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C Azuma

Publications and source records attributed to C Azuma.

At least 37 records · Page 2Linked to original sources
PubMed1999

Human placental cells show enhanced production of interleukin (IL)-8 in response to lipopolysaccharide (LPS), IL-1 and tumour necrosis factor (TNF)-alpha, but not to IL-6.

Interleukin-8 (IL-8) is a chemotactic and activating factor for neutrophils which play important roles in host defence mechanisms. The human placenta constitutively produces IL-8 during pregnancy and enhances its production in chorioamnionitis. The present study was designed to investigate in vitro the regulatory mechanism for IL-8 production in the placentas in normal and inflammatory states. Placental cells produced IL-8 in a dose-dependent fashion when stimulated with lipopolysaccharide (LPS). The purified trophoblasts showed significantly higher IL-8 production than untreated placental cells. The expression of IL-8 gene in the trophoblasts in the third trimester was observed by reverse transcription-polymerase chain reaction (RT-PCR). The placental cells also release IL-8 in a dose-dependent manner, in response to r-(recombinant) IL-1alpha and tumour necrosis factor (TNF)-alpha, but not rIL-6. Moreover, LPS-activated placental cells spontaneously produced a much larger amount of IL-8 and showed increased responses to rIL-1alpha and TNF-alpha. It may, therefore, be proposed that placental cells with multiple endocrine functions exert immunological functions by constitutive production of IL-1 and TNF-alpha, which stimulate placental IL-8 release. This cytokine cascade in the placenta may be augmented by LPS in chorioamnionitis, thereby potentiating the feto-maternal defence mechanisms against infection.

Cells, Cultured↗
PubMed1999

What knockout mice can tell us about parturition.

Many molecules, including steroid and peptide hormones, prostaglandins and cytokines, regulate the preparation, initiation and progression of parturition in mammals. Gene targeting studies show that, in the knockout mice of steroid 5alpha-reductase type 1 gene, prostaglandin F2alpha receptor gene and cytosolic phospholipase A2 gene, parturition was severely disturbed, although live offspring were delivered by Caesarean section. Relaxin gene-disrupted mice also showed protracted labour. However, most knockout mice in which the steroid hormone, prostaglandin, cytokine or peptide hormone (for example, oxytocin, corticotrophin releasing hormone and endothelin) endocrine-paracrine systems are disrupted are inadequate for analysis of the mechanism of parturition because they die before reaching reproductive age or are infertile, or because they reproduce normally. A conditional knockout strategy, for example, using the Cre-LoxP system, should be considered for investigating the biochemical background of parturition to overcome these problems.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1998

Secretory leukocyte protease inhibitor (SLP) concentrations in seminal plasma: SLPI restores sperm motility reduced by elastase.

In this study, we quantified secretory leukocyte protease inhibitor (SLPI) and elastase in ejaculates from normal donors and infertile patients with or without leukospermia and investigated the effect of SLPI on sperm motility reduced by elastase. Western blot analysis revealed that SLPI protein was detected in the seminal plasma. The SLPI titre in the seminal plasma with leukospermia was lower than that in the seminal plasma without leukospermia and in the seminal plasma of fertile donors. The elastase concentration in the seminal plasma with leukospermia was significantly higher than that in the seminal plasma without leukospermia. A significant correlation between SLPI and elastase concentrations in the seminal plasma (r = 0.36, P< 0.01) was observed. There was a positive correlation between SLPI titre in the seminal plasma and sperm motility (r = 0.51, P < 0.001). SLPI recovered the sperm motility reduced by elastase in a dose-dependent manner. Our results suggest that SLPI is a potential substance to treat infertile patients with leukospermia.

Adult↗
PubMed1998

Effect of site directed mutagenesis in the CMGCC region of the alpha-subunit on immunoreactive human thyrotropin.

The cDNA of the common alpha-subunit of human glycoprotein hormone was mutated by site directed mutagenesis in the CMGCC region composed of cysteine-methionine-glycine-cysteine-cysteine (position 28-32). The cDNA of wild-type human thyrotropin (hTSH) beta-subunit and that of wild-type or mutant common alpha-subunits were co-transfected into COS-I cells. The concentration of hTSH determined by two immunoradiometric assay systems was detectable in culture media of COS-I cells transfected with wild-type (CMGCC) and a mutant (CRGCC) alpha-subunits but not four other mutants (YMGCC) (CMRCC) (CMACC) (CMDCC). The present data with the other studies on wild-type or mutant glycoprotein hormones support our hypothesis that an amino acid motif of "C-X-G-X-C" in the common alpha-(CMGCC in human) and beta-(CAGYC in human) subunits play an important role in biosynthesis of glycoprotein hormones in all species.

Amino Acid Substitution↗
PubMed1997

Biparental alleles of HLA-G are co-dominantly expressed in the placenta.

HLA-G is the only major histocompatibility complex molecule expressed in the human placenta and thus has been considered to be necessary for maintenance of pregnancy. We investigated whether HLA-G expression is regulated in a parent-of-origin allele-specific manner. Of six first trimester and three third trimester placentas, three first trimester and two third trimester placentas showed heterozygosity at the PstI polymorphic site in the 3'-untraslated region. Reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed biallelic expression of HLA-G in all the informative cases, indicating that HLA-G is not imprinted during the gestational period, at least at the transcriptional level. As HLA-G has been postulated to be polymorphic not only at the DNA sequence level but also at the peptide level, co-dominant expression of the gene suggests that each parental allele is involved in the allogenic response during pregnancy.

Alleles↗
PubMed1997

Loss of H19 imprinting and up-regulation of H19 and SNRPN in a case with malignant mixed Müllerian tumor of the uterus.

In several human cancers, it has been recently reported that abnormally altered status of genomic imprinting is related to oncogenesis. In this study, we investigated the expression of three imprinted genes in a case with malignant mixed Müllerian tumor of the uterus (MMMT). In the tumor, expression of H19 showed marked upregulation (6.3-fold) with biallelic expression compared with that in the corresponding normal myometrium. The 5'-promoter region of H19 was hypomethylated in the tumor, whereas it was hemimethylated in the myometrium. Expression of the small nuclear ribonucleoprotein polypeptide N gene (SNRPN) was also upregulated by 1.9-fold. However, the insulin-like growth factor II gene (IGF2) was expressed at low levels in both myometrium and MMMT. The overexpression of H19 is caused by reactivation of the repressed allele of H19 due to demethylation of CpG islands within its 5'-promoter region. Whether upregulation of SNRPN is caused by its biallelic expression remains undetermined because restriction fragment length polymorphisms (RFLP) sites were not informative in SNRPN and IGF2. In conclusion, H19 and SNRPN may play significant roles in the tumorigenesis of MMMT and H19 may have tumor-promoting activity in addition to its known tumor-suppressing activity, probably depending on the tissue and the local milieu.

Autoantigens↗
PubMed1997

Hypoxia marker labeling in tumor biopsies: quantification of labeling variation and criteria for biopsy sectioning.

BACKGROUND AND PURPOSE: The error associated with using biopsy-based methods for assessing parameters reflective of the tumor microenvironment depends on the variability in distribution of the parameter throughout the tumor and the biopsy sample. Some attention has been given to intratumoral distribution of parameters, but little attention has been given to their intrabiopsy distribution. We evaluated the intrabiopsy distribution of CCI-103F, a 2-nitroimidazole hypoxia marker. MATERIALS AND METHODS: The hypoxia marker CCI-103F was studied in dogs bearing spontaneous solid tumors. Two biopsies were taken from each of seven tumors, for a total of 14 biopsies. Biopsies were serially sectioned and four to six contiguous slides from each 100-150 microm of the biopsy were used to formulate the best estimate of CCI-103F labeled area throughout the biopsy sample. One, two or four slides were then randomly selected from each biopsy and the labeled area, based on this limited sample, was compared to the estimate obtained from counting all available slides. Random sampling of slides was repeated 1000 times for each biopsy sample. RESULTS: CCI-103F labeling variance throughout the biopsy decreased as the estimated overall labeled area in the biopsy decreased. The error associated with estimating the overall labeled area in a biopsy from a randomly selected subset of slides decreased as the number of slides increased, and as the overall labeled area in the biopsy decreased. No minimally labeled biopsy was classified as unlabeled based on limited sampling. CONCLUSION: With regard to CCI-103F labeling, quantification of the labeled area in four randomly selected slides from a biopsy can provide, in most biopsies, an estimate of the labeled area in the biopsy within an absolute range of +/-0.05.

Animals↗
PubMed1997

The influence of peri-operative blood transfusion during radical hysterectomy on the prognosis of uterine cervical cancer.

To evaluate the clinical implications of peri-operative transfusion in the surgical treatment of uterine cervical cancer, a detailed analysis of the cumulative survival rate was performed using clinical data from 145 patients with FIGO stage Ib cervical cancer of the squamous cell type acquired between 1982 and 1989 at the Center for Adult Diseases. The cumulative survival rate was statistically analyzed using the Kaplan Meier method. Of the 145 patients with stage Ib cancer, 103 were considered to have undergone complete excision and received no further treatment post-operatively, and 42 were considered to have undergone incomplete excision because of the involvement of lymph nodes or the lymphovascular space. Of the 79 patients in the former group who received peri-operative transfusion, 69 received less than seven units (1400 mL) and 10 received more than eight units (1600 mL). The cumulative 5-year survival rate was 100% in the 24 patients who received no transfusions, 91.7% in those who received less than 1400 mL, and 90.0% in those who received more than 1600 mL. Similarly, of the 42 patients in the incomplete excision group, nine did not receive any peri-operative transfusion, 27 received less than 1400 mL, and six received more than 1600 mL. The 5-year survival rate in these groups was 88.9, 77.8 and 50.0%, respectively. The survival rate of our patients with stage Ib cervical cancer without peri-operative transfusion was significantly higher than that of those with transfusion, regardless of post-operative irradiation therapy status, indicating that peri-operative transfusion has an adverse influence on the prognosis in cervical cancer.

Adult↗
PubMed1997

Human decidual cell biosynthesis of leukemia inhibitory factor: regulation by decidual cytokines and steroid hormones.

The production of leukemia inhibitory factor (LIF) is suggested to be critical for the successful implantation of blastocysts into decidua, because LIF expression is essential for the implantation of mouse blastocytes. We investigated the regulation of LIF production by decidual cytokines and steroid hormones. Stimulation of decidual cells by interleukin-1, tumor necrosis factor alpha, or transforming growth factor beta augmented LIF production in a dose-dependent manner. Moreover, estradiol, a steroid hormone that increases during ovulation and early pregnancy, also enhanced LIF production in a dose-dependent manner. These responses were blocked by protein kinase C (PKC) inhibitor but not by other kinase inhibitors, suggesting an important role of PKC in decidual LIF production mediated by cytokines and estradiol. We also showed that stimulating decidual cells with LIF failed to stimulate DNA synthesis and prolactin production in these cells. In summary, LIF was mainly localized in the decidual glands and stroma, and its production was increased by cytokines and estradiol in a dose-dependent fashion; but stimulation of decidual cells by LIF did not influence their proliferation or their prolactin production.

Animals↗
PubMed1997

Increased interleukin-1 and interleukin-1 receptor antagonist levels in cervical mucus in the ovulatory phase in comparison with the follicular phase.

Interleukin-1 (IL-1) receptor antagonist (IL-1ra) levels in the cervical mucus of women in the ovulatory phase are significantly higher than those in the follicular phase. IL-1 titers of women in the ovulatory phase are also significantly higher than those in the follicular phase. A positive correlation between IL-1ra and IL-1 levels in the cervical mucus was observed. Immunohistochemistry using an anti-IL-1ra monoclonal antibody revealed positive staining in the epithelial cells of the endocervix. These results suggest that IL-1ra from cervical epithelial cells protects the reproductive system from the toxicity of IL-1 produced in the endocervix.

Adult↗
PubMed1997

Longevity of pimonidazole adducts in spontaneous canine tumors as an estimate of hypoxic cell lifetime.

The longevity of pimonidazole adducts in tumors was quantified as an estimate of the lifetime of hypoxic cells. Pimonidazole was given before irradiation to 12 dogs bearing spontaneous tumors, and tumors were biopsied 24, 48 and 72 h later. Pimonidazole antigen was quantified in the biopsies using ELISA and immunohistochemistry. Pimonidazole antigen was detectable in the initial biopsy in all dogs. In 5 dogs the amount of detectable antigen decreased to less than 50% of the initial amount, in 5 other dogs the amount of detectable antigen decreased to an amount between 50 and 100% of the initial amount, and in 2 dogs the amount of antigen appeared to increase relative to the initial amount. Tumors with high initial adduct concentration were characterized by greater decreases in adduct concentration than tumors with low initial adduct concentration. Immunohistochemically, labeled cells were present in 11 of 12 tumors. The geographic area in tumor biopsies labeled immunohistochemically with pimonidazole adducts (labeled area fraction) tended to decrease over time in 6 dogs, remain stable in 4 dogs and seemingly increase in 1 dog. There was no relationship in individual tumors between the relative change in antigen concentration and the relative change in labeled area fraction. Hypoxic cells which bind pimonidazole may persist for days during fractionated radiation therapy, and the potential exists for them to exert a negative effect on the host.

Animals↗
PubMed1996

Structure and expression of the mouse oxytocin receptor gene.

To determine the structure of the mouse oxytocin receptor (OTR) gene, we have screened a mouse genomic library and confirmed cDNA sequence with rapid amplification of cDNA ends. Southern blot using human OTR cDNA probes indicated that the mouse genome has a single copy of the gene. The predicted amino acid sequence is 91% identical to human OTR. The gene contains 4 exons and 3 introns. Exons 1 and 2 contain the 5' untranslated region, with exons 3 and 4 encoding the amino acids of the receptor. Intron 3 interrupts the coding at the same location, after transmembrane domain 6, as in OTR genes of other species. The promoter region lacks an apparent TATA box but contains multiple putative interleukin-response elements and estrogen responsive elements. Expression of OTR gene in the uterus during pregnancy reached maximum at day 20 gestation. The information obtained from the mouse OTR gene facilitates further comparative and biochemical analysis for protein structure-function relationships and gene regulatory mechanisms.

Amino Acid Sequence↗
PubMed1996

Elevated nitric oxide concentration in the seminal plasma of infertile males: nitric oxide inhibits sperm motility.

PROBLEM: To evaluate the effect of nitric oxide in the seminal plasma on sperm motility. METHOD: Seminal plasma concentrations of NO2-, a stable end product of nitric oxide, of 108 males of infertile couples and 15 proven fertile donors were measured and compared with spermatogram parameters. Motile sperm was incubated with a nitric oxide-generating drug, sodium nitroprusside, for 6 hr in the absence or presence of oxyhemoglobin, an inhibitor of nitric oxide. RESULTS: The NO2- concentration in the seminal plasma was 6.58 +/- 0.5.6 microM in 26 infertile males with leukocytospermia, 5.51 +/- 0.25 microM in 82 infertile males without leukocytospermia, and 3.91 +/- 0.16 microM in 15 controls. There was a significant correlation between the NO2- concentration and sperm motility. Sodium nitroprusside reduced the sperm motility in a dose- and time-dependent manner and its reduction was completely inhibited by the addition of oxyhemoglobin. CONCLUSION: These findings indicate that nitric oxide concentration in the seminal plasma of infertile males is elevated and that nitric oxide is an inhibitor of sperm motion.

Cell Survival↗
PubMed1996

Maintenance of imprinting of the insulin-like growth factor II gene (IGF2) and the small nuclear ribonucleoprotein polypeptide N gene (SNRPN) in the human uterus and leiomyoma.

The insulin-like growth factor II gene (IGF2) is thought to be involved in the growth of uterine smooth muscle tumors. We studied the allele-specific expression of IGF2 in 20 patients with uterine leiomyomas by analyzing restriction fragment length polymorphisms (RFLP), because IGF2 is a maternally imprinted gene and only the paternal allele is exclusively expressed in human somatic tissue. We also studied the allelic expression of the small nuclear ribonucleoprotein polypeptide N gene (SNRPN), which is reportedly maternally imprinted in humans, and compared the imprinting status with that of IGF2. Nine patients (45%) were heterozygous at the ApaI site of IGF2, nine (45%) were heterozygous at the possible AccII polymorphic site of SNRPN, and three (15%) showed polymorphism in both genes. The genomic DNA of 15 patients showed heterozygosity in either or both of these genes, and the mRNA of these was expressed monoallelically in myometrial tissues and leiomyomas of these patients. These results demonstrated that IGF2 and SNRPN imprinting is completely maintained in human uteri and leiomyomas and that increased expression of IGF2 is not due to biallelic expression.

Autoantigens↗
PubMed1996

Plasma nitric oxide levels in pregnant patients with preeclampsia and essential hypertension.

Nitric oxide (NO) production may be an important causal factor in hypertensive disorders during pregnancy. The plasma concentrations of NO2-(+) NO3-, stable metabolites of NO, were measured in 70 nonpregnant women, 323 normotensive pregnant women, 23 pregnant patients with preeclampsia, and 7 pregnant patients with essential hypertension. The normotensive women had higher plasma concentrations (30.0 +/- 0.6 mumol/l) than nonpregnant women (18.3 +/- 1.0 mumol/l; p < 0.0001). The plasma concentrations in the patients with preeclampsia (45.6 +/- 2.3 mumol/l) were higher than in the normotensive women (30.3 +/- 1.0 mumol/l; p < 0.0001) and were correlated with the systolic blood pressure (r = 0.442; p < 0.05). However, pregnant patients with underlying essential hypertension had significantly lower plasma concentrations (19.1 +/- 3.0 mumol/l; p < 0.005). These findings suggest that NO contributes to maternal vasodilation, the maintenance of uterine quiescence, and the pathogenesis and clinical features of hypertensive disorders during pregnancy.

Adult↗
PubMed1996

Investigation of the oxytocin receptor expression in human breast cancer tissue using newly established monoclonal antibodies.

The expression of the oxytocin (OT) receptor (OTR) in breast cancer was studied using newly established anti-OTR monoclonal antibodies. Immunoblotting indicated that the antibody 2F8 recognized a 70K OTR in the pregnant myometrium and breast cancer tissue. Among 57 breast cancer patients, we detected OTR immunoreactivity in 52 (91.2%) by immunohistochemistry using 2F8. Using another monoclonal antibody for different receptor domains, 1-2, the staining profile was identical in all positive samples. Of 52 OTR-positive samples, 28 were diffusely positive (> 80% of cancer cells were stained), and 24 were partially positive (< 80% cells were stained). The ratio of estrogen receptor-positive samples was slightly higher among those that were diffusely positive, but there was no apparent relationship between OTR expression and other clinical parameters. We also confirmed the expression of the OTR in positively stained samples by means of Northern blotting and RT-PCR at the transcription level. The OTR messenger RNA and RT-PCR product were the same size as those in the pregnant myometrium. We also determined the expression of the OTR using flow cytometry in four breast cancer cell lines (MCF-7, MDA-MB-231, MDA-MB-361, and MDA-MB-468). However, OT had no significant effect on their growth during a short period (7 days) of culture. These findings indicated that the OTR is expressed in breast cancer derived not from the myoepithelium but from the glandular or ductal epithelium; however, the biological function of OT in breast cancer remains to be determined.

Adult↗
PubMed1996

Expression of oxytocin receptor in human pregnant myometrium.

Around the onset of labor, uterine sensitivity to oxytocin (OT) increases tremendously. Although this is considered to reflect OT receptor (OTR) augmentation in myometrium, neither spatial expression of OTR nor the level of the receptor message during the course of pregnancy have been investigated at the molecular level. We examined the localization and expression of the OTR in human myometrium by means of in situ hybridization, immunohistochemistry, and Northern and Western blotting. In the term pregnant myometrium, OTR expressing smooth muscle cells are observed diffusely and heterogeneously. Some of the smooth muscle cells were expressed high levels of the receptor at the messenger RNA and protein level, and they were surrounded with cells weakly positive for the OTR or negative. The level of OTR transcripts increased according to the course of pregnancy. The receptor messenger RNA level reached over 300-fold at parturition compared with the nonpregnant myometrium. In the myometrium at 32 weeks of gestation and not in labor, a relatively large amount (about 100-fold) of the receptor message was expressed. In the nonpregnant myometrium, significant amount of the receptor protein was revealed by Western blotting. We also found that the receptor protein was augmented at term and after the onset of labor. These findings indicated that the expression of OTR changes dynamically at the transcription and protein level during pregnancy and that its expression is heterogeneous in the term myometrium.

Amino Acid Sequence↗