Results 171 to 180 of about 17,684 (208)

Regulation of the density of spermatogonia in the seminiferous epithelium of the Chinese hamster: II. Differentiating spermatogonia

The Anatomical Record, 1987
AbstractIn this study the yield of the proliferation of the differentiating spermatogonia into spermatocytes was determined in five Chinese hamsters. Large differences of up to a factor 2 were found between the numbers of A1 spermatogonia in the various animals.
de rooij, D. G., Lok, D.
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Renewal of spermatogonia in man

American Journal of Anatomy, 1966
AbstractThe spermatogonia of normal adult human testis were investigated in view of clarifying their mode of proliferation and renewal. Three main types of spermatogonia were identified: the dark type A spermatogonia (Ad) tentatively considered as the stem cells, the pale type A spermatogonia (Ap) and the type B spermatogonia (B), these being the more ...
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Development of a Cryopreservation Protocol for Type A Spermatogonia

Journal of Andrology, 2002
ABSTRACTThe aim of this study was to develop a cryopreservation protocol for type A spermatogonia. Testes from 5‐ to 7‐month‐old calves were collected, and type A spermatogonia were isolated using two‐step enzymatic digestion and Percoll separation. Cells were resuspended in minimum essential medium (MEM) supplemented with 1% bovine serum albumin (BSA)
Izadyar, F., Matthijs Rijsenbilt, J.J., den Ouden, K., Creemers, L.B., Woelders, H., de Rooij, D.G.   +5 more
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Regulation of the Differentiation of the Undifferentiated Spermatogonia

2000
In the seminiferous epithelium of adult nonprimate mammals, so-called A-single (As) spermatogonia are the stem cells of spermatogenesis (1–3). Upon division of the As spermatogonia, the daughter cells either migrate away from each other and become two new stem cells, or the cells stay together becoming A-paired (Apr) spermatogonia connected by an ...
de Rooij, D.G., Schrans-Stassen, B.H.G.J., van Pelt, A.M.M., Shuttlesworth, G.A., Meistrich, M.L., Okabe, M., Nishimune, Y.   +6 more
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Absence of spermatogonia in the Prader-Willi syndrome

European Journal of Pediatrics, 1977
Bilateral testicular biopsies in an 81/2 year old boy with the Prader-Willi syndrome showed total absence of spermatogonia. Similar findings in postpubertal cases (Wannarachue et al., 1975) suggest that testicular dysplasia is one of the reasons for hypogonadism in males with the Prader-Willi syndrome.
M L, Katcher, G J, Bargman, E F, Gilbert, J M, Opitz   +3 more
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Action of mitomycin C on mouse spermatogonia

Mutation Research, 1973
Abstract The induction of chromosome aberrations in mouse spermatogonia and bone marrow cells by treatment with Mitomycin (MC) was tested. The following dosages were used: 3.5; 1.75; 0.35; and 0.035 mg/kg body weight. Chromatid interchanges and terminal deletions were induced in both tissues.
A, Manyak, E, Schleiermacher
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Morphology of the reproductive system of the armadillo. The spermatogonia

Journal of Morphology, 1973
AbstractSpermatogonia of the nine‐banded armadillo, Dasypus novemcinctus mexicanus, were studied morphologically using light and electron microscopy and examined histochemically using light microscopy. Immature flat type spermatogonia have ovoid or irregular nuclei with loosely condensed chromatin.
F, Nagy, R H, Edmonds
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Mutagenesis in murine spermatogonia by mopp therapy

Reproductive Toxicology, 1987
Male mice were given mechlorethamine (2.0 mg/kg) followed immediately or 1, 2, 4, or 8 h later by procarbazine (100 mg/kg) and vincristine (0.67 mg/kg) in a protocol that stimulated the drugs and dosages used in a single cycle of clinical MOPP therapy.
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In Vitro Differentiation of Spermatogonia

2017
Presence of functional spermatogonial population secures continuing spermatogenesis, by repeated commencement of spermatogenic cycles from them. In vitro manipulation of spermatogonia, thus, can be divided into two aspects: proliferation of spermatogonia for their maintenance and initiation of their differentiation toward sperm formation.
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Cytogenetic effects of cyclophosphamide on mouse spermatogonia

Human Genetics, 1975
NMRI mice were treated with single doses of cyclophosphamide (Cytoxan) and spermatogonia were analysed for chromosome aberrations at various time intervals after treatment. The maxima of aberrations were found 24 hrs p.i. Chromatid type aberrations were observed exclusively.
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