LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 227

Search options

  1. Book ; Online ; E-Book: Testicular autoimmunity

    Itoh, Masahiro

    a cause of male infertility

    2017  

    Author's details Masahiro Itoh
    Language English
    Size 1 Online-Ressource (XVII, 232 Seiten)
    Publisher Springer
    Publishing place Tokyo
    Publishing country Japan
    Document type Book ; Online ; E-Book
    Remark Zugriff für angemeldete ZB MED-Nutzerinnen und -Nutzer
    HBZ-ID HT019431980
    ISBN 978-4-431-54460-9 ; 9784431544593 ; 4-431-54460-7 ; 4431544593
    DOI 10.1007/978-4-431-54460-9
    Database ZB MED Catalogue: Medicine, Health, Nutrition, Environment, Agriculture

    Kategorien

  2. Article ; Online: Editorial (JSIR2021 Special issue).

    Kawana, Kei / Fukui, Atsushi / Chishima, Fumihisa / Takada, Kazuhide / Itoh, Masahiro

    Journal of reproductive immunology

    2023  Volume 158, Page(s) 103976

    Language English
    Publishing date 2023-06-09
    Publishing country Ireland
    Document type Editorial
    ZDB-ID 424421-7
    ISSN 1872-7603 ; 0165-0378
    ISSN (online) 1872-7603
    ISSN 0165-0378
    DOI 10.1016/j.jri.2023.103976
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  3. Article ; Online: Microenvironment for spermatogenesis and sperm maturation.

    Miyaso, Hidenobu / Ogawa, Yuki / Itoh, Masahiro

    Histochemistry and cell biology

    2022  Volume 157, Issue 3, Page(s) 273–285

    Abstract: The male reproductive system consists of testes, a series of ducts connecting the testes to the external urethral orifice, accessory sex glands, and the penis. Spermatogonial stem cells differentiate and mature in testes and epididymides, and spermatozoa ...

    Abstract The male reproductive system consists of testes, a series of ducts connecting the testes to the external urethral orifice, accessory sex glands, and the penis. Spermatogonial stem cells differentiate and mature in testes and epididymides, and spermatozoa are ejaculated with exocrine fluids secreted by accessory sex glands. Many studies have clarified the detailed structure and function of the male reproductive system, and have shown that various biologic controls, including genomics, epigenetics, and the neuroendocrine-immune system regulate proliferation, differentiation, and maturation of germ cells. In other words (1) genetic deletion or abnormalities, (2) aberration of DNA methylation and histone modifications, as well as small RNA dysfunction, and (3) neuroendocrine-immune disorders are involved in functional failure of the male reproductive system. In this article, we review these three factors for germ cell microcircumstance, especially focused on the immunoendocrine environment. In particular, the relation between factors protecting germ cells with strong auto-immunogenicity and opposite factors compromising this protection are discussed. Reductions in sperm count, concentration, and semen quality are serious problems in developed countries, although the causes are complex and remain unclear. The accumulation of basic knowledge regarding the structure, function, and regulation of the male reproductive system under various experimental conditions will be important to resolve these problems.
    MeSH term(s) Humans ; Male ; Semen Analysis ; Sperm Maturation ; Spermatogenesis/genetics ; Spermatozoa ; Testis
    Language English
    Publishing date 2022-03-05
    Publishing country Germany
    Document type Journal Article ; Review
    ZDB-ID 1222930-1
    ISSN 1432-119X ; 0301-5564 ; 0948-6143
    ISSN (online) 1432-119X
    ISSN 0301-5564 ; 0948-6143
    DOI 10.1007/s00418-021-02071-z
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  4. Article ; Online: Comparative anatomy on the development of sperm transporting pathway between the testis and mesonephros.

    Omotehara, Takuya / Nakata, Hiroki / Nagahori, Kenta / Itoh, Masahiro

    Histochemistry and cell biology

    2022  Volume 157, Issue 3, Page(s) 321–332

    Abstract: The male genital tract is diverse among vertebrates, but its development remains unclear, especially in the rete region. In this study, we investigated the testis-mesonephros complex of rabbit, chicken, and frog (Xenopus tropicalis) by ... ...

    Abstract The male genital tract is diverse among vertebrates, but its development remains unclear, especially in the rete region. In this study, we investigated the testis-mesonephros complex of rabbit, chicken, and frog (Xenopus tropicalis) by immunohistochemistry for markers such as Ad4BP/Sf-1 (gonadal somatic and rete cells in mammals) and Pax2 (mesonephric tubules), and performed a three-dimensional reconstruction. In all investigated animals, testis cords were bundled at the mesonephros side. Rete cells positive for Ad4BP/Sf-1 (rabbit) or Pax2 (chicken and frog) were clustered at the border region between the testis and mesonephros. The cluster possessed two types of cords; one connected to the testis cords and the other to the mesonephric tubules. The latter rete cords were contiguous to Bowman's capsules in rabbit and chicken but to nephrostomes in frog. In conclusion, this study showed that mammals, avian species, and frogs commonly develop the bundle between the testis cords (testis canal) and the cluster of rete cells (lateral kidney canal), indicating that these animals share basic morphogenesis in the male genital tract. The connection site between the rete cells and mesonephric tubules is suggested to have changed from the nephrostome to the Bowman's capsule during vertebrate evolution from anamniote to amniote.
    MeSH term(s) Anatomy, Comparative ; Animals ; Male ; Mammals ; Mesonephros ; Morphogenesis ; Rabbits ; Spermatozoa ; Testis
    Language English
    Publishing date 2022-01-06
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 1222930-1
    ISSN 1432-119X ; 0301-5564 ; 0948-6143
    ISSN (online) 1432-119X
    ISSN 0301-5564 ; 0948-6143
    DOI 10.1007/s00418-021-02057-x
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  5. Article ; Online: Three-dimensional analysis and in vivo imaging for sperm release and transport in the murine seminiferous tubule.

    Kanazawa, Yuta / Omotehara, Takuya / Nakata, Hiroki / Hirashima, Tsuyoshi / Itoh, Masahiro

    Reproduction (Cambridge, England)

    2022  Volume 164, Issue 1, Page(s) 9–18

    Abstract: Spermatozoa released from Sertoli cells must be transported to the epididymis. However, the mechanism of the luminal flow in seminiferous tubules has remained unclear to date. Therefore, in this study, we investigated luminal flow and movements in the ... ...

    Abstract Spermatozoa released from Sertoli cells must be transported to the epididymis. However, the mechanism of the luminal flow in seminiferous tubules has remained unclear to date. Therefore, in this study, we investigated luminal flow and movements in the seminiferous tubules by three-dimensional analysis and in vivo imaging. Serial 5-μm-thick mouse testicular sections at 50-µm-intervals were prepared and stained by Periodic Acid-Schiff-hematoxylin. After three-dimensional reconstruction of the seminiferous tubules, the localization of the released spermatozoa and the stages observed in the sections were recorded in each reconstructed tubule. Luminal movements in the seminiferous tubules were observed by in vivo imaging using a fluorescent-reporter mouse and two-photon excitation microscopy system. Spermatozoa without contact to the seminiferous epithelium were not accumulated toward the rete testis. Additionally, such spermatozoa were found on their way not only to the most proximal rete testis but also a more distant rete testis from any stage VIII seminiferous epithelia. In vivo imaging demonstrated that the direction of the flagella of spermatozoa attached to the seminiferous epithelium was repeatedly reversed. The epithelium at the inner curve of the seminiferous tubule was shaken more actively and had fewer spermatozoa attached compared with the epithelium at the outer curve. Our results hence suggest that the luminal flow in the seminiferous tubules is repeatedly reversed and that this physical force helps spermatozoa to be released from Sertoli cells. In brief: Spermatozoa are released from Sertoli cells and flow in the seminiferous tubule to the rete testis. Our results suggest that the luminal flow in the tubules is repeatedly reversed and that this physical force helps spermatozoa release from the Sertoli cells.
    MeSH term(s) Animals ; Imaging, Three-Dimensional ; Male ; Mice ; Microfluidics/methods ; Microscopy ; Rete Testis/physiology ; Rheology/methods ; Seminiferous Epithelium/diagnostic imaging ; Seminiferous Epithelium/physiology ; Seminiferous Tubules/diagnostic imaging ; Seminiferous Tubules/physiology ; Sertoli Cells/physiology ; Spermatozoa/physiology ; Testis/diagnostic imaging ; Testis/physiology
    Language English
    Publishing date 2022-05-23
    Publishing country England
    Document type Journal Article
    ZDB-ID 2034501-X
    ISSN 1741-7899 ; 1470-1626 ; 1476-3990
    ISSN (online) 1741-7899
    ISSN 1470-1626 ; 1476-3990
    DOI 10.1530/REP-21-0400
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  6. Article ; Online: Histological differences between the central and peripheral areas of the testes of busulfan-administered mice.

    Miyaso, Hidenobu / Yokota, Satoshi / Suga, Kousuke / Hashimoto, Yui / Kouno, Céline / Nagahori, Kenta / Itoh, Masahiro / Kitajima, Satoshi

    The Journal of toxicological sciences

    2024  Volume 49, Issue 4, Page(s) 139–149

    Abstract: Busulfan is an anticancer drug known to cause serious damage to seminiferous tubules in the testes and deplete germ cells in human and animal models. The testicular artery is anastomosed with deferential and cremasteric arteries and is divided into ... ...

    Abstract Busulfan is an anticancer drug known to cause serious damage to seminiferous tubules in the testes and deplete germ cells in human and animal models. The testicular artery is anastomosed with deferential and cremasteric arteries and is divided into capsular arteries, which give rise to the centripetal arteries and then recurrent arteries. The arterial blood in the testicular tissue is supplied by such a consequent system of arterial vessels, in order from the peripheral to the central area. As anticancer drugs are generally distributed throughout the whole body via the bloodstream and the running and distribution of arteries differ among the testicular areas, we hypothesized that the efficacy of busulfan differs in different testicular areas, particularly between the central and peripheral areas. In this study, busulfan was intraperitoneally injected at 40 mg/kg body weight into C57BL/6J male mice. After 28 days, in busulfan-treated mice, the diameters of seminiferous tubules were significantly higher in the central than in the peripheral area of the testes. The seminiferous tubular areas also significantly decreased in the peripheral areas compared with the central areas. The number of germ cells per seminiferous tubule was significantly higher in the central than in the peripheral area. Sertoli cell nuclei were detached into the lumen in the peripheral area. The number of Leydig cells was significantly lower in the peripheral areas. These data suggest that the effects of busulfan differ between the central and peripheral areas of the testis at 4 weeks after busulfan administration.
    MeSH term(s) Male ; Animals ; Humans ; Mice ; Testis ; Busulfan/toxicity ; Spermatogenesis ; Mice, Inbred C57BL ; Seminiferous Tubules
    Chemical Substances Busulfan (G1LN9045DK)
    Language English
    Publishing date 2024-04-01
    Publishing country Japan
    Document type Journal Article
    ZDB-ID 770623-6
    ISSN 1880-3989 ; 0388-1350
    ISSN (online) 1880-3989
    ISSN 0388-1350
    DOI 10.2131/jts.49.139
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  7. Article ; Online: Three-dimensional analysis of mesonephric tubules remodeling into efferent tubules in the male mouse embryo.

    Omotehara, Takuya / Nakata, Hiroki / Itoh, Masahiro

    Developmental dynamics : an official publication of the American Association of Anatomists

    2021  Volume 251, Issue 3, Page(s) 513–524

    Abstract: Background: Spermatozoa are transported to the epididymal duct through efferent tubules. Although the origin of the efferent tubules is thought to be mesonephric tubules (MTs), their detailed developmental process, for example, where the rete testis and ...

    Abstract Background: Spermatozoa are transported to the epididymal duct through efferent tubules. Although the origin of the efferent tubules is thought to be mesonephric tubules (MTs), their detailed developmental process, for example, where the rete testis and efferent tubules are connected, is unclear. We investigated the structural changes of the MTs in the male mouse embryo using a three-dimensional reconstruction method.
    Results: Three to six MTs were connected to the Wolffian duct, and some of them branched, resulting in five to nine tips. Rete cells contacted the three to six tips. The MTs showed a folded shape when the gonadal fate was determined. After the testis development started, they became short and straight but emerged as long and twisting by birth. Before birth, the efferent duct was composed of MTs and a cranial portion of the folded Wolffian duct.
    Conclusions: The contact between the rete testis and efferent tubules is possibly established at the tip of each MT. The MTs regress after gonadal fate is determined but is remodeled to the twisting efferent tubules by birth. The efferent tubules are composed of the MTs but also a cranial portion of the folded Wolffian duct in the mouse.
    MeSH term(s) Animals ; Embryo, Mammalian ; Epididymis ; Male ; Mice ; Rete Testis ; Sex Differentiation ; Spermatozoa ; Testis
    Language English
    Publishing date 2021-08-16
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1102541-4
    ISSN 1097-0177 ; 1058-8388
    ISSN (online) 1097-0177
    ISSN 1058-8388
    DOI 10.1002/dvdy.410
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  8. Article: A Single Administration of Progesterone during the Neonatal Period Shows No Structural Changes in Male Reproductive Tracts in Mice.

    Omotehara, Takuya / Nakata, Hiroki / Nagahori, Kenta / Kuramasu, Miyuki / Ichimura, Koichiro / Itoh, Masahiro

    Acta histochemica et cytochemica

    2023  Volume 56, Issue 6, Page(s) 127–136

    Abstract: The concentration of female-dominant steroid hormones, such as progesterone and estrogen, drops after birth in neonates. We have reported that neonatal estrogen treatment results in inflammation in the epididymis after puberty in male mice. Our recent ... ...

    Abstract The concentration of female-dominant steroid hormones, such as progesterone and estrogen, drops after birth in neonates. We have reported that neonatal estrogen treatment results in inflammation in the epididymis after puberty in male mice. Our recent study discovered that progesterone receptor was specifically expressed in efferent ducts just before birth in male mice. Therefore, this study aimed to reveal the impact of neonatal progesterone administration on the efferent ducts after puberty. Progesterone was subcutaneously administered to neonatal mice on their birthday in three groups: high-dose (200 mg/kg), low-dose (8 mg/kg), and control (cottonseed oil). Their testis and epididymis were collected at 12 weeks old. Semi-serial paraffin sections of these tissues were prepared and evaluated through PAS-hematoxylin staining. Efferent ducts were reconstructed into a three-dimensional structure, and their length and volume were analyzed. Spermatogenesis in the testis and epithelium of the tracts appeared normal, even in individuals administered with progesterone. There were no significant differences in the length and volume of the efferent ducts among the three groups. This study suggests that progesterone treatment in neonatal mice does not cause any structural changes in the male reproductive tracts at puberty, unlike the neonatal estrogen treatment.
    Language English
    Publishing date 2023-12-23
    Publishing country Japan
    Document type Journal Article
    ZDB-ID 280005-6
    ISSN 1347-5800 ; 0044-5991
    ISSN (online) 1347-5800
    ISSN 0044-5991
    DOI 10.1267/ahc.23-00052
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  9. Article: Distribution of Contractile Structures in a Mouse and Human Lymph Node Associated with Lymph Flow.

    Ishi, Yasuhisa / Omotehara, Takuya / Wu, Xi / Kuramasu, Miyuki / Kawata, Shinichi / Itoh, Masahiro

    Acta histochemica et cytochemica

    2023  Volume 56, Issue 6, Page(s) 137–144

    Abstract: Lymph nodes have contractile structures, but their distribution in a lymph node has been less considered in terms of facilitation of lymph flow. Axillary, inguinal, and mesenteric lymph nodes were collected from mice and human cadavers, and their ... ...

    Abstract Lymph nodes have contractile structures, but their distribution in a lymph node has been less considered in terms of facilitation of lymph flow. Axillary, inguinal, and mesenteric lymph nodes were collected from mice and human cadavers, and their sections were immunostained for alpha-smooth muscle actin (αSMA) and high molecular weight caldesmon (H-caldesmon). The αSMA-positive cells were localized in the capsule beneath the ceiling epithelium on the afferent side in both mice and humans. We found an additional layer of the αSMA-positive cells in the human lymph node, surrounding the inner layer perpendicularly. H-caldesmon was expressed only in these cells of the outer layer. In some human lymph nodes highly containing fat tissue in the medulla, the capsule disappeared on the efferent side, resulting in a disrupted sinusoidal lymph pathway. These findings suggest that human lymph nodes have additional smooth muscles in the outer region of the capsule to facilitate lymph flow. The αSMA-positive cells in the outer and inner layers of human lymph nodes probably have different functions in contraction. The presence of lipomatosis in a human lymph node will reduce its contribution to the lymph flow.
    Language English
    Publishing date 2023-12-23
    Publishing country Japan
    Document type Journal Article
    ZDB-ID 280005-6
    ISSN 1347-5800 ; 0044-5991
    ISSN (online) 1347-5800
    ISSN 0044-5991
    DOI 10.1267/ahc.23-00054
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  10. Article ; Online: Two Types of Variational Arteries' Courses From the Superior Mesenteric Artery to Supply the Splenic Flexure: Gross Anatomical Study.

    Okazaki, Tomokazu / Omotehara, Takuya / Kawata, Shinichi / Amano, Takahiro / Enomoto, Masanobu / Nagakawa, Yuichi / Itoh, Masahiro

    Diseases of the colon and rectum

    2023  Volume 67, Issue 1, Page(s) 120–128

    Abstract: Background: Complete mesocolic excision with central vascular ligation is a standard method for managing colon cancer. However, there is no consensus on its procedure, especially for cancer in the splenic flexure of the transverse colon. This is because ...

    Abstract Background: Complete mesocolic excision with central vascular ligation is a standard method for managing colon cancer. However, there is no consensus on its procedure, especially for cancer in the splenic flexure of the transverse colon. This is because various types of variational arteries are distributed to the region, and their running course below and near the pancreas leads to difficulty in ligating the artery.
    Objective: To clarify the arterial distribution to the splenic flexure of the transverse colon using cadavers.
    Design: The arteries in the transverse mesocolon distributed to the colon were dissected in cadavers, and their route was quantitatively visualized using drawing software.
    Settings: This study was conducted at the Department of Anatomy, Tokyo Medical University.
    Patients: Sixty cadavers donated to Tokyo Medical University in 2017-2021 were used.
    Main outcome measures: The arterial courses to the splenic flexure of the transverse colon in the mesocolon and their patterns were evaluated.
    Results: We found 34 variational arteries distributed to the splenic flexure of the transverse colon. Most originated from the superior mesenteric artery and the middle colic artery, with their typical course below the pancreas. We identified another arterial course, crossing the mesocolon away from the pancreas toward the splenic flexure of the transverse colon. Furthermore, the origin of these arteries was not behind the pancreas and can be found in the caudal region of the pancreas.
    Limitations: We cannot discuss how the arteries within the transverse mesocolon are observed by CT examination.
    Conclusions: This study showed 2 types of arterial courses (below the pancreas and within the mesocolon) toward the splenic flexure of the transverse colon for the first time. In the latter case, the complete mesocolic excision with central vascular ligation is likely performed more easily than in the former. See Video Abstract.
    Dos tipos de recorrido variacional de la arteria desde la arteria mesentrica superior para irrigar el ngulo esplnico estudio anatmico macroscpico: ANTECEDENTES:La escisión mesocólica completa con ligadura vascular central es un método estándar para el cáncer de colon. Sin embargo, no hay consenso sobre su procedimiento, especialmente para el cáncer en el ángulo esplénico del colon transverso. Esto se debe a que varios tipos de arterias variacionales se distribuyen en la región, y su recorrido por debajo y cerca del páncreas dificulta la ligadura de la arteria.OBJETIVO:Este estudio tuvo como objetivo aclarar la distribución arterial al SF del colon transverso utilizando cadáveres.DISEÑO:Las arterias en el mesocolon transverso distribuidas al colon fueron disecadas en cadáveres, y su ruta fue visualizada cuantitativamente utilizando un software de dibujo.AJUSTES:Este estudio se realizó en el Departamento de Anatomía de la Universidad Médica de Tokio.PACIENTES:Se utilizaron sesenta cadáveres donados a la Universidad Médica de Tokio en 2017-2021.PRINCIPALES MEDIDAS DE RESULTADO:Se evaluaron los cursos arteriales al ángulo esplénico del colon transverso en el mesocolon y sus patrones.RESULTADOS:Encontramos 34 arterias variacionales distribuidas al ángulo esplénico del colon transverso. La mayoría se originaron en la arteria mesentérica superior y la arteria cólica media, con su trayecto típico por debajo del páncreas. Identificamos otro curso arterial, cruzando el mesocolon alejándose del páncreas hacia el ángulo esplénico del colon transverso. Además, el origen de estas arterias no estaba detrás del páncreas y se pueden encontrar en la región caudal del páncreas.LIMITACIONES:No podemos discutir cómo se observan las arterias dentro del mesocolon transverso mediante un examen de tomografía computarizada.CONCLUSIONES:Este estudio mostró por primera vez dos tipos de trayectos arteriales (por debajo del páncreas y dentro del mesocolon) hacia el ángulo esplénico del colon transverso. En el último caso, es probable que la escisión mesocólica completa con ligadura vascular central se realice más fácilmente que en el primero. (Traducción-Dr. Aurian Garcia Gonzalez ).
    MeSH term(s) Humans ; Colon, Transverse/surgery ; Mesenteric Artery, Superior ; Colonic Neoplasms/surgery ; Cadaver ; Retrospective Studies
    Language English
    Publishing date 2023-07-26
    Publishing country United States
    Document type Video-Audio Media ; Journal Article
    ZDB-ID 212581-x
    ISSN 1530-0358 ; 0012-3706
    ISSN (online) 1530-0358
    ISSN 0012-3706
    DOI 10.1097/DCR.0000000000002967
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

To top