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PubMed2003

Phosphate is a specific signal for ATDC5 chondrocyte maturation and apoptosis-associated mineralization: possible implication of apoptosis in the regulation of endochondral ossification.

UNLABELLED: Involvement of Pi and Ca in chondrocyte maturation was studied because their levels increase in cartilage growth plate. In vitro results showed that Pi increases type X collagen expression, and together with Ca, induces apoptosis-associated mineralization, which is similar to that analyzed in vivo, thus suggesting a role for both ions and apoptosis during endochondral ossification. INTRODUCTION: During endochondral ossification, regulation of chondrocyte maturation governs the growth of the cartilage plate. The role of inorganic phosphate (Pi), whose levels strongly increase in the hypertrophic zone of the growth plate both in intra- and extracellular compartments, on chondrocyte maturation and mineralization of the extracellular matrix has not yet been deciphered. MATERIALS AND METHODS: The murine chondrogenic cell line ATDC5 was used. Various Pi and calcium concentrations were obtained by adding NaH2PO4/Na2HPO4 and CaCl2, respectively. Mineralization was investigated by measuring calcium content in cell layer by atomic absorption spectroscopy and by analyzing crystals with transmission electron microscopy and Fourier transform infrared microspectroscopy. Cell differentiation was investigated at the mRNA level (reverse transcriptase-polymerase chain reaction [RT-PCR] analysis). Cell viability was assessed by methyl tetrazolium salt (MTS) assay and staining with cell tracker green (CTG) and ethidium homodimer-(EthD-1). Apoptosis was evidenced by DNA fragmentation and caspase activation observed in confocal microscopy, as well as Bcl-2/Bax mRNA ratio (RT-PCR analysis). RESULTS: We showed that Pi increases expression of the hypertrophic marker, type X collagen. When calcium concentration is slightly increased (like in cartilage growth plate), Pi also induces matrix mineralization that seems identical to that observed in murine growth plate cartilage and stimulates apoptosis of differentiated ATDC5 cells, with a decrease in Bcl-2/Bax mRNA ratio, DNA fragmentation, characteristic morphological features, and caspase-3 activation. In addition, the use of a competitive inhibitor of phosphate transport showed that these effects are likely dependent on Pi entry into cells through phosphate transporters. Finally, inhibition of apoptosis with ZVAD-fmk reduces pi-induced mineralization. CONCLUSIONS: These findings suggest that Pi regulates chondrocyte maturation and apoptosis-associated mineralization, highlighting a possible role for Pi in the control of skeletal development.

Animals↗
PubMed2007

Ossification of a novel cross-linked porcine collagen barrier in guided bone regeneration in dogs.

BACKGROUND: Collagen membranes for guided bone regeneration (GBR) and guided tissue regeneration (GTR) are used extensively as bioabsorbable barriers. Cross-linking of collagen increases its biodurability and enables the control of its degradation kinetics and barrier function. A novel cross-linking technology was used to produce a porcine type I collagen membrane (GLYM). The purpose of this study was to evaluate the safety, efficacy, and degradation kinetics of GLYM compared to a non-cross-linked bilayer type I and III porcine collagen membrane (BCM) in surgically created defects in dogs. METHODS: After tooth extraction, two mandibular bilateral critical size defects were created in 12 beagle dogs that were randomly assigned to one of five groups: GLYM + bovine bone mineral (BBM), BCM + BBM, BBM alone, sham-operated, or GLYM alone. Dogs were euthanized after 8, 16, and 24 weeks, and sites were prepared for qualitative, semiquantitative, and quantitative light microscopy analyses. RESULTS: Membrane-protected sites displayed bone filling between the BBM particles with almost complete restoration of the original ridge morphology that increased with time up to 16 weeks and remained unchanged at 24 weeks. Both membranes showed marked degradation within 16 to 24 weeks, with BCM inconsistency that was undetectable in one of four sites at 8, 16, and 24 weeks. Membrane ossification was observed in all GLYM sites and in only one BCM site, which progressed with time to 24 weeks. Bone increased by approximately 1 mm on the lingual side, where the GLYM membrane was in direct contact with bone. CONCLUSIONS: Both membranes were safe and effective in supporting bone regeneration in critical size alveolar ridge defects in dogs and completely degraded within 24 weeks with marked BCM inconsistency. In areas of direct contact with bone, all GLYM sites were progressively ossified with time and augmented the original alveolar ridge. To the best of our knowledge, this is the first report of complete ossification of a collagen barrier membrane in GBR procedures.

Absorbable Implants↗
PubMed2003

Acceleration of regenerate ossification during distraction osteogenesis with recombinant human bone morphogenetic protein-7.

BACKGROUND: Bone-lengthening can be accomplished by means of distraction osteogenesis. In the present study, we examined the effect of a single dose of recombinant human bone morphogenetic protein-7 (rhBMP-7) on the rate of new-bone formation during distraction osteogenesis in the rat. METHODS: Fourteen Long-Evans rats were randomized into two groups of seven rats each. An external fixator was applied to the left femur, and a transverse osteotomy was performed. One group was treated with rhBMP-7 in an aqueous solvent, and the other group received the solvent alone and served as the control. rhBMP-7 was administered on the day of surgery by means of a single injection into the osteotomy gap. Distraction was started seven days after surgery at a rate of 0.25 mm every twelve hours. Distraction was continued for twenty days, resulting in a total of 10 mm of lengthening. The regenerate was monitored with use of radiographs and bone-mineral-density measurements at the conclusion of distraction and at two and four weeks after the cessation of distraction. The lengthened femora were harvested, and biomechanical studies were carried out to determine the stiffness and maximum torque to failure. RESULTS: Radiographs showed accelerated regenerate ossification in the BMP-7 group, with a larger amount of new bone compared with the control group. The bone-mineral-density values were dramatically enhanced on Day 20 in the BMP-7 group (103.6 +/- 12.6 mg/cm (2) ) compared with the control group (26.2 +/- 15.1 mg/cm (2) ). These differences continued to be greater at two and four weeks after the cessation of distraction. Normalized values of stiffness (percent stiffness) reached 76.5% +/- 5.4% in the BMP-7 group, compared with 6.6% +/- 0.5% in the control group. The percent maximum torque at failure was 81.1% +/- 1.2% in the BMP-7 group, compared with 20.8% +/- 0.3% in the control group. CONCLUSION: A single injection of rhBMP-7 at the time of osteotomy surgery stimulated the rate of regenerate ossification and increased bone-mineral density during distraction osteogenesis. The biomechanical properties of the newly formed bone were also increased by BMP-7 injection.

Animals↗
PubMed1983

Ossification of thoracic ligamenta flava.

Although ligamentum flavum ossification (LFO) often occurs in normal persons, there are no reports of its detection on lateral chest radiographs made during screening examinations. Review of 1,744 consecutive lateral chest radiographs identified LFO in 6.2% of males and 4.8% of females. LFO occurred mainly at the intervertebral segments from T9-T10 through T12-L1. Most prevalent was the hook-shaped LFO, protruding inferiorly from the inferior facets into the projections of the intervertebral foramina. Though LFO can cause severe neurologic symptoms, none of the affected persons in this study reported such symptoms. LFO was first visualized radiographically when the subjects were 20-40 years old, and it may be a physiologic condition. The LFO in these cases existed independent of thoracic posterior longitudinal ligament ossification, diffuse idiopathic skeletal hyperostosis, and degenerative osteoarthritis.

Adult↗
PubMed1990

Bone ossification and carcass characteristics of wethers given silastic implants containing estradiol.

Administration of growth promotants with estrogenic activity via hastening closure of the growth plate could have an economic impact on lambs because closure results in ovine carcasses being classified as yearlings. Twelve wether lambs approximately 12 mo old were given silastic implants filled with estradiol-17 beta and allotted randomly to be slaughtered 30, 60, 90, or 220 d after implantation to determine time of growth plate closure in relation to date of implanting. Seven comparable wethers not implanted served as controls. Four wethers implanted at 2 mo of age and slaughtered 220 d later also were included. Implanted wethers had serum concentrations of estradiol averaging 13.9 pg/ml over the 220-d implant period; controls averaged 2.7 pg/ml. Estradiol implants increased carcass maturity scores but fat deposition was not altered. Growth plate widths decreased (P less than .05) as wethers grew older and implants were in place for longer periods of time. Metacarpal growth plates in 12-mo-old lambs were completely ossified 220 d after implanting, but control wethers and wethers implanted at 2 mo maintained growth plate widths. Neither metacarpal nor metatarsal bone lengths differed (P less than .05) between control and implanted wethers. Growth plate ossification was not complete until 570 d of age in implanted lambs, even though bone length had stopped increasing by 408 d. Therefore, even though estradiol and other growth stimulants with estrogenic activity increase rate of ossification of the metacarpal growth plate, bone length or mature size is not limited.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2001

A comparison of the USDA ossification-based maturity system to a system based on dentition.

Two studies using commercially fed cattle were conducted to determine the relationship of the USDA bone ossification-based maturity system to one based on the number of permanent incisors present at slaughter. These studies showed that 91.5 to 100% of cattle with zero permanent incisors (< 23.8 mo of age), 89.1 to 97.5% of cattle with two permanent incisors (23.8 to 30.4 mo of age), 75 to 82.2% of cattle with four permanent incisors (30.4 to 38.0 mo of age), 64 to 72.5% of cattle with six permanent incisors (38.0 to 45.3 mo of age), and 40% of cattle with eight permanent incisors (> 45.3 mo of age) were graded as A maturity by the USDA maturity classification system. Kappa tests revealed no statistical relationship between the dentition- and skeletal ossification-based maturity systems. Dentition-based maturity agreed with ossification/lean maturity for only 162 of 1,264 carcasses in Exp. 1 and only 54 of 200 carcasses in Exp. 2. Cattle with two, four, six, or eight permanent incisors were classified in more youthful categories of USDA bone ossification/lean maturity than they should have been. Male cattle were more likely to be misclassified into a younger age category by the USDA system than were female cattle. It seems that determining physiological maturity by number of permanent incisors rather than by the current USDA method of subjectively evaluating skeletal and lean maturity may prove to be a more accurate technique of sorting beef carcasses into less-variable age groups.

Age Determination by Teeth↗
PubMed1992

Osteonecrosis of the femoral head in spontaneously hypertensive rats. Relation to ossific nuclei during growth.

We observed the distribution of the ossific nuclei and the occurrence of osteonecrosis in the femoral capital epiphysis of spontaneously hypertensive rats. In 270 femoral heads, the ossific nuclei were seen in the following sites of the epiphysis: Type 1, the lateral portion in 150 femoral heads; Type 2, the central portion in 5 heads; Type 3, both lateral and central portions in 12 heads; and Type 4, throughout the epiphysis in 62 heads. The number of femoral heads with osteonecrosis in Types 1-4 was 61, 0, 5, and 17, respectively.

Aging↗
PubMed1993

Proximal humeral ossification center of the fetus: time of appearance and the sensitivity and specificity of this finding.

Ultrasonographic examinations were performed on 1,000 pregnant women between the 28th and 40th weeks of gestation who had been seen at a private clinic. For all women the date of last menstruation was known, and none had obstetrical or clinical-surgical complications. All were singleton pregnancies, and cases of fetal malformation were excluded from the study. The proximal humeral epiphyseal ossification center was visualized significantly frequently after the 38th week (P < 0.001). With respect to a gestational age of more than 38 weeks, its specificity was elevated (99%), as also were its positive (91%) and negative (93%) predictive values. Its sensitivity, however, was low (58%). Routine determination of the proximal humeral ossification center is a valuable aid for the estimation of gestational age in the third trimester.

Embryonic and Fetal Development↗
PubMed1997

Iron overloading inhibits endochondral ossification.

The development of bone disease in patients with chronic renal failure is well known. Renal patients frequently suffer anemia and iron oral therapy and/or transfusions are used to treat them. Recent findings show that iron could be a factor that provokes bone lesions but the alterations it causes are not well known. The aim of this work was to study the effect of iron intoxication on endochondral ossification, a recognized model for bone growth evaluation. Male Wistar rats weighing 250-300 g were used. They received 88 mg of dextran-iron per day intraperitoneally during 34 days. The experimental and control groups were killed on day 34. A histomorphometric study of the endochondral plate was performed on histologic sections of tibiae. The results obtained show that iron overloading inhibits endochondral ossification.

Animals↗
PubMed1992

Lethal short limb dwarfism with dysmorphic face, omphalocele and severe ossification defect: Piepkorn syndrome or severe "boomerang dysplasia"?

The authors report a case of lethal neonatal dwarfism characterized by striking micromelia, fused rudimentary and supernumerary digits, large, soft head, pronounced hypertelorism, protruding eyes set laterally, enormous omphalocele and severe deficiency of tubular bone and spine ossification. Histologic examination showed lack of ossification of the cartilaginous anlage of many tubular bones. The cartilage had irregularly distributed chondrocytes. The matrix contained hypocellular and degenerated areas with scattered large chondrocytes. In a few bones a very disorganized growth cartilage was present. The case is similar to that described by Piepkorn et al. (1977) and may represent a severe form of "boomerang dysplasia" (Kozlowski et al., 1981; Tenconi et al., 1983; Kozlowski et al., 1985; Winship et al., 1990).

Abnormalities, Multiple↗
PubMed2003

Optimization of analysis of skeletal ossification of laboratory animals by means of digital radiography software options.

Digital radiography software enables image manipulation and reformatting, thus allowing precise diagnosis and measurements even in cases when exposure parameters are suboptimum and visualized structures are faintly radiopaque. The aim of the paper is evaluation of digital radiography software options in optimization of analysis of skeletal ossification in rats. Wistar at pups at the age 0 to 22 days of postnatal life were radiographed by means of a storage phosphor digital radiography system. In order to optimize viewing conditions as well as density nd linear measurements all available image reformatting options and filters of digital radiography software Digora 2.0 were used and evaluated. Application of digital radiography image enhancement options was found advantageous in optimization and improvement of viewing conditions and it allowed higher accuracy and reproducibility of the measurements. Digital radiography is a novel and precise tool in determination of skeleton ossification and could be used as a supplement to routine staining methods.

Animals↗
PubMedDate not supplied

Effects of ciprofloxacin on secondary ossification centers in juvenile Wistar albino rats.

BACKGROUND: Administration of quinolone therapy is controversial during juvenile age as stated by earlier workers. The fluroquinolones are currently not indicated for young children, because of the arthropathy and adverse effect on growing cartilage shown by studies. However the effects of ciprofloxacin on secondary ossification centers has remained undocumented. This study is therefore aimed to determine the risk of Ciprofloxacin administration on neonatal skeletal differentiation by a prospective and comparative animal study model using Wistar albino rats. METHODS: Ciprofloxacin was administered to newly born Wistar albino rat pups at a dose of 20 mg/kg body weight intraperitoneally twice daily from day-1 to day-14 after birth. These animals were killed by deep ether anaesthesia and fixed in 80% alcohol. They were then bulk stained with Alizarin red and Alcian blue. Finally they were cleared in 4% KOH and stored in glycerin. The fore and hind limbs were disarticulated from the axial skeleton and observed under stereomicroscope for evidence of skeletal differentiation in the form of presence of secondary ossification centers in long hones (left humerus and left femur). The time of appearance of these centers were noted and compared statistically with those in control animals. RESULTS: The study revealed that the skeletal differentiation in long bones was delayed by 2.4 +/- 0.2 days at both proximal and distal ends in humerus and 2.4 +/- 0.2 days at proximal end and 2.2 +/- 0.2 days at distal end of femur in experimental animals as compared with controls. CONCLUSION: The ciprofloxacin administration during post-natally presents a risk to skeletal differentiation and therefore to its growth up to the age of six weeks is albino rate pups.

Animals↗
PubMed2003

[Heterotopic ossification in spinal cord injured patients].

Heterotopic ossification after spinal cord injury, most commonly affecting the hip, can represent a significant problem in function and mobility of the patient. Attempt of reduction by medication is unsatisfactory once it developed. In addition, surgical removal is often associated with infection and recurrence. Disodium etidronate is an agent effecting on prevention of development and prophylaxis of ossification.

English Abstract↗
PubMed2002

[Twy mouse and ossification of the posterior longitudinal ligament of the spine (OPLL)].

Spinal hyperostotic lesions in twy mouse resemble to those observed in human ossification of posterior longitudinal ligament of the spine (OPLL). To investigate pathogenic mechanisms of OPLL, studies have been performed on the spinal lesions of twy mouse. Molecular analyses have shown that osteopontin gene is over-expressed in the spine of twy mouse, and endochondral ossification may not a major process of the spinal lesions. Genetic analyses have shown that twy genotype is caused by a mutation in Npps gene which encodes nucleotide pyrophosphatase. Common polymorphisms in human Npps locus have been analyzed in OPLL patients.

English Abstract↗
PubMed2005

[The effect of absent ossific nucleus of the femoral head on results of surgical treatment for developmental dislocation of the hip].

We have studied retrospectively 33 hips in 26 children at an average of 9 years 5 months after simultaneous open reduction and Dega transiliac osteotomy for developmental dislocation of the hip (DDH). All children were younger than 2 years of life at the time of surgery. The hips were divided into two groups: with present and with absent ossific nucleus of the femoral head on preoperative radiographs. Clinical and radiographic results have been assessed in both groups. No statistically significant difference was found between the groups. We conclude, that absent ossific nucleus of the femoral head as a sole reason should not delay surgery for DDH.

Child↗
PubMed1990

Degeneration and ossification of the yellow ligament in unstable spine.

Lumbar yellow ligaments were obtained from 20 cases of lumbar spinal canal stenosis and 20 cases of degenerative olisthesis with slippage of more than 3 mm. The ligaments were stained with safranin-O, von Kossa, and immunohistochemical staining methods (S-100 protein). In the unstable group the safranin-O staining was more intense, microscopic ossification and chondroblasts were noted more frequently, and S-100 protein was more abundant. These findings show that instability of the lumbar spine accelerates degeneration and chondrometaplasia of the yellow ligament, which may lead to the enchondral ossification of the ligament.

Adult↗
PubMed1991

[Heterotopic ossifications from the trauma surgery viewpoint].

A heterotopic ossification is a non-neoplastic bone formation located in the soft tissues (so-called myositis ossificans). Important aspects of this condition, which is not uncommon after trauma or surgical procedures, are discussed from the trauma surgeon's viewpoint. The results of treatment of heterotopic ossifications are frequently unsatisfactory. Therefore, the importance of preventive measures is emphasized.

Fracture Fixation, Internal↗