Commensal microbiota modulate murine behaviors in a strictly contamination-free environment confirmed by culture-based methods.

BACKGROUND: There is increasing evidence suggesting the existence of an interaction between commensal microbiota, the gut and the brain. The aim of this study was to examine the influence of commensal microbiota on the host behaviors in a contamination-free environment, which was verified by culture-based methods. METHODS: Open-field and marble-burying tests were used to analyze anxiety-like behaviors and locomotor activity in gnotobiotic BALB/c mice with a common genetic background in a sterile isolator. The monoamine levels in several regions of the brain were measured in germfree (GF) mice and commensal fecal microbiota-associated mice (EX-GF). KEY RESULTS: A 24-h exposure to the environment outside the sterile isolators rendered GF mice less anxious than those not contaminated, while there was no change in the locomotion. EX-GF mice, the gnotobiotic mice with normal specific pathogen-free microbiota, were less anxious and active than GF mice using open-field and marble-burying tests. The norepinephrine, dopamine, and serotonin turnover rates were higher in the EX-GF mice than in the GF mice in most regions of the brain, suggesting that monoaminergic neurotransmission might increase in the EX-GF mice comparing the GF mice. Monoassociation with Brautia coccoides reduced the anxiety level, but it did not affect the locomotor activity. In contrast, colonization with Bifidobacterium infantis decreased the locomotor activity, while having little effect on the anxiety level. CONCLUSIONS & INFERENCES: These results strongly support the current view that gut microorganisms modulate brain development and behavior.

Clinical effects of kestose, a prebiotic oligosaccharide, on the treatment of atopic dermatitis in infants.

BACKGROUND: Oligosaccharides may have beneficial properties of the prevention of atopic dermatitis (AD). Kestose, a fructo-oligosaccharide, stimulates the activity of bifidobacteria. OBJECTIVE: To assess the clinical effect of kestose on the treatment of AD in infants. METHODS: A randomized, double-blind, placebo-controlled trial was carried out using 15 and 14 infants with AD in the kestose group and placebo groups, respectively. One to 2 g kestose and maltose were administered to the subjects in the kestose and placebo groups, respectively, everyday for 12 weeks. Clinical evaluations of AD using Severity Scoring of Atopic Dermatitis (SCORAD) and the enumeration of bifidobacteria in the feces using real-time PCR were performed at Weeks 0, 6, and 12. RESULTS: The medians of the SCORAD score were significantly lower in the kestose group than in the placebo group on both Week 6 (25.3 vs. 36.4; P=0.004) and Week 12 (19.5 vs. 37.5; P<0.001). No significant correlation was found between the improvement of the SCORAD score and the count of bifidobacteria. CONCLUSION: Kestose was found to exert a beneficial effect on the clinical symptoms in infants with AD. The mechanism how does kestose improve the symptoms of AD remains to be elucidated.

Potentiation of glucocorticoid receptor (GR)-mediated signaling by the immunosuppressant tacrolimus in rheumatoid synoviocytes.

OBJECTIVE: The immunosuppressant tacrolimus is known to enhance many aspects of glucocorticoid. In this study, we investigated the effects of tacrolimus on glucocorticoid receptor (GR) signaling using rheumatoid fibroblast-like synoviocytes (RA-FLS). METHODS: The nuclear translocation of GR was analyzed by immunocytochemistry. The DNA binding activity of p65 was assayed by a functional ELISA kit using nuclear extracts. GR-associated FK506-binding protein-51 (FKBP-51) was analyzed by Western blotting following immunoprecipitation of glucocorticoid receptor (GR) complexes. RESULTS: High concentrations (10-7M) of Dexamethasone (Dex) induced GR translocation to the nucleus in RA-FLS. However, the nuclear GR translocation did not occur with low concentrations of Dex (10-9M). Tacrolimus treatment of RA-FLS results in potentiation of GR translocation to the nucleus even in the presence of a low concentration of Dex (10-9M). GR-associated FKBP-51 decreased after tacrolimus treatment. Furthermore, tacrolimus also decreased the IL-1Beta-induced DNA binding activity of p65, a subunit of NF-KappaB, in the presence of 10-9 M of Dex. CONCLUSION: These data suggest that tacrolimus exerts anti-inflammatory properties by potentiating the GR signaling through the GR-immunosuppressant-binding proteins (immunophilins) interaction and its nuclear transport in rheumatoid synovium.

Effect of intestinal microbiota on the induction of regulatory CD25+ CD4+ T cells.

When oral tolerance was induced in either specific pathogen-free (SPF) or germ-free (GF) mice, ovalbumin (OVA) feeding before immunization induced oral tolerance successfully in SPF mice. On the other hand, OVA-specific immunoglobulin G1 (IgG1) and IgE titres in OVA-fed GF mice were comparable to those in phosphate-buffered saline-fed GF mice, thus demonstrating that oral tolerance could not be induced in GF mice. The frequencies of CD25(+) CD4(+)/CD4(+) cells in the mesenteric lymph node (MLN) and the absolute number of CD25(+) CD4(+) cells in the Peyer's patches and MLN of naive GF mice were significantly lower than those in naive SPF mice. In an in vitro assay, the CD25(+) CD4(+) cells from the naive SPF mice suppressed more effectively the proliferation of responder cells in a dose-dependent manner than those from the GF mice. In addition, the CD25(+) CD4(+) regulatory T (T(reg)) cells from the naive SPF mice produced higher amounts of interleukin (IL)-10 and transforming growth factor (TGF)-beta than those from the GF mice. When anti-TGF-beta neutralizing antibody, but not anti-IL-10 neutralizing antibody, was added to the in vitro proliferation assay, the suppressive effect of the CD25(+) CD4(+) T(reg) cells from the SPF mice was attenuated to the same level as that of the CD25(+) CD4(+) cells from the GF mice. In conclusion, the TGF-beta-producing CD25(+) CD4(+) T(reg) cells from the MLN of SPF mice played a major role in oral tolerance induction. In addition, as the regulatory function of the CD25(+) CD4(+) cells from the naive GF mice was much lower than that of the CD25(+) CD4(+) T(reg) cells from the SPF mice, indigenous microbiota are thus considered to contribute to the induction and maintenance of CD25(+) CD4(+) T(reg) cells.

A minimally hypomorphic mutation in Btk resulting in reduced B cell numbers but no clinical disease.

Reduced B cell numbers and a mutation in Btk are considered sufficient to make the diagnosis of X-linked agammaglobulinaemia. In the process of conducting family studies, we identified a 58-year-old healthy man with an amino acid substitution, Y418H, in the adenosine-5'-triphosphate binding site of Btk. Immunofluorescence studies showed that this man had 0.85% CD19+ B cells (normal 4-18%) in the peripheral circulation and his monocytes were positive for Btk. He had borderline low serum immunoglobulins but normal titres to tetanus toxoid and multiple pneumococcal serotypes. To determine the functional consequences of the amino acid substitution, a Btk- chicken B cell line, DT40, was transfected with expression vectors producing wild-type Btk or Y418H Btk. The transfected cells were stimulated with anti-IgM and calcium flux and inositol triphosphate (IP3) production were measured. Cells bearing the mutant protein demonstrated consistently a 15-20% decrease in both calcium flux and IP3 production. These findings indicate that even a modest decrease in Btk function can impair B cell proliferation or survival. However, a mutation in Btk and reduced numbers of B cells are not always associated with clinical disease.

An oral introduction of intestinal bacteria prevents the development of a long-term Th2-skewed immunological memory induced by neonatal antibiotic treatment in mice.

BACKGROUND: Recent epidemiological studies indicate that antibiotic use in infancy may be associated with an increased risk of developing atopy. Our previous work on animals demonstrated that kanamycin use during infancy promotes a shift in the Th1/Th2 balance towards a Th2-dominant immunity. OBJECTIVE: The first purpose of this study is to clarify whether or not the supplementation of intestinal bacteria can reverse such a Th2-skewed response induced by neonatal antibiotic use. The second objective is to elucidate the contribution of genetic factors to antibiotic-induced immune-deviation. METHODS: BALB/c or C57BL/6 mice at 3 weeks of age were orally administered 600 microg/day of kanamycin sulphate for seven consecutive days. Thereafter, the mice were inoculated with one type of intestinal bacterial species: Enterococcus faecalis, Lactobacillus acidophilus or Bacteroides vulgatus. Blood samples were collected 10 weeks after the cessation of kanamycin treatment, and the effect of the kanamycin treatment on Th1/Th2 balance was evaluated based on in vivo antibody levels. RESULTS: A kanamycin-induced elevation of the serum IgE levels was reversed by the supplementation with Enterococcus faecalis, and to a lesser extent by that with Lactobacillus acidophilus. The IgE/IgG2a ratio in the mice supplemented with Enterococcus faecalis significantly decreased in comparison with that in the kanamycin-treated mice without any bacterial supplementation, while such a ratio was enhanced in the mice inoculated with Bacteroides vulgatus. No antibiotic-induced Th2-skewed response was seen in C57BL/6 mice that are genetically biased towards Th1-dominant immunity. CONCLUSION: These results suggest that adequate probiotic intervention after antibiotic treatment may improve the intestinal ecosystem, and thereby prevent the Th2-shifted immunity induced by neonatal antibiotic use. In addition, the difference of genetic backgrounds also contributes to such an antibiotic-induced Th2-skewed response.

Total synthesis and antifungal activity of 9-methoxystrobilurin L as the originally proposed 1,4-benzodioxan structure.

Total synthesis of both enantiomers of 9-methoxystrobilurin L as the originally proposed 1,4-benzodioxan structure was successfully achieved. The 1H and 13C NMR spectra of synthesized 9-methoxystrobilurin L were compared with those of a naturally-occurring sample. It was strongly indicated that naturally-occurring 9-methoxystrobilurin L has not the originally reported 1,4-benzodioxan structure but a 1,5-benzodioxepin structure, the same as previously reported 9-methoxystrobilurin K. Antifungal activities of the synthesized compounds toward several typical fungi were also examined, and they were less active than 9-methoxystrobilurin K.

Restraint stress elevates the plasma interleukin-6 levels in germ-free mice.

Several recent reports demonstrated that restraint stress elevates plasma IL-6 levels; however, the precise mechanism whereby stress stimuli trigger the production of IL-6 remains to be clarified. In this study, in order to elucidate whether or not the intestinal microflora contribute to the stress-induced IL-6 elevation, the plasma IL-6 response of germ-free (GF) mice, which are indeed devoid of indigenous microflora, was compared to that of specific pathogen-free (SPF) mice. The plasma IL-6 level increased after 1 h of restraint stress and thereafter gradually decreased in GF mice as well as in SPF mice. In addition, such a stress-induced IL-6 elevation was also found in the mice reconstituted with SPF feces. The expression levels of IL-6 mRNA in the liver increased after 1 h of stress in both GF and SPF mice based on the findings of a semiquantitative RT-PCR method, although no such increase was observed in the spleen and kidney of both groups of mice. These results thus indicate that restraint stress is capable of elevating the plasma IL-6 levels independently of the intestinal microflora and the liver is one of the main sources responsible for the increased plasma IL-6 during stress.

Role of nitric oxide synthase type 2 in acute infection with murine cytomegalovirus.

Whether or not NO plays a critical role in murine CMV (MCMV) infection has yet to be elucidated. In this study, we examined the role of NO in acute infection with MCMV using NO synthase type 2 (NOS2)-deficient mice. NOS2(-/-) mice were more susceptible to lethal infection with MCMV than NOS2(+/+) mice and generated a much higher peak virus titer in the salivary gland after acute infection. A moderate increase in the MCMV titer was also observed in other organs of NOS2(-/-) mice such as the spleen, lung, and liver. The immune responses to MCMV infection including NK cell cytotoxicity and CTL response in NOS2(-/-) mice were comparable with those of NOS2(+/+) mice. Moreover, the ability to produce IFN-gamma is not impaired in NOS2(-/-) mice after MCMV infection. The peritoneal macrophages from NOS2(-/-) mice, however, exhibited a lower antiviral activity than those from NOS2(+/+) mice, resulting in an enhanced viral replication in macrophages themselves. Treatment of these cells from NOS2(+/+) mice with a selective NOS2 inhibitor decreased the antiviral activity to a level below that obtained with NOS2(-/-) mice. In addition, the absence of NOS2 and NOS2-mediated antiviral activity of macrophages resulted in not only an enhanced MCMV replication and a high mortality but also a consequent risk of the latency. It was thus concluded that the NOS2-mediated antiviral activity of macrophages via NO plays a protective role against MCMV infection at an early and late stage of the infection.

Comparison of three signals for secretory expression of recombinant human midkine in Pichia pastoris.

The secretion signals of Saccharomyces cerevisiae alpha mating factor, human midkine itself, and Pichia pastoris acid phosphatase, were tried for the expression of human midkine under the control of the AOX1 gene promoter in P. pastoris. Approximately 28 mg/l, 1.5 mg/l, and 0.2 mg/l of midkine were secreted by using the a mating factor pre-pro-sequence, the midkine signal sequence, and the phosphatase signal sequence in flask cultures, respectively.

The failure of oral tolerance induction is functionally coupled to the absence of T cells in Peyer's patches under germfree conditions.

Although intestinal bacterial flora has been thought to play a role in the induction of oral tolerance, the mechanism has yet to be elucidated. We therefore examined the bacterial flora-dependent acquisition of susceptibility to oral tolerance induction using a gnotobiotic murine model. Germ-free (GF) mice exhibited a significant shortage of T cells in the PPs in comparison to SPF mice. A recovery in the number of such T cells was accomplished in the gnotobiotic mice associated with Bifidobacterium infantis or Escherichia coli but not in the gnotobiotic mice with Clostridium perfringens or Staphylococcus aureus. To examine the susceptibility to oral tolerance induction, these mice were orally given ovalbumin (OVA) as a tolerogen and then injected i.p. with the Ag. The Ag-specific IgG1 in the serum remained at a low level in both SPF and those gnotobiotic mice groups containing a sufficient number of T cells in the PPs. However, no such unresponsiveness in the Ab response was observed in GF or the other gnotobiotic mice groups containing only a few T cells in the tissues. Adoptive cell transfer analysis clearly showed that a sufficient number of T cells in the PPs is required for the induction of oral tolerance. Furthermore, the reduced expression of SLC (secondary lymphoid-tissue chemokine), which is responsible for T-cell migration to lymphoid organs, was observed in the PPs of GF mice, resulting in a shortage of T cells in the tissues. However, the reduced expression of SLC was restored even in the GF mice after conventionalization, thus suggesting that the failure of oral tolerance induction is functionally coupled to the innate absence of T cells under the GF condition.

Semi-interpenetrating polymer networks composed of biocompatible phospholipid polymer and segmented polyurethane.

2-Methacryloyloxyethyl phosphorylcholine (MPC) polymers, which have excellent biocompatibility, have been receiving increasing attention in biomedical and bioengineering fields; however, the mechanical strength of the hydrated MPC polymers is not sufficient for use in these fields as a bulk material. Therefore, we hypothesized that a novel material might be realized by reinforcing the MPC polymer network with segmented polyurethane (SPU). Semi-interpenetrating polymer networks (IPNs) composed of crosslinked MPC polymer and SPU were prepared. The mechanical properties of the IPN membrane were significantly improved compared with those of the MPC polymer membrane. Three-dimensional polymer networks of the MPC polymer in the IPNs were observed after solvent extraction of SPU. An X-ray photoelectron spectrum analysis revealed that the MPC units were exposed on the IPN surface. When the IPN was alternately soaked in water and ethanol, the swelling ratio was found to be completely reversible and no disintegration of the network structure was observed. The permeation coefficient of 1, 4-di(2-hydroxyethoxy)benzene through the IPN membrane was 1.11 x 10(-7) cm(-2)s(-1). The amount of adsorbed protein and the number of adherent platelets on the IPN membrane were effectively reduced compared with those on SPU. We concluded that IPNs composed of the MPC polymer and SPU are a new bulk biomaterial, which possesses both blood compatibility and good mechanical properties.

Dietary nucleic acids promote a shift in Th1/Th2 balance toward Th1-dominant immunity.

BACKGROUND: Dietary sources of nucleic acids and their relative components are known to affect host immune function; however, it has not yet been clarified whether such dietary nucleic acids influence the pathogenesis of allergic reaction. OBJECTIVE: The purpose of this study is to elucidate the effect of dietary nucleic acids on Th1/Th2 balance. METHODS: Both human flora-associated and specific pathogen-free BALB/c mice were maintained on either nucleic acid-free, or -supplemented diets. The effects of nucleic acids on both in vivo antibody levels and in vitro splenocyte cytokine production were compared using these mice. RESULTS: Supplementation of nucleic acids caused a reduction in the serum antibody levels of total IgM, IgG, IgG1, and IgE in the human flora-associated mice without affecting the composition of intestinal flora. In contrast, there was no significant difference of the serum IgG2a levels between nucleic acid-free and -supplemented mice. Such a phenomenon as that, the supplementation of dietary nucleic acids reduces the serum IgE or IgG1 levels, but not the IgG2a level, was also seen in the specific pathogen free mice. Moreover, when the mice were systematically challenged with ovalbumin, the supplementation of nucleic acids also suppressed the serum ovalbumin-specific IgE and IgG1 antibody levels as well as in vitro IL-4 and IL-10 secretion, while enhancing both the serum ovalbumin-specific IgG2a antibody levels and in vitro IFN gamma secretion. CONCLUSION: These results suggested that dietary nucleic acids may play an important role in promoting a shift in Th1/Th2 balance toward Th1-dominant immunity.

Plaunotol suppresses interleukin-8 secretion induced by Helicobacter pylori: therapeutic effect of plaunotol on H. pylori infection.

BACKGROUND: It has been suggested that gastric mucosal injury induced by Helicobacter pylori infection is mediated by interleukin-8 (IL-8). METHODS: We studied the effect of plaunotol, a drug extracted from the Plau-noi tree of Thailand, and reported it to be effective in the treatment of ulcers, of IL-8 secretion induced by H. pylori and of the inhibitory adhesion activity of the bacterium to gastric epithelial cells. Moreover, the therapeutic effect of plaunotol on H. pylori infection was assessed by using the gnotobiotic murine model. RESULTS: Plaunotol inhibited the growth of H. pylori (1.5 x 10(4) c.f.u./mL) at high doses (24-48 microg/mL), but not at low doses (3-6 microg/mL). Interleukin-8 secretion induced by H. pylori was inhibited by coculture with plaunotol in a dose-dependent manner. The adhesion of H. pylori to MKN45 cells was also suppressed by coculture with plaunotol in a dose-dependent manner. An in vivo study showed that plaunotol improved histological gastritis and decreased the H. pylori antibody titre. CONCLUSIONS: These findings suggest that plaunotol has a therapeutic effect on gastritis induced by H. pylori.

The effect of sofalcone on indomethacin-induced gastric ulcers in a Helicobacter pylori-infected gnotobiotic murine model.

BACKGROUND: Sofalcone has been reported to exert anti-ulcer and gastroprotective actions, but its exact mechanism of action remains unknown. In our laboratory, we found that indomethacin-induced gastric ulcers become worse when associated with Helicobacter pylori infection. METHODS: We employed the H. pylori-infected gnotobiotic murine model to examine the effect of sofalcone on indomethacin-induced gastric ulcers in the presence of H. pylori infection. In vitro experiments were also done to evaluate the effects of sofalcone on H. pylori growth, adherence of H. pylori to the MKN45 cells (a human gastric epithelial cell line), and these cells' IL-8 production in the presence of H. pylori. RESULTS: We found that sofalcone produced a significant improvement in ulcer size as well as a substantial reduction in the number of H. pylori colonies in H. pylori-infected gnotobiotic mice. In vitro sofalcone has a significant bacteriocidal effect against H. pylori and can also significantly prevent adherence of this bacterium to MKN45 cells, thus remarkably reducing IL-8 production of these cells in response to stimulation by H. pylori. CONCLUSION: Our results suggest that sofalcone can improve ulcer healing by the mechanisms mentioned above.

A unique, short sequence determines p53 gene basal and UV-inducible expression in normal human cells.

The p53 tumor suppressor protein plays a central role in the cellular defence against agents which cause genetic damage. The induction and activation of p53 upon stress has been shown at post-transcription level by multiple mechanisms, while the regulatory role of p53 gene transcription is still poorly understood. Here we show that the causative mechanisms underlying this activation are attributed in part to the promoter function of p53. In various normal human cells, p53 gene expression is induced transcriptionally by ultraviolet (UV) but not X-ray irradiation. We determined that, by p53 promoter dissection, the 21 bp element (PE21) responsible for this UV activation resides adjacent to, and upstream to the putative NFkappaB binding site. Moreover, the PE21 sequence was found to be a primary determinant for human p53 gene basal expression carrying bi-directional transcriptional initiation activity, which controls the initiation of RNA synthesis about 50 bases downstream, indicating that the sequence plays a critical role in both basal and inducible transcription. Finally, we detected the putative PE21 binding factor(s) in nuclear extracts from non-irradiated and irradiated cells. Since the PE21 sequence does not show any homologies to the conventional TATA or GC box, or to an 'initiatior', all of which determine the initiation site for transcription, the PE21 sequence appears to be a new class in eukaryotic promoter elements. Our results indicate that the mechanism of PE21-directed p53 mRNA transcription has an important role in the cellular stress response as well as tumor suppression.

Production of recombinant human midkine in yeast, Pichia pastoris.

Recombinant human midkine was expressed in the cells of Pichia pastoris under the control of the AOX1 gene promoter. The expression of midkine was efficiently induced by methanol in a high cell density fermentation. Approximately 0.3 g/l culture of midkine accumulated in the cells by 72 h after induction. When the cells were disrupted, midkine was recovered in an insoluble form, and was insoluble even in the presence of 7 M urea. The precipitate was dissolved in the buffer solution (pH 8) containing 8 M guanidine hydrochloride, 10 mM dithiothreitol, 1 mM EDTA and 50 mM Tris-Cl, and then, midkine was renatured by dialysis at high concentration against the buffer solution (pH 8) containing 0.5 M sodium chloride and 20 mM Tris-Cl. The renatured midkine was recovered using a SP-Sepharose column, and purified further by Heparin-Sepharose column chromatography. Approximately 64 mg/l culture of the purified midkine was obtained. The amino acid sequence of amino-terminus and the amino acid composition of midkine were the same as those of Met-midkine that has a methionine residue at the amino-teminus. Mass spectrometry of purified Met-midkine showed a mass of 13370.7 Da (average), almost the theoretical mass for it. The Met-midkine enhanced the proliferation of Chinese hamster ovary (CHO) cells.

A study on the effects of countermeasures for vibrating tool workers using an impact wrench.

The aims of this study were (1) to measure frequency-weighted vibration acceleration and (2) to study the effects of introducing a vibration-proof impact wrench on VWF in workers. The subject pool was 383 male workers who were regularly using an impact wrench and taking special medical examinations for vibration syndrome in a factory from 1982 to 1999. The prevalence of workers with VWF increased gradually after 1982, reached a peak value (4.8%) in 1986, gradually decreased after 1987, and disappeared in 1994. Sixteen subjects who had had VWF at least one time during the observation period were selected for this study. The stages of VWF were at stage I on the Stockholm Workshop scale in all subjects. After the vibration-proof impact wrench was introduced in 1986, the vibration acceleration of the impact wrench measured on the handle decreased from 8.6-11.1 m/s2 to 5.1-7.1 m/s2. The actual time per day that subjects were assumed to use the impact wrench was 108 minutes. The subjects actually used an impact wrench more than the occupational exposure limit allowed. However, VWF disappeared after the introduction of a vibration-proof impact wrench. This might have resulted from the combined effect of introducing the vibration-proof impact wrench and certain countermeasures that were taken against cold working environments.

Differentiation in culture of murine primitive lymphohematopoietic progenitors toward T-cell lineage.

Earlier, we described a stromal cell-free two-step clonal culture system in which murine primitive lymphohematopoietic progenitors produce myeloid and B-lymphoid lineage cells. In the same culture T-cell potential of the progenitors was maintained. We now report that, in addition to myeloid and B-lymphoid cells, putative T-cell progenitors are also produced in culture. Lineage-negative (Lin-) Ly-6A/E+ c-kit+ bone marrow cells from 5-fluorouracil-treated mice were cultured in methylcellulose in the presence of SF (Steel factor), interleukin (IL)-11, and IL-7, and the resulting primary colonies were picked and pooled. When injected into severe combined immune deficiency (scid) mice, the pooled cells reconstituted the T-cell compartment of the scid mice earlier than freshly prepared primitive marrow cells. This reconstitution activity of the pooled primary colony cells was enriched in the Ly-6A/E+ and FcgammaRII/III-/low cell fractions. Reverse transcriptase-polymerase chain reaction (RT-PCR) and DNA-PCR analyses showed that some of the primary colony cells are differentiated sufficiently to express messenger RNA (mRNA) of T-cell receptor (TCR) beta-chain and pre-TCR alpha (pTalpha) and, although not frequently, to perform Dbeta-Jbeta rearrangement of the TCR gene. Micromanipulation studies confirmed the clonal origin of myeloid lineage cells and the cells positive for the T-cell-specific transcripts and D-J rearrangement of TCR beta-chain. These results suggested that, in the presence of SF, IL-11, and IL-7, primitive lymphohematopoietic progenitors differentiate toward T-cell lineage in addition to myeloid and B-cell lineages.

The therapeutic effect of bovine lactoferrin in the host infected with Helicobacter pylori.

BACKGROUND: It remains unclarified whether bovine lactoferrin (bLF) can exert a therapeutic effect on the host infected with Helicobacter pylori. METHODS: Germfree BALB/c mice were orally inoculated with H. pylori to induce infection. Three weeks after infection the mice were given bLF orally once daily for 2 or 4 weeks and were then killed to examine the bacterial number in the stomach and the serum antibody titer to H. pylori. To count the number of epithelium-bound H. pylori, the resected stomach was agitated in phosphate-buffered saline to remove non-bound H. pylori before bacterial enumeration. RESULTS: The administration of 10 mg bLF for 3 to 4 weeks decreased the number of H. pylori in the stomach to one-tenth and also exerted a significant inhibitory effect on the attachment of H. pylori to the stomach. As a result, the serum antibody titer to H. pylori, whose level is presumed to represent the size of the immune response by the host, thereby reflecting the degree of bacterial attack, decreased to an undetectable level. CONCLUSIONS: These findings suggest that bLF exerts an inhibitory effect on colonizing H. pylori by detaching the bacterium from the gastric epithelium and by exerting a direct anti-bacterial effect.