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Kazuo Sengoku

Publications and source records attributed to Kazuo Sengoku.

16 recordsLinked to original sources
PubMed2006

Is a genetic defect in Fkbp6 a common cause of azoospermia in humans?

FK506-binding protein 6 (Fkbp6) is a member of a gene family containing a prolyl isomerase/FK506-binding domain and tetratricopeptide protein-protein interaction domains. Recently, the targeted inactivation of Fkbp6 in mice has been observed to result in aspermic males and the absence of normal pachytene spermatocytes. The loss of Fkbp6 results in abnormal pairing and a misalignment of the homologous chromosomes, and in non-homologous partner switches and autosynapsis of the X chromosome cores in meiotic spermatocytes. In this study, we analyzed whether human FKBP6 gene defects might be associated with human azoospermia. We performed a mutation analysis in all the coding regions of the human FKBP6 gene in 19 patients with azoospermia resulting from meiotic arrest. The expression of the human FKBP6 gene was specific to the testis, and a novel polymorphism site, 245C --> G (Y60X) could be found in exon 3. Our findings suggest that the human FKBP6 gene might be imprinted in the testis based on an analysis using two polymorphism sites.

Amino Acid Sequence↗
PubMed2006

[Galactorrhea].

Explore the source record for details and available documents.

Chiari-Frommel Syndrome↗
PubMed2006

Polymorphic alleles of the human MEI1 gene are associated with human azoospermia by meiotic arrest.

Genetic mechanisms are implicated as a cause of some male infertility, yet are poorly understood. Mouse meiotic mutant mei1 (meiosis defective 1) was isolated by a screening of infertile mice. Male mei1 mice have azoospermia due to meiotic arrest, and the mouse Mei1 gene is responsible for the mei1 phenotype. To investigate whether human MEI1 gene defects are associated with azoospermia by meiotic arrest, we isolated the human MEI1 cDNA based on the mouse Mei1 amino acid sequence. MEI1 is expressed specifically in the testis. Mutational analysis by direct sequencing of all MEI1 coding regions was performed in 27 men (13 European Americans, 13 Israeli and 1 Japanese) having azoospermia due to complete early meiotic arrest. This identified four novel, coding single-nucleotide-polymorphisms (cSNPs), i.e., SNP1 (T909G), SNP2 (A1582G), SNP3 (C1791A) and SNP4 (C2397T) in exons 4, 8, 9 and 14, respectively. Using these cSNPs, an association study was carried out between 26 non-Japanese patients with azoospermia and two sets of normal control men (61 normal European Americans and 60 Israelis). Consequently, SNP3 and SNP4 were shown to be associated with azoospermia among European Americans (P =0.0289 and P =0.0299 for genotype and allele frequencies at both the polymorphic sites, respectively), although no such association was observed among Israelis (P >0.05). Haplotype estimation revealed that the frequencies of SNP3-SNP4 (C-T), SNP3-SNP4 (A-C) and SNP3-SNP4 (A-T) were higher in the European American patients, and the frequency of SNP3-SNP4 (A-T) was also higher than in both control groups. These results suggest that MEI1 may play a role in meiosis during spermatogenesis, especially in European Americans.

Alleles↗
PubMed2005

Three-dimensional magnetic resonance imaging after ultrasonography for assessment of fetal gastroschisis.

A 24-year-old woman (Gravida I, Para I) at estimated 32 weeks of pregnancy was referred to our department for evaluation of a suspected fetal gastroschisis. Ultrasound scan revealed multiple loops of dilated bowel outside the fetal abdomen and absence of membrane surrounding the herniated loops of the intestines. Three-dimensional (3D) magnetic resonance imaging was performed to obtain more information on the bowel both outside and inside the abdomen. Images were constructed with T1-weighted fat-suppressed 3D fast low-angle shot sequences using a maximum intensity projection algorithm. The 3D images made possible the realization of fetal bowel conditions with greater definition and accuracy.

Adult↗
PubMed2004

Nuclear dynamics of parthenogenesis of human oocytes: effect of oocyte aging in vitro.

We investigated in detail the nuclear kinetics of oocyte activation of aged human oocytes following combined activation treatment with calcium ionophore and puromycin. Two types of oocytes were used: (a) 1-day-old oocytes after 20-24 h retrieval, and (b) 2-day-old oocytes after 44-50 h retrieval. A total of 185 unfertilized aged oocytes, 91 1-day-old and 94 2-day-old oocytes, were fixed at 1, 2, 4, 6 and 8 h after activation treatment and then metaphase II (MII), anaphase or telophase II (A/T II) or pronuclear stage were recorded. We demonstrated that a combined calcium ionophore and puromycin treatment induced a high activation rate in both 1-day-old (95.6%) and 2-day-old oocytes (95.2%). Our results also demonstrated that the nuclear progression was faster in 2-day-old oocytes than in 1-day-old oocytes, although nuclear progression in parthenogenetically activated human oocytes requires the longer time periods compared with ICSI fertilization. It is concluded that combined treatment of the calcium ionophore and puromycin allows a high rate of parthenogenetic activation and the nuclear kinetics of parthenogenetically activated human oocytes appears to be more rapid in in vitro aging oocytes.

Calcimycin↗
PubMed2004

Differential expression of heparin-binding epidermal growth factor-like growth factor in the rat ovary.

We investigated the expression of heparin-binding epidermal growth factor-like growth factor (HB-EGF) and its receptors in the rat ovary to define the role of HB-EGF in the ovarian function. The expression pattern of HB-EGF mRNA and protein were studied by semi-quantitative RT-PCR and immuno-histochemistry using an antibody that was specifically stained for the precursor form of HB-EGF in naturally cycling rats and immature pseudo-pregnant rat models. The immuno-histochemical study showed that in naturally cycling rats, HB-EGF was expressed in most granulosa cells of early follicles and all the developing follicles but not in preovulatory follicles. This was supported by the semi-quantitative RT-PCR results in that the lowest level of HB-EGF mRNA during the estrous cycle was found in the evening of proestrous when the HB-EGF negative preovulatory follicles were most prominent. The results suggest that HB-EGF might be a mitogen for granulosa cells and down regulation of its expression may be necessary for the final maturation of follicles. In corpora lutea, luteal cells of older generation stained stronger than those of younger generation. Moreover, luteal cells of late luteal phase stained stronger than those of the mid and early luteal phases in the immature pseudo-pregnant rat models, indicating that the precursor form may be associated with death of luteal cells. Finally, of the two cognate receptors for HB-EGF, erbB1 was expressed in the rat ovary, but erbB4 was specifically not expressed in this organ. The spatial and temporal pattern of HB-EGF expression suggest that HB-EGF may an important local regulator of ovarian function and structure.

Animals↗
PubMed2004

Integrins are not involved in the process of human sperm-oolemmal fusion.

BACKGROUND: We investigated whether integrins are required for the human sperm-oocyte binding and fusion processes. METHODS: The expression of several integrin subunits at the human oocyte plasma membrane was investigated using immunofluorescence microscopy, and the functional role of integrins expressed at the human oocyte surface in sperm-oocyte interaction was studied using a zona-free human oocyte binding and fusion assay. A total of 144 unfertilized oocytes were stained with anti-integrin antibodies and 147 zona-free unfertilized oocytes were inseminated in the presence of various anti-integrin antibodies that were expressed in oocyte plasma membrane. RESULTS: The antibodies of six alpha integrin subunits (alpha(2), alpha(3), alpha(5), alpha(6), alpha(V), alpha(M)) and six beta integrin subunits (beta(1), beta(2), beta(3), beta(4), beta(5), beta(6)) were bound to the surface of fixed unfertilized oocytes. In contrast, the presence of alpha(1) and alpha(4) subunits could not be verified. The human sperm-oocyte binding was only partially inhibited by blocking antibodies of alpha(2), alpha(3), alpha(5), alpha(6), alpha(V), alpha(M), beta(1), beta(2) and beta(3) with a maximum of 55% inhibition, but antibodies of beta(4), beta(5) and beta(6) showed no effect on sperm-oolemmal binding. A similar reduction of the number of fused sperm was observed. However, the ratio of fused sperm to total sperm (bound and fused) was not impaired by all integrin antibodies, suggesting that integrins had no role in the sperm-oolemmal fusion process. CONCLUSIONS: These results suggest that one of the binding mechanisms can be inhibited by integrin antibodies but that this mechanism does not play an essential role in the human sperm-oolemmal binding and fusion processes. The other mechanisms, insensitive to integrins, may involve both binding and fusion processes in human oocytes.

Antibodies↗
PubMed2004

Isolation and expression analysis of the testis-specific gene, human OPPO1.

PURPOSE: To investigate human spermatogenesis, we isolated human testis-specific genes. METHODS: Using mouse amino acid sequences, we found the region including homology in amino acid level in the human genome sequences. The primers encompassing introns were made and RT-PCR and RACE were carried out. The resultant PCR products were sequenced. RESULTS: The full-length cDNA of human OPPO1 was isolated. It encodes 257 amino acid residues. The expression of the human OPPO1 was predominantly in the testis. On the other hand, partial cDNAs of ZNF8, GR194, GR219, GR093, GR046, GR163, and GR200 were expressed in the various tissues. CONCLUSIONS: Our data suggests that the human OPPO1 may play important roles in human spermatogenesis.

Amino Acid Sequence↗
PubMed2003

Treatment of climacteric symptoms with herbal formulas of traditional Chinese medicine.

Hormone replacement therapy (HRT) is not successful or is contraindicated for the treatment of climacteric symptoms in some patients. To investigate whether certain herbal formulas of traditional Chinese medicine (Kampo in Japanese) could be used as an alternative treatment, a longitudinal 'before and after' comparative study was carried out in 18 Japanese women, and the results were compared with those of 16 women who underwent HRT. Kampo improved all the climacteric symptoms. In contrast, improvement of cold limbs, sleeping disorders, shoulder stiffness/lumbago, and fatigue in the HRT group was either not significant or of limited extent. In addition, the serum level of estradiol in postmenopausal women was raised by the combined use of two Kampo formulas. These results suggest that Kampo may be considered an alternative to HRT for the treatment of climacteric symptoms, but vigorous monitoring for potential side effects of increased estrogen levels in some postmenopausal patients is needed.

Drugs, Chinese Herbal↗
PubMed2003

Molecular cloning and expression analysis of the mouse Spot-2 gene in pituitary development.

Mouse Spot-1 is a DNA-binding protein with a domain (His-Thr) encoded by p(CA)n repeats. Spot-1 interacts with the nuclear localization signal (NLS) I of p53 through its His-Thr domain. In this study we describe the cloning and expression patterns of a novel gene encoding a protein containing a His-Thr domain, Spot-2. Spot-2 is exclusively expressed in the pituitary from stage E13.5 to E15.5. Mouse Lhx3 plays a critical role during early organogenesis in the pituitary. The Spot-2 gene appears to be a downstream gene of Lhx3. It is suggested that Spot-2 plays important roles in pituitary development.

Amino Acid Sequence↗
PubMed2002

Isolation and expression analysis of the testis-specific gene, STRA8, stimulated by retinoic acid gene 8.

Retinoids are known to be required for vertebrate reproduction, and in the male, for the maintenance of normal testicular structure and function. Previously several novel retinoic acid responsive genes, collectively designated as the Stra genes, had been isolated in the mouse. The Stra8 gene encodes a cytoplasmic protein and is expressed specific to the developing male gonad during mouse embryogenesis. In adult mouse, its expression is restricted to the premeiotic germ cells. Thus it has been suggested that the mouse Stra8 protein may play a role in the premeiotic phase of spermatogenesis. Recently a lot of genes that are expressed only in male germ cells have been isolated in the mouse. The mouse Stra8, Rnh2, Piwil2, Tex17, and Tuba7 were identified as testis-specific expressed genes. In addition, the Figla was known to be a testis- and ovary-specific gene. Recently we had reported the isolation of the human RNH2 cDNA and its expression, which is limited to the human testis. In the present study, we have isolated full-length cDNA of S TRA8 and partial cDNAs of PIWIL2, FIGLA, TEX17, and TUBA7, and analyzed their expression patterns in human tissues.

Adaptor Proteins, Signal Transducing↗
PubMed2002

The soluble and membrane-anchored forms of heparin-binding epidermal growth factor-like growth factor appear to play opposing roles in the survival and apoptosis of human luteinized granulosa cells.

This study aims to investigate the expression of heparin-binding epidermal growth factor-like growth factor (HB-EGF) and its role in regulating apoptosis of human luteinized granulosa cells (LGC). By using RT-PCR and immunocytochemistry, the expression of HB-EGF and the EGF receptor family was demonstrated. HER4, one of the two cognate receptors for HB-EGF, was found translocated into the nucleus. HB-EGF exists in two forms, the precursor membrane-anchored form and the mature secreted form. Addition of recombinant HB-EGF, which acts as the secreted form, into the cell culture inhibited apoptosis and appeared to stimulate mitosis, indicating that the secreted form is potentially an anti-apoptotic factor and a mitogen for LGC. In contrast, CRM197, a specific inhibitor for the interaction between HB-EGF and the EGF receptor, inhibited rather than enhanced apoptosis, suggesting that the membrane-anchored form constitutively functions as a pro-apoptotic factor for LGC. Furthermore, the finding that apoptosis inhibition by CRM197 in the aggregate cells was much more pronounced than in the single cells indicates that pro-apoptotic activity was carried out in a juxtacrine fashion, as would be expected for the membrane-anchored form of HB-EGF. These data suggest that HB-EGF may be a unique regulator of LGC apoptosis, with two functionally opposing products arising from the same gene.

Apoptosis↗
PubMed2002

The clinical usefulness of salivary progesterone measurement for the evaluation of the corpus luteum function.

The present study was designed to construct reliable daily salivary progesterone profiles throughout the luteal phase to accurately evaluate the corpus luteum function. Furthermore, we investigated the clinical relevance of a simple midluteal salivary progesterone estimation for the diagnosis of luteal phase insufficiency by determining the diagnostic efficiency and cutoff values. A total of 121 women were divided into 3 groups; normal luteal function, luteal phase insufficiency and unclassified group, based on basal body temperature recordings and serum progesterone levels at 3 sampling points during the midluteal phase. Salivary progesterone values across the luteal phase of the normal luteal function group were significantly increased from day 1 to day 4, remained constant from day 5 to day 9 (mean +/- SD, 318 +/- 170 pmol/l on day 5, 287 +/- 169 pmol/l on day 9; urinary LH surge = day 0) and decreased thereafter. Salivary progesterone concentrations in the luteal phase insufficiency group showed significantly lower values compared with those in the normal group between days 3 and 10. The cutoff values of 189 pmol/l in the midluteal phase yielded a sensitivity of 78.0% and a specificity of 76.5%. Our results suggest that daily salivary progesterone profiles during the luteal phase and a simple estimation of midluteal salivary progesterone appeared to be useful for the diagnosis of luteal phase defects.

Adult↗
PubMed2002

Laparoscopic treatment of endometrioma-associated infertility and pregnancy outcome.

Ovarian endometriomas do not respond well to medical treatment with hormonal suppression, and surgical removal of the endometriomas is usually required. In this study, we attempt to identify the optimal laparoscopic procedures in laparoscopic treatment of ovarian-endometrioma-associated infertility. Among cases in which patients received no IVF-ET after the laparoscopic treatment, the pregnancy rate after complete cystectomy of endometriomas was statistically lower than that after fenestration with electrocoagulation of the cyst wall. Among cases in which patients received IVF-ET, there was no difference in ovarian response between patients that had complete cystectomy and fenestration with electrocoagulation of the cyst wall. However, the pregnancy rate in patients who had aspiration alone was statistically lower than that in patients who had aspiration followed by ethanol fixation. Thus, it appears that for patients who do not require follow-up IVF-ET, fenestration with electrocoagulation of the cyst wall is suitable, whereas for patients who need follow-up IVF-ET, ethanol fixation may be a better choice.

Adult↗