211 research outputs found
Nuclear Magnetic Resonance in Dilute Ni-Base Alloys
The nuclear magnetic resonance (NMR) of impurity nuclei have been observed in Ni-base alloys using a steady state method and a spin echo method. Firstly, measurments of the NMR frequency of the Cuv s , Niv 1, Cou y , Feu w and Mnu u nuclei in Ni alloys was measured as a function of temperature in the range from 4.2°K to 550°K, respectively. The temperature dependences of the internal fields are not identical to that of the magnetization of Ni host. The discrepancy depends on the hyperfine constant. Furthermore, the pressure dependence of their fields at 273°K in the range 1 to 8000 kg/cm2 has been measured with the result that the dl_nH_i/dP of Cuv s , Nv 1, Cou y and Mnu u nuclei in Ni alloys are 1.66×10{ w (kg/c㎡){ 1, 1.20×10{ v (kg/c㎡){ 1, 1.74×10{ w (kg/c㎡){ 1 and -3.32×10{ w (kg/cm2){ 1, respectively. It is found that the resonance frequency of the impurity nuclei is not proportional to the bulk magnetization even at constant volume. A brief discussion on mechanisms possible as the source of the exchange interaction is given.Article信州大学理学部紀要 4(1): 25-37(1969)departmental bulletin pape
A Review of ERCC1 Gene in Bladder Cancer: Implications for Carcinogenesis and Resistance to Chemoradiotherapy
The excision repair cross-complementing group 1 (ERCC1) gene performs a critical incision step in DNA repair and is reported to be correlated with carcinogenesis and resistance to drug or ionizing radiation therapy. We reviewed the correlation between ERCC1 and bladder cancer. In carcinogenesis, several reports discussed the relation between ERCC1 single nucleotide polymorphisms and carcinogenesis in bladder cancer only in case-control studies. Regarding the relation between ERCC1 and resistance to chemoradiotherapy, in vitro and clinical studies indicate that ERCC1 might be related to resistance to radiation therapy rather than cisplatin therapy. It is controversial whether ERCC1 predicts prognosis of bladder cancer treated with cisplatin-based chemotherapy. Tyrosine kinase receptors or endothelial-mesenchymal transition are reported to regulate the expression of ERCC1, and further study is needed to clarify the mechanism of ERCC1 expression and resistance to chemoradiotherapy in vitro and to discover novel therapies for advanced and metastatic bladder cancer
Nuclear Magnetic Relaxation Times of Mn⁵⁵ in Dilute MnFe Alloys
Nuclear magnetic relaxation times (T₁ and T₂) were measured in dilute MnFe alloys. The relaxation processes are effected by the Mn-impurity and related by the functions with impurity concentrations.Article信州大学理学部紀要 10(2): 81-84(1976)departmental bulletin pape
Male Infertility and Its Causes in Human
Infertility is one of the most serious social problems facing advanced nations. In general, approximate half of all cases of infertility are caused by factors related to the male partner. To date, various treatments have been developed for male infertility and are steadily producing results. However, there is no effective treatment for patients with nonobstructive azoospermia, in which there is an absence of mature sperm in the testes. Although evidence suggests that many patients with male infertility have a genetic predisposition to the condition, the cause has not been elucidated in the vast majority of cases. This paper discusses the environmental factors considered likely to be involved in male infertility and the genes that have been clearly shown to be involved in male infertility in humans, including our recent findings
Discovery of a TEKTIN-t/TEKT2 Gene Variant Encoding Sperm Flagellar Protein in Japanese Males
テクチンは、ダイニンとともに精子の鞭毛や繊毛の形成に関与したタンパク質である。テクチンには、ヒトにおいて少なくとも6種類の遺伝子の存在が報告されている。テクチン遺伝子のうち、Tektin-t/Tekt2、Tekt3、もしくは Tekt4 が欠失することによって、精子の鞭毛が機能不全を起こし、なかでも Tektin-t/Tekt2 遺伝子の欠失は、雄性不妊症になることがマウスで示されている。男性不妊症の原因にテクチン遺伝子の機能不全が関与することが予想される。私たちは、ヒト TETIN-t/TEKT2 遺伝子の遺伝子多型と男性不妊症との関係について調べるため、282人の原因不明の男性不妊症患者と89人の妊孕性が確認された男性ボランティアの遺伝子の解析を行った。その結果、日本人男性不妊症患者に有意に検出される TETIN-t/TEKT2 遺伝子の変化は見られなかった。これらの結果は、TETIN-t/TEKT2 は、日本人男性不妊症の原因遺伝子となる割合は非常に低くいことを示すとともに、今後の大規模な男性不妊症の原因となる遺伝子の解析に役に立つものと考えられる。TEKTIN proteins contribute to the formation of cilia and flagella together with dynein. At least six types of TEKTIN genes have been reported in humans. The disruption of Tektin-t/Tekt2, Tekt3, or Tekt4 in mice causes sperm flagellar dysfunction, and Tektin-t/Tekt2 null male mice are infertile. To investigate the possible association between variations in TEKTIN-t/TEKT2 and impaired spermatogenesis in Japanese males, we screened for mutations in TEKTIN-t/TEKT2 using DNA from 282 sterile male patients and 89 proven-fertile male volunteers. Six polymorphisms were found in the open reading frame of TEKTIN-t/TEKT2, but no significant differences in genotype frequency were identified in the infertile subjects(P>0.05). We also did not detect a previously reported TEKTIN-t/TEKT2 gene variant in our subjects. These data may be applied to future large-scale genetic analyses of the association between genetic background and male infertility
Genetic Variation in the Testis-Specific GSG3/CAPZA3 Gene Encoding for the Actin Regulatory Protein in Infertile Males
アクチンキャッピング蛋白質 GSG3/CAPZA3 は、受精可能な精子の形態形成に重要な役割を担っている。GSG3/CAPZA3 遺伝子は、イントロンレス遺伝子として哺乳類に保存され、マウスにおいてミッセンス変異が精子の減少と形態異常を誘導し、雄性不妊症の原因となることが知られている。日本人において男性不妊症と GSG3/CAPZA3 遺伝子多型の関係を調べるため、261人の男性不妊症患者と139人の妊孕性が確認された男性ボランティアの遺伝子多型を調べた。その結果、妊孕性が確認された男性ボランティアの一人にアミノ酸置換を伴う一塩基多型がヘテロ接合型として検出された。このことから、GSG3/CAPZA3 遺伝子には、他の精子細胞特異的イントロンレス遺伝子に比べて遺伝子多型が極めてわずかしか存在しないことが示唆された。The actin capping protein GSG3/CAPZA3 plays a physiologically important role in maintaining sperm architecture for fertilization. The GSG3/CAPZA3 gene is conserved in mammals and lacks introns. A missense mutation in the CAPZA3 gene in mice causes male infertility by reducing the concentration and changing the shape of sperm. To investigate possible associations between GSG3/CAPZA3 gene variations and impaired spermatogenesis in Japanese males, we screened for mutations in GSG3/CAPZA3 using DNA from 261 sterile male patients and 139 male volunteers who were fertile. A single nucleotide polymorphism(SNP)was found in one sample in the heterozygous state in the fertile male volunteers. The results indicate that compared with other germ-cell-specific intronless genes the change was restricted in GSG3/CAPZA3 protein
Proximal location of mouse prostate epithelial stem cells: a model of prostatic homeostasis
Stem cells are believed to regulate normal prostatic homeostasis and to play a role in the etiology of prostate cancer and benign prostatic hyperplasia. We show here that the proximal region of mouse prostatic ducts is enriched in a subpopulation of epithelial cells that exhibit three important attributes of epithelial stem cells: they are slow cycling, possess a high in vitro proliferative potential, and can reconstitute highly branched glandular ductal structures in collagen gels. We propose a model of prostatic homeostasis in which mouse prostatic epithelial stem cells are concentrated in the proximal region of prostatic ducts while the transit-amplifying cells occupy the distal region of the ducts. This model can account for many biological differences between cells of the proximal and distal regions, and has implications for prostatic disease formation
Single Nucleotide Polymorphisms of the IZUMO Gene in Male Infertile Patients
IZUMOは精子頭部の膜表面に局在し、マウスの精子と卵の受精に必須なタンパク質である。日本人におけるIZUMO遺伝子の多型と精子形成の異常の関係を解析するために、我々は妊孕性の確認されたボランティアの男性172人と男性不妊症患者892人のゲノムDNAを用いてIZUMO遺伝子の多型と変異の検索を行った。ABI‐PRISM 3730xl Genetic Analyzer and SeqScape software (Applied Biosystems社)を用い解析を行った結果、妊孕性の確認されたボランティアの男性では検出されない一塩基置換を男性不妊症患者に見出した。初回の探索において、男性不妊症患者に4つの一塩基多型(417T>G(Cys139Trp),589A>T(Ser197Cys),939T>A(Phe313Leu),944G>A(Arg315Gln))が有意に検出された。これらの一塩基置換は、別のプライマーセットを用いた塩基配列解析では検出することができなかったが、一塩基多型と男性不妊症の関係の解析において重要な標的候補と考えられる。IZUMO is a surface protein on sperm and essential for egg fusion in mice. To investigate the possible association between variations in the IZUMO gene and impaired spermatogenesis in Japanese males, we screened for mutations in the human IZUMO gene using DNA from 892 sterile male patients and 172 proven-fertile male volunteers. Single Nucleotide Polymorphisms (SNPs) were identified in the heterozygous state in the infertile patients, and neither variant was identified in fertile subjects using an ABI-PRISM 3730xl Genetic Analyzer and SeqScape software (Applied Biosystems). Four single nucleotide polymorphisms (SNPs), 417 T>G (Cys 139 Trp), 589 A>T (Ser 197 Cys), 939 T>A (Phe 313 Leu), and 944 G>A (Arg 315 Gln), were found significantly more often in infertile subjects than in fertile controls in the first screening. Otherwise, the four SNPs were not detected by direct sequencing using the other primers. These results show that four SNPs exist as an analytical target of SNPs that associated with the male infertility n the IZUMO gene
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