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Biomedical subjects

H Tateno

Publications and source records attributed to H Tateno.

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

Dithiothreitol induces sperm nuclear decondensation and protects against chromosome damage during male pronuclear formation in hybrid zygotes between Chinese hamster spermatozoa and Syrian hamster oocytes.

The present study was undertaken to investigate whether a time lag in sperm nuclear decondensation and male pronuclear formation in the course of development of eggs is associated with any occurrence of structural chromosome aberrations in male genomes of hybrid zygotes between Chinese hamster spermatozoa and zona-free Syrian hamster oocytes. Shortly after insemination, hybrid zygotes were treated with dithiothreitol (DTT) at different concentrations (0.1-10.0 mM) for 30 min to reduce protamine disulphide (S-S) bonds and thereby accelerate sperm nuclear decondensation and male pronuclear formation. The incidence of sperm nuclear decondensation and male pronuclear formation increased with increasing DTT concentrations, indicating that a reduction in S-S bonds effectively induces these cytological events. Chromosomes of male genomes in hybrid zygotes generated by treatment with 1.0 mM, 2.5 mM and 10.0 mM DTT were analysed at the first cleavage metaphase. Incidence of structural chromosome aberrations in each treatment was 34.5%, 27.1% and 24.7%, respectively. There was a significant difference between the incidences with 1.0 mM and 10.0 mM DTT treatment. As the time lag in nuclear decondensation and male pronuclear formation was greatest in the 1.0 mM treatment condition, followed in order by 2.5 mM and 10.0 mM, it is suggested that the lag in sperm nuclear development behind egg development is responsible for structural chromosome aberrations in male genomes of hybrid zygotes.

Acridine Orange↗
PubMed1999

Chromosome analysis of BALB/c mouse spermatozoa with normal and abnormal head morphology.

To assess the relationship between mouse sperm head morphology and karyotype, sperm heads with either a normal or an abnormal morphology were injected individually into enucleated mouse oocytes that were karyotyped at the metaphase of the first cleavage. BALB/c male mice that produce an unusually high proportion of morphologically abnormal spermatozoa were used as sperm donors. Abnormal karyotypes were found in a significantly higher proportion of eggs injected with severely misshapen sperm heads (36-38%) as compared to those injected with normal and quasi-normal heads (15-21%) (p < 0.01). Most karyotype abnormalities were structural rather than numerical, the most common being breaks and exchanges of chromosome type in both normal and abnormal spermatozoa.

Animals↗
PubMed1999

Clear cell variant of calcifying epithelial odontogenic tumor (CEOT) in the maxilla: report of a case with immunohistochemical and ultrastructural investigations.

A rare case of clear cell variant of calcifying epithelial odontogenic tumor is presented with immunohistochemical and ultrastructural investigations. A 14-year-old Japanese girl was admitted with a complaint of swelling in the right posterior maxilla. Radiological examination showed a well-circumscribed radiolucent lesion located close to the impacted third molar. After only a partial tumor excision, the tumor recurred 13 years later. It appeared radiologically as an irregular radiodensity, and a subtotal maxillectomy was performed. Histological examination showed sheets and/or strands composed almost entirely of clear vacuolated epithelial cells in a stroma containing intercellular amyloid-like material and calcification. Histochemical and ultrastructural analysis detected cytoplasmic glycogen granules in the clear cells, and positive immunoreactivities for cytokeratins 8, 13 and 19; filaggrin and anti-ameloblastoma antibodies suggested an odontogenic epithelial origin.

Adolescent↗
PubMed1999

Fertility of mouse spermatozoa retrieved from cadavers and maintained at 4 degrees C.

After male animals die, the spermatozoa within the testis and epididymis eventually disintegrate. In this study, the motility, viability and fertility of mouse spermatozoa were examined after retrieval from the epididymis at various days after death. Cadavers were maintained in a refrigerator at 4 degrees C. About 30% of the spermatozoa collected 10 days after death were viable, but they had limited ability to fertilize oocytes in vitro. However, when the spermatozoa were injected into oocytes, the fertilization rate was over 80%. Normal live fetuses were even obtained using immotile spermatozoa retrieved 20 days after death. Therefore, when valuable male animals die unexpectedly and sperm cryopreservation is not possible immediately, temporal storage of cadavers (or epididymis and vas deferens) at 4 degrees C in a regular refrigerator followed by intracytoplasmic sperm injection may help to preserve the genome of individuals. This procedure could be particularly important in endangered species.

Animals↗
PubMed1998

Isolation and characterization of rhamnose-binding lectins from eggs of steelhead trout (Oncorhynchus mykiss) homologous to low density lipoprotein receptor superfamily.

Two L-rhamnose-binding lectins named STL1 and STL2 were isolated from eggs of steelhead trout (Oncorhynchus mykiss) by affinity chromatography and ion exchange chromatography. The apparent molecular masses of purified STL1 and STL2 were estimated to be 84 and 68 kDa, respectively, by gel filtration chromatography. Sodium dodecyl sulfate polyacrylamide gel electrophoresis and matrix-assisted laser desorption ionization time of flight mass spectrometry of these lectins revealed that STL1 was composed of noncovalently linked trimer of 31.4-kDa subunits, and STL2 was noncovalently linked trimer of 21.5-kDa subunits. The minimum concentrations of STL1, a major component, and STL2, a minor component, needed to agglutinate rabbit erythrocytes were 9 and 0.2 microg/ml, respectively. The most effective saccharide in the hemagglutination inhibition assay for both STL1 and STL2 was L-rhamnose. Saccharides possessing the same configuration of hydroxyl groups at C2 and C4 as that in L-rhamnose, such as L-arabinose and D-galactose, also inhibited. The amino acid sequence of STL2 was determined by analysis of peptides generated by digestion of the S-carboxamidomethylated protein with Achromobacter protease I or Staphylococcus aureus V8 protease. The STL2 subunit of 195 amino acid residues proved to have a unique polypeptide architecture; that is, it was composed of two tandemly repeated homologous domains (STL2-N and STL2-C) with 52% internal homology. These two domains showed a sequence homology to the subunit (105 amino acid residues) of D-galactoside-specific sea urchin (Anthocidaris crassispina) egg lectin (37% for STL2-N and 46% for STL2-C, respectively). The N terminus of the STL1 subunit was blocked with an acetyl group. However, a partial amino acid sequence of the subunit showed a sequence similarity to STL2. Moreover, STL2 also showed a sequence homology to the ligand binding domain of the vitellogenin receptor. We have also employed surface plasmon resonance biosensor methodology to investigate the interactions between STL2 and major egg yolk proteins from steelhead trout, lipovitellin, and beta'-component, which are known as vitellogenin digests. Interestingly, STL2 showed distinct interactions with both egg yolk proteins. The estimated values for the affinity constant (Ka) of STL2 to lipovitellin and beta' component were 3.44 x 10(6) and 4.99 x 10(6), respectively. These results suggest that the fish egg lectins belong to a new family of animal lectin structurally related to the low density lipoprotein receptor super- family.

Amino Acid Sequence↗
PubMed1998

No induction of chromosome aberrations in human spermatozoa exposed to extremely low frequency electromagnetic fields.

Clastogenic effects of extremely low frequency electromagnetic fields (ELF-EMFs) on human sperm chromosomes were studied using an interspecific in vitro fertilization system with zona-free golden hamster oocytes. Semen samples from healthy men were exposed to ELF-EMFs (50 Hz, 20 mT) for 2 h at 37 degreesC under 5% CO2 in air. The samples were then cryopreserved in liquid nitrogen for shipment to a cytogenetic laboratory. After thawing the samples, motile spermatozoa were collected using a continuous Percoll density gradient centrifugation and then capacitated for in vitro fertilization with hamster oocytes. Sperm-derived chromosomes were analyzed at first cleavage metaphase. The present experiment was performed twice using semen samples from two different donors. In test-1, incidence of spermatozoa that displayed structural chromosome aberrations was 17.0% (35/206) in the exposed group and 20.8% (55/264) in the control group. In test-2, structural chromosome aberrations were observed in 11.1% (13/117) of exposed spermatozoa and 13.8% (13/94) of spermatozoa in the control group. In both tests, there was no significant difference in the incidence of chromosomally abnormal spermatozoa between the exposed group and the control group. Types of aberrations observed and their incidences per spermatozoon in the exposed group were similar to those of the control group. Despite the small sample size, the present results suggest that ELF-EMFs have no clastogenic effect on human sperm chromosomes.

Animals↗
PubMed1998

Decondensation of the mouse sperm nucleus within the interphase nucleus.

Sperm nuclei incorporated into the cytoplasm (ooplasm) of fertilised mouse eggs at the pronuclear stage remain condensed, whereas those injected into male or female pronuclei decondense. Similarly, sperm nuclei injected into germinal vesicles of immature oocytes or the nuclei of 2-cell embryos decondense, while those entering the cytoplasm of these oocytes/embryos do not. These facts seem to suggest that factors necessary for the decondensation of sperm nucleus are present in interphase nuclei and are released into the ooplasm during nuclear envelope breakdown. Nucleoplasmin, which is synthesised in the cytoplasm and accumulated within the nucleus, is likely a major candidate for these factors.

Animals↗
PubMed1998

Can alcohol retain the reproductive and genetic potential of sperm nuclei? Chromosome analysis of mouse spermatozoa stored in alcohol.

Alcohol is known to preserve genomic DNA and the primary structure of sperm protamines. To determine whether alcohol can retain the genetic and reproductive potential of mammalian sperm nuclei, mature mouse spermatozoa were stored in 70% ethanol or propanol for up to 2 months before injection into oocytes. Live offspring were obtained after injection of spermatozoa stored in 70% ethanol for 1 day at -20 degrees C. About 20% of the spermatozoa stored under this condition had normal chromosomes. The remaining 80% of spermatozoa and all the spermatozoa stored in 70% ethanol for 2 months had structurally aberrant chromosomes, and none could support the development of normal embryos. High concentrations of alcohol do not alter the primary structure of either DNA or small-molecular-weight protamines. However, alcohol may modify protamine-protamine or protamine-DNA interactions in a manner that results in the induction of DNA strand breaks during sperm chromatin decondensation within the oocyte. The limited success in obtaining normal offspring with ethanol-stored spermatozoa is encouraging. It may be possible to overcome these problems and develop a simple method for preserving mammalian spermatozoa without freezing.

Animals↗
PubMed1998

Factors affecting meiotic and developmental competence of primary spermatocyte nuclei injected into mouse oocytes.

Mature mouse oocytes that have received the nuclei of pachytene primary spermatocytes (or metaphase I chromosomes of primary spermatocytes) can develop into fertile offspring. However, success rate in this study was low. No more than 3.8% of transferred 2-cell embryos arising from spermatocyte-injected oocytes developed to full term. Nevertheless, the birth of normal offspring seems to suggest that at least in some primary spermatocytes the functional genomic imprinting is complete before transfer and/or consolidated after the transfer. Although injected spermatocyte nuclei could undergo two successive meiotic divisions within oocytes, abnormalities of both divisions were commonly observed, and sister chromatids often separated prematurely during the second meiotic division. Chromosome breakage/rearrangements were also frequently seen before the first cleavage. Such abnormalities of chromosome behavior are probably the major causes of the poor preimplantation development of zygotes arising from primary spermatocyte-injected oocytes. Thus, clinical use of primary spermatocytes as substitutes for spermatozoa in assisted fertilization is not advisable until the causes of chromosomal abnormalities are better understood through extensive animal studies.

Animals↗
PubMed1997

Parthenogenetic activation of Chinese hamster oocytes by chemical stimuli and its cytogenetic evaluation.

This study was undertaken parthenogenetically to activate Chinese hamster oocytes in vitro by chemical stimuli. Oocytes were exposed to five different chemical agents, ethanol (EtOH), strontium chloride (SrCl2), cycloheximide (CHX), phorbol ester (PMA), and ionophore A23187 (IA23). No parthenogenetic activation was observed in the oocytes treated with 8% EtOH for 8-11 min, 1.7 mM and 5.0 mM SrCl2 for 1 hr, 100 microM and 400 microM CHX for 2 hr, and 81 nM and 162 nM PMA for 5 min. In contrast, 89.7% of oocytes parthenogenetically extruded the second polar body in treatment with 3 microM IA23 for 5 min, but only 22.6% of them formed a pronucleus and developed to 2-cell embryos. The remaining ova stopped their cell cycle immediately after completion of the second meiotic division. They had unichromatid chromosomes (monads), which are called MIII chromosomes. Treatment with 5 microM IA23 for 5 min was so deleterious that > 90% of oocytes were degenerated. However, oocyte activation was significantly improved when the treatment with 3 microM IA23 for 5 min was followed by treatment with 8% EtOH for 10 min, 100 microM CHX for 2 hr, 81 nM PMA for 5 min or 3 microM IA23 for 5 min: rates of pronuclear formation were 54.4%, 84.3%, 34.2%, and 54.6%, respectively. More than 80% of pronucleate ova successfully developed into 2-cell stage. Additive treatment with 5 mM SrCl2 for 1 hr had no positive effect on pronuclear formation. Incidences of aneuploidy (4.6%) and structural chromosome aberrations (1.0%) in parthenogenons produced by combined stimuli of IA23 and CHX were not significantly different from those (3.8% and 1.6%, respectively) in female pronuclei of ova fertilized in vitro, showing that combined treatments with IA23 and CHX cause neither nondisjunction at the second meiotic division nor structural aberrations in MII chromosomes. The present technique for parthenogenetic activation of Chinese hamster oocytes may be useful as an assessment system to detect aneugenic and clastogenic effects of mutagens on mammalian oocytes.

Animals↗
PubMed1996

Histologic features and clinical significance of venous invasion in colorectal carcinoma with hepatic metastasis.

BACKGROUND: In colorectal carcinoma, venous invasion has been related to patient survival. Liver metastasis develops more frequently when venous invasion is present. However, the histologic features and clinical significance of venous invasion are not well understood. METHODS: A histologic study of venous invasion in colorectal carcinoma was performed on 19 patients with synchronous hepatic metastasis (Group A), 16 patients with metacaronous hepatic metastasis (Group B), and 26 patients with Dukes Stage C tumors who survived for 5 years without recurrence (Group C). The histologic features of venous invasion were classified into three types: tumor cells that were distant from the vein walls were categorized as floating type, those filling the lumen of a vein as filling type, and those surrounded by a vein obliterated with inflammatory reaction as occlusive type. RESULTS: Venous invasion was present in 89.5% of Group A patients and 75% of Group B patients, which was significantly higher than the 15.4% observed in Group C patients (P < 0.001). A slight to extensive degree of venous invasion was found in Groups A and B, but no extensive venous invasion was found in Group C. All patients in Groups A and B (except one patient) had floating, filling, or a combination of floating and filling types of venous invasion, whereas all patients in Group C had the occlusive type of venous invasion. A majority of the patients in all three groups showed invasion of extramural veins. CONCLUSIONS: There is a close relationship between venous invasion and the development of liver metastasis in patients with colorectal carcinoma. Patients with no sign of metastasis had a lower incidence and lower extent of venous invasion, and inflammatory damage to the vein walls around the intravenous tumor appeared to reduce the likelihood of distant metastasis.

Adult↗
PubMed1996

Difference in types of radiation-induced structural chromosome aberrations and their incidences between Chinese and Syrian hamster spermatozoa.

The effects of ionizing radiations on sperm chromosomes were studied in the Chinese hamster (Crisetulus griseus) and the Syrian (golden) hamster (Mesocrisetus auratus). Testes of mature male Chinese hamsters (CH) were irradiated with X-rays (0.91, 1.82 and 3.63 Gy) and gamma-rays (1.10, 2.15, 2.95 and 4.01 Gy) at a single acute dosage, whereas the irradiation was done with lower doses of X-rays (0.45, 0.91 and 1.82 Gy) and gamma-rays (0.49, 0.99 and 1.98 Gy) in mature male Syrian hamsters (SH), taking the higher radiosensitivity of this species into consideration. They were mated with normal females within 6 days of exposure. Sperm-derived chromosomes were analyzed in 1125 and 1966 fertilized ova of the CH and the SH, respectively. In both species, there was no great difference in the induction of structural chromosome aberrations between X-irradiated and gamma-irradiated spermatozoa. Chromosome-type aberrations were predominantly induced. The incidence of breakage-type aberrations increased linearly, and that of exchange-type aberrations linear-quadratically with increase of dosage. A species-specific difference in chromosomal radiosensitivity of spermatozoa was clear. In spite of the same radiation dosage, the incidence of chromosomally abnormal spermatozoa in the SH was about twice as high as that in the CH (e.g. 27.0% vs. 14.7% at 0.91 Gy of X-rays). The incidences of breakage-type aberrations (69-89%) were far higher than those of exchange-type aberrations (11-31%) in the SH, while the disparity of the two incidences was much smaller in the CH (46-65% vs. 35-54%). Exchange-type aberrations consisted of both chromosome-type and chromatid-type in the SH, while almost all of them were of the chromosome-type in the CH. These results suggest that the DNA-repairing capacity of oocytes is much higher in the CH than in the SH. Moreover, it seems likely that radiation-induced sperm DNA damage is repaired with both pre-replication repair (excision repair) and post-replication repair systems in SH oocytes, whereas the excision repair system operate most exclusively in CH oocytes.

Analysis of Variance↗
PubMed1996

In vitro fertilisation of Chinese hamster oocytes by spermatozoa that have undergone ionophore A23187-induced acrosome reaction, and their subsequent development into blastocysts.

To enhance potential use of the Chinese hamster, Cricetulus griseus, in developmental and cytogenetic studies of mammalian gametes and embryos, techniques for in vitro fertilisation and embryo culture were developed in the species. Spermatozoa were recovered from the vasa deferentia of mature males, and incubated in modified TYH medium for 1 h at 37 degrees C under 5% CO2 in air. They were then treated with ionophore A23187 (20 microM) for 10 min to induce the acrosome reaction. Following ionophore treatment, superovulated oocytes were collected from hormonally stimulated females and incubated with the acrosome-reacted spermatozoa for 2 h at 37 degrees C under 5% CO2 in air. In this study, 245 oocytes were used for insemination, and 198 (80.8%) were found to be penetrated by sperm; among them, 194 ova (98.0%) were determined to be monospermic. The monospermic ova were then cultured in TYH supplemented with 1 mM hypotaurine under the same gas phase. Within 30 h of fertilisation, 182 ova (93.8%) cleaved to the 2-cell stage, and subsequently 163 ova (84.0%) developed beyond the 2-cell stage. Thus, obstinate developmental arrest at the 2-cell stage ('2-cell block') was not observed in this species. Ultimately, 65.5% of monospermic ova reached morula to blastocyst stages.

Acrosome↗
PubMed1996

Penetration of concanavalin-A-treated Chinese hamster oocytes by golden hamster spermatozoa in vitro, and chromosome analysis of hybrid 1-cell zygotes.

Pretreatment of zona-free Chinese hamster (CH) oocytes with three kinds of lectin--concanavalin A (Con-A), phytohaemagglutinin-P (PHA) and wheat germ agglutinin (WGA)--was attempted in order to improve penetration by golden hamster (GH) spermatozoa in vitro. Con-A had no significant effect on penetration at 2 micrograms/ml, adequately facilitated oocyte-sperm fusion at 4 micrograms/ml, and caused excessive sperm binding and resultant severe polyspermy at 10 micrograms/ml. Neither PHA nor WGA had positive effects on sperm penetration at any concentrations (2-10 micrograms/ml) examined. Using the Con-A (4 micrograms/ml) pretreatment, high rates of interspecific fertilisation and subsequent chromosome analysis of hybrid 1-cell zygotes were achieved. Among 258 CH oocytes used, 212 (82.2%) were fertilised and 153 (72.2% of fertilised ova) developed to the first cleavage metaphase. Eventually, 132 CH-derived chromosome complements and 153 GH-derived ones were successfully karyoanalysed. Incidences of aneuploidy and structural anomaly were 3.1% and 2.3% in CH complements, and 1.4% and 6.5% in GH complements, respectively. These incidences were not significantly different from those obtained by intraspecific in vivo fertilisation, suggesting that our interspecific in vitro fertilisation system does not cause chromosome aberrations.

Animals↗
PubMed1996

Relative biological effectiveness (RBE) of 252Cf fission neutrons for the induction of chromosome damage in human spermatozoa.

Effects of 60Co gamma-rays and 252Cf neutrons on human sperm chromosomes were studied using our interspecific in vitro fertilization system to estimate relative biological effectiveness (RBE) of neutrons. Semen samples were exposed to 0.5, 1.0 and 2.0 Gy of 60Co gamma-rays at 1.7 cGy/ min and 0.25, 0.5 and 1.0 Gy of 252Cf radiation at 1.3-1.7 cGy/ min. In the 60Co experiment, 509 spermatozoa from controls and 902 spermatozoa from the irradiated groups were karyotyped, while in the 252Cf experiment 460 control and 804 irradiated spermatozoa were analysed. In both 60Co and 252Cf experiments, incidences of spermatozoa with radiation-induced structural chromosome aberrations increased linearly with increase of dosage. The RBE of 252Cf neutrons for the induction of chromosomally abnormal spermatozoa was estimated to be 1.6. The number of induced structural chromosome aberrations per spermatozoon also increased linearly. The RBE of neutrons for this index was 2.0. Among structural chromosome aberrations observed, chromosome-type breaks were predominant in both 60Co and 252Cf experiments, and they showed a significant linear dose-dependent increase. Other types of aberrations such as chromosome-type exchanges and chromatid-type breaks also increased linearly with increase in dose. The RBEs of 252Cf neutrons for the induction of these three types of aberrations were 1.6, 3.2 and 3.9, respectively. Thus, the RBEs of neutrons for the induction of chromosome aberrations were smaller in human spermatozoa than in human lymphocytes, and mouse spermatogonia and embryos. This result is discussed from the point of view of DNA-repairing capacity of oocytes.

Animals↗
PubMed1996

Putative linkage between HLA class I polymorphism and the susceptibility to malignant melanoma.

Human leukocyte antigen (HLA) frequencies in 67 melanoma patients were compared to 120 controls in Japan. The frequency of HLA-B13 was increased in melanoma patients compared to controls and was particularly common in nodular melanoma HLA-B61 was decreased in melanoma patients. Almost 50% of acral lentiginous melanoma patients expressed HLA-B51 compared to 0% of nodular melanomas.

Asian People↗
PubMed1995

Chromosome analysis of human spermatozoa exposed to antineoplastic agents in vitro.

We studied in vitro the cytogenetic effects of six antineoplastic agents, bleomycin (BM), cyclophosphamide (CP), daunomycin (DM), methyl methanesulfonate (MMS), mitomycin C (MMC) and triethylenemelamine (TEM) on spermatozoa, using an interspecific in vitro fertilization system between zona-free hamster oocytes and human or bull spermatozoa. In preliminary experiments with bull spermatozoa, clastogenic effects were clearly shown with BM, DM, MMS and TEM, but not with CP and MMC. In main experiments, the effects of the first four chemicals were studied in detail with human spermatozoa. Total numbers of 585 and 512 spermatozoa were karyotyped in the control and the chemical-treated groups respectively. The incidence of spermatozoa with structural chromosome aberrations was 34.5%, 53.0%, 59.3%, and 55.6% in the BM (50 micrograms/ml, 90 min), DM (0.1 microgram/ml, 90 min), MMS (100 micrograms/ml, 120 min) and TEM (0.1 micrograms/ml, 120 min) groups respectively, each showing a significantly higher incidence than the matched controls (10.1-13.5%). Breakage-type aberrations were more frequent than exchange-type aberrations in the BM, MMS and TEM groups, while the exchange-type aberrations were more frequent in the DM group. Exchanges were mainly of the chromatid type in the DM, MMS and TEM groups, while chromosome-type exchanges occurred more frequently in the BM group. These results are discussed in relation to previous data on chemical-induced chromosome aberrations in mammalian somatic cells and in mouse spermatozoa.

Animals↗