the ATP-binding pocket or amplification of the bcr/abl gene. In previous investigations using a nu/nu mouse model, the binding of STI571 to elevated levels of the plasmaprotein -1 acid glycoprotein (AGP) was identified as an additional mechanism of resistance to this therapeutic approach. Here we provide data on the expression of AGP in CML patients under therapy with STI571. Patients received 400 or 600 mg STI571 daily and apart from clinical parameters we determined AGP and C-reactive protein (CRP) plasma levels as well as the quantitative expression of both BCR/ABL and AGP mRNA in peripheral blood cells. Our data suggest that despite elevated AGP levels in 52% of our patients, no upfront resistance against STI571 was present. In conclusion, we demonstrated that during the first 13 weeks of STI571 therapy (i) plasma AGP levels in CML patients correlate with white blood cell count and stage of disease; (ii) patients with elevated AGP responded less rapidly to STI571; (iii) elevated AGP and CRP levels normalized in patients during treatment with STI571, although mRNA levels of AGP remained stable; (iv) initially normal levels of AGP remained in the normal range during treatment with STI571, indicating that STI571 does not trigger AGP expression in humans; and (v) in relapsed patients, elevation of AGP levels is present prior to hematological progress.

Alpha-1-acid glycoprotein

Alpha-1-acid glycoprotein (AGP) or orosomucoid (ORM) is a 41-43-kDa glycoprotein with a pI of 2.8-3.8. The peptide moiety is a single chain of 183 amino acids (human) or 187 amino acids (rat) with two and one disulfide bridges in humans and rats,respectively. The carbohydrate content represents 45% of the molecular weight attached in the form of five to six highly sialylated complex-type-N-linked glycans. AGP is one of the major acute phase proteins in humans, rats, mice and other species. As most acute phase proteins, its serum concentration increases in response to systemic tissue injury, inflammation or infection, and these changes in serum protein concentrations have been correlated with increases in hepatic synthesis. Expression of the AGP gene is controlled by a combination of the major regulatory mediators, i.e. glucocorticoids and a cytokine network involving mainly interleukin-1 beta (IL-1 beta), tumour necrosis factor-alpha (TNF alpha), interleukin-6 and IL-6 related cytokines. It is now well established that the acute phase response may take place in extra-hepatic cell types, and may be regulated by inflammatory mediators as observed in hepatocytes. The biological function of AGP remains unknown; however,a number of activities of possible physiological significance, such as various immunomodulating effects, have been described. AGP also has the ability to bind and to carry numerous basic and neutral lipophilic drugs from endogenous (steroid hormones) and exogenous origin; one to seven binding sites have been described. AGP can also bind acidic drugs such as phenobarbital. The immunomodulatory as well as the binding activities of AGP have been shown to be mostly dependent on carbohydrate composition. Finally, the use of AGP transgenic animals enabled to address in vivo, functionality of responsive elements and tissue specificity, as well as the effects of drugs that bind to AGP and will be an useful tool to determine the physiological role of AGP.

Immunocalins: a lipocalin subfamily that modulates immune and inflammatory responses

A subset of the lipocalins, notably alpha(1)-acid glycoprotein, alpha(1)-microglobulin, and glycodelin, exert significant immunomodulatory effects in vitro. Interestingly, all three are encoded from the q32-34 region of human chromosome 9, together with at least four other lipocalins (neutrophil gelatinase-associated lipocalin, complement factor gamma-subunit, tear prealbumin, and prostaglandin D synthase) that also may have anti-inflammatory and/or antimicrobial activity. This review addresses important features of this genetically linked subfamily of lipocalins (involvement with the acute phase response, immunomodulatory and anti-inflammatory properties, the tissue localization, complex formation with other proteins and receptors, etc.). It is likely that these proteins have evolved to be an integrated part of the body's defense system as part of the extended cytokine network. Its members exert a regulatory, dampening influence on the inflammatory cascade, thereby protecting against tissue damage from excessive inflammation. That most major mammalian allergens are lipocalins may reflect this connection of lipocalins with the immune system. We propose that this immunologically active lipocalin subset be named the 'immunocalins', signifying not only the structural homology and close genetic linkage of its members, but also their protective involvement with immunological and inflammatory processes. As immune mediators, immunocalins appear to use at least three interactive sites: the lipocalin 'pocket', binding sites for other plasma proteins, and binding sites for cell surface receptors.

Involvement of the acute phase protein alpha 1-acid glycoprotein in nonspecific resistance to a lethal gram-negative infection

Resistance to gram-negative infection can be induced by pretreating animals with several agents such as turpentine and interleukin (IL)-1. Because these agents are powerful inducers of acute phase proteins, we wondered whether these proteins, more particularly alpha(1)-acid glycoprotein (alpha(1)-AGP), are involved in nonspecific resistance to infection. Turpentine and IL-1 protect completely against a lethal challenge of Klebsiella pneumoniae when given 48 and 12-48 h before the challenge, respectively. alpha(1)-AGP induction in the serum reached peak values 48 h after turpentine and 12-48 h after IL-1 injection. Administration of alpha(1)-AGP, 2 h before a challenge of K. pneumoniae, significantly increased the survival. Numbers of bacteria cultured from blood and organs were significantly lower in mice pretreated with a protective dose of turpentine, IL-1, or alpha(1)-AGP. These data suggest that alpha(1)-AGP is a possible mediator in turpentine- or IL-1-induced protection because time points of maximal induction of alpha(1)-AGP by turpentine or IL-1 and of optimal protection by alpha(1)-AGP coincide. Transgenic overexpression of rat alpha(1)-AGP protected mice from a K. pneumoniae infection. Bacterial counts in blood and organs were significantly lower in transgenic mice, and only in control mice were large necrotic areas, apoptosis, and blood clots observed in the spleen. Our data suggest that alpha(1)-AGP prevents gram-negative infections and may be an essential component in nonspecific resistance to infection.

Impact of splenectomy and immunochemotherapy on survival following gastrectomy for carcinoma: covariate interaction with immunosuppressive acidic protein, a serum marker for the host immune system. Tumor Marker Committee for the Study Group of Immunochemotherapy with PSK for Gastric Cancer

The role of the spleen in tumor immunology is still controversial in that it can either enhance or suppress the antitumor immune response depending on the tumor-bearing host. To clarify this biphasic effect of the spleen, a clinical evaluation of splenectomy in conjunction with immunotherapy and the host immune status was performed in gastric cancer patients. The effect of splenectomy and immunotherapy in 253 gastric cancer patients enrolled in a prospective randomized trial (SIP) was analyzed using the Cox's proportional hazards model in terms of the covariate interaction of the preoperative immunosuppressive acidic protein (IAP) level. In patients with high IAP levels (>580 microg/ml) with predicted negative antitumor immune reactions, splenectomy improved the prognosis. In patients with lower IAP values, conversely, the preservation of the spleen and immunotherapy demonstrated a significant benefit to survival. The spleen was shown to have a biphasic activity in terms of its antitumor immune response depending on the IAP level of the patient. The effect of immunotherapy is significantly influenced by the activity of spleen cells. The preoperative IAP level is therefore considered to be a possible indicator for the effectiveness of splenectomy and immunotherapy in curatively resected gastric cancer patients.

Do synovial fluid acute phase proteins from patients with rheumatoid arthritis originate from serum?

This study was performed in order to gain insight into the occurrence, glycosylation and the possible origin of the acute-phase proteins alpha1-acid glycoprotein (AGP) and alpha1-protease inhibitor (PI) in sera and synovial fluid from patients with rheumatoid arthritis (RA). Therefore paired sera and synovial fluid samples from patients with RA, and paired synovial fluid samples from right and left knees of patients with varying degrees of arthritis were studied. Crossed affinity immunoelectrophoresis (CAIE) was used with concanavalin A and Aleuria aurantia lectin for the detection of the degree of branching and fucosylation, respectively, and the monoclonal CSLEX-1 for the detection of Sialyl Lewis(X) (SLe(X)) groups on AGP. For PI, not only CAIE, but also high-pressure-anion-exchange chromatography with pulsed amperometric detection was used to study the glycosylation. It was established that the concentrations of AGP and PI were increased in the serum of RA patients compared to normal healthy controls, but that the concentration of both proteins, as well as albumin, was significantly lower in synovial fluid than in serum. Furthermore, the type of glycosylation of both AGP and PI found in RA was significantly different from that found in normals, with increased fucosylation, but there were no major differences in the degree of branching of AGP- or PI-glycans in RA, compared to normals. No differences in glycosylation could be established between serum and synovial fluid in RA. For PI an increased fucosylation was found, both in serum and synovial fluid, using both methods of detection, and it could be established that only the alpha1-->3- and not the alpha1-->6-fucosylation of PI was affected by RA. The increased fucosylation of AGP resulted in an increased expression of SLe(X) on AGP-glycans. Since the alpha1-->3-fucosylation of AGP was significantly increased in both serum and synovial fluid from RA patients, and this correlated with systemic but not with local disease parameters, it can be suggested that acute phase proteins in synovial fluid are most probably of hepatic origin.

Kinetics and role of alpha 1-acid glycoprotein-dependent osmotic transport of water and ions in palmitoyl-L-oleoyl phosphatidylcholine liposomes

alpha 1-Acid glycoprotein isolated from human blood plasma is known to influence cell permeability, although the mechanisms of this process are unclear. Here, the glycoprotein effects on the permeability of osmotically stressed phospholipid liposomes are studied as a model of membrane permeability. Liposomes containing glycoprotein were found to be osmotically sensitive to water and chloride salts of some monovalent (Na+, K+) and bivalent (Mg2+, Ca2+) ions. The permeations of these substances were determined by light-scattering measurements of the volume changes in liposomes after mixing with hyperosmotic solutions of chloride salts. The time courses of scattered light were recorded by means of stopped-flow spectrophotometry. Two processes were studied: the fast water outflow from liposomes and slower ion permeations through the lipid membrane. The second order permeation rate constants were determined at different glycoprotein concentrations for both processes. Values from 66 to 250 x 10(3) for water outflow and 2-500 M-1 sec-1 for the different ion permeations were obtained in order to characterize the permeations of solutes across the lipid membrane. The apparent activation energies also were calculated between 18 and 33 degrees C. The mercurial sulphydryl reagent pCMBS inhibited the ion permeations in the slow phase. When pCMBS was present in this phase, higher activation energies were obtained, indicating more difficult permeations. An interpretation of these results is that membrane permeability is mediated by aqueous pores. Membrane selectivity to monovalent metal ions also was demonstrated, but no correlation was observed between the ion radius of the corresponding metal cation and permeation rate constants. The discovery of non-specific pores in liposomes containing glycoprotein shows that they can serve as vehicles for the water and ions in the processes of passive transport through lipid membranes.

Binding of thalidomide to alpha1-acid glycoprotein may be involved in its inhibition of tumor necrosis factor alpha production

In addition to its well known sedative and teratogenic effects, thalidomide also possesses potent immunomodulatory and antiinflammatory activities, being most effective against leprosy and chronic graft-versus-host disease. The immunomodulatory activity of thalidomide has been ascribed to the selective inhibition of tumor necrosis factor alpha from monocytes. The molecular mechanism for the immunomodulatory effect of thalidomide remains unknown. To elucidate this mechanism, we synthesized an active photoaffinity label of thalidomide as a probe to identify the molecular target of the drug. Using the probe, we specifically labeled a pair of proteins of 43-45 kDa with high acidity from bovine thymus extract. Purification of these proteins and partial peptide sequence determination revealed them to be alpha1-acid glycoprotein (AGP). We show that the binding of thalidomide photoaffinity label to authentic human AGP is competed with both thalidomide and the nonradioactive photoaffinity label at concentrations comparable to those required for inhibition of production of tumor necrosis factor alpha from human monocytes, suggesting that AGP may be involved in the immunomodulatory activity of thalidomide.

Prognostic value of preoperative immunosuppressive acidic protein in patients with gastric carcinoma. Findings from three independent clinical trials. Tumor Marker Committee for the Study Group of Immunochemotherapy with PSK for Gastric Cancer

BACKGROUND

Immunosuppressive acidic protein (IAP) has been reported to have close correlation with the impairment of host immune response. To evaluate the significance of IAP in clinical studies, the prognostic value of preoperative IAP was investigated in clinical trials of patients with gastric carcinoma after curative resection.

METHODS

An appropriate IAP threshold value of 580 micrograms/mL was determined using Cox's proportional hazards model. Five-year survival rates were estimated for high and low IAP groups in three different clinical studies. Meta-analysis was performed based on individual patient data, and summarized hazard ratios were estimated using a stratified proportional hazards model.

RESULTS

Meta-analysis of the three clinical trials demonstrated that patients with preoperative IAP levels above the threshold had significantly poorer cancer related survival (P = 0.0039) and absolute survival (P = 0.0023), even after adjustment for the major prognostic factors.

CONCLUSIONS

Gastric carcinoma patients with an IAP value above the threshold level of 580 micrograms/mL have a higher risk of cancer death and absolute death than patients with an IAP value below the threshold value.

Alpha 1-acid glycoprotein (orosomucoid): pathophysiological changes in glycosylation in relation to its function

The aim of this review is to summarize the research efforts of the last two decades with respect to (i) the determination and characterization of the changes in glycosylation of AGP under various physiological and pathological states; and (ii) the effects of such changes on its possible anti-inflammatory functions. It will become clear that the heterogeneity observed in the glycosylation of AGP in serum, represents various so-called glycoforms of AGP, of which the relative amounts are strictly determined by the (patho) physiological conditions.

Significance of increased neutrophils in patients with advanced colorectal cancer

We examined the ratio of neutrophils to lymphocytes (N/L ratio) in the peripheral blood in patients with colorectal cancer. The ability to produce active oxygen and phagocytosis of neutrophils, G-CSF, sIL-2R and IAP (immunosuppressive acidic protein) were also measured. The N/L ratios were significantly higher in the advanced stages of cancer than in normal controls. The ability to produce active oxygen in the terminal stage was 33% lower than in the control group. The G-CSF levels had no relationship with the neutrophil counts. IAP levels increased with cancer stage, and were inversely related to the ability to produce active oxygen. The IAP levels correlated well with the sIL-2R levels and the N/L ratio. These findings suggest that the ability to produce active oxygen, N/L ratio and IAP reflect anticancer mechanisms and that they may be useful when considering treatment or prognosis of patients with advanced stages of cancer.

Purification of the channel component of the mitochondrial calcium uniporter and its reconstitution into planar lipid bilayers

The purification of the channel-forming component of the mitochondrial calcium uniporter and its channel properties are described. After ethanol and 50% ethanol-water extraction of mitochondria from beef heart or perfused rat liver, the extract was passed through thiopropyl-Sepharose 6B column, and absorbed components were eluted with 2-mercaptoethanol, followed by gel-filtration on Sephadex G-15. The last fraction eluted (M(r) about 2000) was then subjected to reverse-phase high-performance liquid chromatography. Of the more than 10 distinct peaks, only one showed specific Ca(2+)-channel activity in BLM with properties similar to earlier, less extensively purified preparations, i.e., conductance of 20 pS and multiples thereof, clustering of channels, participation of 2 or more subunits in channel formation, and sensitivity to 1 microM ruthenium red. Voltage sensitivity and cooperativity between channels are described. The Ca(2+)-binding glycoprotein with which the peptide was associated was found to have high homology with human acid alpha 1-glycoprotein (orosomucoid) and to show identity with beef plasma orosomucoid in the Ouchterlony immunodiffusion test.