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Your search keyword '"Fibrous sheath"' showing total 7 results
Start Over Descriptor "Fibrous sheath" Publisher elsevier
7 results on '"Fibrous sheath"'

1. IRGC1, a testis-enriched immunity related GTPase, is important for fibrous sheath integrity and sperm motility in mice.

Author

Kaneda Y, Miyata H, Shimada K, Oyama Y, Iida-Norita R, and Ikawa M

Subjects
Animals, Male, Mice, GTP Phosphohydrolases metabolism, Interferons metabolism, Mammals, Mice, Knockout, Proteins metabolism, Sperm Tail metabolism, Spermatozoa metabolism, Sperm Motility, Testis metabolism
Abstract

Immunity-related GTPases (IRGs), also known as p47 GTPases, are a family of interferon-inducible proteins that play roles in immunity defense against intracellular pathogens. Although the molecular functions of IRGs have been well studied, the function of the family member, IRGC1, remains unclear. IRGC1 is unique among IRGs because its expression is not induced by interferon and it is expressed predominantly in the testis. Further, IRGC1 is well conserved in mammals unlike other IRGs. Here, we knocked out (KO) Irgc1 in mice using the CRISPR/Cas9 system and found that the fertility of Irgc1 KO males was severely impaired because of abnormal sperm motility. Further analyses with a transmission electron microscope revealed that the fibrous sheath (FS), an accessory structure of the sperm tail, was disorganized in Irgc1 KO mice. In addition, IRGC1 was detected in the sperm tail and fractionated with FS proteins. These results suggest that IRGC1 is a component of the FS and is involved in the correct formation of the FS., Competing Interests: Declaration of competing interest The authors declare no competing financial interests., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Published
2022
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2. The details of an unusual 'ghost' after transvenous lead extraction: Three-dimensional computed tomography analysis

Author

Kunihiko Kiuchi, Tatsuya Nishii, Shumpei Mori, Koji Fukuzawa, Hirotoshi Ichibori, Kensuke Matsumoto, and Takashi Yamada

Subjects
lcsh:Diseases of the circulatory (Cardiovascular) system, medicine.diagnostic_test, business.industry, Transvenous lead extraction, Computed tomography, Case Report, 030204 cardiovascular system & hematology, behavioral disciplines and activities, Intracardiac injection, Transvenous lead, 03 medical and health sciences, 0302 clinical medicine, nervous system, Fibrous sheath, lcsh:RC666-701, Cardiac rhythm device, medicine, In patient, Device infection, 030212 general & internal medicine, Cardiology and Cardiovascular Medicine, Nuclear medicine, business
Abstract

Transvenous lead extraction (TLE) is performed to prevent deaths in patients with device infections. Intracardiac masses detected by echocardiography, i.e., âghosts,â are reported in 8% of patients after a TLE in retrospective studies and in 14% in prospective studies. We herein describe a case with unusual ghosts after a TLE. Three-dimensional computed tomography (3DCT) is useful for revealing all the details of unusual ghosts. In this case, the residual silicone insulation and âcast,â including the fibrous sheath and severe calcifications could be visualized and differentiated by 3DCT. Keywords: Transvenous lead extraction, Cardiac rhythm device, Device infection, Computed tomography

Published
2017

3. Proteomics and single-cell RNA analysis of Akap4-knockout mice model confirm indispensable role of Akap4 in spermatogenesis.

Author

Fang X, Huang LL, Xu J, Ma CQ, Chen ZH, Zhang Z, Liao CH, Zheng SX, Huang P, Xu WM, Li N, and Sun L

Subjects
A Kinase Anchor Proteins genetics, Animals, Female, Infertility, Male genetics, Infertility, Male metabolism, Intracellular Signaling Peptides and Proteins genetics, Intracellular Signaling Peptides and Proteins metabolism, Male, Mice, Mice, Inbred C57BL, Mice, Knockout, Protein Serine-Threonine Kinases genetics, Protein Serine-Threonine Kinases metabolism, Proteomics methods, RNA metabolism, Sequence Analysis, RNA methods, Single-Cell Analysis methods, Sperm Motility genetics, Sperm Motility physiology, Sperm Tail metabolism, Spermatogenesis physiology, Spermatozoa metabolism, Testis metabolism, A Kinase Anchor Proteins metabolism, Spermatogenesis genetics
Abstract

Sperm fibrous sheath, a unique cytoskeletal structure, is implicated in various sperm physiological functions, such as sperm maturation, motility and capacitation. AKAP4 has been described to be required for structural and functional integrity of the fibrous sheath. We generated Akap4-knockout mice line using CRISPR-Cas9 system. Cytomorphology and motility of sperm and testes were studied, confirming loss of Akap4 led to abnormal sperm morphology, motility and infertility. The proteomic components of testes were studied and Akap4 was found to be significantly decreased in the Akap4-knockout mice. Testis single-cell RNA sequencing and analysis revealed three genes with significant change in the general cell population, i.e., Akap4, Haspin, and Ccdc38. The single-cell RNA expression profiles also showed that the major difference between Akap4-knockout and wild-type testes existed in the elongating cell cluster, where in the Akap4-knockout testes, a subgroup of elongating cells with marker genes involved in cell adhesion and migration were increased, while a subgroup of elongating cells marked by mitochondrial sheath genes were decreased. Our results revealed the complex and well-coordinated procedures of spermatogenesis, and substantiated Akap4's indispensable roles in the integrity of sperm flagellum and the step-wise maturation of spermatozoa., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Published
2019
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4. Human spermatid-specific thioredoxin-1 (Sptrx-1) is a two-domain protein with oxidizing activity

Author

Jiménez, Alberto, Johansson, Catrine, Ljung, Johanna, Sagemark, Johan, Berndt, Kurt D., Ren, Bin, Tibbelin, Gudrun, Ladenstein, Rudolf, Kieselbach, Thomas, Holmgren, Arne, Gustafsson, Jan-Åke, Miranda-Vizuete, Antonio, Jiménez, Alberto, Johansson, Catrine, Ljung, Johanna, Sagemark, Johan, Berndt, Kurt D., Ren, Bin, Tibbelin, Gudrun, Ladenstein, Rudolf, Kieselbach, Thomas, Holmgren, Arne, Gustafsson, Jan-Åke, and Miranda-Vizuete, Antonio

Abstract

Spermatid-specific thioredoxin-1 (Sptrx-1) is the first member of the thioredoxin family of proteins with a tissue-specific expression pattern, found exclusively in the tail of elongating spermatids and spermatozoa. We describe here further biochemical characterization of human Sptrx-1 protein structure and enzymatic activity. In gel filtration chromatography human Sptrx-1 eluates as a 400 kDa protein consistent with either an oligomeric form, not maintained by intermolecular disulfide bonding, and/or a highly asymmetrical structure. Analysis of circular dichroism spectra of fragments 1–360 and 361–469 and comparison to spectra of full-length Sptrx-1 supports a two-domain organization with a largely unstructured N-terminal domain and a folded thioredoxin-like C-terminal domain. Functionally, Sptrx-1 behaves as an oxidant in vitro when using selenite, but not oxidized glutathione, as electron acceptor. This oxidizing enzymatic activity suggests that Sptrx-1 might govern the stabilization (by disulfide cross-linking) of the different structures in the developing tail of spermatids and spermatozoa.

Published
2002

5. THE VASCULATURE OF THE FEMORAL HEAD

Author

Joseph Trueta

Subjects
medicine.medical_specialty, business.industry, Anatomy, Metaphysis, Anastomosis, Short distance, Femoral head, medicine.anatomical_structure, Epiphysis, Fibrous sheath, Medicine, Head (vessel), Radiology, business
Abstract

This chapter focuses on the vasculature of the femoral head. The extra-articular course and anatomical variations of the arteries supplying the femoral head have been repeatedly studied. The lateral epiphyseal arteries (LEA) enter the head superiorly and postero-superiorly, usually two to six in number and often spiral in form for a short distance after their entry; in this position, they always lie within a thick fibrous sheath. There are usually two, three, or four superior metaphyseal arteries arising from the vessels, which soon give rise to the lateral epiphyseal group. There is a free anastomosis inside both the epiphysis and the metaphysis between the vessels that supply each territory; in addition, there is anastomosis between the vessels of the two territories at the site previously occupied by the growth plate.

Published
1968
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6. THE MECHANICAL CHARACTERISTICS OF COSTAL CARTILAGE

Author

M. Abrahams and T.C. Duggan

Subjects
medicine.anatomical_structure, Materials science, Hyaline cartilage, Fibrous sheath, Residual stress, Cartilage, medicine, Perichondrium, Anatomy, Costal cartilage, Standard technique, Hyaline
Abstract

Publisher Summary This chapter discusses the nonmechanical characteristics of costal cartilage. Cartilage homografts are widely used for the correction of nasal and skeletal defects. This material is both easily shaped and capable of withstanding the normal stresses to which the nose will later be exposed. The costal cartilages extend forward from the anterior rib endings and are of the hyaline variety. The material consists of a relatively nonvascular tissue in which aggregates of cells are embedded in a viscid gel and throughout which strands of a fibrous protein are dispensed. Around this tissue is a fibrous sheath, the perichondrium. All hyaline cartilage tends to ossify as the age of the subject increases. The standard technique for evaluating self-locked or residual stress systems is to remove successive layers of the self-stressed material, the slices being cut in a direction parallel to the known or assumed direction of stress to be investigated. The form and distribution of the system of self-locked stresses present in intact costal cartilage has been identified and measured.

Published
1965
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