Biomedical subjects

S Katagiri

Publications and source records attributed to S Katagiri.

At least 37 records · Page 2Linked to original sources

PubMed1998

A delayed-implantation-associated protein prevents resumption of DNA synthesis by the trophectoderm of delayed-implanting mouse blastocysts in vitro.

Objective of this study was to determine the ability of a delayed-implantation-associated protein (MW 170,000, DIAP170K) to inhibit DNA synthesis by mouse blastocysts. Mice were ovariectomized on day 3 of pregnancy and treated with daily injections with 1 mg progesterone till day 7 to induce delayed implantation. Blastocysts were collected on day 8 with or without a single injection of 25 ng estradiol-17 beta on day 7 that activates blastocyst metabolisms (activated blastocysts and delayed-implanting blastocysts respectively). DNA synthesis was determined by measuring [3H]thymidine incorporation by blastocysts. DIAP170K at 10 micrograms/m/ suppressed resumption of DNA synthesis by delayed-implanting blastocysts and suppression was maximal at 50 micrograms/m/. However, DIAP170K did not affect DNA synthesis by blastocysts obtained on day 5 of pregnancy (normal blastocysts) and activated blastocysts. Resumption of DNA synthesis in the inner cell mass (ICM) and trophectoderm from delayed-implanting blastocysts was then separately assessed. DNA synthesis resumed in the trophectoderm of intact blastocysts during 24-hr culture but not in the trophectoderm cultured apart from the ICM. DIAP170K inhibited the resumption of DNA synthesis by the trophectoderm of intact delayed-implanting blastocysts but did not affect DNA synthesis by the ICM. In conclusion, DIAP170K inhibits resumption of DNA synthesis by trophectoderm of delayed-implanting blastocysts. This action of DIAP170K may play a central role in maintaining, but not achieving, dormancy of DNA synthesis by delayed-implanting blastocysts in mice.

Animals↗

PubMed1998

Functional enucleation of mouse metaphase II oocytes with etoposide.

Mouse metaphase II (M II) oocytes were exposed to 50 micrograms/microliters etoposide (ETO) before and after parthenogenetic activation with 7% ethanol and they were washed with 0.75 M sucrose. The ETO treated parthenogenetically activated oocytes were cultured or fused to single blastomeres of late 2-cell stage mouse embryo to test their ability to support development in vitro. In parallel untreated parthenogenetically activated oocytes were cultured to serve as control. None of ETO treated oocytes developed beyond the 2-cell stage, whereas 4% of the reconstituted embryos and 35% of control developed to blastocysts. It is concluded that mouse M II oocytes can be functionally enucleated by ETO treatment and can be used for nuclear transfer experiments.

Animals↗

PubMed1998

In vitro viability of mouse oocytes vitrified in an ethylene glycol-based solution.

Ovulated mouse oocytes denuded of their cumulus cells, were vitrified in a solution containing 7 M ethylene glycol as the sole cryoprotectant using one or two steps of exposure before vitrification and were diluted in 1 M sucrose solution in 5 or 10 min after warming. The results proved that the viability of oocytes are detrimentally affected by exposure to the vitrification solution even without vitrification. At 5 min dilution time, the two-step exposure was superior to the one-step in terms of the post-warming recovery rate of vitrified oocytes with normal morphology and their subsequent development to the blastocyst stage (p < 0.01) after fertilization in vitro. At 10 min dilution time, no significant difference between one- or two-step exposure was found. The effect of the addition of 0.5 M sucrose to the vitrification solution was also determined and did not result in a significant improvement in the viability of oocytes vitrified in one-step and diluted for 10 min. In conclusion, the results in this study indicate that oocytes can be vitrified with 7 M ethylene glycol as the sole cryoprotectant in the vitrification solution, and that the recovery of normal oocytes after one-step exposure in the vitrification solution can be improved by 10 min dilution time. However, the improvement in the recovery rate of oocytes with normal morphology and their subsequent developmental in vitro was not improved by the addition of 0.5 M sucrose to the vitrification solution.

Animals↗

PubMed1997

A somatostatin analogue decreases embryonic loss following superovulation in rats by normalizing insulin-like growth factor-I action in the uterus.

This study was designed to determine whether the somatostatin analogue, octreotide, could prevent embryonic loss by normalizing increased uterine insulin-like growth factor-I (IGF-I) action related to hyperoestrogenaemia following superovulation. Superovulated immature and oestradiol-17beta-treated adult rats were infused with 100 or 300 microg/ml of octreotide respectively, or injected daily with 1 or 10 microg of octreotide from day 1 to day 3 of pregnancy. On day 3, embryos were collected from the oviducts and uteri. Uterine luminal fluid was subjected to embryo culture. The amounts of uterine IGF-I and IGF binding proteins (IGFBP) were determined by radioimmunoassay and ligand binding assay respectively. Octreotide infusion normalized uterine IGF-I action following superovulatory and oestradiol-17beta treatment, by reducing IGF-I concentrations and increasing IGFBP concentrations. Octreotide infusion increased the number of normal embryos by 2.7-fold and 1.7-fold in superovulated and oestradiol-17beta-treated rats respectively, and reversed the detrimental effects of uterine luminal fluid on embryonic development caused by superovulatory and oestradiol-17beta treatment. Daily injections with octreotide had similar but reduced effects in all parameters examined in both treatment groups. In conclusion, octreotide may reduce embryonic loss, at least in part, by normalizing IGF-I action following superovulation.

Animals↗

PubMed1997

Role for insulin-like growth factor I in the regulation of electrolyte composition of uterine luminal fluid.

A potential role for insulin-like growth factor I (IGF-I) in the regulation of the uterine electrolyte environment was studied in conjunction with hyperoestrogenaemia caused by superovulation. Uterine luminal fluid from immature rats treated with 4 (control), 10, 20 and 40 i.u. (superovulation) pregnant mares' serum gonadotrophin (PMSG, day -2) and the electrolyte composition was determined on day 3 of pregnancy. Superovulation increased total cation content in uterine flushes by more than twofold, suggesting a comparable increase in the uterine luminal fluid volume. Percentages of K+ and HCO-3 content to total cations or anions increased by 27% and 16%, respectively, and those of Na+ and Cl- decreased by 26% and 15%, respectively, after superovulation. Daily injections with 1.0 micrograms or more oestradiol, from day 0 to day 2, in the 4 i.u. PMSG-primed immature rats caused similar changes in total cation content and electrolyte composition of uterine luminal fluid. Anti-IGF-I antibody infusion in the superovulated or oestradiol-treated immature rats restored the alterations in cation composition but had no effect on anion composition and total cation content. IGF-I was infused into adult rats to achieve increased IGF-I action observed after superovulation. IGF-I infusion altered electrolyte composition, as is observed after superovulation or oestradiol treatment, but had no effect on total cation content. In conclusion, hyperoestrogenaemia caused by superovulation may alter the uterine electrolyte environment for preimplantation embryonic development. IGF-I appears to play a central role in mediating this action of oestrogen.

Animals↗

PubMed1997

Elevated serum lipoprotein (a) levels associated with ulcerative colitis in a young Japanese patient.

Thromboembolism has been shown to play a role in the pathogenesis of inflammatory bowel disease (IBD). A possibility exists that lipoprotein (a) [Lp(a)], a newly-discovered prothrombotic factor, also participates in the development of at least some cases of IBD. Marked elevation of serum Lp(a) levels was observed in a young patient with ulcerative colitis. A biopsy specimen of the rectal mucosa showed findings compatible with ulcerative colitis, as well as small vessel thrombus occurring within the muscularis mucosa in the rectum. Serum Lp(a) levels were markedly elevated on admission (71 mg/dl), with a gradual decrease to 46 mg/dl on discharge. Moreover, serum Lp(a) levels decreased in parallel with clinical improvement. In the quiescent clinical stage, no small vessel thrombus was observed in the mucosa on follow-up colonoscopy. The association between IBD and hyper-Lp(a)-emia would be presumable but it has been, to our knowledge, previously unreported. The case reported here would be the first young patient, suggesting the presence of hyper-Lp(a)-emia and small vessel thrombus formation occurring in association with the development of ulcerative colitis.

Adult↗

PubMed1996

VLA-5 in the plasma cell line, FR4ds, acts as a common regulator of VLA-4 and VLA-6 in spreading induced by fibronectin and laminin.

VLA-5 recognizes the GRGDSP sequence of fibronectin (FN) in the extracellular matrix (ECM). We examined the role of beta1 integrin in the spreading of the human plasma cell line, FR4ds, induced by FN and laminin (LN). We first examined the role of VLA-5 in the spreading induced by FN. Anti-alpha4 antibody induced 46.4% inhibition, whereas anti-alpha5 had no effect. A combination of anti-alpha4 and anti-alpha5 enhanced the inhibition of spreading significantly. Complementary inhibition was also demonstrated using the GRGDSP peptide plus anti-alpha4 and the GRGDNP peptide of LN plus anti-alpha4. The results suggested that VLA-5 is a regulator of VLA-4 and that it is involved in the recognition of GRGDNP. We then examined the role of VLA-5 in the spreading induced by LN. Anti-alpha6 induced 53.1% inhibition. Anti-alpha5 alone had no effect. A combination of alpha5 and anti-alpha6, however, significantly enhanced the inhibition of spreading. The combination of GRGDSP plus anti-alpha6 and GRGDNP plus anti-alpha6 resulted in complete inhibition. These results suggested that VLA-5 participates in the recognition of LN cooperatively with VLA-6 and that VLA-5 is a common regulator of VLA-4 and the LN receptor, VLA-6.

Cell Movement↗

PubMed1996

The role for the uterine insulin-like growth factor I in early embryonic loss after superovulation in the rat.

OBJECTIVES: To examine possible roles of the insulin-like growth factor (IGF) system in increased early embryonic loss after superovulation. DESIGN: Changes in the uterine IGF system were examined in superovulated rats. Insulin-like growth factor I (IGF-I) was infused to the right uterine horns to mimic enhanced IGF-I actions after superovulation. Uterine luminal fluids were collected after IGF-I infusions and embryos were cultured with uterine luminal fluids. MAIN OUTCOME MEASURES: Steroid hormones, IGF-I, IGF binding protein (IGFBP), and IGF-I receptor levels, developmental rate, and cell numbers of embryos. RESULTS: Elevated IGF-I levels and suppressed IGFBP levels were found from days 1 to 3 of pregnancy after superovulation. Uterine luminal fluids of the IGF-I infusion and superovulation groups impaired embryo development in vitro. Anti-IGF-I antibody infusions after superovulation reversed detrimental effects of superovulation. Dialysis of uterine luminal fluids of the IGF-I infusion and superovulation groups before culture improved embryo development. CONCLUSIONS: Enhanced IGF-I actions in the uterus after superovulation may be responsible for the increase of early embryonic loss. The detrimental factor for embryo development seems a small molecule and is likely a local product of the uterus in which IGF-I actions are enhanced.

Animals↗

PubMed1996

Mutants with altered sensitivity to a calmodulin antagonist affect the circadian clock in Neurospora crassa.

Two newly isolated mutant strains of Neurospora crassa, cpz-1 and cpz-2, were hypersensitive to chlorpromazine with respect to mycelial growth but responded differently to the drug with respect to the circadian conidiation rhythm. In the wild type, chlorpromazine caused shortening of the period length of the conidiation rhythm. Pulse treatment with the drug shifted the phase and inhibited light-induced phase shifting in Neurospora. By contrast to the wild type, the cpz-2 strain was resistant to these inhibitory effects of chlorpromazine. Inhibition of cpz-2 function by chlorpromazine affected three different parameters of circadian conidiation rhythm, namely, period length, phase and light-induced phase shifting. These results indicate that the cpz-2 gene must be involved in or related closely to the clock mechanism of Neurospora. By contrast, the cpz-1 strain was hypersensitive to chlorpromazine with respect to the circadian conidiation rhythm.

Calmodulin↗

PubMed1996

Immunohistological analysis of tumour growth factor beta 1 expression in normal and inflamed salivary glands.

AIM: To determine whether transforming growth factor-beta 1 (TGF-beta 1) has a pathogenetic role in disease of the salivary glands. METHODS: An indirect immunohistochemical technique was used to analyse TGF-beta 1 expression in six specimens of normal salivary gland and 23 surgical specimens. RESULTS: TGF-beta 1 was strongly expressed in the ductal epithelial cells of normal salivary gland tissues (six of six cases) and in inflammatory conditions (eight of 11 cases). In contrast, TGF-beta 1 was not detectable in ductal epithelial cells expressing HLA-DR around infiltrating CD4+ CD45RO+ activated T cells, in the salivary gland tissue of patients with Sjögren's syndrome. CONCLUSION: Because TGF-beta 1 has an essential role in the mucosal immunity of salivary glands, abnormal expression of this cytokine must be regarded as a candidate in the pathogenesis of Sjögren's syndrome.

Adult↗

PubMed1996

An improved technique for molecular cytogenetic analysis of human preimplantation embryos with fluorescence in situ hybridization.

OBJECTIVE: To develop a method for the cytogenetic evaluation of preimplantation embryos using nonradioactive centromeric probes for chromosomes 1, 16 and X. STUDY DESIGN: The embryos used for this study were either fragmented or polyploid embryos rejected from an in vitro fertilization program. Prior to in situ hybridization, the embryos were treated with 0.5% protease. After application of gradual fixation, conventional hybridization protocol was followed. RESULTS: Ten of 11 embryos showed hybridization signals suggesting that the success rate of in situ hybridization of human embryos is improved when a modified method of digesting the zona pellucida and gradual fixation with removal of the cytoplasm are used. CONCLUSION: The method described in this study demonstrates that the zona pellucida is the key to successful in situ hybridization of whole human embryos. When the zona pellucida is removed, penetration by a probe becomes possible.

Chromosome Aberrations↗

PubMed1996

Biopsy of labial salivary glands and lacrimal glands in the diagnosis of Sjögren's syndrome.

OBJECTIVE: To determine the diagnostic value in Sjögren's syndrome (SS) of evaluating the presence of focal adenitis in labial salivary gland (LSG) and lacrimal gland (LG) biopsy specimens. METHODS: We studied 105 cases with suspected SS and performed biopsies prospectively. The diagnostic criteria of Fox, et al were followed. The Chisholm-Mason grading standard and Greenspan focus score were used for evaluation. RESULTS: Epimyoepithelial islands and severe lymphocyte infiltration with germinal centers were observed only in LG biopsy specimens (5.9 and 3.5%, respectively). The lymphocytic focus scores of LG (2.5 +/- 2.1/4 mm2) were significantly higher than those of LSG specimens (1.3 +/- 1.1/4 mm2) in 23 cases with both biopsy results (p < 0.05). Six of the 32 LSG biopsies were normal while their LG biopsies were significantly higher. Conversely, 5 of the 32 LG biopsies were aided by corresponding LSG biopsies, since in LG biopsies no glandular tissue was obtained. Evaluation of both specimens for the same patient was significantly more effective in diagnosing SS than using either specimen alone (p < 0.01). CONCLUSION: LG biopsy specimens have a more evident histopathology than LSG biopsy specimens. We recommend that both LSG and LG biopsies be performed in patients with suspected SS to reduce false negative results and improve diagnostic accuracy.

Biopsy↗

PubMed1996

Decreased reflex tearing is associated with lymphocytic infiltration in lacrimal glands.

OBJECTIVE: To investigate whether reflex tearing measured by the Schirmer test with nasal stimulation is better correlated with lymphocytic infiltration of the lacrimal gland and is thus a more appropriate test for Sjögren's syndrome (SS). METHODS: 272 patients with dry eye (age 55.5 +/- 13.5 years) with regular Schirmer test results < 10 mm were recruited for the study. They were divided into 2 groups depending on the results of the Schirmer test with nasal stimulation. 24 age and sex matched patients from each group were selected for lacrimal gland biopsy and 10 patients for salivary gland biopsy, and the levels of systemic autoantibodies and degrees of ocular surface staining and lymphocytic infiltration of the lacrimal and salivary glands were compared. RESULTS: Of the 272 patients, 187 (68.8%) had good reflex tearing (GT) and 85 (31.2%) had poor reflex tearing (PT). There were no significant differences in the age or sex of the 2 groups. Lymphocytic infiltration of the lacrimal gland was observed in 7 GT cases and 22 PT cases out of 24 cases. Lymphocytic infiltration of the salivary gland was also higher in the PT (6 of 10) than the GT group (2 of 10). CONCLUSION: Evaluation of reflex tearing by the Schirmer test with nasal stimulation identifies 2 groups of patients with dry eye. Those with poor reflex tearing were more likely to have autoantibodies and lymphocytic infiltration of the exocrine glands consistent with SS.

Adult↗

PubMed1995

Laminin and fibronectin promote the chemotaxis of human malignant plasma cell lines.

We examined chemotaxis of human plasma cells (PCs) in response to extracellular matrix proteins (ECMs) in the human PC cell lines FR4ds and OPM-1ds. The FR4ds cells expressed beta 1+, beta 3-, alpha 2-, alpha 3-, alpha 4+, alpha 5+, alpha 6+, and alpha v+ integrins, whereas the OPM-1ds cells expressed beta 1+, beta 3-, alpha 2-, alpha 3+, alpha 4+, alpha 5-, alpha 6+, and alpha v+. Fibronectin (FN) and laminin (LN) promoted the chemotaxis of the PCs. An inhibitory assay with anti-integrin monoclonal antibodies (MoAbs) showed that anti-alpha 4 MoAb partially inhibited the chemotaxis of FR4ds and completely inhibited the chemotaxis of OPM-1ds. Anti-alpha 5 MoAb alone had no effect on either of these two lines. Nevertheless, anti-alpha 5 MoAb completely inhibited chemotaxis when it was added with anti-alpha 4 in FR4ds, demonstrating a novel complementary role of VLA-5 toward VLA-4 in the chemotaxis induced by FN. LN facilitated chemotaxis both in OPM-1ds expressing alpha 3 and alpha 6 integrins and in FR4ds expressing alpha 6 integrin alone. Anti-alpha 6 MoAb completely inhibited FR4ds chemotaxis, whereas anti-alpha 3 and -alpha 6 MoAb had synergistic inhibitory effects on the chemotaxis of OPM-1ds. These results indicated that the distribution of PCs in human tissue are determined by at least two factors: the concentration of the ECM proteins FN and LN and the expression of integrins.

Antibodies, Monoclonal↗

PubMed1995

Increased levels of Epstein-Barr virus DNA in lacrimal glands of Sjögren's syndrome patients.

Many Sjögren's syndrome patients complain primarily of dry eye. Epstein-Barr virus DNA has recently been found in the lacrimal glands of Sjögren's syndrome sufferers and normal individuals, and lacrimal glands are thought to be a target organ for latent Epstein-Barr virus infection. In this study, we performed lacrimal and salivary gland biopsies on 9 Sjögren's syndrome patients. Extracted Epstein-Barr virus DNA was assayed by polymerase chain reaction and compared to that of healthy individuals. An increased level of Epstein-Barr virus DNA was observed in all of the lacrimal glands and 8 of the 9 salivary glands from the Sjögren's syndrome patients. However, the amount of genome in the lacrimal gland was more than 10 times that in the salivary glands, not only in the Sjögren's syndrome patients but also in the controls. This may explain the pathogenesis of dry eye in patients with Sjögren's syndrome, and why the lacrimal gland tends to be so prominently affected. It may also suggest a therapeutic approach for this and possibly other types of dry eye.

Base Sequence↗

PubMed1995

[Examination of toxin production from environmental Bacillus cereus and Bacillus thuringiensis].

Emetic toxin- and entero toxin-producing activities were examined for 524 strains of Bacillus cereus and 90 strains of Bacillus thuringiensis to determine the distribution and contamination in natural environment, including foods, vegetable, soil and etc. Emetic toxin was assayed by the production of acid from HEp-2 cells induced by the culture supernatants of Bacillus, which was developed as an improved method for the detection of B. cereus heat-stable emetic-toxin by us. In the 524 strains of B. cereus tested, 11 out of 60 strains obtained from bean paste and 5 out of 20 strains obtained from peach produced emetic toxin which was detected by the HEp-2 cell method. All these emetic toxin-producing isolate strains were classified into H1 serotype. The 90 strains of B. thuringiensis did not produce emetic toxin, but the 47 strains produced entero toxin.

Bacillus cereus↗

PubMed1995

[The expression pattern of adhesion molecules and their role of the tumor cells in patients with multiple myeloma].

The expression pattern of beta 1 integrin on the surface of tumor cells in patients with multiple myeloma (MM) is reviewed and compared with that of other B cell malignancies. The expression pattern of beta 1 integrin of plasma cells of healthy individuals was also compared with that of malignancies of plasma cells. Normal immature CD10+ B cell precursors in bone marrow are alpha 4+ and alpha 5+, while mature peripheral B cells are alpha 4+ and alpha 5+. In contrast to mature peripheral B cells, it is reported that plasma cells are alpha 4+ and alpha 5+. There are three points following in the phenotype characteristic of MM cells; (i) MM cells are alpha 4 strong positive, (ii) MM cells are beta 1 strong positive and (iii) MM cells are alpha 6strong positive. Because alpha 6+ cell lines of malignant plasma cells showed spread and chemotaxis on stimulation with laminin, alpha 6 beta 1 integrin might contribute of MM cells to transit laminin rich basement membrane of blood vessel to exit to the extravascular space. The difference of the phenotype between plasma cells and MM cells is the expression of alpha 5; plasma cells express alpha 5, but MM cells are lost in one half of the cases. The functional role of VLA-5 in MM cells is reviewed.

Amino Acid Sequence↗

PubMed1994

An improved method for detecting cytostatic toxin (emetic toxin) of Bacillus cereus and its application to food samples.

We developed an improved HEp-2 cell assay method for the detection of Bacillus cereus toxin, which affects the proliferation of HEp-2 cells. The cytostatic toxin was stable upon exposure to heat, pH 2, pH 11 and trypsin, which suggests it is an emetic. Using the HEp-2 cell assay, we examined the distribution and contamination of B. cereus strains that produced an emetic toxin in various foods. Although there were 228 enterotoxin producers among 310 B. cereus strains obtained from foods, 16 of them produced the cytostatic type (emetic toxin). All of the strains that produced the cytostatic toxin were of the H.1 serotype.

Bacillus cereus↗