Academic literature on the topic 'Deoxypyridinoline'

Metabolic syndrome is a cluster of medical conditions composed of ‎abdominal obesity, ‎hyperglycemia, hypertension, and lipid abnormalities, in which ‎each can affect bone in ‎different ways. We examine ‎the association between metabolic syndrome and metabolic bone disease ‎‎(osteoporosis) by ‎measuring adipose tissue marker (chemerin) and bone resorption ‎marker ‎‎(deoxypyridinoline) in ‎the serum of osteoporotic postmenopausal women with ‎and without ‎metabolic syndrome. ‎ A case-control study included 112 postmenopausal women from 51 to 67 years of ‎age. ‎Women were ‎selected from Osteoporosis Clinic- Al Yarmouk Teaching ‎Hospital and were ‎divided into two ‎groups: group (1)- patients group included 57 ‎postmenopausal women with ‎osteoporosis (35 ‎osteoporotic women with metabolic ‎syndrome and 22 osteoporotic women ‎without metabolic ‎syndrome) and group ‎‎(2)-control group included 55 postmenopausal women ‎without ‎osteoporosis and ‎metabolic syndrome. A serum sample was taken from each woman and ‎analysed ‎for ‎assessing chemerin, deoxypyridinoline, fasting serum glucose, and lipid profile. We found ‎a significant increase (p-value<0.001) in the mean value of serum chemerin ‎and ‎deoxypyridinoline ‎levels in patients compared to controls. ‎In ‎conclusion, chemerin is an adipose tissue marker associated with metabolic syndrome ‎and ‎may ‎have an impact on bone turn over and development of metabolic bone ‎disease ‎which ‎enhanced by the strong positive correlation between chemerin and bone ‎resorption ‎marker ‎‎(deoxypyridinoline).

Osteocalcin and deoxypyridinoline levels were measured in 55 RA patients during and after glucocorticoid therapy with prednisone, methylprednisolone and cortisone. A decrease of 27% of the bone resorption marker deoxypyridinoline (from 10.13 to 7.4) and an increase of 23% of the bone formation marker osteocalcin (from 16.3 to 20.1) were also clinically confirmed by the presence of osteoporosis in 74% of patients receiving corticosteroid treatment as compared with only 31% in the control group.

1. To investigate whether there is a nyctohemeral rhythm in bone turnover, we measured serum bone Gla-protein (osteocalcin, an index of osteoblast activity) concentration every 2 h and urinary deoxypyridinoline (a marker of bone collagen resorption) excretion for 8 h periods in 10 pubertal girls (aged 10–14 years), 15 premenopausal women (aged 20–49 years) and 17 postmenopausal women (aged 50–75 years). 2. The serum concentration of bone Gla-protein and the urinary excretion of deoxypyridinoline were five times higher in the pubertal girls than in the premenopausal women. The urinary excretion of deoxypyridinoline in the postmenopausal women was twice that in the premenopausal women. 3. There was a nyctohemeral pattern in all age groups with mean night-time increases of 28% (P<0.001) in the urinary excretion of deoxypyridinoline and of 5% (P<0.001) in the serum bone Gla-protein concentration. 4. There also were nyctohemeral patterns in the urinary excretion of calcium (P<0.02), sodium (P<0.001) and potassium (P<0.001), with decreases at night. There was a negative correlation between the night-time changes in the urinary excretion of deoxypyridinoline and calcium, especially in adult women (P<0.01). 5. The serum level of parathyroid hormone increased with age, but this effect was only observed at night (01.00 to 07.00 hours). There was a nyctohemeral rhythm of the serum intact parathyroid hormone level at all ages, with a peak in the afternoon and night. 6. Thus, at night, there is a large increase in bone resorption and a small increase in osteoblastic activity, representing a nyctohemeral rhythm of bone turnover. Although the amplitudes of bone formation and bone resorption are greater during growth, the pattern of nyctohemeral changes present during growth continues up to the age of 75 years.

Abstract The collagen crosslinks, pyridinoline and deoxypyridinoline, have been developed as urinary markers of bone resorption but, despite wide clinical application of the technique, comparatively little attention has been paid to the standardization of these compounds. In this study, pyridinoline and deoxypyridinoline have been purified from bone and converted completely to monochloride trihydrochloride salts. In addition to mass spectrometry and NMR spectroscopy, the purity of the isolated materials was assessed by microelemental analysis including the chloride counterions. These purified compounds were used to establish individual molar absorptivity values as primary standardization criteria for the two crosslinks. For pyridinoline in 0.1 mol/L HCl, epsilon at 295 nm was 5490 L mol(-1) cm(-1); in 50 mmol/L sodium phosphate, pH 7.5, epsilon at 325 nm was 5785. The corresponding values for deoxypyridinoline at acid and neutral pH were 5160 and 5290 L mol(-1) cm(-1). The availability of standardization criteria for the crosslinks will allow more meaningful comparisons of clinical data between different laboratories.

<p>This study was designed to understand whether the post-menopausal Chinese women (n=175) receiving tablet containing vitamin D (500 IU) and calcium (500 mg) had lower incidence of bone fracture compared to the post-menopausal Chinese women ((n=175) receiving a diet rich in calcium, vitamin D, and protein (milk, cheese, and yogurt, soybeans, spinach, fish including fatty fish, cheese, egg). This study assessed whether the levels of serum osteocalcin and urinary free deoxypyridinoline could be used as predictors of early bone trauma during post-menopausal period. After randomization, subjects were followed-up for up to 3 years to capture required data. The results suggested that therapeutic intervention (vitamin D and calcium) does not predict bone fracture among the post-menopausal Chinese women. However, correlation analysis revealed that the decreased level of serum osteocalcin and urinary free deoxypyridinoline were associated with higher incidence of fracture. The results suggest that the low level of serum osteocalcin and urinary free deoxypyridinoline cause increase susceptibility of fracture among the post-menopausal Chinese women.</p>

The purpose of this study was, first to explore metabolic interactions between Cu and ascorbic acid in guinea-pigs, particularly with respect to any possible disadvantages of high ascorbatein the presence of low Cu intakes, and second, to test the hypothesis that variations in ascorbate and/or Cu status might inhence collagen cross-linking, either by inducing a change in thecross-links: hydroxyproline ratio, or by inducing a change in the pyridinoline: deoxypyridinoline cross-linls ratio. Four matched groups, each of eight male weanliig Dunkin-Hartley guinea-pigs, were maintained on purified diets containing either no added Cu, or 150 mg Cu/kg diet, and either 0·1 g or 30 g ascorbic acid/kg diet. They were then killed 8 weeks later, and the following indices were measured body and organ weights; blood haemoglobin; adrenal ascorbate concentrations; Cu concentrations in plasma, liver and femur; superoxide dismutase (EC 1.15.1.1) activity in whole blood and liver; hydroxyproline, pyridinoline and deoxypyridinoline in femur and in urine. The principal observations were: Cu intake significantly affected blood and tissue Cu concentrations and superoxide dismutase activity; and ascorbic acid intake significantlyaffected adrenal ascorbate levels and the deoxypyridinoline: pyridinoline cross-links ratio, especially in bone (femur). There was evidence of a significant interaction between ascorbateand Cu with respect to adrenal and plasma Cu concentrations, blood superoxide dismutase activityand body weights. We conclude that interactions between ascorbate and Cu at the functional level were present but modest, and that a new and potentially powerful functional index of ascorbate status may exist within the deoxypyridinoline: pyridinoliie collagen cross-link ratio.

Мета дослідження: визначення взаємозв’язків між дезоксипіридиноліном (ДПД) сечі та даними ультразвукової денситометрії у осіб працездатного віку, які постійно проживають в умовах промислового регіону.

Disc degenerative changes are directly or indirectly associated with spinal pain and disability. Literature revealed a high prevalence of disc degeneration in the thoracic region, however thoracic MRI degeneration trends and information on disc biochemical matrix constituents are limited for thoracic discs compared to lumbar and cervical discs. The objective of this thesis was to use MRI to investigate the prevalence of disc degenerative changes affecting the human thoracic spine, and to determine the factors affecting spinal disc biochemical matrix. A 3-point subjective MRI grading scale was used to grade the films. The feasibility of using archived formalin-fixed cadaver material was investigated to analyse collagen and elastin crosslinks. The prevalence of degenerative changes in human thoracic discs and vertebrae (T1 to T12) was determined retrospectively from an audit of 216 MRI cases, using sagittal T1- and T2-weighted MR images. In a subsequent series of ex-vivo studies, human thoracic discs and LF from 26 formalin-fixed and two fresh spines, involving all thoracic levels, were examined macroscopically to determine the degeneration status. Subsequently, disc and ligament tissues were analysed biochemically for collagen (pyridinoline and deoxypyridinoline) and elastin (desmosine and isodesmosine) crosslinks. These crosslinks were extracted from hydrolysed samples by cellulose partition chromatography, and analysed by reverse-phase HPLC. Collagen content was determined using its hydroxyproline content, and proteoglycan content was assayed using a modified DMB assay for chondroitin sulphate. Finally the MRI and macroscopic assessments of thoracic discs, were compared with the biochemical data from two fresh cadaver thoracic spines. The 3-point MRI grading scale had a high inter- (k = 0.57 to 0.78) and intra-rater (k = 0.71 to 0.87) reliability. There were no significant differences in the collagen and elastin content and extent of collagen crosslinks between formalin fixed and unfixed ligament and disc tissues, after 25 weeks of formalin fixation. From the in-vivo MRI series of investigations (n = 216 MRI films), the prevalence of thoracic disc degenerative and vertebral morphological changes revealed significant age, gender and spinal level trends (p < 0.05).Generally, males had a higher propensity for disc degeneration in contrast to females, especially older females, where the trend showed a higher prevalence of osteophytes and vertebral body changes. In particular, the mid and lower thoracic levels have a higher prevalence of degenerative changes, except for osteophytes and anterior vertebral wedging. With increased age, there was a concomitant increase in anterior wedging and bi-concavity and disc degenerative changes except for end-plates. The biochemical investigations on the ex-vivo series of formalin-fixed thoracic discs (n = 303) also revealed significant changes in the disc matrix due to degeneration status, age, gender and spinal regional factors. With increased age, normal disc matrices have significantly lower collagen content and extent of pyridinoline (p < 0.001). In contrast, the degenerated disc matrix revealed significantly higher collagen content and extent of deoxypyridinoline (p < 0.05). These findings suggest that an altered matrix existed in normal ageing discs, which render the disc prone to injury and degeneration over the life span. The higher collagen and deoxypyridinoline in degenerated disc matrices reflects an increase in chondrocyte synthesis, and is also a novel finding, suggesting that they may be used as markers of ageing and degeneration processes. The biochemical investigations on another series of ex-vivo spinal LF tissues (n = 364), revealed that this had a lower collagen and pyridinoline, but significantly higher elastin and deoxypyridinoline compared to spinal discs (p < 0.05). Elastin crosslinks however were difficult to detect in spinal discs, being present in negligible amounts in a few lumbar discs. The elastin crosslinks in the LF were not significantly affected by age, but were significantly higher in calcified, and female ligamentum tissues, and also in the lumbar region (p < 0.05). These MRI prevalence findings enhanced our knowledge of vertebral body and disc degeneration trends in the thoracic region and contributed to the interpretation of MR images for pathology in the human thoracic spine. Information on the associated collagenous and elastic changes in the disc and ligamentum matrices provide original data and insight on the pathogenesis of degeneration in the disc matrix from a biochemical perspective, highlighting gender, age and spinal level influences on the matrix tensile strength and cellular synthetic activities.

Le collagène de type I osseux subit une série de modifications post-traductionnelles au cours du processus de maturation. Un certain nombre de ces modifications sont quantifiables par dosage : c’est le cas des molécules de pontage enzymatiques pyridinoline (PYD) et désoxypyridinoline (DPD), de la pentosidine (PEN) qui est un produit de glycation, et de la forme native (α) et isomérisée (β) des C-télopeptides (α et β CTX) du collagène de type I. A l’aide d’un modèle de maturation in vitro d’os bovin foetal, nous avons montré que le taux de solubilisation du collagène osseux par la cathepsine K augmente avec la durée d’incubation des os à 37°C. Nous avons également montré que cette augmentation est corrélée au taux des modifications post-traductionnelles du collagène mesurées. Lors d’une étude précédente utilisant ce même modèle de maturation d’os foetal, nous avions déterminé que les modifications post-traductionnelles du collagène osseux influençaient les propriétés mécaniques de l’os. Dans le cadre de ce travail de thèse et pour compléter cette étude, nous avons mis au point un modèle pour étudier isolément l’influence des molécules de pontage PYD et DPD sur les propriétés mécaniques de l’os. Ce modèle utilise de l’os cortical bovin traité aux U.V. puis soumis à des tests de flexion trois points. Dans la même optique, nous avons contribué à la mise au point d’un dosage en chromatographie en phase liquide à haute performance qui permet de quantifier à la fois les formes matures et immatures des molécules de pontage pyridinoliques (PYD, DPD, HLNL et DHLNL) sur le même chromatogramme
Type I bone collagen undergoes a series of posttranslational modifications during maturation process. Some of them are quantifiable by assays: the enzymatic cross-links pyridinoline (PYD) and deoxypyridinoline (DPD), the advanced glycation end product pentosidine (PEN), and the native (α) and isomerized (β) forms of the type I collagen C-telopeptides (α and β CTX). With an in vitro model of bovine fetal bone maturation, we showed that bone collagen solubilization by cathepsin K increases with the duration of bone incubation at 37°C. We also showed a correlation between this increase of solubilization and the level of measured collagen posttranslational modifications. In a previous study, using the same fetal bovine bone maturation, our results had suggested a link between bone collagen posttranslational modifications and bone mechanical properties. In the aim to complete this study, we developed a model to focus on PYD and DPD influence in bone mechanical properties. This model uses bovine cortical bone subjected to ultraviolet light before three points binding tests. In the same purpose, we contributed to develop a High-Performance Liquid Chromatography essay, quantifying mature and immature forms of pyridinium crosslinks (PYD, DPD, HLNL and DHLNL) in an unique chromatogram

碩士
文化大學
應用化學系
85
AbstractQuantitation of urinary cross-links of bone collagen has been used extensively as bone resorption markers. They correlate well with radioisotopic measurements of systemic bone loss. Among them，the assay of free deoxypyridinoline (Dpd) has been claimed a reliable，objective foundation on which therapeutic decision about metabolic bone disorders，notably osteoporosis，Paget''s disease and bone-related malignancy are based. Judging the clinical significance of change of Dpd between consecutively observed data requires decision making criteria that are derived from the intra-individual biological variation of the analytes. It is essential for physicians to be aware of this type of biological variation before any rational decision can be made.Until recently，a number of investigations presented the valve of critical difference ( CD ) for Dpd that is the minimal valves between Dpd results that must occur before significance can be claimed. Costong et al. noted that the use of laboratory data in patient monitoring is considerably improved when CD is acknowledged. CD value is actually a dependent variable on intra-individual biological variation and derived through the simplified equation of " 2.77 ( ( SDa2 + SDb2 )1/2 " . The formula，though straightforward，has two fundamental assumptions. First，the successive test results are statistically independent ，and，second，the true biological variation of Dpd excretion is constant over all persons studied. Based on these two assumptions，the investigators deliberately ignored variance heterogeneity and serial correlation that may possibly exist. In reality，it may not be the case. For instance ，in situation in which serial data are examined over a short interval ，e.g ，as might be common in patient group ，the effect of serial correlation cannot be overlooked. Moreover，the value of CD derived by the referenced authors may not be ubiquitously valid if heterogeneity among individual variances turns out to be substantial.We therefore decide to assess these two assumptions in series of Dpd results obtained from 50 individual subjects and，based on these results. presents an appropriate CD value to guide clinical decision in monitoring situation.Dpd (deoxypyridinoline) is collagen cross-linking molecule found in bone. Dpd is a more specific and reliable indicator of bone resorption. Serial data of urinary excretion of free deoxypyridinoline ( Dpd ) is evaluated in a cohort of 50 healthy subjects over of 3 months. Our purpose is to derive appropriate critical difference ( CD ) value for this marker. Intra-individual coefficient variance over the study period was 11.0 %. Analytical variation contributes a small contribution to the total variation for Dpd/Cr assay. Among the 50 subjects studies，the biological variance within-subject varied considerably from person to person (CV((i2)=61%(. Serial correlation however was statistically insignificant. The results combine with the level of index of individuality ( I.I = 0.40 ) illustrate the uniqueness of Dpd/Cr ratio distribution in each individual subject. We conclude that it is necessary for physicians to build critical difference for Dpd/Cr ratio for each patient monitored. Conventional population-based reference range in this respect is of limited value. We here propose that the 95th percentile of individual CD ( CD95 ) ( 43.8% ) avoid problem of many false alarms and would greatly improve the utility of this bone marker in monitoring situation. Based on these results， presents an appropriate CD value to guide clinical decision in monitoring bone resorption.