Fermented milk retains beneficial effects on skeletal muscle protein anabolism after processing by centrifugation and supernatant removal.

Lactobacillus-fermented milk can stimulate anabolic effects in skeletal muscle. Fermented milk containing Lactobacillus produces aqueous molecules, such as free AA and lactate. This study aimed to investigate how processing fermented milk by centrifugation and removal of supernatant affects AA absorption and postprandial skeletal muscle protein synthesis (MPS) when mice are fed fermented milk. We gavaged male Sprague-Dawley rats with skim milk (S), fermented milk (F), or processed fermented milk (P), and examined the total AA content in portal vein blood (reflecting AA absorption) and plantaris muscle MPS at 30, 60, and 90 min following administration. Relative to fasted rats, at 30 min the total AA concentration in portal vein blood from rats in the P groups was significantly higher, followed by F and S, respectively. The MPS rates were higher for the F or P groups compared with the S group. Phosphorylation levels of p70S6 kinase in the P and F groups were significantly higher than those for the S group 30 min after administration, although the level of Akt phosphorylation was similar among the groups. These results suggested that fermentation improves AA absorption that in turn enhances postprandial MPS via Akt-independent mechanisms, and that processed fermented milk retains these favorable effects on MPS.

Restricted usage of T cell receptor V alpha-V beta genes in infiltrating cells in the hearts of patients with acute myocarditis and dilated cardiomyopathy.

Prolonged myocardial cell damage initiated by acute myocarditis is thought to be one of the most important etiology of dilated cardiomyopathy. To investigate the immunological mechanisms involved in the pathogenesis of dilated cardiomyopathy, we analyzed the phenotypes of infiltrating cells and examined the expression of perforin in infiltrating cells in the hearts of patients with dilated cardiomyopathy as well as acute myocarditis. We also examined the expression of HLA and intercellular adhesion molecule-1 (ICAM-1) in myocardial tissue of these patients. Furthermore, to evaluate the antigen specificity of infiltrating T cells and persistence of viral genomes in the myocardial tissue, we analyzed the expression of T cell receptor (TCR) V alpha and V beta genes as well as enterovirus genomes by PCR. We found infiltration of perforin-expressing killer cells and enhanced expression of HLA class I and ICAM-1 in the myocardial tissue. We also found that the repertoires of TCR V alpha as well as V beta gene transcripts were restricted, indicating that a specific antigen in the hearts was targeted. Because no enterovirus genomes were detected in all patients, it is strongly suggested that a cell-mediated autoimmune mechanism triggered by virus infection may play a critical role in the pathogenesis of dilated cardiomyopathy. However, we could not exclude the possibility that viruses other than enteroviruses could be pathogenic in these patients.

Glycaemic control boosts glucosylated nanocarrier crossing the BBB into the brain.

Recently, nanocarriers that transport bioactive substances to a target site in the body have attracted considerable attention and undergone rapid progression in terms of the state of the art. However, few nanocarriers can enter the brain via a systemic route through the blood-brain barrier (BBB) to efficiently reach neurons. Here we prepare a self-assembled supramolecular nanocarrier with a surface featuring properly configured glucose. The BBB crossing and brain accumulation of this nanocarrier are boosted by the rapid glycaemic increase after fasting and by the putative phenomenon of the highly expressed glucose transporter-1 (GLUT1) in brain capillary endothelial cells migrating from the luminal to the abluminal plasma membrane. The precisely controlled glucose density on the surface of the nanocarrier enables the regulation of its distribution within the brain, and thus is successfully optimized to increase the number of nanocarriers accumulating in neurons.There are only a few examples of nanocarriers that can transport bioactive substances across the blood-brain barrier. Here the authors show that by rapid glycaemic increase the accumulation of a glucosylated nanocarrier in the brain can be controlled.

L-tryptophan 2,3-dioxygenase of a moderate thermophile, Bacillus brevis. Purification, properties and a substrate-mediated stabilization of the quaternary structure.

L-Tryptophan 2,3-dioxygenase (L-tryptophan: oxygen 2,3-oxidoreductase ( decycling ), EC 1.13.11.11) from Bacillus brevis, a moderately thermophilic bacteria, was purified to apparent homogeneity. The enzyme had a molecular weight of 110 000 and consisted of four subunits of equal molecular size. The enzyme exhibited the typical absorption spectra of a protohemoprotein . The amino acid composition and catalytic properties of the thermophilic enzyme were almost similar to those of its mesophilic counterpart from Pseudomonas acidovorans. However, the stabilities of the enzyme differed markedly between the two. The thermophilic enzyme was more resistant to heat and several chemical denaturants. The addition of L-tryptophan protected the enzyme from heat- and SDS- denaturations , and the tryptophan-mediated stabilization was more evident for the thermophilic enzyme. The effect of L-tryptophan on the stabilization of the thermophilic enzyme was more effective in preventing the dissociation of the tetrameric form of the enzyme (i.e. stabilizing it) in the case of the native, as compared to the mesophilic enzyme.

Dietary soybean protein moderates the deleterious disturbance of lipid metabolism caused by exogenous oxidized cholesterol in rats.

Effects of dietary protein on oxidized cholesterol-induced disturbance of lipid metabolism were examined in 4 week old male Sprague-Dawley rats, using casein and soybean protein as dietary protein source. The rats were given one of the two proteins in 0. 078% cholesterol (control), 0.25% cholesterol or 0.25% oxidized cholesterol mixture (containing 0.078% cholesterol) diets. Dietary oxidized cholesterol, compared to cholesterol, tended to inhibit hepatic sterol biosynthesis in casein-fed rats, whereas this inhibitory action was slightly moderated by intake of soybean protein. As a result, the hepatic 3-hydroxy-3-methylglutaryl-CoA reductase activity was rather higher in the rats fed oxidized cholesterol than in those fed cholesterol in the soybean protein-fed group. The hepatic cholesterol 7alpha-hydroxylase activity tended to be higher in the rats fed oxidized cholesterol than in those fed control diet in the soybean protein-fed group, despite the fact that oxidized cholesterol lowered the hydroxylase activity in the casein-fed group. On the other hand, dietary oxidized cholesterol tended to slightly enhance the hepatic Delta6 desaturase activity in the casein-fed group; however, this observation was not shown in the soybean protein-fed group. Moreover, dietary soybean protein facilitated fecal oxidized cholesterol excretion and simultaneously inhibited the accumulation of oxidized cholesterol in serum and liver. In conclusion, dietary soybean protein alleviated the deleterious actions of exogenous oxidized cholesterol on hepatic cholesterol and linoleic acid metabolism, although these efficacies were not necessarily significant. A great part of these moderations may be exerted by the specific hypocholesterolemic function of soybean protein, such as the stimulation of fecal oxidized cholesterol excretion, the change of hormonal release and modulation of lipoprotein catabolism.

Effects of dietary protein type on oxidized cholesterol-induced alteration in age-related modulation of lipid metabolism and indices of immune function in rats.

Exogenous oxidized cholesterol disturbs both lipid metabolism and immune functions. Therefore, it may perturb these modulations with ageing. Effects of the dietary protein type on oxidized cholesterol-induced modulations of age-related changes in lipid metabolism and immune function was examined using differently aged (4 weeks versus 8 months) male Sprague-Dawley rats when casein, soybean protein or milk whey protein isolate (WPI) was the dietary protein source, respectively. The rats were given one of the three proteins in diet containing 0.2% oxidized cholesterols mixture. Soybean protein, as compared with the other two proteins, significantly lowered both the serum thiobarbituric acid reactive substances value and cholesterol, whereas it elevated the ratio of high density lipoprotein-cholesterol/cholesterol in young rats, but not in adult. Moreover, soybean protein, but not casein and WPI, suppressed the elevation of Delta6 desaturation indices of phospholipids in both liver and spleen, particularly in young. On the other hand, WPI, compared to the other two proteins, inhibited the leukotriene B4 production of spleen, irrespective of age. Soybean protein reduced the ratio of CD4(+)/CD8(+) T-cells in splenic lymphocytes. Therefore, the levels of immunoglobulin (Ig)A, IgE and IgG in serum were lowered in rats given soybean protein in both age groups except for IgA in adult, although these observations were not shown in rats given other proteins. Thus, various perturbations of lipid metabolism and immune function caused by oxidized cholesterol were modified depending on the type of dietary protein. The moderation by soybean protein on the change of lipid metabolism seems to be susceptible in young rats whose homeostatic ability is immature. These observations may be exerted through both the promotion of oxidized cholesterol excretion to feces and the change of hormonal release, while WPI may suppress the disturbance of immune function by oxidized cholesterol in both ages. This alleviation may be associated with a large amount of lactoglobulin in WPI. These results thus showed a possibility that oxidized cholesterol-induced perturbations of age-related changes of lipid metabolism and immune function can be moderated by both the selection and combination of dietary protein.

Tumor cell growth inhibition and extracellular signal-regulated kinase (ERK) phosphorylation by novel K vitamins.

2-(2-hydroxy-ethylsulfanyl)-3-methyl-1,4-naphthoquinone or CPD-5, a K vitamin analog, was previously indicated to be a potent growth inhibitor for Hep 3B hepatoma cells in vitro. Here, we show that CPD-5 and two newly synthesized analogs, 2-(2-hydroxy-ethylsulfanyl)-3-methyl-5- nitro-1,4-naphthoquinone (PD-37) and 2-(2-hydroxy-ethylsulfanyl)-3- methyl-5-acetylamino-1,4-naphthoquinone (PD-42), are potent growth inhibitors of 13 different human cancer cell lines, with IC50 values in the range of 3-54 microM. Phospho-ERK was induced by each of three K vitamin analogs in every cell line in a dose-dependent manner, at growth inhibitory doses. ERK phosphorylation and growth inhibitory effects were strongly correlated, with p=0.0080 for CPD-5, p=0.0076 for PD-37 and p=0.0251 for PD-42. The induction of phospho-ERK and growth inhibition were antagonized by thiol-containing anti-oxidants, but not by catalase, consistent with a possible arylating mechanism. The data show a novel class of growth inhibitors with a wide spectrum of action that induces ERK hyper-phosphorylation, as a possible new growth inhibitory feature.

Pemphigus IgG activates and translocates protein kinase C from the cytosol to the particulate/cytoskeleton fractions in human keratinocytes.

We have demonstrated previously that pemphigus vulgaris (PV)-IgG induces activation of phospholipase C (PLC), production of inositol 1,4,5-trisphosphate, and a rapid transient increase in [Ca2+]i in cultured human keratinocytes, leading to secretion of plasminogen activator and cell-cell detachment in cell culture. In the current study, to examine the involvement of protein kinase C (PKC) in the mechanism of blister formation in PV, we studied the PV-IgG-induced translocation of PKC isozymes from the cytosol to the particulate/cytoskeleton (p/c) fractions and the activation of PKC in human keratinocytes. Cells cultured in Eagle's minimum essential medium were incubated with PV-IgGs for 30 s, 1 min, 5 min, or 30 min. PV-IgG binding to the cell surface antigen (desmoglein III) induced translocation of PKC-alpha from the cytosol to the p/c fractions within 30 s, with a peak at 1 min that lasted at least 30 min. PKC-delta also was translocated within 1 min and reached a peak at 5 min but was reduced to basal levels at 30 min. Alternatively, PKC-eta translocation to the p/c fraction was induced slowly, taking more than 5 min, and was reduced to approximately half-maximum at 30 min, whereas PKC-zeta translocation reached a maximum at 30 s, rapidly returning to baseline by 5 min after PV-IgG stimulation. The total PKC activity in the p/c fraction also was increased after PV-IgG exposure, peaked at 1 min, and was sustained for at least 30 min. These findings suggest that a unique activation profile of PKC isomers may be involved in mediating the intracellular signaling events induced by PV-IgG binding to desmoglein III in cultured human keratinocytes.

Pemphigus IgG induces expression of urokinase plasminogen activator receptor on the cell surface of cultured keratinocytes.

We previously found that the binding of pemphigus IgG to desmogleins caused marked activation of phospholipase C, a transient increase in inositol 1,4,5-trisphosphate production, and a concomitant increase in the intracellular calcium concentration in DJM-1 cells, a squamous cell carcinoma line. The binding of pemphigus IgG to cell membranes increased the activity of urokinase plasminogen activator in culture medium and induced subsequent cell-cell detachment in DJM-1 cells. Because urokinase plasminogen activator activates the conversion of plasminogen to plasmin by binding to urokinase plasminogen activator receptor evading inhibitors in serum, it is likely that plasmin is generated only in microenvironments adjacent to urokinase plasminogen activator receptor on the cell surface. It is not known whether pemphigus IgG causes acantholysis by inducing urokinase plasminogen activator receptor expression on the cell surface and secreting urokinase plasminogen activator in inhibitor-rich environments. We examined the effects of pemphigus IgG on urokinase plasminogen activator receptor expression in DJM-1 cells and normal keratinocytes by immunoblot analysis and immunofluorescence microscopy using antibodies to urokinase plasminogen activator receptor. IgG were obtained from serum samples from eight patients with bullous pemphigoid, five patients with pemphigus vulgaris, seven patients with pemphigus foliaceus, and eight normal subjects. Pemphigus vulgaris and pemphigus foliaceus IgG significantly increased the urokinase plasminogen activator receptor expression on the surface of DJM-1 cells and normal keratinocytes after 3- and 7-d incubation compared with normal IgG. These results suggest that enhanced urokinase plasminogen activator activity and urokinase plasminogen activator receptor expression activates plasmin in the limited cell surface of pemphigus IgG-bound keratinocytes and may contribute to the pathogenesis of differential acantholysis in pemphigus vulgaris and pemphigus foliaceus.

Pharmacologic evidence for involvement of phospholipase C in pemphigus IgG-induced inositol 1,4,5-trisphosphate generation, intracellular calcium increase, and plasminogen activator secretion in DJM-1 cells, a squamous cell carcinoma line.

The precise mechanism for acantholysis after pemphigus IgG binds to the cell surface is as yet unknown, although involvement of proteinases such as plasminogen activator (PA) has been suggested. We previously reported that pemphigus IgG, but not normal nor bullous pemphigoid IgGs, caused a transient increase in intracellular calcium ([Ca++]i) and inositol 1,4,5-trisphosphate (IP3) concentration in cultured DJM-1 cells (a squamous cell carcinoma line). To clarify whether phospholipase C is involved in this process after the antibody binds to the cell surface, we examined the effects of a specific phospholipase C inhibitor (U73122) on the pemphigus IgG-induced increase in [Ca++]i, IP3, PA secretion, and cell-cell detachment in DJM-1 cells. [Ca+2]i and IP3 contents were determined with or without 30-min pre-incubation with U73122 or an inactive analogue (U73343) with fura-2 acetoxymethylester and a specific IP3 binding protein, respectively. PA activity in the culture medium was measured after various incubation periods with pemphigus IgG by two-step amidolytic assay. The detachment of cell-cell contacts was examined by detecting the retraction of keratin filament bundle from cell-cell contact points to the perinuclear region by immunofluorescence microscopy using anti-keratin antibody. Pemphigus IgG immediately increased [Ca++]i and IP3 content. PA activity in the culture medium has also been increased at 24 h after pemphigus IgG was added in association with cell-cell detachment. However, pre-incubation with U73122 (1-10 microM), but not with U73343 (10 microM), dramatically reduced the pemphigus IgG-induced increases in [Ca++]i, IP3, and PA activity and inhibited the pemphigus IgG-induced cell-cell detachment. Both U73122 and U73343 caused no effects on cell viability and IgG binding to the cell surface. These results suggest that phospholipase C plays an important role in transmembrane signaling leading to cell-cell detachment exerted by pemphigus IgG binding to the cell surface.

Pemphigus IgG, but not bullous pemphigoid IgG, causes a transient increase in intracellular calcium and inositol 1,4,5-triphosphate in DJM-1 cells, a squamous cell carcinoma line.

It is still unclear what kinds of mechanisms are involved in blister formation after antibodies bind to the antigens in pemphigus and bullous pemphigoid. The effects of IgGs from pemphigus vulgaris, pemphigus foliaceus, and bullous pemphigoid sera on intracellular calcium concentration ([Ca++]i) and inositol 1,4,5-trisphosphate were examined in a human squamous cell carcinoma cell line (DJM-1 cells) and in cultured human keratinocytes to clarify whether signal transduction via calcium is involved. IgGs were purified with protein A affinity column from the sera of five pemphigus vulgaris patients, three pemphigus foliaceus patients, eight bullous pemphigoid patients, and 14 normal volunteers. Keratinocytes were cultured in Eagle's minimum essential medium containing 1.8 mM Ca++ and loaded with fura-2/AM, followed by addition of the IgGs. Subsequently, [Ca++]i was determined by measuring the fluorescence ratio (F340/F360) with videomicroscopy. Pemphigus IgGs (seven of eight cases) induced a rapid and transient increase in [Ca++]i in both the cells, whereas a [Ca++]i increase was caused by very few IgGs from bullous pemphigoid (one of eight cases) and normal sera (two of 14 cases). The pemphigus IgG-induced transient [Ca++]i increase was not affected by chelating extracellular Ca++ with ethyleneglycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetracetic acid. In addition, monoclonal antibodies acid. In addition, monoclonal antibodies against 180-kD and 230-kD antigens did not exert this change. Pemphigus IgGs that caused a [Ca++]i increase induced rapid and transient production of inositol 1,4,5-trisphosphate, peaking at 20 seconds. These findings suggest that IgG from pemphigus induces Ca++ mobilization by inositol 1,4,5-trisphosphate from internal stores, and that mechanisms of antibody-transmitted signaling in pemphigus may differ from those in bullous pemphigoid.

Different effects of azole-antifungal agents on the regulation of intracellular calcium concentration of Trichophyton rubrum.

Prior studies have indicated that intracellular calcium concentration ([Ca2+]i) is involved in fungal cell growth. However, it has not been known whether antifungal drugs affect signal transduction via calcium in fungal cells. In this context, we examined the effects of antifungal drugs, itraconazole, bifonazole and ketoconazole, on [Ca2+]i in Trichophyton rubrum. Itraconazole (1-5 ng/ml) induced a rapid and transient [Ca2+]i increase, peaking at 15-20s in hyphal cells of T. rubrum, but not in spores. The slow descending phase of the [Ca2+]i increase induced by itraconazole was depleted by chelating extracellular calcium with ethylene glycol bis (beta-aminoethyl ether)-N, N,N',N'-tetraacetic acid (EGTA), suggesting that the increase in [Ca2+]i is biphasic: Ca2+ mobilization from the internal pool and influx from the outside of the cell. At 10 ng/ml and 100 ng/ml, however, itraconazole induced an explosive and sustained calcium increase in both spores and hyphae. At less than 1 ng/ml, no [Ca2+]i increase was caused in both hyphae and spores. On the other hand, although some hyphal cells showed a transient [Ca2+]i increase, most of the cells did not show any changes of [Ca2+]i after the addition of ketoconazole at 10 ng/ml. Both spores and hyphal cells incubated with 100 ng/ml of bifonazole or ketoconazole showed a gradual increase of intracellular calcium concentration until 5 min, when the measurement was ceased. These findings suggest that signal transduction via calcium might be involved in some biological effects of itraconazole on T. rubrum, and that bifonazole and ketoconazole could differently affect [Ca2+]i in T. rubrum from itraconazole. In addition, the determination of [Ca2+]i changes induced by antifungal agents may contribute to clarification of the biological effects on fungal membranes.

Decreased integrin alpha 2, but normal response to TGF-beta in scleroderma fibroblasts.

The distribution and amount of integrin alpha2 were studied in cultured fibroblasts from normal subjects and scleroderma patients by immunofluorescence and immunoblotting using a monoclonal antibody against the human integrin alpha2 subunit. Integrin alpha2 was concentrated at the perinuclear regions in a dot-like pattern in normal fibroblasts on the glass coverslips until the 14th day after planting, and the staining pattern of integrin alpha2 was gradually changed to a dispersed dot-like pattern by the 19th day as examined by immunofluorescence microscopy by using the anti-integrin alpha2 antibody. No difference was observed in the distribution patterns between normal and scleroderma fibroblasts. By immunoblotting study, the amount of integrin alpha2 in scleroderma fibroblasts (n = 10) was less than that of normal fibroblasts (n = 10) (P < 0.01) in both cytosol and cytoskeleton-associated fractions. Furthermore, transforming growth factor beta (TGF-beta) increased the amount of integrin alpha2 in both normal fibroblasts and scleroderma cells by 33%. The total amount of integrin alpha2 in TGF-beta-stimulated scleroderma fibroblasts was less than that in TGF-beta-stimulated normal fibroblasts. These findings suggest that the amount of integrin alpha2, a collagen receptor, is reduced in scleroderma fibroblasts, but the integrin alpha2 production by TGF-beta stimulation is not impaired in scleroderma fibroblasts.

Effects of gamma-linolenic acid and its positional isomer pinolenic acid on immune parameters of brown-Norway rats.

Male Brown-Norway rats given purified diets containing safflower oil (SFO, linoleic acid, 18:2 n-6), evening primrose oil (EPO, gamma-linolenic acid, 6,9,12- 18:3 n-6) or Korean pine seed oil (PSO, 5,9,12- 18:3) at the 10% level were immunized twice with intraperitoneal ovalbumin, on days 14 and 35 of the feeding diets, and killed one day after the second booster. The relative population of CD4+ T-lymphocytes in the spleen was significantly lower in rats fed SFO than in those fed EPO or PSO, while that of CD8+ subsets remained unchanged. There was a significant increase in the splenic production of IgG and IgE in the PSO group compared to the SFO group, while EPO significantly increased IgE. The periodical response patterns of the serum levels of IgG and IgE varied depending on the source of dietary fats, and the initial rise of total immunoglobulins tended to be higher in the EPO group. The release by peritoneal exudate cells of histamine was comparable among three groups irrespective of saturation by calcium ionophore A23187, while PSO significantly increased leukotriene B4 production. These observations not only indicate specific roles of gamma-linolenic acid but also diverse influences of different octadecatrienoic acids in various immune measurements.

Effects of long-term treatment with desipramine on microtubule proteins in rat cerebral cortex.

The molecular mechanism of the action of antidepressants beyond the receptor level has not yet been elucidated. We have investigated the effects of long-term treatment with desipramine on the phosphorylation state of microtubule-associated protein 2 (MAP2) and microtubule assembly in the rat cerebral cortex. Phosphorylation of MAP2 was detected by immunoblotting after immunoprecipitation of MAP2 in the soluble fraction. The degree of phosphorylation of serine residues of MAP2 was significantly increased after chronic administration of desipramine without changes in the total concentration of MAP2. Microtubule assembly in crude brain extracts was monitored in terms of changes in turbidity measured at 350 nm using a spectrophotometer. Chronic but not acute treatment with desipramine inhibited microtubule assembly, assayed in the presence of a phosphatase inhibitor, calyculin A, whereas the inhibition was completely nullified in the absence of calyculin A. Desipramine had no direct effect on microtubule assembly in vitro. These results raise the possibility that the changes in the degree of phosphorylation of MAP2 and microtubule assembly represent intracellular modifications involved in functional changes elicited by long-term treatment with desipramine.

A newly developed peripheral anterior chamber depth analysis system: principle, accuracy, and reproducibility.

AIM: To develop a new, non-contact system for measuring anterior chamber depth (ACD) quantitatively, and to investigate its accuracy as well as interobserver and intraobserver reproducibility. METHODS: The system scanned the ACD from the optical axis to the limbus in approximately 0.5 second and took 21 consecutive slit lamp images at 0.4 mm intervals. A computer installed program automatically evaluated the ACD, central corneal thickness (CT), and corneal radius of curvature (CRC) instantly. A dummy eye was used for investigating measurement accuracy. The effects of CT and CRC on the measurement results were examined using a computer simulation model to minimise measurement errors. Three examiners measured the ACD in 10 normal eyes, and interobserver and intraobserver reproducibility was analysed. RESULTS: The ACD values measured by this system were very similar to theoretical values. Increase of CRC and decrease in CT decreased ACD and vice versa. Data calibration using evaluated CT and CRC successfully reduced measurement errors. Intraobserver and interobserver variations were small. Their coefficient variation values were 7.4% (SD 2.3%) and 6.7% (0.7%), and these values tended to increase along the distance from the optical axis. CONCLUSION: The current system can measure ACD with high accuracy as well as high intraobserver and interobserver reproducibility. It has potential use in measuring ACD quantitatively and screening subjects with narrow angle.

Simultaneous measurement of volatile sulfur compounds using ascorbic acid for oxidant removal and gas chromatography-flame photometric detection.

A method for the simultaneous measurement of volatile sulfur compounds (COS, H2S, CS2, CH3SH, DMS) is established with preconcentration and GC-flame photometric detection (FPD). Prior to preconcentration of ambient air, it was necessary to remove SO2, water vapor and atmospheric oxidant. SO2 and water vapor were removed using a glass fiber filter and a cooled PTFE water trap loop, respectively. In order to remove atmospheric oxidant, the efficiency of an ascorbic acid scrubber was examined. It was found that an ascorbic acid scrubber enabled measurement of volatile sulfur compounds without adsorption and reaction loss. The detection limits for COS, H2S, CS2, CH3SH and DMS were 20, 34, 35, 263 and 44 pg of S, respectively.

Decreased bradykinin binding sites in fibroblasts from progressive systemic scleroderma.

The numbers of bradykinin receptors (BK-R) in cultured dermal fibroblasts from patients with progressive systemic sclerosis (PSS) and from healthy controls were measured using a receptor binding assay. The numbers of BK-R were significantly fewer in PSS fibroblasts than in control fibroblasts (P < 0.02). However, no differences in affinity were observed in BK-R between PSS and control fibroblasts. The BK-R mRNA levels were determined in PSS and control fibroblasts by Northern blot hybridization using BK-R cDNA, but no significant differences were found. These findings suggest that the decrease in BK-R in PSS fibroblasts might occur during a posttranslational step.

Modified antigen-binding of human antibodies with glycosylation variations of the light chains produced in sugar-limited human hybridoma cultures.

We have characterized the effects of serum and N-acetylglucosamine in a glucose-deprived condition on the glycosylation of antibody light chains, as well as the resulting biological properties of those antibodies. We have chosen for our investigation the human hybridoma lines producing monoclonal antibodies reactive to lung adenocarcinoma. Each antibody possess a N-glycosylated carbohydrate chain in the hypervariable region of the light chains. When the cell lines were grown in the absence of glucose, variant light chains with varying molecular masses were found to be secreted. Analysis of these light chains produced in a glucose-deprived condition revealed that the changed molecular-mass of the variant light chains is due to different glycosylation. Addition of N-acetylglucosamine or fetal calf serum to the glucose-free medium led to the creation of other light chains that exhibit increased antigen binding activity.

Cholesterol oxidation in meat products and its regulation by supplementation of sodium nitrite and apple polyphenol before processing.

The levels of cholesterol oxidation derivatives (OxChol) in eight commercial species of meat products were examined. These products contained more than 1 mg/100 g of OxChol, and 7beta-hydroxycholesterol + 5beta-epoxycholesterol (111-1092 microg/100 g), 5alpha-epoxycholesterol (80-712 microg/100 g), cholestanetriol (0-368 microg/100 g), and 7-ketocholesterol (708-1204 microg/100 g) were detected. To know the interaction of sodium nitrite supplementation against cholesterol oxidation in meat products, sausage was produced with or without varying levels of sodium nitrite and stored in the refrigerator for 15 days. As a result, cholesterol oxidation in sausage was inhibited by addition of sodium nitrite in a dose-dependent manner. This observation may be associated with inactivation of O(2)(-) radical and stabilization of polyunsaturated fatty acids (PUFAs). In fact, the levels of OxChol in sausage increased, accompanying the decrease of coexisting linoleic acid when sodium nitrite was not added to sausage meat. Thus, cholesterol oxidation in meat products seems to be considarably promoted by the oxidation of coexisting PUFAs. On the other hand, additive apple polyphenol also inhibited linoleic acid oxidation in sausage and then suppressed cholesterol oxidation through its radical scavenging effects. Therefore, apple polyphenol, having a large amount of an oligomer of catechin, may interfere with cholesterol oxidation in meat processing or storage of meat products through its antioxidative action and be useful as a new antioxitant for meat products when it is added to the original meat before processing.