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Biomedical subjects

M Hiroi

Publications and source records attributed to M Hiroi.

At least 109 records · Page 6Linked to original sources
PubMed1996

In situ localization of messenger ribonucleic acid for an oviduct-specific glycoprotein during various hormonal conditions in the golden hamster.

The oviductal epithelium secretes specific glycoproteins that associate with the egg after ovulation. Several published reports including our preliminary studies have suggested that ovarian steroids regulate the secretion of oviduct-specific glycoproteins in several mammalian species. The objective of this study, using golden hamsters, was to analyze the hormonal effects on gene expression of these molecules more precisely during various hormonal conditions (estrous cycle, ontogeny, pregnancy, GnRH analogue treatment, and ovariectomy) by in situ hybridization. The message for the hamster oviduct-specific glycoprotein (HOGP) was detected by a digoxigenin-labeled single-strand specific DNA probe in paraffin sections. Data from these studies show the following. 1) In the oviduct, the signal was detected in both the perinuclear region and the basal region in the ampulla but was predominantly detected in the basal region in the isthmus. 2) The signal intensity was high in the ampulla compared with the isthmus. 3) During a normal estrous cycle, the message level was significantly altered between the estrous and diestrous stages in the ampulla but not in the isthmus. In addition, the signal did not disappear at any stage in either the isthmus or ampulla. 4) The HOGP message was first observed from around 14 days of age and then decreased in parallel with serum estradiol levels during aging. 5) The signal was also observed in the oviductal epithelium of pregnant animals at term and of postpartum animals. 6) When we treated the animals with TAP-144-SR (GnRH analogue) or performed an ovariectomy, which caused diminution of serum estradiol and progesterone levels, the message of HOGP was significantly decreased. Moreover, the message expression was greatly induced after estradiol administration to GnRH analogue-treated animals, whereas a high level of serum progesterone slightly inhibited HOGP message expression. These results suggest that elevation of the serum estradiol/ progesterone level affects the HOGP gene expression in the ampulla. However, a high serum estradiol level did not induce the gene expression rapidly, suggesting that an adequate serum hormonal level over a given period of time may be important for the HOGP gene expression.

Animals↗
PubMed1996

Proliferation marker MIB-1 correlates well with proliferative activity evaluated by BrdU in breast cancer: an immunohistochemical study including correlation with PCNA, p53, c-erbB-2 and estrogen receptor status.

The proliferative activity of 30 cases of non-treated invasive ductal breast carcinoma was evaluated by bromodeoxyuridine (BrdU), proliferation marker (MIB-1) and proliferating cell nuclear antigen (PCNA), and the relation between these proliferation markers and histological subtype and histological grade were investigated. In addition, the association of these proliferation markers with overexpression of p53 protein, c-erbB-2 oncoprotein, estrogen receptor (ER) status and clinicopathologic findings were also examined. The BrdU labeling index (LI), MIB-1 score and PCNA labeling rate (LR) correlated with the histological grade. However, there was no statistical difference in proliferative activity among the histological subtypes. A linear strong correlation was demonstrated between BrdU LI and MIB-1 score (r = 0.732). Significant correlation was also found between BrdU LI and PCNA LR (r = 0.446); however, the relation between MIB-1 score and PCNA LR was weak. BrdU LI and MIB-1 score correlated positively with tumor size, TNM stage and overexpression of p53, and negatively with the presence of ER. PCNA LR correlated only with p53. These results indicate that MIB-1 is closely associated with BrdU in clinicopathologic findings and is a more useful tool for evaluating cell proliferation than PCNA. However, it will be necessary to consider the clinical significance of MIB-1 immunohistochemistry cautiously until further widespread clinical and pathological studies are performed.

Adult↗
PubMed1996

Histological grade in invasive ductal carcinoma of breast correlates with the proliferative activity evaluated by BrdU: an immunohistochemical study including correlations with p53, c-erbB-2 and estrogen receptor status.

Thirty cases of invasive ductal carcinoma of the breast were classified to histological subtype according to the General Rules for Clinical and Pathological Recording of Breast Cancer of the Japanese Breast Cancer Society and histologically graded using the Nottingham method and the correlation of histology with proliferative activity was investigated using bromodeoxyuridine (BrdU). In addition, the overexpression of p53 protein, c-erbB-2 oncoprotein and estrogen receptor (ER) were immunohistochemically examined in order to discuss the relationship with histological subtype and histological grade. Histological grade correlated positively to the BrdU labeling index (LI) and overexpression of p53. High grade carcinoma demonstrated c-erbB-2 more frequently and exhibited a low incidence of ER. However, no significant relationship was found between BrdU LI, overexpression of p53 and c-erbB-2 and histological subtype. These results suggest that the histological grade does represent the proliferative activity of tumor cells and that adding the histological grade to the pathological diagnosis in invasive ductal breast carcinoma may be useful from the clinicopathological aspect concerning tumor behavior.

Adult↗
PubMed1996

Detection of HIV-1 and HIV-2 antibodies among Chlamydia trachomatis infected pregnant women in Japan.

An anonymous unlinked HIV antibody test was conducted on 1632 Chlamydia trachomatis (C. trachomatis) antibody positive women from 10 institutes of 7 prefectures in Japan. All the sera were negative for both HIV-1 and HIV-2 antibodies. The result may support the suggestion that HIV prevalence is low among general population in Japan. Such a test as this study will be useful not only for developing a reliable HIV surveillance system but also for the study of sexual behavior of general population, since C. trachomatis infection is sensitive to reflect sexual contact.

Adult↗
PubMed1996

[Elucidation of the mechanism of fertilization and clinical application of assisted reproductive technology].

Fertilization is the process including many events such as maturation of egg and sperm, attachment, binding, acrosomal reaction, penetration, fusion, cortical reaction, zona reaction and nuclear fusion of both gamete, whereby individual gametes from the female and male unite to create offspring. Although the reason for mechanism of fertilization is still not clearly understood, this process may accelerate the rate adaptation in evolution. In this special lecture, I would like to present our experimental and clinical results especially concerning with morphological, physiological, biochemical and molecular approach on the mechanism of fertilization. 1. Development and maturation of follicles and oocytes. It is well known that pituitary FSH, LH control the ovarian function. Follicular development and ovum maturation are also controlled by both pituitary gonadotropins and local factors such as autocrine and paracrine agents. When hMG is injected during 1-6 day of menstrual cycle, several dominant follicles are developed. If hMG is injected after selection of dominant follicles, only one dominant follicle develop in the ovary. When PMS-treated immature rats were injected with immature or mature follicle fluids, rats injected with mature follicular fluid showed strongly suppress in the ovarian weights and numbers of ovulated follicles. Also mature follicle suppress aromatization from and androstenedione to estradiol. These findings mean that mature follicular fluid contains inhibitory factors. Apoptosis of granulosa cells and follicular steroids are related to fertilization. 2. Intracellular calcium of oocyte. Intracellular calcium concentration is known to start to increase in a periodic manner after fertilization in oocytes of mammalians. In 65% of tested mouse oocytes, fertilization occurred during 4 hours observation after sperm insemination in vitro. An initial long lasting intracellular calcium concentration was observed and followed by periodic manner. This calcium oscillation is inhibited by calcium blockers such as verpamil and nifedipine, but increased by high concentration of extracellular calcium concentration in the medium. Role of increase of intracellular calcium are understood to prevent polysperm and activate metabolism of oocytes. 3. Glucose metabolism of oocytes. Mouse embryo utilizes pyruvate as an essential nutrient until the 8-cell stage, and glucose thereafter. We have devised non-radiometrie and enzymatic microassay method to measure glucose, deoxyglucose, deoxyglucose 6-phosphate incorporated into individual mouse oocytes and preimplantation embryo. In parallel, the activities of several enzymes of glycolytic pathway were also determined. In this study, glucose metabolism is necessary to develop in fertilized ova with changing activity of enzymes. 4. Molecular bases of ovarian fluid. The zona pellucida ZP is involved in a number of events in fertilization, all these fertilization events occur in the oviduct. Oviductal glycoprotein 200-240 KD has been identified from oviductal zona pellucida. Monoclonal antibody of oviductal glycoprotein reacted with ZP of oviductal egg but not with the ovarian egg. Anti-ZPO antibody inhibit to bind sperm to ZP. Sequences in mouse and hamster oviduct specific glycoprotein are estimated, this glycoprotein mRNA was observed in only oviduct by northern blotting method. These molecular gene expression was observed by in situ hybridization in the oviduct of estrous cycle of hamster. 5. Microinsemination of sperm. Microinsemination of sperm into oocyte is widely used in clinical medicine. Sperm penetration assay (hamster test) is useful method to estimate fertilization capacity of sperm. But immotile sperm cannot estimate it. So modified micro sperm penetration assay was established to estimate fertilization capacity of sperm by using micro-manipulator. Subzonal sperm injection (SUZI) and intracytoplasmic sperm injection (ICSI) promotes fertilization and cleavage rate in immotile

Animals↗
PubMed1995

Placental transfer of lidocaine hydrochloride after prolonged continuous maternal intravenous administration.

We treated a patient with arrhythmia during pregnancy with prolonged intravenous administration of lidocaine hydrochloride. This was a case of twin-to-twin transfusion syndrome and the arrhythmia was caused by ritodrine therapy. In total, 14.1 g lidocaine (50 mg.hr-1 for 282 hr) were used. Since there are no descriptions of human placental transfer of lidocaine after such a prolonged continuous intravenous administration, we measured lidocaine concentrations in maternal and fetal serum, and in the amniotic fluid (AF) at delivery. Fetal serum lidocaine concentrations (donor: 0.83 microgram.ml-1; recipient: 0.82 microgram.ml-1) were lower than in the maternal serum (1.6 micrograms.ml-1), while the AF lidocaine concentrations (donor: 1.05 micrograms.ml-1; recipient: 1.04 micrograms.ml-1) were higher than those of the fetal sera. The fetal/maternal concentration ratios of lidocaine were 0.52 for the donor and 0.51 for the recipient, which were similar to those described previously after administration of lidocaine in labour.

Adult↗
PubMed1995

Molecular characterization of a hamster oviduct-specific glycoprotein.

There is growing evidence that the oviduct is not a passive conduit for gamete and embryo transport but serves a function for the gametes and/or embryos. The oviductal epithelium secretes one or more specific glycoproteins that associate with the egg after ovulation. Several published reports including our preliminary studies have suggested that the egg-associating glycoprotein(s) from the oviduct exists in several mammalian species including golden hamster. However, little or almost no biochemical characterization of the hamster oviduct-specific glycoprotein (HOGP) has been reported. To analyze the molecular structure of the HOGP in detail, we have attempted molecular cloning of cDNA corresponding to HOGP. A cDNA library constructed from the hamster oviduct in the phage vector lambda ZAPII was screened with digoxigenin-labeled, baboon oviduct-specific glycoprotein cDNA as the probe. A single positive clone was isolated, and the nucleotide sequence of the isolated cDNA was determined. Rapid amplification of cDNA end was carried out to obtain a proximal 5' cDNA end of the clone. The cDNA clone consisted of 2387 bp, and the coding region contained 2013 bp translating to 671 amino acids. The amino acid sequence deduced from the cDNA sequence confirmed the chemically determined NH2-terminal sequence of a HOGP and suggested that the derived amino acid sequence contained a signal peptide region (21 amino acids) and 650 amino acids (70,890 daltons) of the mature form of the HOGP region. The amino acid sequence of HOGP appeared to have eight potential N-glycosylation sites. Northern blot analysis revealed that a single message of approximately 2.5 kb was present in oviductal RNA but not in the RNA of several other hamster tissues. The HOGP showed high amino acid sequence homology with baboon, bovine, and human oviduct-specific glycoprotein. These results demonstrate that an oviduct-specific glycoprotein homologue gene exists in various mammalian species including rodent.

Amino Acid Sequence↗
PubMed1994

Development of glucose utilization studied in single oocytes and preimplantation embryos from mice.

Superovulated mouse oocytes and embryos were isolated and incubated with nontracer concentrations of 2-deoxyglucose, an analog of glucose, which is transported into the cells by glucose transporter and phosphorylated by hexokinase to 2-deoxyglucose 6-phosphate; it is not rapidly metabolized further, and accumulates in the cytosol. Using our non-radiometric and enzymatic microassay method, we determined 2-deoxyglucose and 2-deoxyglucose 6-phosphate amounts in individual oocytes and preimplantation embryos after the incubation. Hexokinase activity increased continuously and exponentially during development from follicular oocytes to blastocysts. Endogenous glucose and glucose 6-phosphate decreased precipitously from follicular oocytes to unfertilized and ovulated oocytes. Fertilization induced rapid increases in glucose and glucose 6-phosphate concentrations, which increased exponentially thereafter during embryonic development. 2-Deoxyglucose incorporation and 2-deoxyglucose 6-phosphate formation were undetectable in unfertilized oocytes. However, when cumulus-oocyte complexes were incubated with 2-deoxyglucose, 2-deoxyglucose was incorporated into cumulus cells surrounding follicular oocytes and transported via the gap junctions into the follicular oocytes. Fertilization triggered facilitative 2-deoxyglucose transport in one-cell embryos, and the capacities of 2-deoxyglucose incorporation and 2-deoxyglucose 6-phosphate formation developed along with the maturation of preimplantation embryos.

Animals↗
PubMed1994

Cumulus mass maintains embryo quality.

OBJECTIVE: To determine if co-culture of early stage embryos with their own cumulus mass improves embryo quality. DESIGN: Before insemination, cumulus masses along with cumulus matrices were separated from the oocytes surrounded by a few remaining cumulus cells. Fourteen hours after insemination, fertilized oocytes were each placed onto the cumulus cells, and matrix and co-culture commenced. The embryos were observed every 24 hours. Fifty-three oocytes were treated in co-culture (C) and 59 oocytes were treated in routine culture (U). RESULTS: Thirty-four (C) and 43 (U) oocytes were fertilized and placed on growth media for further culture. Twenty-four hours after culture, 10 embryos (29%) in C and 12 (28%) in U were good quality, and 4 embryos (12%) in C and 7 (16%) in U were of poor quality. Seventy-two hours after culture, 10 (29%) in C and 8 (18%) in U were of good quality, and 3 (9%) in C and 13 (30%) were of poor quality. The percentage of good quality embryos in the co-culture group was significantly higher than in the control group after 72 hours. Conversely, the percentage of poor quality embryos in the co-culture group was significantly lower than that in the control group after 72 hours. CONCLUSION: Co-culture maintains embryo quality over prolonged culture times. This facilitates the development of good quality embryos for ET.

Cells, Cultured↗
PubMed1993

Aberrant expression of the p53 tumor suppressor gene in adult T-cell leukemia and HTLV-I-infected cells.

By immunoprecipitation analysis, enhanced p53 expression was detected in 3 of 4 adult T-cell leukemia (ATL) cell lines, 1 of 3 HTLV-I-infected cell lines and 1 of 5 fresh ATL samples, compared with phytohemagglutinin-stimulated peripheral blood lymphocytes. Among these 5 high expressers, p53 missense mutations were indicated in 2 ATL cell lines and 1 fresh ATL sample by extensive p53 cDNA and genomic DNA polymerase chain reaction single-strand conformation polymorphism analysis. No mutation was found throughout the entire coding region of the remaining 2 high expressers (1 ATL and 1 HTLV-I-infected cell lines) and low expressers of p53 (2 HTLV-I-infected cell lines). Tax oncoprotein expression was found in these 2 high p53 expressers in which p53 mutation was not present, but not in low p53 expressers or cells carrying this mutation. The levels of p53 mRNA were similar among the samples regardless of p53 levels. Posttranscriptional mechanisms other than missense mutation would thus appear to increase p53 in the Tax-expressing cells but not in cells containing undetectable levels of Tax. No complex formation between p53 and Tax was observed.

Adult↗