Antitumor effect of beta2-microglobulin in leukemic cell-bearing mice via apoptosis-inducing activity: activation of caspase-3 and nuclear factor-kappaB.

We have reported previously that beta2-microglobulin (beta2m) induces apoptosis in leukemic cells in vitro, and that an interaction between beta2m and HLA class I antigen induces apoptosis. Here we examined whether beta2m can induce apoptosis in leukemic cells in vivo and whether it has an antitumor effect in tumor-bearing mice. Daily administration of 50 or 250 microg of beta2m induced apoptosis and an antitumor effect on K562 leukemia cell-bearing mice in the same manner as tumor necrosis factor-alpha. In tumor tissues in beta2m-treated mice, both caspase-3 and nuclear factor-kappaB (NF-kappaB) were stained more strongly than in control mice by anti-caspase-3 and anti-NF-kappaB p65/Rel A polyclonal antibodies. We also observed the in vivo immunological effects of beta2m on lymphoid and hematopoietic organs, such as thymus, bone marrow, Peyer's patches, liver, and spleen in normal mice. Using antibodies against caspase-3 and NF-kappaB, immunohistochemical staining showed that no specific tissues were damaged or stained in normal mice. We conclude that beta2m stimulates caspase-3 and NF-kappaB pathways to induce apoptosis, making it a useful approach to a new therapy for leukemia.

Expression of Jagged1 gene in macrophages and its regulation by hematopoietic growth factors.

OBJECTIVE: Serrate/Jagged and Delta are cell surface ligands for Notch receptors that may influence hematopoietic cell fate decisions and are known to be expressed in bone marrow stromal cells. In a series of screenings of cDNAs constructed by a cDNA library subtraction technique, we identified Jagged1, one of the Notch ligands, as a gene up-regulated by macrophage colony-stimulating factor (M-CSF) in bone marrow macrophages. Therefore, we compared stromal cells and macrophages for expression of Notch ligands including Jagged1 and analyzed the regulation of their expression by cytokines. MATERIALS AND METHODS: Murine bone marrow macrophages were prepared by culturing femoral bone marrow cells with M-CSF. Primary bone marrow fibroblastic stromal cells were prepared by a culture system that we recently developed. The expression of Notch ligands was analyzed by either Northern blot analysis or reverse transcriptase polymerase chain reaction. RESULTS: The bone marrow macrophages expressed Jagged1 but not Jagged2 and Delta1 at a level that was detectable by Northern blot analysis. Expression of the Jagged1 gene was markedly up-regulated by growth factors for the cells, i.e., M-CSF, granulocyte-macrophage colony-stimulating factor, and interleukin-3. Expression of Jagged2 and Delta1 seldom was affected by the stimuli. The primary bone marrow fibroblastic stromal cells, and murine stromal cell lines, such as PA6 and ST2, also expressed Jagged1 transcript, at levels comparable to the steady-state level in macrophages. However, expression of the Jagged1 gene was little affected when these cells were stimulated with fibroblastic growth factor and platelet-derived growth factor. CONCLUSIONS: We demonstrated that bone marrow macrophages as well as stromal cells constitutively produced Jagged1 and that the expression was markedly up-regulated by hematopoietic growth factors, M-CSF, granulocyte-macrophage colony-stimulating factor, and interleukin-3. The results highlight the involvement of macrophages and these growth factors in hematopoietic cell fate decisions via the production of Jagged1.

Purification and quantification of lactoperoxidase in human milk with use of immunoadsorbents with antibodies against recombinant human lactoperoxidase.

BACKGROUND: Two heme-containing peroxidases, secretory lactoperoxidase and leukocyte-derived myeloperoxidase, which play host defense roles through antimicrobial activity, were previously identified in human colostrum. Within several days after the start of lactation, the relative contribution of myeloperoxidase to the peroxidase activity in milk was shown to decline as the number of milk leukocytes decreased. OBJECTIVE: Our knowledge of lactoperoxidase in human milk is still limited. The objective of this study was to use specific antibodies as a means of simplifying the purification and quantification of lactoperoxidase. DESIGN: Polyclonal antibodies were raised against recombinant human lactoperoxidase. Immunoglobulin G (IgG) was isolated by means of a protein A column and was characterized by immunoblotting. For the purification of lactoperoxidase from whey, a cation-exchange column and an immunoaffinity column with coupled IgG were used. The concentration of lactoperoxidase was determined by a sandwich enzyme-linked immunosorbent assay by using purified native lactoperoxidase as a standard. Native and biotinylated IgG were used as capture and detector antibodies, respectively. RESULTS: Two bands with molecular masses of approximately 80 and 100 kDa were detected in an immunoblot of human whey. Similar heterogeneity was observed in the sodium dodecyl sulfate-polyacrylamide gel electophoresis profile of purified lactoperoxidase. The mean (+/-SD) concentration of lactoperoxidase in 26 whey samples was estimated to be 0.77 +/- 0.38 mg/L. The concentrations were positively correlated with the peroxidase activity detected in these samples. CONCLUSION: Lactoperoxidase is commonly present in human milk throughout the lactation period and is likely to contribute to the protective effects of milk.

Susceptibility of Helicobacter pylori and its urease activity to the peroxidase-hydrogen peroxide-thiocyanate antimicrobial system.

The susceptibility of Helicobacter pylori to the antimicrobial system involving lactoperoxidase, hydrogen peroxide and thiocyanate was investigated. The inhibitory effect of the system on the urease activity of H. pylori, which plays a role in its colonisation of the stomach, was also investigated. Twelve H. pylori strains examined, including 10 clinical isolates, were all inhibited by the peroxidase system in brain-heart infusion broth supplemented with fetal calf serum, but to different extents. The killing effect was observed within 3 h. Although bacterial viability recovered afterwards, there was still a clear difference between cultures incubated in the presence of the complete system and control cultures incubated in the absence of lactoperoxidase, after incubation for 24 h. The urease activity and viability of H. pylori were both inactivated by this system in phosphate buffer. These effects were dependent on the concentrations of both lactoperoxidase and hydrogen peroxide and were abolished by the addition of cysteine. Furthermore, these effects were observed when bovine lactoperoxidase was replaced by recombinant human lactoperoxidase or native or recombinant human myeloperoxidase. The peroxidase system found in saliva and milk may contribute to the host defence against H. pylori infection and inhibition of transmission via the oral route.

13-Week oral repeated administration toxicity study of bovine lactoferrin in rats.

Bovine lactoferrin (LF), which is an iron-binding glycoprotein in milk, was administered orally to groups of 12 males and 12 female rats at dose levels of 200, 600 and 2000mg/kg/day once daily for 13 weeks and its toxicity on repeated administration was examined. Throughout the administration period, there were no deaths caused by administration of the test compound, nor were there any adverse effects noted in the general condition of the animals. The study findings concerning body weight and food consumption, ophthalmology, urinalysis including water consumption, haematology, blood chemistry, necropsy, organ weights and histopathology revealed that there were no apparent changes due to administration of LF. Therefore, the level of LF at which no adverse effect was observed was considered to be 2000mg/kg/day for both sexes.

Enhanced anti-Candida activity of neutrophils and azole antifungal agents in the presence of lactoferrin-related compounds.

We investigated the effects of lactoferrin (Lf)-related compounds on growth inhibition of Candida albicans by neutrophils or antifungal agents in vitro. Human neutrophils partially inhibited the growth of C.albicans. The growth inhibition caused by human neutrophils was augmented by the addition of human Lf at concentrations which did not show any inhibitory effect in the absence of neutrophils. Similar observations were obtained also with the following combinations: human neutrophils + bovine Lf, murine neutrophils + bovine Lf, and murine neutrophils + iron saturated bovine Lf, but not in the case of murine neutrophils + human transferrin. The minimum inhibitory concentration (MIC) of azole antifungal agents, clotrimazole, ketoconazole, fluconazole, and itraconazole was reduced by 1/4 to 1/16 in the presence of a sub-MIC level of each of bovine Lf, bovine Lf pepsin hydrolysate, and the antimicrobial peptide "lactoferricin B" (Lfcin B). Other types of antifungal agents, amphotericin B, nystatin, and flucytosine did not show such combined effects with these Lf-related compounds. The anti-Candida activity of bovine Lf or Lfcin B in combination with clotrimazole was shown to be synergistic by checkerboard analysis. Clinically isolated azole-resistant C. albicans strains were more susceptible to bovine Lf or Lfcin B than azole-susceptible strains. Trailing growth of an azole-resistant strain in the presence of fluconazole was reduced by the addition of sub-MIC levels of bovine Lf or Lfcin B. These results suggest that Lf-related compounds even at relatively low concentrations may function as an antifungal effector in combination with neutrophils thereby modulating azole antifungal efficacies in vivo.

The mechanism of in vivo bacteriostasis of bovine lactoferrin.

Recently we have reported that orally administered bovine Lf(bLf) exerts bacteriostatic effects against bacterial overgrowth in the intestine of specific-pathogen-free (SPF) mice fed milk. In this animal model, the in vivo bacteriostatic effect of bLf against the proliferation of intestinal Enterobacteriaceae, the bacteria most sensitive to bLf, was independent of the iron-chelating ability of bLf. In addition various proteolytic hydrolysates of bLf (with differing antibacterial activities in vitro) showed the same bacteriostatic effect as undigested bLf. These results suggest that the mechanism of in vivo bacteriostasis of Lf differs from the in vitro mechanism reported. In SPF mice fed milk differing in concentrations of lactose, glucose and galactose, the proliferation of intestinal Enterobacteriaceae was dependent on the carbohydrate concentration in the diet. The addition of 2% bLf to the diets significantly suppressed this carbohydrate-dependent proliferation of bacteria except in the case of diets containing excess carbohydrate. In germ-free mice fed sterile milk, the addition of 2% bLf to milk resulted in a significant decrease in concentrations of lactose, glucose and galactose in the cecal contents. In an in vitro assay system using everted sacs of the small intestine of SPF mice, both bLf and its pepsin hydrolysate apparently stimulated glucose absorption. Based on these findings, we propose that the in vivo mechanism of action of ingested bLf involves the stimulation of carbohydrate absorption resulting in a bacteriostatic effect against Enterobacteriaceae in the intestine of mice fed milk.

Effects of orally administered bovine lactoferrin on the immune system of healthy volunteers.

A protective effect of bovine lactoferrin (Lf) during lethal bacteraemia has been reported in mice. Also, protective effects of orally administered bovine Lf have been reported in cases of intractable stomatitis in cats and Cryptocaryon irritans infection in red sea bream. In this study, we examined the effects of orally administered bovine Lf on the immune system of healthy volunteers. Ten healthy male volunteers (age range of 31 to 55 years old) were given bovine Lf (2 g/body/day) for 4 weeks. Blood samples were drawn before, during and after administration of Lf. Phagocytic activity and superoxide production activity of polymorphonuclear leukocytes (PMN) were evaluated from the number of PMN phagocytizing polymer particles and by the dichlorofluorescein (DCFH) oxidation assay, respectively. The expression levels of CD11b, CD16 and CD56 molecules on leukocytes were quantified using flow cytometry. The phagocytic activity of PMN increased during the period of Lf administration in 3 of the 10 volunteers. In 2 of the 3 volunteers in which the phagocytic activity increased, PMN expressed CD16 at higher levels corresponding to the increase in 3 of the 10 volunteers, whereas the CD11b+ lymphocytes and CD56+ lymphocytes increased in 4 volunteers including the same 3 volunteers who showed an increase in CD16+. These results suggest that the proportion of natural killer (NK) cells among the lymphocytes might have increased in these subjects. It was demonstrated that the phagocytic activity or superoxide production activity of PMN or the proportions of CD11b+, CD16+ and CD56+ in lymphocytes was influenced by Lf administration in 7 of the 10 volunteers, while the effects of Lf on the immune system differed in individual cases. These results suggest that Lf administration may influence primary activation of the host defense system.

Docosahexaenoic acid status of patients with extrahepatic biliary atresia.

Docosahexaenoic acid (DHA) is believed to be an important long-chain polyunsaturated fatty acid (LCPUFA), which may be essential for neurofunction in infants. Patients with extrahepatic biliary atresia (EBA) may have DHA deficiency secondary to fat malabsorption. The authors investigated DHA and other LCPUFA levels in plasma and red blood cell (RBC) phospholipids of patients after the Kasai portoenterostomy and after supplementation with essential fatty acids. Ten children aged 8 to 17 months (mean, 12.6 months) comprised the study group. Five were jaundiced and five had a normal bilirubin level. The patients received 1 mL/kg of fat emulsions (10% Intralipid, containing 50% linoleic acid and 9% alpha-linolenic acid) in addition to an age-appropriate diet. Additional supplements were ursodeoxycholic acid (UDCA) (15 mg/kg/d) and taurine (100 mg/kg/d). The percentages of DHA in both plasma and RBC phospholipids of patients in the jaundiced group were significantly lower than those of normal children. Patients in the jaundice-free group had significantly lower levels of DHA and higher levels of linoleic acid in both plasma and RBC phospholipids in comparison to the normal group. This study shows that postoperative EBA patient become DHA-deficient even when supplemented with fat emulsions (largely composed of linoleic acid) that contain DHA's precursor, alpha-linolenic acid. This demonstrates a deficiency in the long-chain acid desaturase activity of these patients. It is recommended that excessive/linoleic acid intake be avoided and that all EBA patients have small amounts of DHA added to their lipid supplementation.

Effects of ursodeoxycholic acid treatment on essential fatty acid deficiency in patients with biliary atresia.

To assess whether ursodeoxycholic acid (UDCA) treatment has any beneficial effect on essential fatty acid (EFA) deficiency in patients who have had a Kasai operation for extrahepatic atresia (EBA), responses of serum fatty acids to UDCA administration (15 mg/kg/d) were investigated in eight jaundice-free patients and in eight patients with jaundice (serum total bilirubin > or = 1.0 mg/dL). All patients were also given taurine supplementation (100 mg/kg/d). Serum fatty acid composition was determined before and 6 months after UDCA treatment. Serum total bile acid concentration and serum total bilirubin value, as a part of conventional liver function tests, were measured before and during UDCA therapy. Before UDCA treatment, the concentrations of linoleic acid and arachidonic acid were significantly lower (P > .05 for the former; P > .01 for the latter) in both the jaundice and jaundice-free groups than in the controls. After 6 months of treatment, the linoleic acid concentration significantly increased (P > .05), to the normal range, in the jaundice-free group, but not in the jaundice group. The arachidonic acid concentration did not increase significantly in either group. The serum total bile acid concentration was lower in six of the eight jaundice-free patients and in four of the eight jaundice patients. The serum total bilirubin value decreased in six of the eight jaundice-free patients and in four of the eight jaundice patients; however, the degree of improvement was not statistically significant in either group. No side effects developed, and there were no changes in blood chemistry values unrelated to liver disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Essential fatty acid deficiency in congenital biliary atresia: successful treatment to reverse deficiency.

Supplementation of lipid intake by infusion of solutions of essential fatty acid (EFA)-rich powder through Suruga II enterostomy was carried out for the treatment of EFA deficiency in nine children with postoperative congenital biliary atresia (CBA). Infusion of EFA-rich powder dissolved in excreted bile was effective in six patients except for a case who had a total bile acid concentration in the excreted bile that was less than critical micellar level. Administration of EFA-rich powder dissolved in a mixture of the patient's own bile and 1 to 2 mmol/L taurocholate (TC) solution corrected EFA deficiency in three children with total bile acid concentration lower than the critical level. Our results therefore show that infusion of EEA-rich lipid through Suruga II enterostomy after dissolving in the excreted bile is an effective treatment for EFA deficiency in postoperative patients with CBA, and that 1 to 2 mmol/L TC solution used as artificial bile facilitates lipid absorption in cases with total bile acid in the bile less than the critical micellar level.

Mutagenicity of bovine lactoferrin in reverse mutation test.

The mutagenicity of bovine lactoferrin, which is an iron-binding glycoprotein in milk, was evaluated by the Ames mutagenicity test. A total of 5 test strains including 3 base-pair substitution-type strains, Salmonella typhimurium TA100, TA1535 and Escherichia coli WP2uvrA, and 2 frameshift-type strains, TA98 and TA1537, were used in the test. The test was performed by both the direct method and the metabolic activation method with preincubation applied in each instance. The concentration range of the test solution was 0.16 to 5.00 mg/100 microliters (plate). Results of the test revealed that the number of revertant colonies at each concentration of the test solutions was less than 1.4 times that of the control group. In the test system used, bovine lactoferrin did not exhibit mutagenicity.

Numerous huge iron particles appeared around micro blood vessels under intestinal epithelial cells in infant mice fed excess iron with protein.

In infant mice (2 weeks old) fed a diet with excess iron for one week, numerous huge iron particles around micro blood vessels under the basement membrane of intestinal epithelial cells were observed by electron microscopy. The frequency of occurrence of these particles (0.24 +/- 0.04 micron diameter) was markedly higher in mice fed a casein-based diet than in mice fed an amino acid-based diet. The quantity of these particles in both groups decreased in proportion to the term of 2 or 3 weeks. Changes in morphological features, such as opening of the intercellular junctions between intestinal epithelial cells, were also observed in these experimental groups. On the other hand, in mice fed the casein-based diet with excess iron, fat globules appeared in the intestinal epithelial tissue (intestinal epithelial cells, interstitial tissue, lympha) and the occurrence of these increased gradually in proportion to the term of feeding. These fat globules were not observed in mice fed the amino acid-based diet with excess iron. These phenomena might be elicited temporally in infant mice fed excess iron together with protein. The mechanisms of fat globule formation remain unclear.

Investigation of morphological changes in absorptive cells in young adult and infant mice fed different amounts of iron for a long-term.

The changes in fine structure of the intestinal tract in young adult (4 week-old) and infant (2 week-old) mice fed a diet containing different amounts of iron salt (Fe-0, Fe-2.5, Fe-25: 0, 2.5 and 25 mg Fe/100 g diet, respectively) for a long-term (1 or 2 weeks) were investigated. The hepatic iron levels in infant mice fed Fe-25 for 2 weeks were significantly higher than those observed after 1 week of feeding, but there was no such increase in young adult mice during the feeding period. Observations of fine structure indicated typical signs of impairment of enterocytes due to excess iron such as the opening of intercellular junctions between adjacent epithelial cells and the marked appearance of eosinophilic leukocytes outside the basement membrane in young adult and infant mice fed Fe-25. The frequency of the opening in intercellular junctions increased in young adult mice fed Fe-25 for 2 weeks, but decreased in infant mice. On the contrary, under iron-deficient conditions, the frequency in infant mice was higher than that in young adult mice. The appearance of eosinophilic leukocytes indicated that some immunological reaction was elicited in both groups of mice fed Fe-25 for 2 weeks.

[A predictive model for affect of atopic dermatitis in infancy by neural network and multiple logistic regression].

OBJECTS: To analyze the predictive accuracy of the predictive model for affect of atopic dermatitis in infancy, from the data of the epidemiological survey, which were conducted for 10,000 of mothers of infants and children in 1993. SUBJECTS AND METHODS: A total of 4610 replies were received: 2714 from mothers of infants (12 month old) and 1,896 from mothers of children (2 years old). The sensitivity, specificity and predictive accuracy were calculated from probabilistic model by neural network analysis (NNA) and multiple logistic regression analysis (MLA). RESULTS: Risk factors for probabilistic model by NNA were family history (father, mother, siblings, grand father, grand mother), food restriction, food allergy, age, food restriction of mother, egg introduced time, cow's milk introduced time. The sensitivity, specificity and predictive accuracy of NNA model was 88.6%, 99.5% and 96.4%, respectively and MLA model was 75.1%, 82.6% and 82.3%, respectively. CONCLUSION: These results suggest that the NNA is a good and useful method for prediction of onset of AD than MLA. Furthermore, It is necessary to investigate the artificial neural networks for diagnosis and/or treatment by physician.

[Epidemiological research on incidence of atopic disease in infants and children in relation to their nutrition in infancy].

Incidence and relative risk of atopic disease (atopic dermatitis; AD, bronchial asthma; BA, allergic rhinitis; AR) in Japanese infants and children in relation to their nutrition in infancy was analyzed from the data of the epidemiological survey which was conducted for 10,000 mothers of infants and children in 1993. A total of 4,610 replies were received: 2,714 from mothers of infants (12 months old) and 1,896 from mothers of children (2 years old). The subjects were allocated to following 3 groups based on their nutrition during first 3 months after birth; the breast-fed group (BF), the formula-fed group (EF), the mixed-fed group (MF). Incidence of atopic disease in BF, FF and MF was 23.5%, 22.2% and 21.8%, respectively and no statistical difference could be found among these 3 groups. AD was developed 17.0%, 14.4% and 13.9%; BA was 4.4%, 8.5% and 5.2%; AR was 4.9%, 6.5% and 5.8% in BF, FF and MF, respectively. Incidence of AD was significantly different between BF and MF (p < 0.01). Incidence of BA was also significantly different between BF and FF (p < 0.01). Risk of onset of BA and AR in FF was higher (adjusted odds ratio 2.2, 95% confidence interval 1.5-3.2 and adjusted odds ratio 1.5, 95% confidence interval 1.0-2.2, respectively) than that of BF controlled by age and family history with Cochran-Mantel-Haenzel test. With multiple logistic regression analysis, relative risk of the onset of BA in FF at the age of one year was 2.1, 95% confidence interval 1.2-3.5 and at the age of two years old was 2.5, 95% confidence interval 1.4-4.4. These results suggest that the breast-fed have certain suppression effects on incidence of bronchial asthma in infants and children.

[Intestinal flora of infants with cow milk hypersensitivity fed on casein-hydrolyzed formula supplemented raffinose].

We studied the intestinal flora of infants with cow milk hypersensitivity fed on casein-hydrolyzed formula (MA-1) and the influence of that supplemented with Raffinose (MA-1[R]). Infants with cow milk hypersensitivity were fed with MA-1 for 2 weeks, after which the formula was changed to MA-1[R]. Fourteen subjects were enrolled in this study and divided into two groups; three who fed with breast or conventional milk in addition to MA-1 or MA-1[R](BM group) and 11 mainly fed with MA-1 or MA-1[R] (TF group). Intestinal flora was investigated at two weeks after MA-1 feeding and at two weeks after MA-1[R] feeding, respectively. Bifidobacterium was detected as the most predominant bacteria in all examples in the BM group, and that count and the ratio in all bacteria remained high even after changing MA-1 to MA-1[R]. On the other hand, bacteria count and ratios of Bifidobacterium in all bacteria were conspicuously low in the TF group as compared with the BM group. And with the change from MA-1 to MA-1[R] in the TF group, the bacterial number and the occupation ratio of Bifidobacterium were increased, and Enterobacteriaceae bacterial count and the occupation ratio were decreased. The change of the intestinal flora with MA-1[R] feeding was mainly caused by the breeding action of Raffinose on bifidobacteria. Further studies are needed from a viewpoint of clinical effectiveness about the influence of normalization of the intestinal flora for the treatment of food hypersensitivity.

Inhibition of Escherichia coli respiratory enzymes by the lactoperoxidase-hydrogen peroxide-thiocyanate antimicrobial system.

AIMS: The lactoperoxidase-hydrogen peroxide-thiocyanate antimicrobial system (LPAS) is known to inhibit bacterial respiration. In the present study, several respiratory enzymes of Escherichia coli were compared in terms of their susceptibility to the LPAS. METHODS AND RESULTS: Exposure of E. coli to the LPAS, upon which 99.6% of the bacteria were killed, resulted in the following percentage of inactivation of substrate-specific membrane oxidases: succinate (94.2%) > NADH (84.6%) > glycerol-3-phosphate (67.8%) > DL-lactate (64.1%). With the same treatment, substrate-specific membrane dehydrogenases were inactivated as follows: succinate (99.1%) > DL-lactate (53.8%) > glycerol-3-phosphate (45.0%) > NADH (36.8%). Terminal oxidase, however, measured using a ubiquinone analogue (2,3-dimethoxy-5-methyl-6-decyl-1,4-benzoquinone) after reduction, was only 21.4% inactivated by the LPAS. CONCLUSION: These data suggest that dehydrogenases are the primary targets of the LPAS in the respiratory chain of E. coli. SIGNIFICANCE AND IMPACT OF THE STUDY: This study has determined for the first time the primary targets of LPAS in the bacterial respiratory chain.