bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clusterin (SGP‐2) in epididymal luminal fluid and its association with epididymal spermatozoa in androgen‐deprived rats
Authors: Mattmueller Danette R. , Hinton Barry T. 
Published: February 2005

AbstractClusterin is a heterodimeric glycoprotein synthesized and secreted by rat Sertoli cells and epididymal epithelium. The goal of this study was to determine the presence of clusterin in the luminal fluid of the cauda epididymides and its association with the membranes of developing spermatozoa in the presence and absence of androgen. We have previously demonstrated by two‐dimensional (2‐D) Western blot probing for clusterin that in epididymal fluid the amounts of clusterin were: caput < corpus < cauda. Luminal fluid from cauda epididymides was collected from control and orchiectomized rats (6 and 12 days) and orchiectomized animals that received testosterone implants. Equal volumes of fluid were analyzed by 2‐D Western blot probing for clusterin. Following orchiectomy, there was an increase in clusterin in the luminal fluid after 6 days and maximal amount after 12 days compared with control cauda fluid. Orchiectomized animals which received testosterone treatment showed levels of clusterin comparable to that of controls. Serum clusterin was detected in fluid of orchiectomized animals with and without testosterone. Western blots of cauda sperm membrane extracts of control animals and orchiectomized animals treated with testosterone had a very low level of epididymal clusterin, whereas extracts collected from orchiectomized animals revealed high levels of clusterin. We suggest that, in the normal animal, clusterin is secreted into the lumen of the proximal epididymis where it binds to the sperm membrane. In the distal epididymis, clusterin dissociates from sperm and is processed (proteolysis/endocytosis). We hypothesize that, in the absence of androgen, the processing and regulation of clusterin is disrupted. © 1992 Wiley‐Liss, Inc.
Tight junctions and cavitation in the human pre‐embryo
Authors: Gualtieri Roberto , Santella Luigia , Dale Brian 
Published: February 2005

AbstractIn the human morula, tight junctions are found between all cell pairs, at all levels of cellular apposition, associated with underlying masses of microfilaments. In cavitating morula, lanthanum tracer gained access to the intercellular spaces, except at the intersections with nascent extracellular cavities, marking the first assembly of zonulae occludentes. Presumptive trophectoderm cells contained vacuoles and larger cavities often associated with secondary lysosome‐like bodies. Since the vacuoles and intracellular and extracellular cavities contain electron‐dense polygranules of about 23 nm diameter, they may have common origins. In trophectoderm cells of the early blastocyst, the large intracellular vacuoles and cavities were absent, and the zonulae occludentes were located apically. Mechanisms for nascent blastocoele formation are discussed. © 1992 Wiley‐Liss, Inc.
Modulation of vascular cell behavior by transforming growth factors β
Authors: Madri Joseph A. , Bell Leonard , Merwin June Rae 
Published: February 2005

AbstractThe vascular cell responses to the type 1, 2, and 3 isoforms of transforming growth factor‐β (TGF‐β1, TGF‐β2, TGF‐β3) were studied using bovine aortic endothelial (BAECs) and smooth muscle cells (BASMC3) as well as rat epididymal fat pad microvascular endothelia (RFCs). Three distinct bioassays indicated that TGF‐β3 elicits results that do not differ significantly from those of the TGF‐β1 isoform in all three cell populations. These assays are: inhibition of proliferation, cell migration, and neovascularization. By contrast the cellular responses to TGF‐β1 and TGF‐β3 differed from those to TGF‐β2. Three distinct receptor assays revealed the preesnce of type I and type II TGF‐β1 cell surface binding proteins on BAECs, BASMCs, and RFCs. Experimentation to decipher cell surface binding by the different isoforms revealed that iodinated TGF‐β1 bound to the surface of all three vascular cell types can be competed off in similar fashion by either TGF‐β1 or TGF‐β3; however, competition with TGF‐β2 produced unique binding profiles dependent on the cell type examined. The ratios of type I to type II TGF‐β receptors in these three vascular cell types vary from 1:1 in BAECs to 1.5:1 in RFCs to 3:1 in BASMCs and can be correlated with the differences noted in cellular responses to TGF‐β1 and TGF‐β2 in proliferation, migration, and in vitro angiogenic assays.In summary, both the TGF‐β1 and TGF‐β3 isoforms of the transforming growth factor‐β family evoke comparable responses in proliferation, migration, angiogenic and cell surface bindinga ssays using three distinct vascular cell types, while the biofunctions of TGF‐β2 on these cells are distinct. These findings support the hypothesis that there are different responses to the TGF‐βs depending on the cell type and experimental conditions as well as the TGF‐β concentration and isoform. © 1992 Wiley‐Liss, Inc.
Müllerian inhibiting substance in reproduction and cancer
Authors: Donahoe Patricia K. 
Published: February 2005

AbstractDuring embryogenesis normal male phenotypic development requires the action of Müllerian Inhibiting Substance (MIS) which is secreted by Sertoli cells of the fetal testis. As testes differentiate in genetic (XY) males, they produce MIS which causes regression of the Müllerian ducts, the anlagen of the female reproductive tract. Soon thereafter, testicular androgens stimulate the Wolffian ducts. In females, on the other hand, MIS is not produced by grandulosa cells until after birth, before which, estrogens induce Müllerian duct development, while the Wolffian ducts passively atrophy in the absence of androgenic stimulation. High serum MIS levels in males are maintained until puberty, whereupon they fall to baseline levels. In females MIS is undetectable in serum until the peripubertal period when values approach the baseline levels of males. This distinct pattern of sexual and ontogenic expression presupposes and requires tight regulation.MIS may play a role in gonadal function and development. Our laboratory has shown that an important role for ovarian MIS is to inhibit oocyte meiosis, perhaps providing maximal oocyte maturation prior to selection for ovulation and subsequent fertilization. Furthermore, Vigier et al. (Development 100:43–55) have recently obtained evidence that MIS may influence testicular differentiation, coincident with inhibition of aromatase activity. Current structure‐function studies demonstrate that MIS, like other growth regulators in its protein family, requires proteolytic cleavage to exhibit full biological activity. MIS can be inhibited by epidermal growth factor. This antagonism, which is common to all MIS functions so far investigated, is associated with inhibition of EGF receptor autophosphorylation. We have provided evidence that bovine MIS can inhibit female reproductive tract tumors arising in adults. More recent work with highly purified recombinant human MIS (rhMIS) has extended these early observations, showing that this recombinantly made fetal inhibitor can also suppress tumors of Müllerian duct origin and thus may prove to be useful in the clinical management of gynecologic neoplasms. Recent investigations have identified ocular melanoma as another potential target for rhMIS therapy in humans. © 1992 Wiley‐Liss, Inc.
TGF‐β regulation of epithelial cell proliferation
Authors: Moses Harold L. 
Published: February 2005

AbstractThe predominant effect of TGF‐β1 on cell proliferation is inhibition. Earlier studies demonstrated that TGF‐β1 inhibition of skin keratinocyte proliferation involves suppression of c‐myc transcription and indirect evidence suggested that the protein product of the retinoblastoma gene (pRB) may be involved in this process. Skin keratinocytes transformed by SV40 and human papilloma virus‐16 (HPV‐16) or HPV‐18 resisted growth inhibition and suppression of c‐myc mRNA by TGF‐β. Transient expression of HPV‐16 E7 gene, adenovirus E1A, and SV40 large T antigen (TAg) blocked the TGF‐β1 suppression of c‐myc transcription. Studies with transformation‐defective mutants of E1A and TAg suggested that a cellular protein(s) that interacts with a conserved domain of the DNA tumor virus oncoproteins mediates TGF‐β1 suppression of c‐myc transcription and keratinocyte growth. Transient expression of pRB in skin keratinocytes repressed human c‐myc promoter/CAT transcription as effectively as TGF‐β1. The same c‐myc promoter region, termed the TGF‐β Control Element (TCE), was required for regulation by both TGF‐β1 and pRB. TCE bound a cellular protein of approximately 106 kDa and this binding was decreased by TGF‐β1 treatment. Our data indicate that pRB can inhibit c‐myc transcription and suggest the involvement of cellular factor(s) in addition to pRB in the TGF‐β1 pathway for the suppression of c‐myc transcription and growth inhibition. The possible involvement of pRB in the TGF‐β1 pathway for suppression of c‐myc transcription has a number of implications; c‐myc is a cellular proto‐oncogene involved in positively regulating cell proliferation. TGF‐β1 may therefore act through the tumor suppressor gene product, pRB, to negatively regulate c‐myc transcription and subsequently cell growth. This would implicate tumor suppressor genes in the response pathway for diffusible growth inhibitors, perhaps analogous to nuclear proto‐oncogene involvement in the growth factor pathway. © 1992 Wiley‐Liss, Inc.
Construction of the nuclear matrix at the transition from maternal to zygotic control of development in the mouse: An immunocytochemical study
Authors: Prather R. S. , Schatten G. 
Published: February 2005

AbstractThe nuclear matrix is thought to be responsible for DNA organization, DNA replication, RNA synthesis, and RNA processing. We have looked for the presence of nuclear matrix antigens during early mouse embryogenesis. Antibodies to peripheral and interior antigens (P1, PI1, PI2, and lamin B) were used to immunolocalize nuclear matrix antigens in germinal vesicle oocytes, metaphase II oocytes, zygotes, two‐cell‐stage embryos, and eight‐cell stage embryos. All antibodies reacted with the nuclei of germinal vesicle oocytes, and two‐ and eight‐cell‐stage embryos; however, only P1 and lamin B were present at the pronuclear stage. In eggs collected at the pronuclear stage and cultured to the late two‐cell stage in the presence of α‐amanitin, the matrix morphology was altered for PI1 and PI2. α‐Amanitin had no affect on the distribution of P1 or lamin B antigens. If α‐amanitin was added 2 hr after cleavage to the two‐cell stage, the normal staining pattern of PI2 was retained. These results suggest that the presence of specific components of an internal matrix is correlated with normal genomic activity.
Multiple sites of HOX‐7 expression during mouse embryogenesis: Comparison with retinoic acid receptor mRNA localization
Authors: Lyons Gary E. , Houzelstein Denis , Sassoon David , Robert Benoîct , Buckingham Margaret E. 
Published: February 2005

AbstractWe report results from a study of Hox‐7 expression during mouse embryonic and fetal development and compare the localization of Hox‐7 transcripts with those of the retinoic acid receptors. Transcripts were detected by in situ hybridization. Hox‐7 expression occurs in (1) cephalic neural crest and its derivatives, (2) sites of ectomesodermal interaction, (3) extraembryonic tissues, and (4) endocardial cells. Hox‐7 does not seem to be involved in defining rostrocaudal boundaries, but instead appears to be expressed along the proximodistal axes at these sites. We further investigated the active sites of morphogenesis, which involve an ectomesodermal interaction (e.g., limb buds, visceral arches), including genital tubercle and tail ridge. These are regions highly positive for Hox‐7 transcripts, and many are known to be sites for the expression of γ‐retinoic acid receptors (RARs) and cellular retinoic acid binding proteins. Most regions that express Hox‐7 are subregions of γ‐RAR expression. In the developing limb bud, expression of Hox‐7 takes place in the interdigital region, where it overlaps areas of β‐RAR expression.
Regulated temporal and spatial expression of the calcium‐binding proteins calcyclin and opn (osteopontin) in mouse tissues during pregnancy
Authors: Waterhouse Paul , Parhar Ranjit S. , Guo Xiaojia , Lala Peeyush K. , Denhardt David T. 
Published: February 2005

AbstractIn situ hybridization and northern/slot blot analyses were used to quantify the expression of calcyclin (2A9, 5B10), osteopontin (opn, secreted phosphoprotein, 2ar) and calmodulin mRNAs in mouse tissues that support pregnancy. High‐to‐moderate levels of the mRNAs of all three genes were detected at discrete locations in the uterus, decidua and placenta as a function of gestation time. Calmodulin expression was constant in these tissues; calcyclin mRNA was high during early pregnancy and declined after day 8–9 of gestation; and opn mRNA was undetectable before day 7, with maximal levels on days 9–12 in each of these tissues. Calcyclin, but not opn, expression was also observed in the chorioamnion after day 12. Calcyclin was expressed throughout the decidua on day 8 but became restricted to the primary (antimesometrial) decidual zone and decidua lateralis on day 9, and the decidua capsularis after day 9. By contrast, opn mRNA was localized on day 9 to the mesometrial triangle, which contains a large population of granulated metrial gland cells, and to the decidua basalis. These two genes may serve as markers for the two types of decidual tissue. We suggest that one function of OPN, which may be an indicator of cells in the decidua that have a bone marrow genealogy, is to mediate the flux of calcium from the maternal circulation to the developing embryo.
Expression of interleukin‐6 in porcine, ovine, and bovine preimplantation conceptuses
Authors: Mathialagan Nagappan , Bixby James A. , Roberts R. Michael 
Published: February 2005

AbstractA porcine interleukin‐6 (pIL6) cDNA has been cloned from pig spleen cDNA library to provide information that would allow us to study IL‐6 mRNA expression during pregnancy of several domestic Artiodactyla. The cDNA is 1058 bp long and with a single open reading frame that encodes a 212 amino acid polypeptide with 28‐residue signal sequence. It shares 61% and 43% amino acid sequence identity with human and mouse IL‐6, respectively. PCR procedures with primers designed from regions of sequence conserved between human and pig have been used to identify IL‐6 cDNA in λgt11 libraries constructed from day 15–16 (sheep), day 17 (cattle), and day 13–17 (pig) conceptus mRNA. The presence of IL‐6 mRNA in elongating preimplantation ovine (days 13–25), porcine (days 13–21), and bovine (days 16–20) conceptuses was also demonstrated by PCR after reverse transcription of total ribonucleic acid with reverse transcriptase and by solution hybridization with a pIL‐6 cRNA probe. These observations suggest that IL‐6 is a product of these early conceptuses and may be involved in early maternal responses to the presence of an embryo within the uterus.
Changes in camp phosphodiesterase activity and cAMP concentration during mouse preimplantation development
Authors: Dardik Alan , Schultz Richard M. 
Published: February 2005

AbstractCyclic nucleotide phosphodiesterase (PDE) activity and cAMP amounts were measured in mouse preimplantation embryos at the 1‐cell, 2‐cell, 8‐cell/ morula, and mid‐blastocyst stages. PDE activity remained constant between the 1‐cell and 2‐cell stages. It decreased by the 8‐cell stage and continued to decrease by the mid blastocyst stage to about 14% of the 1‐and 2‐cell values. By contrast, cAMP amounts remained essentially constant at 0.05 fmole/embryo (0.3 μM) from the 1‐cell to the blastocyst stage and increased to 0.175 fmole in the fully expanded blastocyst that was close to hatching. Measurements of embryo volume indicated that intracellular volume remained essentially constant up to the blastocyst stage. The morphological changes in cell shape that accompany differentiation of the trophectoderm and that are coupled with blastocoel expansion decresed the intracellular volume. This decrease resulted in an increase in the cAMP concentration to about 0.4 μM by the mid‐blastocyst stage. Previous studies indicate that either cAMP or TGF‐α/EGF can stimulate the rate of blastocoel expansion. Although TGF‐α/EGF can elevate cAMP levels in other cell types, TGF‐α, at a concentration that maximally stimulates the rate of blastocoel expansion, did not elevate cAMP in blastocysts. Thus, it was unlikely that elevation of cAMP is the mechanism by which TGF‐α stimulates the rate of blastocoel expansion.
Migration of centromere proteins in rabbit spermatids
Authors: Courtens Jean‐Luc , Biggiogera Marco , Rothfield Naomi F. , Burnier Michel , Fakan Stanislav 
Published: February 2005

AbstractHuman autoantibodies were used to localize centromere proteins by immunoelectron microscopy, immunofluorescence, and confocal microscopy in isolated cells and in cryosections of rabbit testis. A computer‐assisted three‐dimensional reconstruction of the positions and sizes of fluorescent spots allowed us to follow their movements during the different phases of spermiogenesis. In very young spermatids, the centromeres were distributed within a space separated from both the external nuclear limits and the nuclear core. They moved towards the nuclear limits and the nuclear core. They moved towards the nuclear center in cap phase spermatids, where they clustered into a few large centromeric masses. In preelcngating spermatids, the immunolabeled proteins were dispersed within an equatorial area, where they formed one large mass. In late spermatids, the mass moved towards the posterior part of the nucleus, and, in the spermatozoon, the two basal knobs located at the base of the nuclei were the only strongly immunolabeled structures, while no labeling of the main part of the nucleus was observed. Since the number of centromeres remained close to the number of chromosomes until the cap phase of spermatid differentiation, we hypothesize that the labeling of young spermatids corresponds to centromeric proteins associated with their specific DNA counterparts, while the centromere proteins, possibly detached from their DNA loci, were released from nuclei of old spermatids in the same way as are histones and transition proteins.
The fall of biological maturation promoting factor (MPF) and histone H1 kinase activity during anaphase and telophase in mouse oocytes
Authors: Fulka R. J. , Jung T. , Moor R. M. 
Published: February 2005

AbstractCell fusions have been used to determine the biological activity of the MPF complex in murine oocytes during their progression through anaphase and telophase to metaphase II. Oocytes (1) at metaphase I, (2) during the anaphase‐telophase transition, or (3) at metaphase II were fused to germinal vesicle‐staged (immature) oocytes. The hybrids were cultured for 1 h in the presence of db cAMP before fixation and nuclear evaluation. Metaphase! oocytes invariably induced germinal vesicle breakdown (GVBD) in the immature partner. By contrast, anaphase/telophase oocytes never induced GVBD in immature oocytes. The capacity to induce GVBD reappears after the formation of the second metaphase plate. In a second study, histone H1 kinase activity was measured during mouse oocyte maturation in single oocytes. H1 kinase activity was low in GV oocytes, increased sharply at MI, declined during anaphase and telophase and increased again at MII. After egg activation, H1 kinase activity was reduced to basal levels. These results provide direct evidence that a drop in activity of MPF in murine oocytes occurs concomitantly with the exit from metaphase I; MPF activity remains low until the cell re‐enters metaphase.
Collection of acrosome‐reacted human sperm using monoclonal antibody‐coated paramagnetic beads
Authors: Okabe Masaru , Matzno Sumio , Nagira Morio , Ying Xing , Kohama Yasuhiro , Mimura Tsutomu 
Published: February 2005

AbstractA monoclonal antibody (MAb) against human acrosome‐reacted sperm was attached to paramagnetic polystyrene beads. Human sperm prepared by the swim‐up method were (1) incubated in m‐BWW, (2) incubated and ionophore treated, or (3) incubated with 5% seminal fluid. After treatment, sperm were mixed with the beads and incubated for 1 hr. Variously treated sperm showed different binding abilities to the beads. Sperm bound to the beads were collected by a magnet and subjected to triple staining. Most of the collected sperm were acrosome reacted. The results suggested that the beads can be used to estimate the acrosomal status of sperm, and that the use of antibody‐coated paramagnetic beads provides a convenient way of collecting acrosome‐reacted sperm. The acrosomal status detected by the beads was also compared with the ability of sperm to fuse with zonafree hamster eggs. It was found that greater bead‐binding ability correlated with more sperm fusing with zona‐free hamster eggs.
Evidence for differential maturation of reciprocal sperm segregants in the murine RB(6.16) translocation heterozygote
Authors: Aranha Ivar P. , Martin‐DeLeon Patricia A. 
Published: February 2005

AbstractThe fertilizing ability of unaged sperm and those aged experimentally in the cauda by surgically ligating the corpus epididymis in males carrying the Rb(6.16) translocation was studied. Chromosomally normal females were inseminated with unaged sperm delivered by males mating at 3‐day intervals, and aged sperm were studied after matings on 6–14 postoperative days. The sperm chromosome complement was analyzed in first‐cleavage metaphase zygotes after sequential G‐ and C‐banding of the chromosomes. Of 283 metaphasic zygotes in the control group, 183 (or 64.7%) were analyzed and showed a ratio of 2.7:1 for chromosomally normal and balanced segregants of the translocation, deviating significantly (P < 0.001) from the expected 1:1. The ratio of X‐ to Y‐bearing sperm also deviated from expected (P > 0.01) mostly due to a significant deficiency (P > 0.05) of balanced sperm that were X‐bearing. Fertilized oocytes were recovered from matings of 10 males on days 6–8 post‐operatively, and, of 139 metaphasic one‐cell zygotes, 101 (or 72.3%) were analyzed. These showed a Mendelian ratio of 1:1 for normal and balanced segregants. The sex ration in the aged group (57Y:41X) also showed no deviation from 1:1. The results, which reveal significant physiological distortions for both the segregation and the sex ratios in males heterozygous for the Rb(6.16) translocation, suggest that differential maturation of the translocation‐bearing sperm and the chromosomally normal reciprocal exists. The findings further support the concept that sperm chromosomal complement affects their maturation and function, and that factors on chromosome 6 and the X or Y chromosome additively affect sperm function. © 1992 Wiley‐Liss, Inc.