bluuebunny/crossref_metadata_2025 huggingface dataset:
Retinoic Acid can Induce a Secondary Axis in Developing Buds of a Colonial Ascidian, Polyandrocarpa misakiensis
Authors: Hara Kenji , Fujiwara Shigeki , Kawamura Kazuo
Published: January 2005

We have examined the effect of retinoic acid (RA) on axial pattern formation during bud development of the ascidian, Polyandrocarpa misakiensis. A bead containing various concentrations of RA was implanted into the distal portion of a bud at a site where morphogenic events do not normally occur. Control buds were implanted with beads containing dimethyl sulfoxide (DMSO), the solvent of RA. No apparent effect was observed in these buds containing beads treated with DMSO. In contrast, beads containing 100 μg/ml of RA could induce ectopic structures in the distal portion of buds in about 30% of the cases. The resulting animals had completely duplicated antero‐posterior axes. Histological studies showed that, within two days of RA treatment, atrial epithelial cells situated just beneath the implanted bead became thickened and formed a gut rudiment that resembled the posterior structure of the animal. The effect of RA treatment was dose‐dependent. The minimum concentration of RA required to induce a secondary axis was 100 ng/ml. Beads containing 1 mg/ml of RA had a lethal effect on the cells that surrounded the beads. These results are discussed in relation to the role of RA in axis formation and the mechanism by which positional values are specified during normal and aberrant bud development in ascidians.
Testicular Development Induced by a Recessive Mutation during Gonadal Differentiation of Female Common Carp (Cyprinus carpio, L.)
Authors: Komen Johannes , Yamashita Masakane , Nagahama Yoshitaka
Published: January 2005

The phenotypic effects of a new recessive mutation mas−1, which in homozygous condition induces testicular development in XX animals of common carp (Cyprinus carpio L.), are described. Sexual differentiation of XX; mas−+/mas−1 and XX; mas−1/mas−1 animals was compared with the gonad development of XX wild type females and XY males. In XX females gonadal differentiation starts with the formation of an ovarian cavity and entry into meiosis of germ cells at around 80 days post hatching (ph). Male gonads remain quiescent until 120 days ph during which period they develop a network of loose connective tissue. Spermatogenesis starts with tubule formation and the differentiation of germ cells into spermatogonia type B. Heterozygous XX; mas−+/mas−1 animals developed as normal females, but in homozygous XX; mas−1/mas−1 animals two types of gonad development were observed. In the first type, germ cells did not enter meiosis until 100 days ph when they differentiated as spermatogonia. An ovarian cavity was not formed but male specific connective tissue developed instead. These gonad developed as normal testes. In the second type, germ cells differentiated at 80 days ph as either oocytes or spermatocytes, which resulted in the gonads developing as ovotestes. The formation of an ovarian cavity was in most cases incomplete. The phenotypic effects of mas−1 are interpreted as a timing mismatch between mas activation and female sex differentiation.
Regulation of Cell Number in Formation of the Dorsal Root Ganglion Revealed by Transplantation of Quail Neural Crest Cells into Chick Embryos
Authors: Asamoto Ken , Nojyo Yoshiaki , Aoyama Hirohiko
Published: January 2005

Neural crest cells appear transiently in early embryogenesis on the dorsal surface of the neural tube and subsequently migrate along specific pathways. Some migrate to between the neural tube and somites, aggregating to form the rudiments of dorsal root ganglia (DRG). The size of DRG at a given somite level is almost constant in all chick embryos. To determine the mechanisms controlling the size of DRG, we transplanted neural crest cells of 2.5‐day‐old quail embryos into 2.5‐day‐old chick embryos between the neural tube and the somites, and examined the size of DRG in these chimeric embryos with extra neural crest cells 2 days after the operation, when natural cell death in DRG had not yet occurred. The DRG on the operated side were composed of both chick and quail cells in various proportions. The cell numbers of these chimeric DRG were almost the same as those of the normal DRG on the opposite side. That is, there were significantly fewer chick cells in chimeric DRG than in DRG composed of only chick cells on the opposite unoperated side. This finding indicates that the size of DRG is not determined in migrating neural crest cells but is regulated by the circumstances.
Mesoderm and Neural Inductions on Newt Ectoderm by Activin A
Authors: Moriya Naomi , Asashima Makoto
Published: January 2005

Mesoderm‐inducing activity of human recombinant activin A was examined on presumptive ectoderm of the Japanese newt, Cynops pyrrhogaster, by using the animal cap assay, Activin A induced neural tissues and mesodermal tissues such as brain, neural tube, notochord, muscle, mesenchyme, coelomic epithelium and blood‐like cells after 14 days cultivation. These tissues were induced by activin A at concentrations ranging from 0.5– 100 ng/ml. Dose‐dependent inducing activity of activity A on newt ectoderm was slightly different from that on other animals, including Xenopus. Wide range of concentration of activin A (0.5– 100 ng/ml) could induce the neural tube, notochord, mesenchyme and coelomic epithelium on the newt ectoderm. Though the percentage of induced explants (two out of 23 explants, 8.7%) was low, the pulsating heart was induced. This paper showed first that activin could induce the mesodermal and neural tissues in newt presumptive ectoderm. Since activin homologues were present In Xenopus and chick embryos, it is likely that activin may be one of the natural inducers in a wide range of species.
Remodeling of Human Sperm Chromatin Mediated by Nucleoplasmin from Amphibian Eggs
Authors: Itoh Toru , Ohsumi Keita , Katagiri Chiaki
Published: January 2005

The molecular events associated with decondensation of human sperm nuclei were analyzed by incubating sperm with egg extracts from an amphibian, Bufo japonicus. Acid‐urea‐Triton polyacrylamide gel electrophoresis (AUT‐PAGE) showed that the nuclear basic proteins of human sperm consist mainly of protamines (HPI, HPII) with minor amounts of nucleosomal histones. On incubation of lysolecithin (LC)‐ and dithiothreitol (DTT)‐treated human sperm with the egg extract, the nuclei lost HPI and HPII within 15 min in association with extensive nuclear decondensation, and the acquirement of a whole set of nucleosomal histones. Incubation of LC‐DTT‐sperm with nucleoplasmin purified from Bufo eggs also induced nuclear decondensation and loss of protamines within 30 min. Native‐PAGE and Western blot analyses of incubation medium indicated tight association of the released protamines to nucleoplasmin, strongly suggesting that protamines are removed from sperm nuclei not enzymatically but by their specific binding to nucleoplasmin. On incubation of LC‐DTT‐sperm with nucleoplasmin and exogenous nucleosomal core histones, micrococcal nuclease‐protected DNA fragments were released, although their unit repeat length was slightly less than that of somatic nucleosomes. Thus remodeling of human sperm during fertilization can be mimicked under defined conditions with nucleoplasmin and exogenous histones.
The Activin A‐Dependent Proliferation of PCC3/A/1 Embryonal Carcinoma Cells in Serum‐Free Medium
Authors: Atsumi Tadao , Miwa Yoko , Eto Yuzuru , Sugino Hiromu , Kusakabe Moriaki , Kitani Hiroshi , Ikawa Yoji
Published: January 2005

Examination of the growth requirements of murine embryonal carcinoma cells (EC cells) or embryonic stem cells (ES cells) in serum‐free medium revealed that PCC3 EC cells required activin A to grow and/or survive in such medium. In the absence of activin A, PCC3 cells began to disintegrate within 3 days under any serum‐free conditions examined. P19 and AT805 EC cells grew even in serum‐free medium without activin A but their growth rates were slightly facilitated by its addition. F9 EC cells also grew in the medium without activin A and its addition somewhat inhibited their growth rate. Three independently isolated ES cell lines and feeder‐dependent PSA‐1 EC cells also grew in serum‐free medium without activin A if leukemia inhibitory factor (LIF) was supplemented. The addition of activin A had little effect on their growth rates. These findings suggest that PCC3 EC cells are a sort of nutritional mutant requiring activin A, thus making them useful in stidies on the growth regulatory mechanisms of EC/ES cells and/or the action of activin on EC/ES cells.
Vitellogenin Incorporation into Oocytes of Rainbow Trout, Oncorhynchus mykiss, in Vitro: Effect of Hormones on Denuded Oocytes
Authors: Shibata Naoki , Yoshikuni Michiyasu , Nagahama Yoshitaka
Published: January 2005

An in vitro culture procedure to measure vitellogenin (VTG) incorporation into oocytes without follicle cell layers was developed using oocytes of the rainbow trout, Oncorhynchus mykiss. Oocytes incorporated VTG specifically and linearly for up to 24 hr. The maximum incorporation observed was 314 μg/24 hr/oocyte, using vitellogenic (3.6 mm diameter) oocytes.

The effect of hormones was examined by adding insulin, growth hormone, prolactin, gonadotropins (GTH‐I, GTH‐II), thyroid hormones, testosterone, estradiol‐17β, or 17α, 20β‐dihydroxy‐4‐pregnen‐3‐one to the medium. The results indicated that insulin and thyroxine stimulated uptake of VTG by 13% and 12%, respectively. Insulin specifically stimulated VTG incorporation and did not cause any change in background uptake of insulin. The lack of an effect of gonadotropins hormones on denuded oocytes suggests that the previously observed stimulation of VTG incorporation into follicle cell‐enclosed oocytes in vivo and in vitro by GTH‐I is most likely mediated by the somatic cells of the ovarian follicle.
Spectrin and Ankyrin‐like Proteins in the Egg of Discoglossus pictus (Anura): Their Identification and Localization in the Site of Sperm Entrance versus the Rest of the Egg
Authors: Tatone Carla , Carotenuto Rosa , Colonna Rosella , Chaponnier Christine , Gabbiani Giulio , Giorgi Mauro , Campanella Chiara
Published: January 2005

The Discoglossus pictus egg has a specific site of sperm‐egg interaction, the dimple, which has a well‐defined cytoskeleton. We studied whether there are cytoskeletal and cytoskeleton‐related proteins typically involved in the polarization of plasma membrane proteins. The identity and the localization of the molecules cross‐reacting with antispectrin, antifodrin and antiankyrin antiobodies were investigated by immunofluoresecence and immunoblotting of the proteins of the dimple (D) and of the rest of the egg (dimple‐less‐egg; DLE). Two polypeptides of about 254‐and 246‐kD were detected in the D and DLE, and localized in the egg cortex. A third molecule, weakly cross‐reacting with antispectrin and antifodrin, was found in the subcortical cytoplasm. The 246‐kD polypeptide was labile in samples prepared for SDS‐PAGE; a mild prefixation of eggs prevented its dispersion. Mild fixation was also needed to retain antispectrin reactivity in cryostat sections of the DLE cortex, while this is not necessary in D. A molecule of about 204‐kD, cross‐reacting with antiankyrin, was detected in the cortex of the whole egg. These data and the finding that the concentrations of both the 254‐kD polypeptide and ankyrin are about 12‐fold higher in D than in the DLE, suggest that, in D, spectrin has a specific organization.
Histological studies on male sterility of hybrids between laboratory and wild mouse strains
Authors: Yoshiki Atsushi , Moriwaki Kazuo , Sakakura Teruyo , Kusakabe Moriaki
Published: January 2005

In this study the cellular mechanisms of male sterility in F1 hybrids (BNF1) between BALB/c and wild‐derived M.MUS‐NJL (NJL) was investigated. Cell proliferation and differentiation in the sterile testis were examined by bromodeoxyuridine‐labeling and use of germ cell stage‐specific antibodies. In BNF1 testes, spermatogonia actively proliferated with a seminiferous epithelial cycle, and were retained in the basal layer of the tubules. However, preleptotene, leptotene and zygotene spermatocytes moved to the adluminal region. Immunohistological data with germ cell stage‐specific antibodies indicated the presence of few, if any, pachytene spermatocytes in BNF1 testes. Thus, spermatogenesis seemed to be blocked at the zygotene stage. For examination of germ cell‐Sertoli cell interactions, testes of aggregation chimeras between BNF1 and C3H/HeN were analyzed immunohistologically with C3H‐specific antibody. Results showed that spermatogenesis of C3H‐germ cells was normal, even when these cells in contact with BNF1‐Sertoli cells. Differentiation of BNF1‐germ cells progressed from zygotene to pachytene stage spermatocytes when these cells were surrounded by C3H‐Sertoli cells, but never proceeded beyond the pachytene stage. These observations suggest that at least two different cellular factors may be involved in spermatogenesis, one acting in the germ cells and the other mediated by Sertoli cells. Furthermore, mating experiments revealed that the degree of spermatogenesis varied in different F1 hybrids, and that the major sterility factor was closely linked to the T‐locus on chromosome 17.
Involvement of Collagen Synthesis in Tissue Reconstitution by Dissociated Sponge Cells
Authors: Shimizu Katsuhiko , Yoshizato Katsutoshi
Published: January 2005

Cells dissociated from the sponge Haliclona permollis reconstituted a new body by the following three consecutive processes: (1) Reaggregation, cells aggregate as a spheroidal mass. (2) Spreading, aggregates flatten and spread. (3) Reconstruction, aggregates coalesce into a reconstituted body. Cells in the process of reconstitution incorporated 14C‐proline into proteins, converting 17% of it to hydroxyproline and synthesize collagen molecules during this process. Inhibitors of collagen biosynthesis did not affect the reaggregation, but caused incomplete morphogenesis in the processes of spreading and reconstruction: cycloheximide and 2,2′‐dipyridyl inhibited spreading while 3‐aminopropionitrile induced incomplete reconstruction. These findings suggested that spreading and reconstruction, but not reaggregation require both synthesis and cross‐linking of collagens. Three polypeptides with molecular weights of 58 K, 160 K and 180 K were identified in sponge cells as collagens by immunoblot analysis with antibodies against sea urchin collagen and studies on susceptibilities to collagenase and pepsin. The 58 KDa polypeptide appeared in reconstituted bodies but not in dissociated cells, suggesting its importance in tissue reconstitution by dissociated cells.
Lithium Chloride and Trypan Blue Induce Abnormal Morphogenesis by Suppressing Cell Population Growth
Authors: Ghatpande Satish K. , Vaidya Prashant K. , Mulherkar Leela , Modak Sohan P.
Published: January 2005

Full primitive streak stage chick embryos were cultured in vitro for 20 hrs and monitored every 4 hr for morphology, cell number and blastoderm area. In normal embryos, the cell population growth is exponential and correlates directly with Increasing morphological rank. The chick blastoderm area expands in two waves, one immediately after gastrulation and another after 16 hr in culture, while cell population growth is predominant between 4–16 hr. Trypan blue and LiCI inhibit cell population growth, epiboly and shaping of organ primordia. Both teratogens induce a similar spectrum of abnormalities although the severity of abnormal development is greater with LiCl for the given dose. In most abnormal embryos the cell population size and blastoderm area are inhibited most, which is detectable already after 12 hr of culture. We have established that the cell population growth, morphogenesis and area expansion constitute a parametric hierarchy with the cell population growth as the most independent parameter in regulating normal morphogenesis.
Morphological Differentiation of the Microvasculature During Follicular Development, Ovulation and Luteinization of Mouse Ovaries
Authors: Shimoda Kohji , Sato Eimei , Tanaka Toshiaki , Takeya Tatsuo , Toyoda Yutaka
Published: January 2005

The chronological changes of the microvasculature during follicular development, ovulation and luteinization of mouse ovaries were examined by observation of serial histological sections, lectin angiographs and resin‐corrosion casts. Graafian follicles possessing oocytes with germinal vesicles were surrounded by a few layers of basket‐like capillary wreath adjacent to the follicular basement membrane. Just before ovulation 11–12 hr after hCG administration, some theca cells differentiated into hypertrophic cells, and the follicular basement membrane underwent fragmentation. Then the capillaries within the theca interna became dilated, and hyperpermeable and appeared to be injured. The capillary wreath extended into the follicle via the hypertrophied theca interna. After ovulation, the follicular wall became markedly edematous. Capillary branches invaded the granulosa cell layer of the ruptured follicle from the region of extravasation to form an intricate capillary network. The capillary network occupied the whole corpus luteum until 24 hr after hCG administration.
Promotion of Zygote Formation by Protein Kinase Inhibitors during the Sexual Development of Dictyostelium mucoroides
Authors: Kawai Shinobu , Maeda Yasuo , Amagai Aiko
Published: January 2005

To analyze the possible involvement of protein kinases in the sexual development (macrocyst formation) of the cellular slime mold Dictyostelium mucoroides‐7 (Dm7), the effects of several protein kinase inhibitors were examined. K252a, a potent inhibitor of protein kinase activities, promoted the sexual cell fusion, through enhancement of gamete formation. In contrast, staurosporine (structurally and functionally similar to K252a) inhibited markedly the progress of development including cell aggregation, thus resulting in the failure of cells to form mature macrocysts. The effective period of K252a was 5–7 hr after starvation, during which Dm7 cells could acquire fusion competence, and the inhibitory effect of cAMP on zygote formation was nullified by the co‐application of K252a. Although KT5720 (a specific inhibitor of cAMP‐dependent protein kinase) and W7 (a calmodulin inhibitor) had no effects on zygote formation when applied separately, their combined application enhanced zygote formation like K252a did. Neither calphostin C (a specific inhibitor of Ca2+‐dependent protein kinase) nor herbimycin A (a specific inhibitor of tyrosine kinase) exerted a stimulative influence upon macrocyst formation. These results strongly suggest that the two signal transduction pathways mediated by cAMP‐dependent protein kinase (PKA) and calmodulin are closely related to zygote formation, their blockage being favorable to zygote formation.
Isolation and Characterization of Goldfish cdc2, a Catalytic Component of Maturation‐Promoting Factor
Authors: Kajiura Hiroko , Yamashita Masakane , Katsu Yoshinao , Nagahama Yoshitaka
Published: January 2005

We have isolated a cdc2 cDNA from a library constructed from immature goldfish oocytes. The isolated clone has a PSTAVR sequence, instead of the PSTAIR sequence common to cdc2 in other species. Its product was characterized by monoclonal antibodies against its C‐terminal amino acid sequence. The antibodies recognized an anti‐PSTAIR‐reactive 35 kDa protein in immature oocyte extracts, which was not recognized by anti‐goldfish cdk2 antibody. In addition to the 35 kDa cdc2, mature oocytes contained a 34 kDa cdc2, which was a component of MPF purified from carp eggs. Upon gel filtration column, the 35 kDa cdc2 migrated at monomeric position, while the 34 kDa cdc2 migrated at around 100 kDa, where cyclin B also comigrated. These results strongly suggest that the 35 kDa protein is monomeric inactive cdc2, while the 34 kDa protein is cyclin B‐bound active cdc2. The finding that the 35 kDa inactive cdc2 does not form a complex with any other proteins in immature oocytes is in contrast to the situation in Xenopus and starfish, in which cdc2‐cyclin B complex exists already as pre‐MPF in immature oocytes.
Activin Receptor Type II Gene Expression is Induced During Embryonic Development and Differentiation of Murine F9 Embryonal Carcinoma Cells
Authors: Wu Tsung‐Chieh J. , Wang Lai , Jih Ming H. , Wan Yu‐Jui Y.
Published: January 2005

The functional role of activins in mesoderm induction has been shown in early amphibian embryos; however, its role in early mammalian embryogenesis is still unknown. The protein and mRNA for activin subunits are present in mouse preimplantation embryos. In this study we report on the expression of activin receptor type II (ActR‐II) gene in pre‐ and post‐implantation mouse embryos and the regulation of ActR‐II mRNA in F9 embryonal carcinoma cells that served as a model for murine embryonic development. The results show that ActR‐II gene is expressed in ovulated mature oocytes, becomes decreased at 2‐celll stage, and is substantially activated in day‐6 embryo at the stage when ectoderm and endoderm are formed. When F9 cells are treated with retinoic acid (RA) and undergo endodermal differentiation, ActR‐II mRNA is induced. The 6.0 kb transcript is enhanced more than the 3.0 kb transcript. suggesting that these two mRNA species are controlled by different promotors. Addition of cyclic AMP analogue, which further induces differentiation of F9 cells into parietal endoderm, does not further enhance ActR‐II gene expression. The effect of RA on ActR‐II mRNA levels is direct and does not require ongoing protein synthesis. Furthermore, all‐trans‐RA is more effective than 9‐cis‐RA in the induction of ActR‐II gene expression. The results of this study demonstrate that the ActR‐II gene is activated during endodermal differentiation and suggest that activin action in mammalian embryonic development is mediated through increased activin receptor gene expression.
Effect of Ca2+‐free Seawater Treatment on 1‐Methyladenine Production in Starfish Ovarian Follicle Cells
Authors: Mita Masatoshi
Published: January 2005

When follicle cells from ovaries of the starfish Asterina pectinifera were washed with Ca2+‐free seawater (CaFSW), the production of 1‐methyladenine (1‐MeAde) in response to gonad‐stimulating substance (GSS) decreased to a large degree. The cyclic AMP content of CaFSW‐treated follicle cells was much lower than that of non‐treated cells, and the level was increased slightly by GSS, but not to a degree sufficient for production of 1‐MeAde. The production of 1‐MeAde and cyclic AMP in the presence of GSS was dependent on extracellular Ca2+ concentration, and was considerably reduced at a Ca2+ concentration below 1 mM. Thus, the decrease of 1‐MeAde production by follicle cells after treatment with CaFSW is due to the low levels of cAMP. Furthermore, an ADP‐ribosylation experiment using [α‐32P]NAD+ in the presence of cholera toxin and pertussis toxin with membrane preparations of follicle cells treated with CaFSW revealed the presence of two types (stimulatory and inhibitory) of G‐proteins. However, activity of the adenylyl cyclase was not influenced by GSS regardless of the presence or absence of GTP. These findings may suggest that GSS is unable to bind to its receptor in follicle cells after washing with CaFSW.
Several Cell Responses to Insulin of Cultured Cells Derived from Micromeres, Isolated from Sea Urchin Embryos at the 16 Cell Stage
Authors: Kuno Shin‐ichi , Mitsunaga‐Nakatsubo Keiko , Nagura Takanori , Fujiwara Akiko , Yasumasu Ikuo
Published: January 2005

In micromere‐derived cells of sea urchin embryos, treatment with insulin started for up to 24 h during culture at 20°C resulted in augmentation of 32P incorporation into protein (protein phosphorylation) followed by activation of 32P incorporation into RNA (RNA synthesis) and then induced pseudopodial cable growth, accompanied by considerable decreases in the rates of protein phosphorylation and RNA synthesis. This augmentation of RNA synthesis and cable growth induced by insulin were blocked by H‐7, which inhibited protein phosphorylation, and were also inhibited by actinomycin D without any inhibition of protein phosphorylation. Similar results were obtained on treatment with horse serum, found to contain insulin‐like compounds. In cells treated with horse serum treated cells, high rates of protein phosphorylation and RNA synthesis were maintained even after the initiation of cable growth and about 5 h later, spicule rods were produced. Insulin treatment did not induce spicule rod formation. In cells treated with horse serum, actinomycin D treatment started at the time of initiation of cable growth, cables were formed but formation of spicule rods was blocked. These results suggest that horse serum contains some other substance besides insulin‐like ones, which induces expression of genes that are indispensable for spicule rod formation.
Cloning of Protamine cDNA of the Medaka (Oryzias latipes) and Its Expression during Spermatogenesis
Authors: Tamura Masaru , Yamamoto Hiroaki , Onitake Kazuo
Published: January 2005

Protamines or sperm specific basic proteins are highly basic low molecular weight proteins that substitute histones in the chromatin of sperm during spermatogenesis. They condense sperm DNA into a highly compact, stable and inactive complex. In this study, cDNA of protamine of the medaka, Oryzias latipes, was cloned to elucidate the molecular mechanisms involved in spermatogenesis. A medaka testis cDNA library constructed in lambda gt11 showed 2.78X106 independent recombinants. Several positive clones were obtained by immunoscreening with polyclonal antiserum against medaka protamine. Sequencing showed that one of these positive clones, named MP‐1, encoded arginine clusters characteristic of protamine. The putative amino acid sequence of MP‐1 revealed a remarkable extent of homology with other fish protamines, such as 71% identity with thynnin Y, a sperm specific basic protein isolated from the bluefin tuna, Thunnus thynnus. Northern hybridization using a MP‐1 cDNA probe showed that MP‐1 mRNA is present exclusively in the testes and that it gave three detectable bands: a major band of 280 b, and two others of 400 b and 500 b. In situ hybridization of a complementary RNA probe (digoxigenine‐UTP‐labeled MP‐1 RNA) revealed that MP‐1 mRNA is localized in some secondary spermatocytes and spermatids, but not in primary spermatocytes or spermatogonia. These results differ from those obtained in studies on the rainbow trout by solution hybridization and in situ hybridization.
Differentiation of Primary Spermatocytes to Elongated Spermatids by Mammalian FSH in Organ Culture of Testes Fragments from the Newt, Cynops pyrrhogaster
Authors: Ji Zai‐Si , Abeé Shin‐Ichi
Published: January 2005

Our previous studies (10, 11) showed that mammalian follicle‐stimulating hormone (FSH) alone was indispensable and sufficient for the initiation and promotion of spermatogenesis from secondary spermatogonia to primary spermatocytes in organ culture of testes fragments from the newt, Cynops pyrrhogaster. The present study demonstrated that FSH promoted in the same model system the differentiation of primary spermatocytes even further: to the stage of elongated spermatids. When testes fragments, consisting of somatic cells and germ cells (mostly primary spermatocytes), were cultured in a control medium for three weeks, only round spermatids and spermatogonia were observed; both the diameter of the cysts and the viability of the germ cells decreased to about 10–15% of the original level. On the other hand, when the medium was supplemented with FSH, elongated spermatids appeared by the second week; both the diameter of the cysts and the viability of the germ cells were maintained at a higher level than in the control medium. The effect of FSH was dose‐dependent. However, neither transferrin, androgens (testosterone and 5α‐dihydrotestosterone) nor luteinizing hormone (LH) was effective. The addition of cyanoketone, a specific inhibitor of 3β‐hydroxy‐Δ5‐steroid dehydrogenase (3β‐HSD) (32), to the FSH‐containing medium did not prevent the differentiation promoted by FSH, indicating that it is unlikely that Δ4‐steroid metabolites produced in fragments by FSH acted directly on germ cells. Insulin was found to improve the viability of germ cells during a 2 week of culture period. In the presence of FSH, the cells in various differentiative stages had morphological characteristics very similar to those in vivo, whereas in the absence of FSH primary spermatocytes showed abnormal features in their nuclei and cytoplasm, indicating that they were deteriorating. These results and our previous results (1–3) suggest that FSH promotes primary spermatocytes to differentiate into elongated spermatids probably by stimulating Sertoli cells to secrete factors which then act on the germ cells.
Complex Cell Type‐Specific Transcriptional Regulation by the Promoter and an Intron of the Mouse P‐Cadherin Gene
Authors: Hatta Masayuki , Takeichi Masatoshi
Published: January 2005

Expression of cell‐cell adhesion molecule cadherins is dynamically regulated during development. We describe the structure of the promoter of the mouse P‐cadherin gene and its transcriptional activity. The P‐cadherin promoter had a tandem of B2 repetitive elements showing structural similarities to the E‐cadherin gene promoter. Transcriptional properties of the P‐cadherin promoter were surveyed along about 10 kbp of the 5° flanking region by CAT assay in several cell lines expressing or not expressing P‐cadherin mRNA. The P‐cadherin promoter exhibited complex profiles of transcriptional activity. When the promoter was introduced into P‐cadherin positive cell lines, its activity greatly varied with the cell lines. Moreover, this promoter was active even in some of P‐cadherin negative cell lines. Analyses of 5° deletions of the promoter suggest that multiple elements are differentially used by different cell lines. We also detected enhancer‐like elements in the 2nd intron, which can activate both the P‐cadherin and thymidine kinase promoters. The activity of each enhancer varied with cell lines, being independent of endogenous P‐cadherin expression. These results suggest that P‐cadherin gene transcription is regulated by highly complex combinations of elements in the promoter and the 2nd intron studied here and other regions for the cell‐type specific expression.
Improvement of Germ Line Transmission by Targeting β‐galactosidase to Nuclei in Transgenic Mice
Authors: Kimura Shigemi , Niwa Hitoshi , Moriyama Mako , Araki Kimi , Abe Kuniya , Miike Teruhisa , Yamamura Ken‐ichi
Published: January 2005

The Escherichia coli lacZ gene has frequently been used as a reporter in cell lineage analysis, in determining the elements regulating spatial and temporal gene expression, and in enhancer/gene trap detection of developmentally regulated genes. However, it is uncertain whether lacZ expression affects eukaryotic cell growth and development. By using a gene trap, we previously isolated the promoter, Ayu1, which is active in ES cells and in several tissues including the gonads. We used this promoter and the nuclear location signal of the SV40 large T gene to locate β‐galactosidase either in the cytoplasm or the nucleus. Transgenic lines containing β‐galactosidase in the cytoplasm of a wide variety of cell types did not transmit the transgene to their offspring. In contrast, transgenic mice, containing β‐galactosidase in the nucleus, did transmit the transgene successfully. Interestingly, lacZ expression in the brain was more restricted when β‐galactosidase activity was detected in the cytoplasm. These data suggested that cytoplasmic β‐galactosidase affects certain developmental processes or gametogenesis resulting in transmission distortion of the transgene, and that this effect can be reduced by targeting β‐galactosidase to the nucleus. We also found that Ayu1‐driven lacZ expression in the duodenum of adult transgenic mice was sexually dimorphic, being positive in females and negative in males.
Idiopathic necrotizing dermatitis: Current management
Authors: Lui PC , Petersen D , Kimble RM , Raven RJ , Pearn JH
Published: January 2005

Objectives:  To identify and demonstrate necrotizing dermatitis in infancy; an uncommon, puzzling syndrome, in which anecdotal reporting and personal experience indicates that one third of cases may require skin grafting. Much informed discussion about the pathogenesis of this distressing syndrome centres on the role of spider envenomation; and in particular on the speculative role of the Australian White‐tailed spider, Lampona cylindrata.

Methods:  We present here six cases of necrotizing dermatitis treated surgically at the Royal Children's Hospital and Mater Children's Hospital in Brisbane over the period from 1991 to 1999. Clinical history, surgical details and pathological investigations were reviewed in each case. Microbiological investigation of necrotic ulcers included standard aerobic and anaerobic culture.

Result:  Nocardia and Staphylococcus were cultured in two cases, but no positive bites were witnessed and no spiders were identified by either the children or their parents. All cases were treated with silver sulphadiazine crème. Two of the infants required general anaesthesia, excision debridement and split skin grafting. The White‐tailed spider, Lampona cylindrata, does not occur in Queensland, but Lampona murina does; neither species has necrotizing components in its venom. Circumstantial evidence is consistent with this syndrome being due to invertebrate envenomation, possibly following arachnid bites.

Conclusion:  In our experience there is insufficient evidence to impute a specific genus as the cause, at this stage of scientific knowledge. If the offending creature is a spider, we calculate that the syndrome of necrotizing dermatitis occurs in less than 1 in 5000 spider bites.
Long‐term endocrine effects of cancer treatment: Experience of the Royal Children's Hospital, Melbourne
Authors: Hameed R , Zacharin MR
Published: January 2005

Objectives:  To evaluate the frequency and degree of severity of endocrine late effects in patients treated for childhood cancer and to assess the value of the late effects clinic for continued monitoring of these patients.

Method:  Data was collected on all patients who attended the late effects clinic at the Royal Children's Hospital (RCH) between 1998‐2003. Endocrine function was assessed by clinical and biochemical evaluation at the time of presentation and at ongoing intervals of 3‐12 months as clinically indicated.

Results:  A total of 249 children attended the late effects clinic. Two hundred and thirty five endocrine diagnoses were made in 155 (62%) patients, of whom 63 patients had multiple endocrinopathies.

Conclusion:  Our audit supports the need for ongoing prospective surveillance in survivors of childhood cancer. Appropriate and timely interventions in such patients can help to reduce morbidity and improve quality of life.
Management of post‐operative bladder spasm
Authors: Chiang D , Ben‐Meir D , Pout K , Dewan PA
Published: January 2005

Objective:  Pain management following bladder surgery in children is often complicated by bladder spasm. The overall severity of spasm can be reduced with opioids, anticholinergic medication and sedatives, although breakthrough spasms often occur. At the Royal Children's Hospital, Melbourne, intravesical bupivacaine has been used to manage postoperative bladder spasm to good effect. The administration of intravesical bupivacaine is analysed in this prospective audit of locally applied intravesical anaesthetic and compared with other methods.

Method:  From February to August 2003, histories of 58 patients who had intravesical bupivacaine were studied and compared with six other methods of management of postoperative bladder spasm.

Conclusion:  Data showed that epidural anaesthesia was the most effective treatment of pain, with a pain score reduction of 6.6, compared with a reduction of 6.1 with intravesical bupivacaine, and 4.5 using intravenous morphine. However, intravesical bupivacaine was the most effective method for the relief of bladder spasm.
Acute osteomyelitis and septic arthritis in children
Authors: Goergens ED , McEvoy A , Watson M , Barrett IR
Published: January 2005

Objective:  To review the clinical presentation, clinical management and organisms responsible for acute haematogenous osteomyelitis (AHO) and septic arthritis (SA) in the post Haemophilus influenzae type B (Hib) vaccine era and to evaluate current Australian antibiotic guidelines for these conditions.

Methods:  A retrospective chart review of children less than 16 years of age presenting to The Children's Hospital at Westmead in the period from January 1998 to July 2002 with an ICD discharge code consistent with AHO or SA.

Results:  During the 4½‐year period 120 511 children were admitted to The Children's Hospital at Westmead. There were 102 cases of AHO and 47 cases of SA during this time. An organism was identified either by blood culture or tissue biopsy in 45% of children with AHO and 38% with SA. Staphylococcus aureus was the most common identifiable causative organism accounting for 76% of isolated organisms in AHO and 39% of isolated organisms in SA. Methicillin‐resistant S. aureus (MRSA) was responsible for 9% of AHO and 6% of SA cases. There were no cases due to Haemophilus influenzae or Kingella kingae during the study period. The majority (66%) of children with AHO were managed non‐operatively with intravenous and then oral antibiotics. Thirty‐five (34%) children had operative treatment to drain pus. In contrast, 74% of the patients with SA had one or more surgical procedures performed to drain pus from involved joints.

Conclusions:  Staphylococcus aureus remains the most common organism causing AO and SA; however, community‐acquired methicillin‐resistant strains are now occurring. Haemophilus influenzae is no longer a common cause of SA. Our study supports the current Australian antibiotic guidelines that recommend flucloxacillin alone as the empiric treatment of choice of both AHO and SA in children fully immunised against Hib. However the possibility of community‐acquired MRSA should be considered, particularly in high risk groups such as indigenous Australian children or children from regional areas with a high rate of community‐acquired MRSA.
Severe spontaneous intracranial hypotension and Marfan syndrome in an adolescent
Authors: Milledge JT , Ades LC , Cooper MG , Jaumees A , Onikul E
Published: January 2005

Abstract:  We describe a 14‐year‐old girl with Marfan syndrome who presented with severe postural headache. Dural ectasia was demonstrated radiologically. Cerebrospinal fluid (CSF) pressure was immeasurable on formal measurement. Radionucleide cisternography failed to demonstrate a CSF leak. We consider that the underlying fibrillinopathy in Marfan syndrome rendered the dura sufficiently permeable to CSF leakage to cause the low CSF pressure headache. The patient was treated successfully with epidural autologous blood patch.
Brucellar arthritis of knee in a child
Authors: Palanduz A , Telhan L , Yıldırmak Y , Memioğlu N , Arapoğlu M , Kayaalp N
Published: January 2005

Abstract:  A 15‐month‐old boy was admitted with fever and a swollen knee. His mother had been treated for brucellosis 11 months ago. At that time he had been asymptomatic and had both negative blood culture and serum agglutination tests and breastfeeding had been stopped. The infant had been healthy since then. On admission, blood and joint fluid were obtained for culture and he was commenced on cefuroxim. Gram‐negative coccobacillary organisms were seen in the joint fluid. Both cultures remained sterile. He had a positive serum agglutination test with a titer of 1/640. Cefuroxim was then stopped and the child was commenced on a specific course of treatment: gentamicin, trimethoprim‐sulfamethoxazole and rifampicin. The infant recovered with this treatment. We conclude that this was brucellar arthritis of the knee and was probably acquired by breastmilk after an exceptionally long incubation period.
Social support as a predictor of health status among older adults living alone in Japan
Authors: Saito Emiko , Sagawa Yoko , Kanagawa Katsuko
Published: January 2005

Abstract The purpose of this study was to determine social support as a predictor of health status among older adults living alone, based on a 2‐year longitudinal study in a rural area of Japan. The self‐reported questionnaires were distributed to 624 older adults living alone and were collected during home visits by welfare commissioners as baseline survey. After the follow‐up survey of 493 respondents as the baseline survey, we analyzed 340 persons who lived alone over the last 2 years. Women had significantly higher emotional and instrumental support scores than men. Receiving positive support from the neighborhood had a significant effect on retaining activities of daily living for older women living alone. Our results suggest that receiving social support from the neighborhood brought an improvement in the health status of older adults, particularly women living alone.
Role stress in nurses: Review of related factors and strategies for moving forward
Authors: Chang Esther M. , Hancock Karen M. , Johnson Amanda , Daly John , Jackson Debra
Published: January 2005

AbstractThe aim of this paper was to review the literature on factors related to role stress in nurses, and present strategies for addressing this issue based on the findings of this review while considering potential areas for development and research. Computerized databases were searched as well as hand searching of articles in order to conduct this review. This review identified multiple factors related to the experience of role stress in nurses. Role stress, in particular, work overload, has been reported as one of the main reasons for nurses leaving the workforce. This paper concludes that it is a priority to find new and innovative ways of supporting nurses in their experience of role stress. Some examples discussed in this article include use of stress education and management strategies; team‐building strategies; balancing priorities; enhancing social and peer support; flexibility in work hours; protocols to deal with violence; and retention and attraction of nursing staff strategies. These strategies need to be empirically evaluated for their efficacy in reducing role stress.
How nurses’ experiences of domestic violence influence service provision: Study conducted in North‐west province, South Africa
Authors: Christofides Nicola J. , Silo Zanele
Published: January 2005

Abstract This study was undertaken to determine whether nurses’ experiences of domestic violence (DV) influence their management of DV and rape cases. In total, 212 nurses were interviewed in two South African health districts using a standardized questionnaire. We measured sociodemographic characteristics, quality of care in the areas of rape and DV management, and experiences of DV in their own lives and amongst family and friends. A total of 39% nurses reported having experienced either physical or emotional abuse themselves and 40.6% amongst family and friends. Having personally experienced DV had no influence on DV identification and management. Those with experience from friends and family were more likely to have provided better care for patients who presented after DV (mean quality of care score = 23.1), while nurses who reported no personal experience of DV, either in their own lives or among family and friends, had a lower quality of care score of 19.8 (P = 0.02). Having ever intervened in a domestic dispute was associated with higher quality of care (P < 0.001). This suggests that the greater degree to which nurses identify with DV and intervene, the more likely they are to provide higher quality of care. Training of nurses in DV must try to build such empathy.
Core ethical issues of clinical nursing supervision
Authors: Berggren Ingela , Barbosa da Silva António , Severinsson Elisabeth
Published: January 2005

AbstractClinical nursing supervision enables supervisees to reflect on ethically difficult caring situations, thereby strengthening their professional identity, integrating nursing theory and practice, and leading to the development of ethical competence. The aim of this study was to develop an understanding of the core ethical issues of clinical nursing supervision, using previous research as well as philosophical analysis of the theories of three moral philosophers: Harald Ofstad, Richard Hare and Carol Gilligan. The ultimate aim of this study was to develop a general model for ethical decision‐making and to establish its relevance for clinical nursing supervision. The findings highlight four important values for the development of a basis for ethical decision‐making. These values are caring, dignity, responsibility and virtue.
The social mind‐body: Anthropological contributions to the study of the self
Authors: Arnault Denize Saint
Published: January 2005

Self is formed because of the interaction between the body and the society. Culture defines the range of options for being a human within a certain time, place and group. The self is developed within the sociocultural context, which tells us what we should be, how we should interact with society, what we should feel and what those feelings mean, as well as how our body should look, be used and be cared for. This multidimensional model of culture allows us to define the dimensions of the self, and explain how the culturally derived self understands, reacts to and acts upon the individual body within a social context. The view of the self posited here allows us to research the experiential connection between the mind, the body and the society.
Mind and body: The gerontological perspective
Authors: Chenoweth Lynn , Jeon Yun‐Hee , Banks Christine
Published: January 2005

In all areas of care for the older person, whether it be in the hospital, nursing home or community, person‐centered care is what is aimed for. Holistic care is person centered. Therefore, what nurses do for older persons, how they do it and how they feel about what they do, all matter. This is the basis for all therapeutic encounters, acting as a creative impetus as well as a buffer from stress. This change in focus supports the patient/client and their families in ways that are empowering, uplifting, hopeful and powerful. It also protects the nurse from burnout.
Implicit memory and the maintenance of function in dementia: The complementarity between mind and body
Authors: Whall Ann L.
Published: January 2005

Since the time of Nightingale the discipline of nursing across the world has recognized that the health of the mind and the body are inextricably linked. With the advent of Postmodernism in the mid to late 20th century, the context of care and such mental health topics as patient's beliefs and desires were restored to their rightful place. Dementia was no longer viewed as a hopeless dead‐end. The latest Neomodernist period of science is seen as requiring the use of physical as well as mental means to support health.