Fate and seasonal change of Escherichia coli resistant to different antibiotic classes at each stage of conventional activated sludge process.

This study investigated the impact of each treatment stage of the activated sludge process on the fate of antibiotic resistant bacteria (ARB) in wastewater treatment plants (WWTPs). Wastewater and sludge samples were collected monthly at each stage of a commercial-scale WWTP. After 20-25 strains of indicator Escherichia coli were isolated from each sample on Chromocult Coliform Agar, antibiotic resistance of the isolates to amoxicillin (AMX), ciprofloxacin (CIP), norfloxacin (NFX), kanamycin (KM), sulfamethoxazole/trimethoprim (ST) and tetracycline (TC) were tested with the Kirby-Bauer disk diffusion method.

Down-regulation of endogenous Wt1 expression by Sry transgene in the murine embryonic mesonephros-derived M15 cell line.

Wt1 is one of numerous candidate genes comprising the hypothetical chain of gene expression essential for male sex differentiation of the bipotential indifferent gonads during embryogenesis. However, the evidence in the literature is ambivalent regarding the position of Wt1 relative to Sry in this scheme; Wt1 might act either upstream or downstream of Sry. In the present study, the effects of Sry expression upon Wt1 were investigated using M15 cells (XX karyotype), which are derived from murine embryonic mesonephros and express endogenous Wt1.

Design of hammerhead ribozymes that cleave murine Sry mRNA in vitro and in vivo.

As the first step in investigating the possiblity of applying ribozyme technology to artificial control of the sex ratios at birth in farm animals, where the demand for females exceeds that for males, we designed a hammerhead ribozyme (HHRz) and 2 tRNA(val)-hammerhead ribozyme complexes (tRNARz3 and tRNARz4), and examined their effects upon murine Sry mRNA in vitro and in cells. We demonstrated that HHRz and tRNARz3 could effectively cleave the target Sry mRNA in vitro. For the purpose of experiments in vivo, HHRz was cloned into the highly efficient pUC-CAGGS mammalian expression vector (pCAG/HHRz), and the tRNA ribozyme complexes were cloned into the pol III promoter-driven pPUR-KE vector (pPUR/tRNARz3 and pPUR/tRNARz4); the ribozyme vectors were co-transfected with the target vector (pCAG/Sry).

Long term adrenal insufficiency induces skeletal muscle atrophy and increases the serum levels of active form myostatin in rat serum.

Skeletal muscle wasting is a common symptom in the adrenal insufficiency such as Addison's disease. Although it has been suspected that several cytokines and/or growth factors are responsible for the manifestation of the symptom, the precise mechanisms underlying the phenomenon have so far been poorly understood. Myostatin is predominantly expressed in skeletal muscles and involved in the regulation of skeletal muscle mass.

Expression and localization of matrix metalloproteinases (MT1-MMP, MMP-2) and tissue inhibitor of metalloproteinase-2 (TIMP-2) during synepitheliochorial placentation of goats (Capra hircus).

Matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) play key roles during the placentation of highly invasive haemochorial type. Our knowledge is yet scanty, however, regarding the roles played by MMPs and TIMPs in the placentation of non-invasive synepitheliochorial type. In the present study, expression patterns of MT1-MMP, MMP-2 and TIMP-2 mRNAs as well as the encoded proteins in the endometrium and the placenta were examined on Days 35, 75, and 100 of pregnancy, representing roughly the 1st, 2nd and 3rd trimesters of caprine gestation, by means of quantitative RT-PCR analysis, in situ hybridization, immunoblotting, gelatin zymography and immunohistochemistry.

Analysis of transcriptional control elements in the 5'-upstream region of ovine interferon-tau gene using feeder-independent caprine trophoblast cell line, HTS-1.

Interferon-tau (IFNtau) is a protein secreted from the embryonic trophectoderm of ruminant ungulates during peri-implantation period. This protein acts on the uterine endometrium, which indirectly maintains corpus luteum function, and is therefore considered essential for the process of maternal recognition of pregnancy. Transcriptional regulation of IFNtau genes had been examined using human choriocarcinoma cell lines, JEG-3 or JAR, however, molecular mechanisms by which cell and term specific IFNtau expression are regulated have not been elucidated.

Dynamics of betaig-h3 mRNA expression during pregnancy in the uterus and the placenta of the mouse: a possible regulatory factor for trophoblastic invasion.

Changes in the betaig-h3 gene expression levels in the uterus during different reproductive stages and those in the placenta on different days of gestation in the mouse were examined by Northern blot analysis. The levels of betaig-h3 expression rose steeply from the baseline level at proestrus to the maximum at estrus and then declined rapidly from 1st day of diestrus onward. During pregnancy, high levels of betaig-h3 mRNA were detected in the uterus on Day 4 of gestation, when the trophoblastic invasion of the implanted blastocysts was very active.

Establishment of feeder-independent cloned caprine trophoblast cell line which expresses placental lactogen and interferon tau.

A feeder-independent cloned trophoblast cell line, HTS-1, was established from a mature placenta of Shiba goat (Capra hircus). During the growth phase, single HTS-1 cells exhibited ruffled membranes or lamellipodia often accompanied by elongated cell shape, indicating highly motile nature of the cells. At or near confluence, HTS-1 cells formed monolayers with few sign of cellular overlapping.

Content and localization of myostatin in mouse skeletal muscles during aging, mechanical unloading and reloading.

Changes in myostatin content and localization in mouse skeletal muscles were investigated during aging, hindlimb suspension (HS) and reloading after HS. During aging, the content of myostatin among solubilized proteins in gastrocnemius and plantaris muscles (Gast/Plant) was initially low and increased until their wet weight/body weight ratio reached a peak. It remained unchanged with further aging, although gradual atrophy of the muscles was seen to occur.

Essential role of ZP molecules in tubal transport of embryos in mice.

Our understandings of the molecular and cellular mechanisms underlying tubal transport of embryos are poor. This study describes the essential role of the molecules on the zona pellucida (ZP) in the tubal transport of mouse embryos. The bovine and porcine embryos that were interspecifically transferred to the mouse oviduct were selectively retained in the oviduct and rarely transported to the uterus.

Expression of membrane-type 1 matrix metalloproteinase (MT1-MMP) mRNA in trophoblast and endometrial epithelial cell populations of the synepitheliochorial placenta of goats (Capra hircus).

Membrane-type 1 matrix metalloproteinase (MT1-MMP), a membrane-bound matrix metalloproteinase, plays crucial roles in cellular migration through the matrix during embryogenesis, wound healing, and the invasion of host tissues by cancer cells. Mammalian trophoblast cells exhibit different degrees of invasiveness towards the endometrium in different species during gestation. The highly invasive trophoblast cells of primates and rodents which form hemochorial placentae have often been compared to metastatic cancer cells, and are known to express MT1-MMP at their invasive edge.

The trophinin gene encodes a novel group of MAGE proteins, magphinins, and regulates cell proliferation during gametogenesis in the mouse.

Trophinin is a membrane protein that mediates apical cell adhesion between trophoblastic cells and luminal epithelial cells of the endometrium and is implicated in the initial attachment during the process of human embryo implantation. The present study identified novel trophinin gene transcripts, which encode proteins structurally distinct from trophinin protein in the mouse. We designated these proteins "magphinins," because they share consensus amino acid sequences with MAGE (melanoma-associated antigen) superfamily proteins.

A transgenic mouse model for investigating the response of the upstream region of whey acidic protein (WAP) gene to various steroid hormones.

The limitations of studies of clarification of response elements of whey acidic protein (WAP) gene to hormones using mammary cell lines has been shown. We studied the response of the upstream region (2.6 kb) of WAP to various steroid hormones using gonadectomized mWAP/hGH transgenic mice.

Possible role for the c-ski gene in the proliferation of myogenic cells in regenerating skeletal muscles of rats.

Skeletal muscle regeneration after injury involves various processes, such as infiltration by inflammatory cells, the proliferation of satellite cells and fusion to myotubes. The c-ski nuclear protein has been implicated in the control of cell proliferation and/or terminal differentiation in the growth of skeletal muscle. However, there have been no reports concerning the involution of c-ski in the regeneration of injured skeletal muscle in mammals.

Differential gene expression of beta-1,4-galactosyltransferases I, II and V during mouse brain development.

Since most brain glycoproteins from beta-1,4-galactosyltransferase (beta-1,4-GalT) I knockout mice were galactosylated without apparent reduction the gene expression of novel beta-1,4-GalTs II and V which are involved in N-linked oligosaccharide biosynthesis in addition to beta-1,4-GalT I was studied during mouse brain development. Isolation and characterization of beta-1,4-GalT II and V cDNAs from mouse brains indicates that they are also functioning in the brain. Northern blot analysis revealed that the beta-1,4-GalT I gene is expressed mainly in mid-embryonic stages, while the expression level of beta-1,4-GalT II transcript remains constant and of beta-1,4-GalT V transcript increases during mouse brain development after birth.

In vitro studies on PGC or PGC-like cells in cultured yolk sac cells and embryonic stem cells of the mouse.

The present study aims: 1) to determine those conditions which promote the proliferation of primordial germ cells (PGCs) of the migratory phase in the yolk sac; and 2) to examine the effects of yolk sac cells as a feeder layer under the conditions mentioned above upon the embryonic stem (ES) cells (R1) with high potential for entering the germ line in vivo in chimeras. In murine yolk sac cells obtained on Day 10.5-11.

Co-injection of restriction enzyme with foreign DNA into the pronucleus for elevating production efficiencies of transgenic animals.

The microinjection method for production of transgenic farm animals requires specialized techniques and results in intolerably low production efficiencies. We investigated whether or not co-injection of foreign DNA constructs with restriction endonuclease into the pronucleus of mouse zygotes would improve the integration frequencies of foreign DNA into the host genome. Two kinds of DNA constructs that have no EcoRI site in their sequences were used for co-microinjection.

Comparative analysis of HOXC-9 gene expression in murine hemochorial and caprine synepitheliochorial placentae by in situ hybridization.

Mammalian placentae exhibit wide structural diversity among different species and are formed under intricate interplay between the embryonic trophoblast and the maternal endometrial cells. Increasing evidence in the literature indicates a possible role played by homeobox genes in the complex placental organogenesis. Although the expression of all HOX 9 paralogs has been demonstrated both in highly invasive murine hemochorial placentae and in non-invasive caprine synepitheliochorial placentae, no reports so far published in the literature described the patterns of gene expression of Hoxc-9 in the murine nor those of HOXC-9 in the caprine placenta at cellular levels.

Expression of milk protein genes is induced directly by exogenous STAT5 without prolactin-mediated signal transduction in transgenic mice.

STAT5 is a member of the family of STAT (signal transducer for activating transcription), which was isolated from nuclear extracts of the lactating gland of sheep. It was reported that, in vitro, STAT5 could be activated directly by prolactin (PRL) without PRL-mediated signal transduction. The present study was conducted to investigate above the possibility in vivo, using the transgenic mice overexpressing ovine STAT5 (oSTAT5) under the control of MMTV promoter.

Molecular cloning of cDNA for equine follistatin and its gene expression in the reproductive tissues of the mare.

A cDNA clone encoding equine follistatin was isolated from an equine ovarian cDNA library. Out of 1.2 x 10(5) independent clones screened, one positive clone was isolated and its cDNA sequence determined.

Wilms' tumor suppressor gene (WT1) as a target gene of SRY function in a mouse ES cell line transfected with SRY.

With the aim of identifying the gene(s) located downstream from SRY, we transfected an ES cell line with XX karyotype, TMA-18, with a Sry DNA construct and established cell lines, TS18-1 and TS18-2, where the transfected Sry was expressed in the functional linear mRNA form. Among the five potential SRY-target genes examined, i.e.

Expression and localization of membrane type matrix metalloproteinase-1 (MT1-MMP) in trophoblast cells of cultured mouse blastocysts and ectoplacental cones.

Membrane type matrix metalloproteinases (MT-MMPs) possess a C-terminal transmembrane domain and are expressed on the cell membrane. It was suspected, therefore, that MT1-MMP might play an important role in the trophoblastic invasion during implantation. The patterns of expression and localization of membrane type matrix metalloproteinase-1 (MT1-MMP) were examined immunocytochemically in cultured mouse blastocysts and excised extoplacental cones (EPCs).

Developmental fate of single embryonic stem cells microinjected into 8-cell-stage mouse embryos.

Embryonic stem (ES) cells are pluripotent and capable of differentiating into somatic as well as germ cell lineages when conjoined with blastomeres of early mouse embryos. However, the developmental potential of single ES cells has not been fully investigated. We injected single murine ES cells (A3-1 cell line) of 129 origin into 8-cell mouse embryos (B6xBDF1) and examined the patterns of distribution of ES-cell-derived cells in the blastocysts as well as in the fully grown chimeric mice.

Growth hormone-releasing hormone (GHRH)-GH-somatic growth and luteinizing hormone (LH)RH-LH-ovarian axes in adult female transgenic mice expressing human GH gene.

We have examined alterations in the hypothalamo-pituitary GH-somatic growth axis and the hypothalamo-pituitary LH-ovarian axis in a line of transgenic ICR mice expressing human GH (hGH) under the influence of the whey acid protein promoter. Transgenic female mice weighed twice as much as control females and were infertile. The size of the anterior pituitary (AP) was 1/3 that of the controls.