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Biomedical subjects

S Shimamura

Publications and source records attributed to S Shimamura.

At least 37 records · Page 2Linked to original sources
PubMed1997

Biologic activity of proteoglycan macrophage colony-stimulating factor.

We compared the biologic activities of 85-kDa macrophage-CSF (85-kDa M-CSF), which is fully active, and a proteoglycan M-CSF (PG-M-CSF). Both originate from the same precursor, but the latter retains the carboxyl-terminal portion, which must be proteolytically removed from the precursor to generate 85-kDa M-CSF and which is uniquely modified by a chondroitin sulfate glycosaminoglycan chain. PG-M-CSF supported the formation of murine macrophage colonies such as 85-kDa M-CSF. Furthermore, PG-M-CSF stimulated the proliferation of murine bone marrow macrophages, an M-CSF-dependent murine cell line, and an M-CSF-responsive human cell line established by transfer of the human M-CSF receptor gene. PG-M-CSF and 85-kDa M-CSF had equivalent specific biologic activities on a molar basis in all bioassays. The activity of PG-M-CSF was not affected by enzymatically removing the glycosaminoglycan chain when assayed by the formation of macrophage colonies and proliferation of the bone marrow macrophages. We analyzed the phosphorylation on tyrosine residue(s) of the M-CSF receptor in response to these M-CSFs that trigger mitogenic responses. PG-M-CSF rapidly (within 10 min) induced receptor phosphorylation in human cells with the same potency as 85-kDa M-CSF. These results indicate that PG-M-CSF is not a latent form or precursor of 85-kDa M-CSF but a fully biologically active cytokine.

Animals↗
PubMed1997

Identification of binding domains for basic fibroblast growth factor in proteoglycan macrophage colony-stimulating factor.

We recently demonstrated that proteoglycan macrophage colony-stimulating factor (PG-M-CSF) binds basic fibroblast growth factor (bFGF) and neutralizes the biological activity of bFGF. In this study, we identified the binding sites of PG-M-CSF for bFGF. We examined the binding of bFGF to overlapping 12-mer peptides with the sequence of the putative binding region. High affinity binding was detected at two peaks; one consisted of the three adjacent peptides, 212-223, 213-224 and 214-225 and the other, of the three adjacent peptides, 246-257, 247-258 and 248-259. The synthetic peptide (212VDPGSAKQRPPRST225) did not inhibit bFGF binding to another peptide (246PQPRPSVGAFNPGM259), and vice versa. However, both peptides inhibited the bFGF-induced but not platelet-derived growth factor-induced stimulation of DNA synthesis in murine Balb/c 3T3 cells.

3T3 Cells↗
PubMed1997

Properties of primary murine stroma induced by macrophage colony-stimulating factor.

The ability of purified human macrophage colony-stimulating factor (M-CSF) to accelerate the formation of stromal cells from murine bone marrow cells was investigated. The liquid culture of the marrow cells with M-CSF resulted in the formation of monolayers of macrophages on day 7. When the M-CSF was removed on that day and the residual adherent cells were cultured in the absence of M-CSF for an additional 7 days, many colonies appeared with cells that were morphologically distinguishable from M-CSF-derived macrophages. The appearance of the colonies was dependent on the concentration of M-CSF used at the beginning of the culture. Each colony was isolated as a single clone and analyzed. All clones were negative for esterase staining. These cells did not express M-CSF receptor mRNA and did not show a mitogenic response to M-CSF. On the contrary, these cells could be stimulated to proliferate by fibroblast growth factor and platelet-derived growth factor. The polymerase chain reaction analysis of these cells demonstrated constitutive expression of mRNA for M-CSF, stem cell factor, and interleukin (IL)-1, but not IL-3. Some clones expressed mRNA for granulocyte/M-CSF and IL-6. We also examined the ability of the cells to maintain murine bone marrow high proliferative potential colony-forming cells (HPP-CFC) in a coculture system. Most of the clones showed a significant increase in total HPP-CFC numbers after 2 weeks of coculture, although the extent of stimulation differed among clones. These results suggested that the colonies established by M-CSF were composed of functional stromal cells that were phenotypically different from macrophages.

Animals↗
PubMed1997

Bifidobacterium longum, a lactic acid-producing intestinal bacterium inhibits colon cancer and modulates the intermediate biomarkers of colon carcinogenesis.

The human colon can be described as a complex microbial ecosystem, comprising several hundred bacterial species. Some of these enteric bacteria are beneficial to the host and have been shown to exert antimutagenic and anticarcinogenic properties. We have investigated the colon tumor inhibitory activity of Bifidobacterium longum, a lactic acid-producing enterobacterium. The modifying effects of this lactic culture on colonic mucosal and/or tumor cell proliferation, ODC activity and ras-p21 oncoprotein expression in colon carcinogenesis were also analyzed. Male F344 rats were fed a modified AIN-76A diet containing 0 or 2% lyophilized cultures of B. longum and s.c. administered azoxymethane (AOM) dissolved in normal saline at a dose of 15 mg/kg body wt, once weekly for 2 weeks. Vehicle controls received an equal volume of normal saline s.c. Animals were maintained on control or experimental diets until termination of the study. Animals intended for analysis of cell proliferation were killed 20 weeks after the second AOM injection, whereas animals intended for colon tumor analysis and measurement of ODC activity and ras-p21 expression were killed 40 weeks after the last AOM injection. The data demonstrate that dietary administration of lyophilized cultures of B. longum resulted in significant suppression of colon tumor incidence and tumor multiplicity and also reduced tumor volume. Results also revealed that ingestion of B. longum significantly inhibited AOM-induced cell proliferation, ODC activity and expression of ras-p21 oncoprotein. Data suggest that oral administration of probiotic B. longum exerts strong antitumor activity, as indicated by modulation of the intermediate biomarkers of colon cancer, and consequently reduced tumor outcome.

Animals↗
PubMed1997

Structures of the sugar chains of recombinant macrophage colony-stimulating factor produced in Chinese hamster ovary cells.

The structures of the N- and O-linked sugar chains of recombinant human macrophage colony-stimulating factor (rhM-CSF) from Chinese hamster ovary (CHO) cells were studied. rhM-CSF is a homodimeric glycoprotein. Sugar composition analysis revealed that rhM-CSF contained 4.1 mol N-acetylgalactosamine, 10.3 mol N-acetylglucosamine, 5.0 mol mannose, 10.0 mol galactose, 1.4 mol fucose, and 11.8 mol sialic acid per mol of the monomer. The N- and O-linked sugar chains liberated by hydrazinolysis were N-acetylated, and the reducing-end sugar residues were tagged with 2-aminopyridine. The pyridylamino (PA-) sugar chains thus obtained were purified by HPLC. The structures of the PA-sugar chains were analyzed by a combination of reversed-phase and size-fractionation HPLC, and exoglycosidase digestions, from which the structures of the rhM-CSF sugar chains were estimated to be as follows: monosialo biantennary sugar chain (9 mol%), monosialo fucosylbiantennary sugar chain (10 mol%), disialo biantennary sugar chain (30 mol%), disialo fucosylbiantennary sugar chain (28 mol%), disialo triantennary sugar chain (7 mol%), trisialo triantennary sugar chain (11 mol%), and trisialo fucosyltriantennary sugar chain (5 mol%) for the N-linked sugar chains, and asialo (27 mol%), monosialo (51 mol%), and disialo (22 mol%) Galbeta1-3GalNAc for the O-linked sugar chains. Sialic acid residues were linked to the N-linked sugar chains through an alpha2-3 linkage.

Animals↗
PubMed1996

Identification of bifidobacteria from dairy products and evaluation of a microplate hybridization method.

Sixteen strains of Bifidobacterium isolated from 15 dairy products such as yogurt, cultured milk, butter and cheese were characterized on the basis of phenotypic characteristics and DNA similarities were examined by a microplate hybridization method. Three of the strains were identified as Bifidodobacterium longum, one strain was identified as Bifidobacterium bifidm, and one strain was assigned to the species Bifidobacterium breve on the basis of phenotypic characteristics, and this identification was confirmed by the analysis of DNA similarities. The remaining 11 strains could not be identified by examining their phenotypic characteristics and, contrary to the product label information, these strains were identified as Bifudidobacterium animalis on the basis of DNA similarities. The applicability of the colorimetric hybridization method in micro dilution wells to genetic identification of Bifidobacterium species was also studied.

Bifidobacterium↗
PubMed1996

Glycans of bovine lactoferrin function as receptors for the type 1 fimbrial lectin of Escherichia coli.

Bovine lactoferrin strongly inhibited the hemagglutination activity of type 1 fimbriated Escherichia coli. In addition, it agglutinated these bacteria. The agglutination reaction was specifically inhibited by glycopeptides derived from bovine lactoferrin or alpha-methyl-D-mannoside. These observations indicate that the glycans of bovine lactoferrin can serve as receptors for type 1 fimbrial lectin.

Agglutination↗
PubMed1996

Effects of lactoferrin and lactoferricin on the release of interleukin 8 from human polymorphonuclear leukocytes.

Human or bovine lactoferrin (LF) and lactoferricin (LFcin), a peptide derived from the N-terminal region of LF, each have the ability to stimulate the release of neutrophil-activating polypeptide interleukin 8 (IL-8) from human polymorphonuclear leukocytes (neutrophils, PMNs). This finding suggests that LF and LFcin may both function as immunomediators for activating the host defense system. A basic peptide, protamine, exerted the same effect as that of LF and LFcin, suggesting the importance of the basic nature of LF and LFcin in acting as an inducer of IL-8 release from PMNs.

Amino Acid Sequence↗
PubMed1995

Lobar dysmorphism of the kidney.

We report a case of a 38-year-old woman with lobar dysmorphism of the kidney. Lobar dysmorphism is a pathology classified under renal pseudotumor, which has received little attention. It is presumed that these cases will increase in number with advances in imaging diagnosis. Dynamic CT scan is useful for the diagnosis of this disease.

Adult↗
PubMed1995

A case of Gartner's duct cyst with a right aplastic kidney.

We report a case of a Gartner's duct cyst with a right aplastic kidney. This was discovered when the right kidney was not identified in an examination for epigastric pain. CT and MRI proved useful in the diagnosis. An MRI showed a tubular structure ascending from the cyst and a complication of a bicornate uterus. As the patient was asymptomatic, the patient was followed without treatment.

Child↗
PubMed1995

[Clinical efficacy of lomefloxacin (100 mg or 300 mg) single-dose therapy in female acute uncomplicated cystitis].

Female acute uncomplicated cystitis responds relatively well to antimicrobial chemotherapy. In particular, new quinolones are suited for use as antimicrobial agents in single-dose therapy of female acute uncomplicated cystitis since they have a long serum half-life and express potent antimicrobial activity against the causative microbes of this infection. Lomefloxacin (LFLX) is one such new quinolone which shows a long serum half-life, expresses potent antimicrobial activity against Escherichia coli (E. coli) and maintains an effective urinary drug concentration for approximately three days after a single administration. The authors carried out a comparative investigation of the clinical efficacy of single doses of 100 mg and 300 mg of LFLX in the treatment of female acute uncomplicated cystitis. The clinical efficacy rates with these doses, evaluated on the 3rd day after administration, were 98.2% (56/57 cases) for the 100mg-LFLX dose and 100% (62/62 cases) for the 300-mg LFLX dose. When the evaluation was performed on the 7th day after administration, the clinical efficacy rates were 91.3% (42/46 cases) for the 100-mg LFLX dose and 95.8% (46/48 cases) for the 300-mg LFLX dose. In addition, the microbial eradication rates were 73.7% (42/57 cases) for the 100-mg LFLX group and 75.8% (47/62 cases) for the 300-mg LFLX group on the 3rd day after administration, and 71.7% (33/46 cases) for the 100-mg LFLX group and 83.3% (40/48 cases) for the 300-mg LFLX group on the 7th day after administration. Although there were no statistically significant differences between the two LFLX dosage groups for these parameters at either of the evaluation times, the rates for the 300-mg LFLX dose were slightly superior. The investigators judged the efficacy of the LFLX treatment as having been insufficient in 12 patients, and urological examinations performed on six of those cases determined that there were mild underlying diseases in four cases, such as stenosis of the urethral meatus. On the basis of the findings described above, it is clear that a single 100-mg dose of LFLX provided sufficient clinical efficacy in the treatment of female acute uncomplicated cystitis, but the efficacy of the 300-mg dose of LFLX was even better. In addition, it was surmised that performance of detailed urological examinations provides an opportunity to detect mild underlying diseases that may be the cause of the intractability in female acute uncomplicated cystitis cases showing an insufficient response to treatment with antimicrobial agents such as LFLX.

Acute Disease↗
PubMed1995

[Long-term monitoring of female acute uncomplicated cystitis cases after lomefloxacin single-dose therapy].

Female acute uncomplicated cystitis responds relatively well to antimicrobial chemotherapy, but this is also a disease which shows a high frequency of recurrence. However, there have been no published reports regarding long-term monitoring of the course of this disease after therapy has been administered. Accordingly, using primarily a questionnaire, the authors carried out long-term monitoring (for a mean of 242 days) of the natural course of cases of female acute uncomplicated cystitis after single-dose therapy with lomefloxacin (LFLX), a new quinolone antimicrobial agent. The subjects of this study were female patients diagnosed as having acute uncomplicated cystitis with pain upon urination, pyuria (> or = 10 WBCs/hpf) and bacteriuria (> or = 10(4) cfu/ml). LFLX was orally administered as a single dose of 100 mg or 300 mg, and the therapeutic efficacy was evaluated on the 3rd and 7th days thereafter. In principle, the evaluation of cure was performed on the 7th day after LFLX administration, and monitoring was conducted to detect early recurrence during the next 7 days (i.e., through the 14th day after treatment). Then the subjects were monitored for late recurrence during a mean follow-up period of 242 days by means of a questionnaire. Confirmation of recurrence was carried out to the greatest extent possible. It was possible to carry out long-term monitoring of the natural course of 101 cases of female acute uncomplicated cystitis in which the clinical efficacy on the 3rd day after LFLX treatment had been evaluated as good or excellent.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1995

Orally administered bovine lactoferrin inhibits bacterial translocation in mice fed bovine milk.

Feeding of bovine milk to mice induced a high incidence of bacterial translocation from the intestines to the mesenteric lymph nodes, and the bacteria involved were mainly members of the family Enterobacteriaceae. Supplementation of the milk diet with bovine lactoferrin or a pepsin-generated hydrolysate of bovine lactoferrin resulted in significant suppression of bacterial translocation. Our findings suggest that this ability of lactoferrin to inhibit bacterial translocation may be due to its suppression of bacterial overgrowth in the guts of milk-fed mice.

Administration, Oral↗
PubMed1995

Bacteriostatic effect of orally administered bovine lactoferrin on proliferation of Clostridium species in the gut of mice fed bovine milk.

When milk-fed mice were orally inoculated with Clostridium ramosum C1, this strain proliferated in the gut and became the dominant component of the fecal microflora. In this experimental model, bovine lactoferrin (bLF) administered with milk suppressed the proliferation of this strain in vivo and decreased the numbers of C. ramosum and other bacteria in the feces. This bacteriostatic effect of bLF was dependent on the concentration of bLF, the duration of feeding, and the administered dose of C. ramosum C1. Compared with bovine serum albumin, ovalbumin, bovine whey protein isolate, or bovine casein, only bLF showed this specific activity. A similar effect of bLF was observed after oral inoculation with C. ramosum JCM 1298, C. paraputrificum VPI 6372, or C. perfringens ATCC 13124. A hydrolysate prepared by digestion of bLF with porcine pepsin showed the same inhibitory effect on proliferation of C. ramosum in vivo as occurred with undigested bLF. These results indicate that ingested bLF can exert a bacteriostatic effect against clostridia in the gut even after it has been digested to some extent.

Administration, Oral↗
PubMed1995

Effects of lactoferrin and its peptides on proliferation of rat intestinal epithelial cell line, IEC-18, in the presence of epidermal growth factor.

The cell growth-stimulating activity of lactoferrin (LF) in combination with epidermal growth factor (EGF) was evaluated by using a rat intestinal epithelial cell line, IEC-18. LF was found to be more effective than EGF for inducing an increase in cell numbers when cultured for over 6 days using a medium containing 0.2% fetal calf serum (FCS), although the 3H-thymidine incorporation-stimulating activity of EGF was more potent than that of LF. A synergistic effect of LF and EGF was observed in both cell proliferation and DNA synthesis assays. The increase in cell numbers when stimulated with LF plus EGF corresponded to about 5 times that of the control. Iron was not required for manifestation of these effects of LF. On the other hand, iron-saturated transferrin (TF) had cell-growth-stimulating activity, but iron-free TF did not, either in the presence or absence of EGF. These results indicate that LF induces cell proliferation by a mechanism distinct from that of TF. A pepsin-generated hydrolysate of LF (LFH) had an activity similar to that of undigested LF, and a peptide with cell-growth-stimulating activity from bovine LFH was isolated by monitoring its effects in combination with EGF on DNA synthesis in IEC-18 cells. Sequence analysis indicated that the peptide has the structure Ala-Glu-Ile-Tyr-Gly-Thr-Lys-Glu-Ser-Pro-Gln-Thr-His-Tyr-Tyr, corresponding to residues 79-93 of bovine LF.

Amino Acid Sequence↗
PubMed1995

Identification and molecular analysis of Lactococcus lactis rpoD operon.

The complete nucleotide sequence of an open reading frame (ORF) preceding the Lactococcus lactis rpoD gene is reported. It was suggested that this ORF encodes Lactococcus lactis DNA primase and that the L. lactis rpoD operon consists of only two genes. Northern hybridization analysis showed that i) there are four mRNAs transcribing the rpoD gene (from upstream, M1-M4), ii) only the 3.7-kb transcript M1 includes the entire rpoD operon, iii) the shortest transcript M4 exists at both logarithmic and stationary phases of growth while the other three transcripts appear only at logarithmic phase, and iv) no apparent induction at the transcriptional level but transient repression of M1 was found when the growth temperature was shifted from 30 degrees C to 42 degrees C. 5'-ends of all four mRNAs were identified by primer extension analyses.

Amino Acid Sequence↗