Evaluation of Nonacog Beta Pegol Long-term Safety in the Immune-deficient Rowett Nude Rat (Crl:NIH-Foxn1rnu)

Nonacog beta pegol is a 40-kDa polyethylene glycosylated (PEGylated) human recombinant coagulation factor IX, intended for the treatment of hemophilia B. Human coagulation factors are immunogenic in animals; therefore, to evaluate the long-term toxicity of nonacog beta pegol, an immune-deficient, athymic rat (Rowett nude; Crl:NIH-Foxn1(rnu)) was used. Rats (n = 216) were given intravenous nonacog beta pegol 0, 40, 150, 600, or 1,200 IU/kg every 5th day for 26 weeks. To avoid infections, the animals were housed in a full-barrier environment with sterilized food and bedding. Standard toxicity end points were unaffected by treatment. All treated animals were exposed to nonacog beta pegol throughout the study, and no animals developed antidrug antibodies. Immunohistochemical staining revealed PEG in choroid plexus epithelial cells in a dose-dependent manner. Transmission electron microscopy showed that PEG was distributed in cytoplasmic vesicles of these cells, with no apparent effect on cellular organelle structures. Fourteen (6.5%) animals were euthanized or died prematurely due to nontreatment-related infections in the urogenital system and skin. In conclusion, the athymic rat is a suitable model for testing chronic toxicity of human proteins that are immunogenic in animals. Nonacog beta pegol was generally well tolerated, with no adverse effect of PEG on choroid plexus epithelial cells.

The role of Serpine-1 and Tissue inhibitor of metalloproteinase type-1 in early host responses to Staphylococcus aureus intracutaneous infection of mice

Staphylococcus aureus is a common cause of skin and soft tissue infections in animal and humans. In the current study, we hypothesized that early host responses to S. aureus infection leading to the recruitment of neutrophils and control of the bacterium at the site of infection depend on the expression of Serpine-1 and Tissue inhibitor of metalloproteinase type-1, two important endogenous proteinase inhibitors that possess regulatory properties on a variety of pathophysiological conditions. Using a mouse model of skin infection and single-gene and double-gene knockout mice, however, our observations showed that Serpine-1 and Tissue inhibitor of metalloprotease type-1 did not impact the number of bacteria accumulating at the site of infection. Double-gene knockout mice further had the same volume of accumulating host cells at the site of infection, while single Tissue inhibitor of metalloprotease type-1 knockout mice showed a decreased number of cells. Follow-up studies demonstrated changes in Serpine-1, Tissue inhibitor of metalloprotease type-1 and IL-6 plasma levels following challenge. In addition, double-gene knockout mice did not differ from wild-type mice in white blood cell, granulocyte and leucocyte counts, while single-gene genotypes differed in these phenotypes.

Salivary tissue inhibitor of metalloproteinases-1 localization and glycosylation profile analysis

Salivary tissue inhibitor of metalloproteinases-1 (TIMP-1) has been associated with pathological conditions in the oral cavity, but the origin of TIMP-1 in saliva remains unknown. Hence, we studied the localization of TIMP-1 in salivary gland tissue and also investigated if TIMP-1 found in blood and saliva is identical. Human salivary gland tissue samples (four parotid gland and four submandibular gland biopsies) were analysed for the presence of TIMP-1 mRNA and protein expression. To assess TIMP-1 glycosylation profiles in blood and saliva, the protein was isolated from plasma and unstimulated and stimulated whole saliva as well as stimulated parotid and submandibular saliva and analysed by MALDI-TOF mass spectrometry. TIMP-1 protein was demonstrated in mucous acinar cells of the submandibular gland and in ductal cells of both the parotid and submandibular gland. However, no TIMP-1 mRNA was detected in any of these cells. The glycosylation profiles of TIMP-1 isolated from whole saliva and saliva from the major glands were highly similar. In contrast, a significant difference was found between the glycoprofiles of salivary TIMP-1 and plasma TIMP-1. Although no clear evidence of TIMP-1 transcription in major salivary glands was demonstrated our results suggest that TIMP-1 in saliva does not originate from plasma.

TIMP-1 expression in human colorectal cancer is associated with TGF-B1, LOXL2, INHBA1, TNF-AIP6 and TIMP-2 transcript profiles

The balance of activity between the endogenous enzyme inhibitors known as tissue inhibitors of metalloproteinases and their targets, the matrix metalloproteinases, in the extracellular matrix is thought to play an important role in tumour cell invasion. Supporting this notion, we have shown that colorectal cancer patients have increased plasma levels of the tissue inhibitor of metalloproteinases-1 (TIMP-1), and that high plasma TIMP-1 levels are associated with short colorectal cancer patient survival. However, although TIMP-1 has been extensively studied in cancer, very little is known about how it is regulated. To further elucidate potential mechanisms of regulation of this protein, we did a number of experiments to look at associations between the transcript profile of TIMP-1 with known matrix metalloproteinases (MMPs) as well as with expression profiles of other genes differentially regulated in human colorectal cancer (CRC) and the other TIMPs 2-4, which have also been associated with the progression of colorectal cancer. Genome-wide expression profiling of 172 CRC and normal mucosa samples was used to identify transcript changes for the genes under investigation. We found that TIMP-1 was up-regulated in CRC samples compared with normal tissue, while TIMP-2 was down-regulated. Eight MMPs were up-regulated in CRC compared with normal tissue. Correlating up-regulated genes with the TIMP-1 transcript, we identified 13 that were also up-regulated in cancerous tissue. Among these were genes associated with the synthesis of extracellullar matrix, genes involved in the TGF-beta signalling pathway, and genes that are likely transcribed by the tumour cells. These insights add to the complex picture emerging about the regulation of TIMPs in colorectal cancer.

Gender-dependent physiological implications of combined PAI-1 and TIMP-1 gene deficiency characterized in a mouse model

The endogenous proteinase inhibitors plasminogen activator inhibitor type 1 (PAI-1) and tissue inhibitor of metalloproteinase type 1 (TIMP-1) are two distinct proteins with separate molecular pathways. However, a close relationship between PAI-1 and TIMP-1 has been proposed indicating some degree of functional overlap due to their involvement in ECM turnover, tissue remodeling, and cellular migration and signaling. To study the housekeeping physiological implications of PAI-1 and TIMP-1, we generated a combined PAI-1 and TIMP-1 gene-deficient mouse model. We present the results on generating this specific mouse model with particular emphasis on phenotypical characteristics, blood leukocyte counts, histology, and gene expression studies of PAI-1 and TIMP-1 in various organs. We observed a significant deviation in segregation of offspring only in male mice (P < 0.01) predominantly caused by PAI-1 deficiency. In addition, the body weight in 3- and 20-wk-old male and 20-wk-old female mice was significantly different between genotypes (P <or= 0.0008). Furthermore, blood leukocyte counts were significantly different between genotypes in 20-wk-old male mice (P <or= 0.0002), whereas no significant differences were observed between genotypes in 20-wk-old female mice (P >or= 0.13). Quantifying the relative expression of PAI-1 and TIMP-1 revealed upregulation of PAI-1 (P < 0.001) in male mice only. Our data highlight the complex roles of PAI-1 and TIMP-1 on physiological parameters such as segregation of offspring (embryonic development and survival), body weight (metabolism), blood leukocyte counts (immunity), and gene expression (regulatory redundancy). We conclude that PAI-1 and TIMP-1 seem to possess gender-dependent regulatory properties on various housekeeping physiological parameters and stress the potential implications in pathological conditions.

Transcription levels of endothelin-1 and endothelin receptors are associated with age and leaflet location in porcine mitral valves

The aim of the study was to investigate the expression levels of endothelin-1 (ET-1) and ET(A) and ET(B) receptors (ET(A)-R and ET(B)-R) in porcine mitral valves and associate the transcription levels to age, leaflet location and deposition of mucopolysaccharides (MPS). Tissue samples from the chordal and inter-chordal insertion area of the anterior mitral valve leaflet from 11 sows (> or = 2 years of age) and 10 slaughter pigs (approximately 6 months old) were obtained and the relative gene expression levels of ET-1, ET(A)-R and ET(B)-R measured by semi-quantitative real-time PCR. A separate tissue sample was taken for histopathological grading of MPS deposition. The transcription levels of ET-1 (P < 0.0001) and ET(A)-R (P < 0.0004) were significantly higher in leaflets from the sows compared with slaughter pigs. The gene expression of ET(B)-R was not associated to age (P = 0.38), but increased in chordal insertion areas compared with inter-chordal areas (P = 0.01). The expression of ET-1 and ET(A)-R mRNA did not differ significantly between the two leaflet locations. The valve leaflets from sows had a significantly increased degree of MPS deposition compared with slaughter pigs upon histological examination (P = 0.04). In conclusion, an age-related valvular degeneration is observed in porcine mitral valve leaflets and ET-1 is suggested to be involved through action of both ET(A) and ET(B) receptors.

Identification of alternatively spliced TIMP-1 mRNA in cancer cell lines and colon cancer tissue

TIMP-1 is a promising new candidate as a prognostic marker in colorectal and breast cancer. We now describe the discovery of two alternatively spliced variants of TIMP-1 mRNA. The two variants lacking exon 2 (del-2) and 5 (del-5), respectively, were identified in human cancer cell lines by RT-PCR. The del-2 variant was, furthermore, detected in extracts from 12 colorectal cancer tissue samples. By western blotting additional bands of lower molecular mass than full-length TIMP-1 were identified in tumor tissue, but not in plasma samples obtained from cancer patients. The two splice variants of TIMP-1 may hold important clinical information, and either alone or in combination with measurement of full-length TIMP-1 they may improve the prognostic and/or predictive value of TIMP-1 analyses.

Concentrations of TIMP1 mRNA splice variants and TIMP-1 protein are differentially associated with prognosis in primary breast cancer

BACKGROUND

TIMP-1 protein is a prognostic factor for recurrence-free and overall survival (OS) time in breast cancer. We evaluated the prognostic value of TIMP1 mRNA and a novel TIMP1 mRNA splice variant in 1301 primary breast cancer patients.

METHODS

We measured mRNA transcripts of full-length TIMP1 (TIMP1-v1) and the novel splice variant lacking exon 2 (TIMP1-v2) by use of real-time RT-PCR in frozen primary tumor samples. Transcript concentrations are correlated with histomorphological and biological factors, TIMP-1 protein, and distant metastasis-free survival (MFS) and OS time.

RESULTS

TIMP1-v1 and TIMP1-v2 alone were not informative with respect to predicting prognosis. However, the PCR assay designed to measure the combination of v1 + v2 showed that high concentrations of this combination were associated with good prognosis. In Cox multivariate regression analysis, which also included the traditional prognostic factors, increasing concentrations were independently associated with prolonged MFS (P = 0.004) and OS (P = 0.048). Including TIMP-1 protein and TIMP1-v1+v2 mRNA together in the multivariate model revealed that protein and mRNA were both independently associated with prognosis, with hazard ratios pointing in opposite directions.

CONCLUSION

High concentrations of TIMP1-v1+2 mRNA are associated with good prognosis in patients with primary breast cancer. Since high concentrations of TIMP-1 protein are associated with poor prognosis, the presence of possible posttranscriptional mechanisms requires further investigation.

TIMP-1 gene deficiency increases tumour cell sensitivity to chemotherapy-induced apoptosis

Tissue inhibitor of metalloproteinases-1 (TIMP-1) is one of four inhibitors of the matrix metalloproteinases, which are capable of degrading most components of the extracellular matrix. However, in recent years, TIMP-1 has been recognised as a multifunctional protein, playing a complex role in cancer. In this regard, several studies have demonstrated an antiapoptotic effect of TIMP-1 in a number of different cell types. Since chemotherapy works by inducing apoptosis in cancer cells, we raised the hypothesis that TIMP-1 promotes resistance against chemotherapeutic drugs. In order to investigate this hypothesis, we have established TIMP-1 gene-deficient and TIMP-1 wild-type fibrosarcoma cells from mouse lung tissue. We have characterised these cells with regard to TIMP-1 genotype, TIMP-1 expression, malignant transformation and sensitivity to chemotherapy-induced apoptosis. We show that TIMP-1 gene deficiency increases the response to chemotherapy considerably, confirming that TIMP-1 protects the cells from apoptosis. This is to our knowledge the first study investigating TIMP-1 and chemotherapy-induced apoptosis employing a powerful model system comprising TIMP-1 gene-deficient cells and their genetically identical wild-type controls. For future studies, this cell system can be used to uncover the mechanisms and signalling pathways involved in the TIMP-1-mediated inhibition of apoptosis as well as to investigate the possibility of using TIMP-1 inhibitors to optimise the effect of conventional chemotherapy.

147 IDENTIFICATION OF PRIMORDIAL GERM CELLS IN PORCINE EMBRYOS FROM THE PRIMITIVE STREAK STAGE

In embryonic stem cell research, Oct-4 is one of the most widely used markers of pluripotency. Moreover, at least in the mouse, this marker is restricted to primordial germ cells (PGCs) after gastrulation. Vimentin is often used as a marker of mesoderm/mesenchyme in embryonic tissues and appears to localize to the same embryonic cells as Oct-4, at least in the bovine epiblast. The expression of neither of these markers has been completely addressed in the pig. Therefore, the purpose of the present study was to examine the expression of Oct-4 and vimentin in the porcine epiblast during differentiation and establishment of the three germ layers, i.e. the process of gastrulation. A total of 410 porcine embryos were collected at 8 to 17 days post-insemination from 29 sows of the Danish Landrace breed. Embryos were categorized based on stereo-microscopic observations into the following stages: pre-streak stages 1 and 2, primitive streak stage, neural groove stage, and somite stage. Specimens were fixed at all stages, dehydrated and embedded in paraffin wax. Selected embryos at each stage (n = 28) were completely cut into serial sections for immunohistochemical evaluation of Oct-4 and vimentin. Pre-streak stage 1 embryos were defined by lack of polarization of the embryonic disk, whereas in pre-streak stage 2 embryos a crescent shaped thickening was seen at the posterior pole of the disk. This thickening, marking the first morphological anterior-posterior polarization of the embryo proper, was shown to be a site of incipient ingression of cells from the epiblast. Immunohistochemical analyses localized Oct-4 to nuclei and vimentin to cytoplasm of both founding and ingressing epiblast cells. During formation of mesoderm and endoderm, at the primitive streak stage, solitary Oct-4 positive cells, i.e. potential PGCs, were seen scattered in the endoderm. Cells of the epiblast displayed positive labeling for Oct-4 until specification for the ectoderm cell lineage at the subsequent neural groove stage. In mesoderm, Oct-4 likewise disappeared by the time of formation of the first somites, defining the following somite stage. Thus, at this stage the only cells labeled for Oct-4, i.e. potential PGCs, were seen solitarily scattered in the endoderm. By the 15-somite stage, such cells were no longer visible in the endoderm but were seen located in the mesoderm, spreading from the stalk of the yolk sac and allantois and extending through the mid- and hindgut areas into the incipient genital ridge. Vimentin localized to the mesenchyme and most other derivatives of neural crest and mesodermal origin. In conclusion, based on Oct-4 labeling and distribution pattern, we strongly believe that we have identified the porcine PGCs from the primitive streak stage.

Confinement and clearance of OCT4 in the porcine embryo at stereomicroscopically defined stages around gastrulation

In the areas of developmental biology and embryonic stem cell research, reliable molecular markers of pluripotency and early lineage commitment are sparse in large animal species. In this study, we present morphological and immunohistochemical findings on the porcine embryo in the period around gastrulation, days 8-17 postinsemination, introducing a stereomicroscopical staging system in this species. In embryos at the expanding hatched blastocyst stage, OCT4 is confined to the inner cell mass. Following detachment of the hypoblast, and formation of the embryonic disk, this marker of pluripotency was selectively observed in the epiblast. A prominent crescent-shaped thickening at the posterior region of the embryonic disk marked the first polarization within this structure reflecting incipient cell ingression. Following differentiation of the epiblast, clearance of OCT4 from the three germ layers was observed at defined stages, suggesting correlations to lineage specification. In the endoderm, clearance of OCT4 was apparent from early during its formation at the primitive streak stage. The endoderm harbored progenitors of the "fourth germ layer," the primordial germ cells (PGCs), the only cells maintaining expression of OCT4 at the end of gastrulation. In the ectodermal and mesodermal cell lineages, OCT4 became undetectable at the neural groove and somite stage, respectively. As in the mouse, PGCs showed onset of c-kit expression when located in extraembryonal compartments. They appeared to follow the endoderm during extraembryonal allocation and the mesoderm on return to the genital ridge.

Preterm birth makes the immature intestine sensitive to feeding-induced intestinal atrophy

Preterm birth and formula feeding predispose to small intestinal dysfunction, which may lead to necrotizing enterocolitis (NEC). In piglets, we tested whether the physiological and environmental transitions occurring at birth affect the response of the immature intestine to enteral feeding. Pig fetuses (106 days gestation, term = 115 days) were prepared with esophageal feeding tubes and fed either sow's colostrum (n = 8) or infant formula (n = 7) in utero. After 24 h of oral feeding, the pig fetuses were delivered by cesarean section and their gastrointestinal morphology and function were compared with those of preterm newborn (NB) littermates that were not fed (n = 8) or fed colostrum (n = 7) or formula (n = 13) for 24 h after birth. Before birth, both colostrum and formula feeding resulted in marked increases in intestinal mass, brush-border enzyme activities, and plasma glucagon-like peptide 2 concentrations, to levels similar to those in NB colostrum-fed piglets. In contrast, NB formula-fed piglets showed reduced intestinal growth, decreased brush-border enzyme activities, and intestinal lesions, reflecting NEC. NB formula-fed pigs also showed impaired enterocyte endocytotic function and decreased antioxidative capacity, whereas brush-border enzyme mRNA levels were unaltered, relative to NB colostrum-fed pigs. Our results indicate that the feeding-induced growth and enzyme maturation of the immature intestine are not birth dependent. However, with a suboptimal diet (milk formula), factors related to preterm birth (e.g., microbial colonization and metabolic and endocrine changes) make the immature intestine sensitive to atrophy and development of NEC.

Functional challenge affects aquaporin mRNA abundance in mouse blastocysts

The aquaporins (AQPs) are a family of channel proteins that facilitate diffusion of water across cell membranes. Three members of the AQP family have been detected in the mouse blastocyst: AQP 3 and 8 are located in the basolateral domain and AQP 9 predominantly in the apical domain of the trophoblast cells. These are believed to be involved in facilitating the accumulation of fluid into the blastocyst cavity. We have investigated the ability of mouse embryos to regulate AQP gene expression in response to different treatments expected to affect the passage of water across the trophoblast cells using real-time PCR. In the first experiment 8-cell embryos were allowed to develop to blastocysts in media from 300 to 400 mOsm. Blastocyst formation was unaffected by media made hyperosmolar by glycerol, whereas blastocyst formation was significantly reduced in sucrose-based 350 and 400 mOsm media. AQP 8 mRNA levels were reduced when embryos were cultured in glycerol-based hyperosmolar media. The mRNA levels of AQP 3, 7, 9, and 11 were not significantly affected by hyperosmolar media. In the second experiment blastocysts were punctured (0 hr) and allowed to re-expand. AQP mRNA levels were examined after 2, 6, and 10 hr. Compared to control embryos, the expression of AQP 3, 7, and 9 were upregulated after 2 hr. Upregulation was sustained only for AQP 9 and this was sustained up to 6 and 10 hr after puncture. In the third experiment we compared expression of AQPs between in vitro cultured and in vivo developed blastocysts. We found that in vitro culture resulted in lower levels of AQP 8, 9, and 11 compared to in vivo development. These experiments show that mouse embryos are capable of regulating AQP mRNA abundances in response to environmental alterations.

229 EFFECT OF CULTURE CONDITIONS ON AQUAPORIN mRNA ABUNDANCE IN MOUSE BLASTOCYSTS

It is known that culture conditions can alter gene expression of the pre-implantation embryo. We have previously shown that aquaporins (AQPs) are expressed in the mouse embryo and that they are involved in the passage of water across the trophoblast cells during blastocyst formation. This study was conducted to investigate whether AQP mRNA abundance is altered by culturing embryos in vitro compared to in vivo developed embryos. Furthermore we wanted to investigate if AQP mRNA abundance was influenced by the osmolality of the media. It is possible to compare the effect of hyperosmolality that the embryo may be able to compensate for by adding glycerol which can cross some AQPs, compared to the addition of sucrose which can not cross the membranes. Mouse embryos were obtained by superovulating B6D2F1 mice followed by culture of the flushed presumptive zygotes in KSOM to the blastocyst stage (in vitro) or by flushing blastocysts from the uterus (in vivo). For the study of the influence of osmolality on AQP mRNA abundance, zygotes were flushed and cultured to the compacted 8-cell stage and then placed in media of increasing osmolality, using either glycerol or sucrose. The osmolalities of the media were 243 (control), 300, 350, and 400 mOsm. Embryos were cultured to the blastocyst stage and frozen in liquid nitrogen. Embryonic RNA was extracted using a Dynabeads mRNA Capture kit (Dynal, Oslo, Norway). Real time PCR was performed on embryonic cDNA on a Lightcycler (Roche Diagnostics, 2650 Hvidovre, Denmark) using aquaporin-specific primers and primers for β-actin and GAPDH. The results of the quantitative RT-PCR analysis showed that in vitro-cultured embryos had a lower mRNA abundance for AQP 8, 9, and 11 compared to the in vivo-developed embryos but that the AQP 3 mRNA abundance was unaltered. Analysis of the housekeeping genes showed that GAPDH mRNA levels were unchanged in vitro, whereas β-actin was up-regulated in vitro. The osmotically challenged embryos showed the following blastocyst rates compared to the controls: glycerol 300: 100%; glycerol 350: 100%; glycerol 400: 100%; sucrose 300: 100%; sucrose 350: 78%; and sucrose 400: 0%. Thus, glycerol up to 400 mOsm had no effect on blastocyst rates, whereas addition of sucrose reduced blastocyst formation, with a total inhibition at 400 mOsm. Analysis of the mRNA abundance showed a reduction of AQP 8 in the glycerol solutions. The level was reduced to 30% of the control group at 300 mOsm, to 27% at 350 mOsm and to 8% at 400 mOsm. There was no corresponding reduction of AQP 8 mRNA abundance in sucrose solutions. Further, AQP 3, 7, 9, and 11 mRNA levels as well as β-actin and GAPDH mRNA levels were unaltered in the osmotically challenged embryos. In conclusion, this study shows that embryonic culture affects the abundance of several AQPs and that compensation of a glycerol-induced osmotical challenge induces down-regulation of AQP 8 expression. Embryos tolerate high glycerol concentrations better than high sucrose concentrations but the possible role of AQP 8 in this process is unclear at present.

Aquaporin proteins in murine trophectoderm mediate transepithelial water movements during cavitation

Mammalian blastocyst formation is dependent on establishment of trophectoderm (TE) ion and fluid transport mechanisms. We have examined the expression and function of aquaporin (AQP) water channels during murine preimplantation development. AQP 3, 8, and 9 proteins demonstrated cell margin-associated staining starting at the 8-cell (AQP 9) or compacted morula (AQP 3 and 8) stages. In blastocysts, AQP 3 and 8 were detected in the basolateral membrane domains of the trophectoderm, while AQP3 was also observed in cell margins of all inner cell mass (ICM) cells. In contrast, AQP 9 was predominantly observed within the apical membrane domains of the TE. Murine blastocysts exposed to hyperosmotic culture media (1800 mOsm; 10% glycerol) demonstrated a rapid volume decrease followed by recovery to approximately 80% of initial volume over 5 min. Treatment of blastocysts with p-chloromercuriphenylsulfonic acid (pCMPS, > or =100 microM) for 5 min significantly impaired (P < 0.05) volume recovery, indicating the involvement of AQPs in fluid transport across the TE. Blastocysts exposure to an 1800-mOsm sucrose/KSOMaa solution did not demonstrate volume recovery as observed following treatment with glycerol containing medium, indicating glycerol permeability via AQPs 3 and 9. These findings support the hypothesis that aquaporins mediate trans-trophectodermal water movements during cavitation.

Cloning and characterization of the bovine EGR4 gene and evaluation as candidate gene for bovine spinal dysmyelination

Genes of the early growth response (EGR) family encode transcription factors with a highly conserved DNA binding zinc finger domain, which regulate a variety of genes, e.g. late myelin genes. Here, the cloning, genomic structure and expression of the bovine orthologue of the EGR4 gene are reported. The gene consists of two exons and encodes a 482 amino acid protein with a Cys2His2 zinc finger structure. The predicted protein shares between 80 and 87% identity to mouse, rat and human EGR4 proteins and all four species share almost complete identity in the DNA-binding domain. The bovine transcript is alternatively spliced by retaining intronic sequence, giving rise to two different mRNAs differing in three nucleotides and resulting in an extra alanine residue in the longer variant of the predicted protein. The gene was mapped by radiation hybrid (RH) mapping to markers on bovine chromosome 11. EGR4 transcripts were detected by reverse transcriptase polymerase chain reaction (RT-PCR) in the frontal cortex and cerebellum, and a low expression level was also detected in the liver. The EGR4 gene was evaluated as a candidate gene for bovine spinal dysmyelination (BSD). Sequencing of the gene from a homozygous affected animal and a heterozygous carrier revealed a single base mutation that leads to an amino acid substitution at residue 322 in EGR4. Genotype analysis of this polymorphism in a pedigree segregating for BSD, as well as in a panel of different cattle breeds, and sequence analysis of the entire coding region suggested that the EGR4 is not the gene responsible for BSD. Furthermore, 87 animals of different cattle breeds were screened for single-nucleotide polymorphisms (SNPs) resulting in the identification of two SNPs in EGR4.

mRNAs encoding aquaporins are present during murine preimplantation development

The present study was conducted to investigate the mechanisms underlying fluid movement across the trophectoderm during blastocyst formation by determining whether aquaporins (AQPs) are expressed during early mammalian development. AQPs belong to a family of major intrinsic membrane proteins and function as molecular water channels that allow water to flow rapidly across plasma membranes in the direction of osmotic gradients. Ten different AQPs have been identified to date. Murine preimplantation stage embryos were flushed from the oviducts and uteri of superovulated CD1 mice. Reverse transcription-polymerase chain reaction (RT-PCR) methods employing primer sets designed to amplify conserved sequences of AQPs (1-9) were applied to murine embryo cDNA samples. PCR reactions were conducted for up to 40 cycles involving denaturation of DNA hybrids at 95 degrees C, primer annealing at 52-60 degrees C and extension at 72 degrees C. PCR products were separated on 2% agarose gels and were stained with ethidium bromide. AQP PCR product identity was confirmed by sequence analysis. mRNAs encoding AQPs 1, 3, 5, 6, 7, and 9 were detected in murine embryos from the one-cell stage up to the blastocyst stage. AQP 8 mRNAs were not detected in early cleavage stages but were present in morula and blastocyst stage embryos. The results were confirmed in experimental replicates applied to separate embryo pools of each embryo stage. These results demonstrate that transcripts encoding seven AQP gene products are detectable during murine preimplantation development. These findings predict that AQPs may function as conduits for trophectoderm fluid transport during blastocyst formation.

Localisation of RAD50 and MRE11 in spermatocyte nuclei of mouse and rat

Synaptonemal complexes (SCs) are zipperlike structures that are assembled between homologous chromosomes during meiotic prophase. They consist of two axial elements (AEs) (one along each of the two homologous chromosomes), which, in mature SCs, are connected by numerous transverse filaments along their length. Several proteins involved in the later steps of meiotic recombination most probably function in close association with the AEs of SCs, because the proteins involved in these steps have all been localised along AEs or SCs by immunocytochemical methods. It is not known at which step in meiotic recombination this association with the AEs is established. In order to shed some light on this issue, we analysed the localisation of two proteins that are involved in early steps of meiotic recombination, RAD50 and MRE11, relative to AEs and SCs by immunofluorescence labelling of paraffin sections of the mouse testis, using affinity-purified polyclonal antibodies against RAD50 and MRE11, and monoclonal and polyclonal antibodies against SC components. The localisation patterns of MRE11 and RAD50 within spermatocytes were very similar. MRE11 and RAD50 appeared in high abundance in preleptotene spermatocytes, just before SC components could be detected. From preleptotene until early zygotene they were present throughout the nucleus. In mid and late zygotene, MRE11 and RAD50 concentrated in distinct areas; in early pachytene the two proteins had almost disappeared from the nucleus, except from the sex vesicle (the chromatin of the XY bivalent), where they persisted in high abundance until diplotene. We propose that MRE11 and RAD50, together with other proteins, prepare chromatin throughout the early meiotic prophase nucleus for the initiation of meiotic recombination. Possibly, only a small fraction of the RAD50- and MRE11-containing (pre)recombination complexes associates transiently with AEs, where further steps in meiotic recombination can take place.

A high proportion of bovine blastocysts produced in vitro are mixoploid

Fluorescence in situ hybridization with chromosome 6- and chromosome 7-specific probes was used to assess the extent of chromosome abnormalities in developing bovine blastocysts at 7-8 days after insemination in vivo or in vitro. Interphase nuclei (N = 10 946) were analyzed from 151 blastocysts produced in vitro and from 28 blastocysts recovered from superovulated animals. This revealed that 72% (109 of 151) of the in vitro-produced blastocysts were mixoploid, i.e., were a mixture of normal, diploid, and polyploid cells. However, only a small fraction of the total number of cells were chromosomally abnormal. Of the mixoploid blastocysts, 83% (91 of 109) contained less than 10% polyploid cells, 13% (14 of 109) contained 11-25% polyploid cells, and only 4% (4 of 109) of the blastocysts had more than 25% polyploid cells per blastocyst. In contrast, a significantly lower proportion (25%) of mixoploidy was found in 28 bovine blastocysts developed in vivo (p < 0.0001). All of the mixoploid blastocysts that had developed in vivo contained less than 10% polyploid cells. No entirely aneuploid blastocysts, i. e., blastocysts in which all cells had the same type of chromosome abnormality, were found in either of the groups. Taken together, the most common chromosome abnormalities observed were diploid-triploid mixoploidies and diploid-tetraploid mixoploidies. Thus, our results confirm earlier reports that morphologically normal bovine blastocysts developed in vivo are often mixoploids. We further show that in vitro-produced bovine blastocysts have a high rate of mixoploidy. Although the difference in mixoploidy rate detected in this study may not be general, it is an interesting phenomenon for further studies.

The efficacy, tolerability, and safety of 1200 mg/d of oxaprozin and 1500 mg/d of nabumetone in the treatment of patients with osteoarthritis of the knee

This 6-week, multicenter, double-masked, placebo-controlled study compared the efficacy, tolerability, and safety of the recommended starting dose of oxaprozin (1200 mg/d) and a 1500-mg/d dose of nabumetone in the treatment of patients with moderate-to-severe osteoarthritis (OA) of the knee. A total of 347 patients with a mean age of 61.1 years were randomized to receive oxaprozin (116 patients), nabumetone (115 patients), or placebo (116 patients). Adults of either sex who were older than 18 years of age were eligible for entry into the study, if they had had OA of the knee for at least 6 months. Efficacy variables included knee pain on weight bearing, knee pain on motion, patients' and physicians' global assessments of OA, pain intensity as measured on a visual analog scale, and time to walk 50 feet as quickly as possible. Efficacy variables were assessed at baseline and at weeks 1, 2, 4, and 6. Between-group differences in efficacy variables were evident by week 1. Mean improvements were significantly greater with oxaprozin than with placebo for all efficacy variables at all time periods, except knee pain on motion at weeks 2 and 4 and time to walk 50 feet at weeks 1, 2, and 4. Mean improvements were significantly greater with nabumetone than with placebo for all efficacy variables at all time periods, except the following: knee pain on weight bearing at weeks 2, 4 and 6; knee pain on motion at weeks 2 and 4; patients' global assessment at week 4; and pain intensity as measured on a visual analog scale at weeks 2 and 4. There were, however, no significant differences between oxaprozin and nabumetone in any of these efficacy variables. Adverse events were reported by 83 (71.6%) patients who took oxaprozin, by 80 (69.6%) patients who took nabumetone, and by 57 (49.1%) patients who took placebo. Adverse events were reported for significantly more patients taking oxaprozin or nabumetone than placebo. However, adverse events tended to be mild or moderate and rarely resulted in patients withdrawing from the study. Combined with the results of an earlier study, the results of this study showed that a 1500-mg/d dose of nabumetone, which is higher than the recommended starting dose of 1000 mg/d, is required for efficacy equivalent to that of the recommended starting dose of oxaprozin, 1200 mg/d, in relieving the symptoms of OA. Thus nabumetone may require dosage titration from the recommended starting dose. Oxaprozin and nabumetone were found to have similar tolerability profiles, as shown by adverse-event monitoring and withdrawal rates, as well as clinically similar safety profiles, as demonstrated by physical examinations, hematologic and biochemical laboratory testing, hemoccult testing, and adverse-event monitoring and symptom assessment.

Comparison of the efficacy and safety of oxaprozin and nabumetone in the treatment of patients with osteoarthritis of the knee

This multicenter, 6-week, double-blind, placebo-controlled, parallel-group study compared the efficacy and safety of oxaprozin 1200 mg once daily with that of nabumetone 1000 mg once daily in patients with moderate-to-severe osteoarthritis (OA) of the knee. To be eligible, patients had to experience a flare of OA within 2 weeks of discontinuing their usual OA medication (nonsteroidal anti-inflammatory drug or analgesic). Eligible patients were assessed at baseline and then randomized to receive oxaprozin (n = 109), nabumetone (n = 110), or placebo (n = 109). Efficacy assessments were performed at weeks 1, 2, 4, and 6. Primary efficacy variables included knee pain on weight bearing, knee pain on motion, and patient's and physician's global assessments of OA. Secondary efficacy variables included pain intensity, time to walk 50 feet, and duration of morning stiffness. Safety was evaluated by use of routine laboratory analyses; physical examination at screening, baseline, and week 6 (or study termination); assessment of symptoms at baseline and at each visit; and testing stools for occult blood at screening and between week 4 and the final visit. Adverse events were monitored throughout the study. Between-group differences in efficacy variables were evident by week 1. The mean change in improvement from baseline with oxaprozin compared with placebo was statistically significant in favor of oxaprozin at weeks 1, 2, 4, and 6 for all primary efficacy variables. The mean change in improvement from baseline with nabumetone compared with placebo, however, was statistically significant only at week 1 for knee pain on motion, patient's global assessment, and physician's global assessment. The mean change in improvement from baseline was statistically significant (P < or = 0.035) in favor of oxaprozin versus nabumetone at weeks 2 and 6 for all four primary efficacy variables and also at week 4 for knee pain on motion. The incidence of adverse clinical events between treatment groups was not statistically significant. However, nine oxaprozin-treated patients had asymptomatic liver enzyme elevations reported as adverse events. Four of these patients had reversible elevations of aspartate aminotransferase and alanine aminotransferase greater than three times the upper limit of normal range (P < 0.05); two of these patients were taking other medications known to induce liver enzyme abnormalities. The study showed that oxaprozin 1200 mg once daily was statistically significantly more efficacious than nabumetone 1000 mg once daily for the treatment of patients with moderate-to-severe OA of the knee. Both drugs were clinically well tolerated.

3′-End formation of transcripts from the yeast rRNA operon

Deletion analysis of artificial rRNA minigenes transformed into Saccharomyces cerevisiae revealed that a 110 bp long fragment corresponding to positions -36 to +74 relative to the 3'-end of the 26S rRNA gene, is both necessary and sufficient for obtaining transcripts whose 3'-termini are identical to those of 26S and 37S (pre-)rRNA. These termini are produced via processing of longer transcripts because in an rna 82.1 mutant the majority of the minigene transcripts extend further downstream. Since the rna 82.1 mutation inactivates an endonuclease involved in the 3'-processing of 5S pre-rRNA it is concluded that the maturation of 37S- and that of 5S pre-rRNA requires a common factor. Comparison of the spacer sequences between Saccharomyces carlsbergensis, Saccharomyces rosei and Hansenula wingei revealed several conserved sequence blocks within the region between +10 and +55. These conserved sequence tracts, which are part of a longer region showing dyad symmetry, are supposed to be involved in the interaction with the processing component(s). Deletion of the sequences required for the formation of the 3'-ends of 26S rRNA and 37S pre-rRNA revealed a putative terminator for transcription by RNA polymerase I situated at position +210. This site maps within a DNA fragment that also contains the enhancing element for rDNA transcription by RNA polymerase I.