Reindeer BMP extract in the healing of critical-size bone defects in the radius of the rabbit.

Background: Native BMP extracts from reindeer effectively induce ectopic new bone formation in vivo, but their bone healing properties have not yet been evaluated. We investigated the effect of reindeer BMP extracts on the healing of long bone defects.

Methods: The implants tested contained 5 mg or 10 mg of unsterilized BMP extract from reindeer and 10 mg of gamma-sterilized BMP extract administered with collagen carrier (Lyostypt, B.

Effect of gamma irradiation on the osteoinductivity of morphogenetic protein extract from reindeer bone.

Background: Bone morphogenetic proteins (BMPs), which are capable of stimulating the production of new bone, must be sterilized before preclinical and clinical use to reduce the risk of infections and associated complications. In this study, we investigated the effects of gamma sterilization on the osteoinductivity of native reindeer BMP extract in the Balb/C mouse thigh muscle pouch model.

Methods: 5 mg of native reindeer BMP extract and 5 mg of bovine serum albumin were administered separately either in gelatine capsules or mixed with gelatine as injections.

Osteoinductivity of partially purified native ostrich (Struthio camelus) bone morphogenetic protein: comparison with mammalian species.

Bone morphogenetic proteins (BMPs) are members of the TGF-beta superfamily. They are capable of inducing ectopic bone formation. Until now, the main interest has been focused on mammalian osteoinductive BMPs, and there are no reports of native BMP extracts of birds.

The effect of different mineral frames on ectopic bone formation in mouse hind leg muscles induced by native reindeer bone morphogenetic protein.

Introduction: Bone morphogenetic proteins (BMPs) require carrier material for slow release and framing material for osteoconduction.

Materials And Methods: The effect of a frame on early bone formation induced by partially purified native reindeer BMP in composite implants containing 3 mg of BMP, type IV collagen and tricalcium phosphate (TCP/Col/BMP) or hydroxyapatite (HA/Col/BMP) or biphasic tricalcium phosphate-hydroxyapatite (TCP/HA/Col/BMP) or biocoral (NC/Col/BMP) was evaluated using a mouse hind leg muscle pouch model. Collagen with native reindeer BMP (Col/BMP) and corresponding implants without native reindeer BMP served as controls.

Influence of ethylene oxide sterilization on the activity of native reindeer bone morphogenetic protein.

We studied the effects of ethylene oxide sterilization (Steri-Vac 4XL, temperature 29 degrees C, exposure time 4 h 10 min, ethylene oxide concentration 860 mg/l) on the osteoinductivity of partially purified native reindeer bone morphogenetic protein (BMP) in a hind leg muscle pouch model of male NMRI mice. BMP was administered in implants containing 3 mg in a collagen carrier. Implants without sterilization and without BMP served as controls.

New bone formation induced by injection of native reindeer bone morphogenetic protein extract.

Background And Aims: Bone morphogenetic proteins (BMPs) are usually administered with a solid framing material during open surgery. In some instances, percutaneous administration of injectable BMP would be preferable. We tested the new bone-forming activity of injectable native reindeer BMP extract in the Balb/C mouse thigh muscle pouch model.

Abnormal ornithine decarboxylase activity in transgenic mice increases tumor formation and infertility.

A transgenic mouse line carrying ornithine decarboxylase cDNA as the transgene under the control of a mouse mammary tumor virus long terminal repeat (MMTV LTR) promoter was generated in order to study whether ornithine decarboxylase transgene expression will have any physiological or pathological effect during the entire life of a transgenic mouse. The high frequency of infertile animals and the loss of pups made the breeding of homozygous mice unsuccessful. However, a colony of heterozygous transgenic mice was followed for 2 years.

Expression of ODC and its regulatory protein antizyme in the adult rat brain.

Ornithine decarboxylase and its inhibitor protein, antizyme are key regulators of polyamine biosynthesis. We examined their expression in the adult rat brain using in situ hybridization and immunocytochemistry. Both genes were widely expressed and their expression patterns were mostly overlapping and relatively similar.

Mutation of aspartate-233 to valine in mouse ornithine decarboxylase reduces enzyme activity.

Ornithine decarboxylase is the first and key enzyme in mammalian polyamine biosynthesis. All eukaryotic ornithine decarboxylases contain several highly conserved regions and the amino acid residues 232-238 form one of the most highly conserved sequences. This region contains a glycine-rich sequence typically found in a number of pyridoxal 5'-phosphate-dependent or nucleotide-binding proteins.

The expression of ornithine decarboxylase antizyme mRNA and protein in rat motoneurons.

The distribution of ornithine decarboxylase antizyme messenger ribonucleic acid (AZ mRNA) and AZ-like immunoreactivity (LI) was studied in the brainstem and spinal cord motoneurons and in the extraocular and triceps surae muscles of rat. In situ hybridization showed AZ mRNA in the gray matter of the spinal cord at different levels of spinal cord with highest AZ mRNA levels in the ventral horn of the spinal cord. No apparent changes in AZ mRNA contents were seen after unilateral transection of the sciatic nerve in lumbar motoneurons.

Association between high levels of ornithine decarboxylase activity and favorable prognosis in human colorectal carcinoma.

Several studies have documented increased expression of ornithine decarboxylase (ODC) in neoplastic colorectal tissue versus normal-appearing colonic mucosa. The present study was undertaken to determine whether there is an association between the degree of overexpression of ODC in colorectal carcinomas and survival in a series of 74 patients. A high level of tumor ODC expression was found to be significantly associated with greater survival in our patient series.

Activation of rat brain ornithine decarboxylase by GTP.

The activity of ornithine decarboxylase (ODC) measured in different regions of rat brain was highest in the hippocampus and lowest in the cerebellum. The ODC activity of a crude extract of the cerebellum was increased by the addition of GTP to the enzyme assay. Following dissociation of the ODC-antizyme complex by Sephadex G-75 chromatography in buffer containing 0.

Developmental expression of ornithine and S-adenosylmethionine decarboxylases in mouse brain.

The activities of the two key enzymes in mammalian polyamine synthesis, ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (AdoMetDC) in mouse brain show distinct, but inverse, changes during ontogeny. The level of ODC activity is about 70 fold higher at the time of birth than in the adult mouse, whereas AdoMetDC activity is very low after birth and increases as the brain matures. The correlation between the changes in enzyme activities and in the levels of the corresponding mRNAs diminishes dramatically during development.

Identification of epidermal cell subpopulations with increased ornithine decarboxylase activity following treatment of murine epidermis with 12-O-tetradecanoylphorbol-13-acetate.

Ornithine decarboxylase (ODC), the initial enzyme in the polyamine biosynthetic pathway, has been used as a marker for the hyperplasia that occurs following exposure of mouse epidermis to the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). Using flow cytometry in combination with polyclonal antibodies to ODC, we examined the levels of ODC-associated immunoreactive protein present within mouse epidermal cells at 4 and 24 h after a single topical application of TPA, as well as following chronic exposure to TPA and in papillomas. Basal levels of ODC-specific antibody binding were detectable in acetone-treated CD-1 mouse epidermis and were increased 3-fold at 4 h after TPA treatment.

Properties of ornithine decarboxylase in human colorectal adenocarcinomas.

Ornithine decarboxylase (ODC) activity was measured in colon adenocarcinomas and adjacent normal-appearing colon mucosa from a total of 40 patients undergoing surgical resections. The enzyme activity was measured in the presence and absence of GTP, since recent work has demonstrated a GTP-activatable form of ODC in some murine and human tumors. In general, ODC specific activity was higher in adenocarcinomas than in adjacent normal-appearing mucosa.

Flow cytometric detection of ornithine decarboxylase activity in epidermal cell subpopulations.

Using flow cytometry in combination with membrane permeabilization techniques to enhance binding of antibodies with immunoreactive protein within the cytoplasm, we have developed a method to examine the ornithine decarboxylase (ODC) activity present within subpopulations of epidermal cells following acute and chronic exposure to the phorbol ester tumor promoter 12-0-tetradecanoylphorbol-13-acetate (TPA). The method described has the sensitivity to detect basal levels of ODC as well as increases in ODC at early time points following treatment with TPA and has the additional advantage of allowing subpopulation identification and characterization.

Activation of human squamous cell carcinoma ornithine decarboxylase activity by guanosine triphosphate.

Previous studies have demonstrated the presence in mouse epidermal tumors of a structurally and functionally altered ornithine decarboxylase (ODC). In this report, the enzymatic properties of ODC from normal human skin and squamous cell carcinomas are examined. Some tumors contained a more heat stable ODC than the enzyme found in normal skin.

Activation of mouse epidermal tumor ornithine decarboxylase by GTP: evidence for different catalytic forms of the enzyme.

In crude extracts of epidermal papillomas induced by an initiation-promotion protocol, ornithine decarboxylase (OrnDCase) activity was increased by the addition of GTP to the enzyme assay. No effect of GTP on the phorbol ester-induced enzyme isolated from normal epidermis was observed. Kinetic analyses indicated that the major effect of the nucleotide on the tumor-derived enzyme was to lower the apparent Km for L-ornithine.

Purification of mouse brain ornithine decarboxylase reveals its presence as an inactive complex with antizyme.

Mouse brain ornithine decarboxylase (ODC) was purified to near-homogeneity by using (NH4)2SO4 precipitation and chromatography on heparin-Sepharose, pyridoxamine phosphate-agarose and DEAE-cellulose. On SDS/polyacrylamide-gel electrophoresis, the final preparation gave one protein band similar to that obtained for purified mouse kidney enzyme, corresponding to an Mr of 53.000.

Ornithine decarboxylase activity in brain regulated by a specific macromolecule, the antizyme.

Mouse brain ornithine decarboxylase activity is about 70-fold higher at the time of birth compared with that of adult mice. Enzyme activity declines rapidly after birth and reaches the adult level by 3 weeks. Immunoreactive enzyme concentration parallels very closely the decrease of enzyme activity during the first postnatal week, remaining constant thereafter.

Phenothiazines and structurally related compounds as inhibitors of adenosylmethionine decarboxylase: effects on the purified enzyme.

The effects of chlorpromazine, imipramine, thioridazine, chlorprothixene, amitriptyline, desipramine and triflupromazine on adenosylmethionine decarboxylase purified from rat liver have been studied. The compounds caused competitive inhibition of the enzyme at 10(-5) - 10(-3) M concentrations. For chlorprothixene and triflupromazine the inhibition was linear, while the other drugs showed increasing, nonlinear inhibition at higher concentrations.

The inverse changes of mouse brain ornithine and S-adenosylmethionine decarboxylase activities by chlorpromazine and imipramine. Dependence of ornithine decarboxylase induction on beta-adrenoceptors.

Intraperitoneal injection of chlorpromazine and imipramine increases mouse brain ornithine decarboxylase but decreases S-adenosyl-L-methionine decarboxylase activity. Maximal effect was obtained 6-8 hr after treatment at which time single dose of chlorpromazine (50 mg/kg) stimulated ornithine decarboxylase activity 7-fold and decreased S-adenosylmethionine decarboxylase activity to 50% from the control level. Correspondingly, ornithine decarboxylase activity was 5.

Detection of ornithine decarboxylase antizyme in mouse brain.

Ornithine decarboxylase, the rate-limiting enzyme in polyamine synthesis, is known to be regulated by a macromolecular inhibitor, termed antizyme, in a number of cellular systems. The present results show that the antizyme is also a functional component of polyamine metabolism in the brain. It could be demonstrated both in normal randomly selected mice and in animals which had been subjected either to intracerebroventricular injection of saline, which is known to cause a transient activation of ornithine decarboxylase, or to 1,3-diamino-2-propanol, an antizyme-inducing agent.