Cross-linked Carboxyterminal Telopeptide Of Type Research Articles

Salivary type I collagen degradation end‐products and related matrix metalloproteinases in periodontitis

Type I collagen degradation end-products and related matrix metalloproteinases (MMPs) were examined aiming to detect potential markers of periodontitis in saliva, with high sensitivity and specificity. The salivary concentrations of MMP-8, MMP-9 and MMP-13, tartrate-resistant acid phosphatase serum type 5b, C-terminal cross-linked telopeptide of type I collagen (CTx), N-terminal cross-linked telopeptide of type I collagen (NTx) and cross-linked carboxyterminal telopeptide of type I collagen were analysed in 230 subjects. Oral health examination included panoramic radiography. The concentrations of MMP-8, MMP-9 and MMP-13 in saliva were higher in subjects with generalized periodontitis than in controls. Of the tested salivary markers, MMP-8 was the only marker capable of differentiating subjects with severe alveolar bone loss from those with slight bone loss (p<0.001). The association between the salivary MMP-8 levels and periodontitis remained significant after the adjustment with age, gender and smoking. In addition, significant correlations were found between the tested markers and periodontal parameters. Enzymes and end-products of type I collagen degradation have different associations with each other and with periodontal status that may reflect their roles in the cascade leading to alveolar bone loss. MMP-8 is a strong biomarker candidate for detecting alveolar bone destruction.

Correlation of Serum Biomarkers in Adults with Single Ventricles with Strain and Strain Rate Using 2D Speckle Tracking

With advances in cardiac care, patients with congenital heart disease, including single ventricle (SV) physiology, now survive into adulthood. These patients often suffer from congestive heart failure (CHF) with overexpression of serum biomarkers. Strain and strain rate (SR) may better describe the myocardial mechanics of a failing SV. Our objective was to determine the correlation between strain/SR and biomarkers in adult patients with SV and CHF. Adult patients (age ≥8 years) with a SV were enrolled. Strain/SR in a 16-segment model of a SV was measured using 2D speckle echocardiography. Serum levels of interleukin 6, interleukin 8, matrix metalloproteinase 9, procollagen I C-terminal peptide (PCIP), cross-linked carboxy-terminal telopeptide of type I collagen (ICTP), pro-B-type natriuretic peptide, nitrotryrosine, tissue growth factor beta (TGF-β), tumor necrosis factor alpha, vascular endothelial growth factor, and creatinine (Cr) were measured. Patients underwent a complete 6 Minute Walk Test (MWT). Pearson correlation coefficient was used. P <.05 was considered significant. Ten patients with SV (LV = 7, RV = 3) were enrolled. Mean age was 35.5 years (25-42 years). Mean single ventricular ejection fraction (SVEF) was 47%. ICTP correlated with the basal, mid, and apical anterolateral SR, as well as apical anterior and inferior SR. PCIP correlated with mid anterolateral, basal anteroseptal, and mid inferolateral SR. TGF-β correlated with apical inferior SR. Cr correlated with mid inferior-septal and apical lateral SR. 6 MWT negatively correlated with the apical anterior septum SR. ICTP, Cr, and PCIP correlated best with segmental SR values. Our results provide a preliminary platform for future studies to follow the results of treatment modalities using strain/SR and biomarkers for CHF in this population.

SERUM CONCENTRATIONS OF PROTEIN REGULATORS OSTEOBLASTOGENESIS AND OSTEOCLASTOGENESIS IN PATIENTS WITH ENDOGENOUS HYPERCORTICISM

Purpose. Endogenous Cushing’s syndrome (CS), usually affecting young and otherwise healthy patients, is a good model to validate the effects of supraphysiological levels of glucocorticoids in humans. This study evaluates circulating levels of extracellular antagonists of Wnt/ß-catenin signaling pathway (sclerostin, Dickkopf1 (Dkkl), secretedfrizzled-related protein 1 (SFRP1)) along with osteoprotegerin (OPG) and soluble receptor activator of nuclear factor kappa-beta ligand (RANKL) in patients with CS as compared to healthy individuals. Materials and methods. Forty patients with clinically and biochemically evident CS and 40 sex, age and body-mass index matched healthy individuals provided fasting serum samples (8:00-10:00AM) for measurement of sclerostin, SFRP1 and Dkkl, RANKL., OPG along with bone turnover markers. Serum samples on RANKL., OPG., Dkkl, SFRP1, sclerostin were frozen and then concurrently measured by an enzyme immunoassay (ELISA) using commercially available reagents. Serum samples on osteocalcin (OC), carboxyterminal cross-linked telopeptide of type I collagen (CTx), cortisol in serum and saliva were assayed by electrochemiluminescence (ECLIA) Cobas e601 Roche. Urinary free cortisol (24hUFC) was measured by an immunochemiluminescence assay (extraction with diethyl ether) on a Vitros ECi. All participants were questioned regarding any recent low traumatic fractures. Patients with CS underwent standard spinal radiographs in anterior-posterior and lateral positions of the vertebrae Th4-L4 (Axiom Icons R200 "Siemens"). Results. Patents with CS (30 (26-40) years old with 24hUFC 2575 (1184-4228) nmol/l (Me (Q25-Q75)) had suppressed OC and normal CTx levels as compared to healthy subjects. A significant correlation, which we observed between OC and CTx (po=0.724 (p&lt;0.001)) among the healthy volunteers, weakened to a non-significant level (po - 0.285 (p=0.083)) when analyzing patients with CS only. 24hUFC correlated with OC po = - 0.464 p=0.003, but not with CTx po= 0.245 (p=0.132) in patients with CS. Patients with CS had higher sclerostin levels versus healthy control subjects (p=0.032). Differences in sclerostin were due to the lack of lower sclerostin values rather than an increase in protein levels above the upper-limits of the healthy control individuals. Sclerostin levels higher than 662 pg/ml were four times more frequent in patients with CS as compared to healthy subjects (OR=4,19, 95% CI 1,44-12,22), p=0,006. Dkk1, SFRP1 did not differ from the control group. Patients with CS had a significantly lower level of RANKL (0.083 (0.075 0.093) pmol/L) as compared to healthy subjects (0.106 (0.089 0.131) pmol/L) p&lt;0.001. Conversely, no difference was found between the OPG level in patients with CS (6.65 (4.92-7.66) pmol/L) and healthy individuals (5.77 (5.00-6.40) pmol/L), p=0.14. RANKL was lower (p=0.02) and OPG was higher (p=0.04) in patients with CS and low traumatic fractures (n=19) versus patients without fractures (n=21). Conclusions. Patients with CS have higher sclerostin level as compared to healthy subjects. Hypercotisolism prevents the normal physiological suppression of sclerostin rather than raising its absolute level. Of all the tested proteins (sclerostin, Dkk1, SFRP1, RANKL., OPG) only sclerostin seems to be a promising therapeutic approach to treating osteoporosis in patients with endogenous CS.

Low dose of propranolol down‐modulates bone resorption by inhibiting inflammation and osteoclast differentiation

Bones are widely innervated, suggesting an important role for the sympathetic regulation of bone metabolism, although there are controversial studies. We investigated the effects of propranolol in a model of experimental periodontal disease. Rats were assigned as follows: animals without ligature; ligated animals receiving vehicle and ligated animals receiving 0.1, 5 or 20 mg·kg(-1) propranolol. After 30 days, haemodynamic parameters were measured by cardiac catheterization. Gingival tissues were removed and assessed for IL-1β, TNF-α and cross-linked carboxyterminal telopeptides of type I collagen (CTX) by elisa, or intercellular adhesion molecule 1 (ICAM-1), receptor activator of NF-κ B ligand (RANKL) and osteoprotegerin (OPG) by Western blot analysis. Sections from the mandibles were evaluated for bone resorption. Also, we analysed the ability of propranolol to inhibit osteoclastogenesis in vitro. Propranolol at 0.1 and 5 mg·kg(-1) reduced the bone resorption as well as ICAM-1 and RANKL expression. However, only 0.1 mg·kg(-1) reduced IL-1β, TNF-α and CTX levels as well as increased the expression of OPG, but did not alter any of the haemodynamic parameters. Propranolol also suppressed in vitro osteoclast differentiation and resorptive activity by inhibiting the nuclear factor of activated T cells (NFATc)1 pathway and the expression of tartrate-resistant acid phosphatase (TRAP), cathepsin K and MMP-9. Low doses of propranolol suppress bone resorption by inhibiting RANKL-mediated osteoclastogenesis as well as inflammatory markers without affecting haemodynamic parameters.

Safety evaluation of vitamin A in growing dogs

The safe upper limit for inclusion of vitamin A in complete diets for growing dogs is uncertain, with the result that current recommendations range from 5.24 to 104.80 μmol retinol (5000 to 100 000 IU vitamin A)/4184 kJ (1000 kcal) metabolisable energy (ME). The aim of the present study was to determine the effect of feeding four concentrations of vitamin A to puppies from weaning until 1 year of age. A total of forty-nine puppies, of two breeds, Labrador Retriever and Miniature Schnauzer, were randomly assigned to one of four treatment groups. Following weaning at 8 weeks of age, puppies were fed a complete food supplemented with retinyl acetate diluted in vegetable oil and fed at 1 ml oil/100 g diet to achieve an intake of 5·24, 13·10, 78·60 and 104·80 μmol retinol (5000, 12 500, 75 000 and 100 000 IU vitamin A)/4184 kJ (1000 kcal) ME. Fasted blood and urine samples were collected at 8, 10, 12, 14, 16, 20, 26, 36 and 52 weeks of age and analysed for markers of vitamin A metabolism and markers of safety including haematological and biochemical variables, bone-specific alkaline phosphatase, cross-linked carboxyterminal telopeptides of type I collagen and dual-energy X-ray absorptiometry. Clinical examinations were conducted every 4 weeks. Data were analysed by means of a mixed model analysis with Bonferroni corrections for multiple endpoints. There was no effect of vitamin A concentration on any of the parameters, with the exception of total serum retinyl esters, and no effect of dose on the number, type and duration of adverse events. We therefore propose that 104·80 μmol retinol (100 000 IU vitamin A)/4184 kJ (1000 kcal) is a suitable safe upper limit for use in the formulation of diets designed for puppy growth.

Protective effect of atorvastatin on bone tissue in orchidectomised male albino Wistar rats

Recent studies have shown that atorvastatin influences bone metabolism. We investigated its bone protective effect in orchidectomised rats after 12weeks of treatment. Eight-week-old rats were divided into 3 groups: sham-operated group, control group after orchidectomy and experimental group after orchidectomy with atorvastatin administration (12mg/kg/day). Bone mineral density and bone marker concentrations of aminoterminal propeptide of procollagen type I (PINP), osteoprotegerin (OPG), insulin-like growth factor 1 (IGF-1) in serum, and carboxy-terminal cross-linking telopeptide of type I collagen (CTX-I), bone alkaline phosphatase (BALP), bone morphogenetic protein 2 (BMP-2) in bone homogenate were measured. Total serum calcium and tibial calcium content was determined. Femurs were used for three-point bending test of the shaft and compression testing of the femoral neck. Bone markers (CTX-I, BALP, BMP-2) in control rats were higher vs. sham-operated rats. Atorvastatin reduced CTX-I, BMP-2 and OPG compared to controls. IGF-1 was decreased in control rats vs. sham-operated rats; atorvastatin increased IGF-1 vs. control rats. Atorvastatin exerts a positive effect on bone metabolism by increasing bone mineral density of the whole body, which had decreased under the effects of orchidectomy. Three-point bending test revealed an increase in maximal load values of the left femurs after atorvastatin administration compared to controls. The diameter of the left femur and length of both femurs were increased after atorvastatin administration compared to controls. Our findings suggest that atorvastatin has a beneficial effect on bone metabolism in orchidectomised rats by decreasing bone turnover, with resulting improvement in bone mineral density and bone biomechanical properties.

Distinct effects of pioglitazone and metformin on circulating sclerostin and biochemical markers of bone turnover in men with type 2 diabetes mellitus

Patients with type 2 diabetes mellitus (T2DM) have an increased risk of fractures and thiazolidinediones (TZDs) increase this risk. TZDs stimulate the expression of sclerostin, a negative regulator of bone formation, in vitro. Abnormal sclerostin production may, therefore, be involved in the pathogenesis of increased bone fragility in patients with T2DM treated with TZDs. We measured serum sclerostin, procollagen type 1 amino-terminal propeptide (P1NP), and carboxy-terminal cross-linking telopeptide of type I collagen (CTX) in 71 men with T2DM treated with either pioglitazone (PIO) (30 mg once daily) or metformin (MET) (1000 mg twice daily). Baseline values of sclerostin and P1NP were compared with those of 30 healthy male controls. Compared with healthy controls, patients with T2DM had significantly higher serum sclerostin levels (59.9 vs 45.2 pg/ml, P<0.001) but similar serum P1NP levels (33.6 vs 36.0 ng /ml, P=0.39). After 24 weeks of treatment, serum sclerostin levels increased by 11% in PIO-treated patients and decreased by 1.8% in MET-treated patients (P=0.018). Changes in serum sclerostin were significantly correlated with changes in serum CTX in all patients (r=0.36, P=0.002) and in PIO-treated patients (r=0.39, P=0.020), but not in MET-treated patients (r=0.17, P=0.31). Men with T2DM have higher serum sclerostin levels than healthy controls, and these levels further increase after treatment with PIO, which is also associated with increased serum CTX. These findings suggest that increased sclerostin production may be involved in the pathogenesis of increased skeletal fragility in patients with T2DM in general and may specifically contribute to the detrimental effect of TZDs on bone.

Additive effect of zoledronic acid on serum prostate‐specific antigen changes for hormone‐sensitive prostate cancer patients with bone metastasis treated by combined androgen blockade

Combined androgen blockade is widely used to treat patients with advanced prostate cancer. Recently, zoledronic acid was proven to be effective in preventing skeletal-related events for prostate cancer patients with bone metastases. Aim of the present study was to assess the effect of adding zoledronic acid to combined androgen blockade in the treatment of hormone-naïve metastatic prostate cancer patients by analyzing the changes of biomarker levels. Patients were treated with either a combination of combined androgen blockade and zoledronic acid (n=23) or combined androgen blockade alone (historical control combined androgen blockade group, n=42). Zoledronic acid was injected intravenously at 4 mg every 4 weeks for 2 years. Prostate-specific antigen and bone turnover markers (alkaline phosphatase and pyridinoline cross-linked carboxyterminal telopeptide of type 1 collagen) were examined before treatment and at 3, 6, and 12 months after treatment. Sequential changes of prostate-specific antigen, alkaline phosphatase and pyridinoline cross-linked carboxyterminal telopeptide of type 1 collagen for the two groups versus pretreatment levels were compared. Prostate-specific antigen values in both groups significantly declined at 3, 6 and 12 months compared with pretreatment levels. However, the decline of the prostate-specific antigen was lower in the combined androgen blockade group. Alkaline phosphatase significantly declined at 6 and 12 months in the combination of combined androgen blockade and zoledronic acid group, with no significant changes seen in the combined androgen blockade group. The addition of zoledronic acid to combined androgen blockade showed prostate-specific antigen and bone turnover markers response compared with combined androgen blockade therapy only, suggesting a potential antitumor effect of zoledronic acid in the management of metastatic prostate cancer patients.

Comparison of total and intact aminoterminal propeptide of type I procollagen assays in patients with breast cancer with or without bone metastases

Aminoterminal propeptide of type I procollagen (PINP) reflects bone formation. Two different antigens exist in human serum: intact PINP and a monomeric form. The intact PINP assay measures trimeric form and the total assay measures both forms. The structure and origin of the monomeric form is still unclear. Automated intact and total PINP assays were compared in breast cancer patients with (n = 60) or without bone metastases (n = 226). In addition, cross-linked carboxyterminal telopeptide of type I collagen (ICTP) was measured from the same patients and compared with the concentration of PINP monomer (difference between intact and total PINP). Monomeric PINP was purified from human ascitic fluid and characterized by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The correlations were good (r > 0.948) between intact PINP and total P1NP in all patient groups. The correlation between the monomeric form and ICTP was lower in patients without bone metastases (r = 0.507) than in patients with bone metastases (r = 0.894). This indicates that the monomeric form reflects the degradation of type I collagen because bone metastases are osteolytic in nature. After several steps in the purification of the monomer form there was a single peak. Only the single band was visible in the SDS-PAGE gel. The alpha1-chain of intact PINP consists of 161 amino acids with a molecular weight of 14224.02. The purified monomer peptide in MALDI-TOF MS was smaller, 10576.41, and most likely cleaved after the arginine residue (amino acid number 120) with a trypsin-like protease. Intact and total PINP assays give similar results in many conditions, but there are differences, for example in breast carcinoma, which should be recognized.

Heterogeneity of biological bone markers in Idiopathic Male Osteoporosis

In men with idiopathic osteoporosis, histomorphometric studies reported both increased resorption and decreased remodeling. We aimed at examine bone remodeling in these patients by biological marker measurement. We compared pre-treatment carboxy-terminal cross-linking telopeptide of type I collagen (CTX) and bone alkaline phosphatase (bALP) levels in 49 men, mean age 59 ± 14 year, with idiopathic osteoporosis with fractures (40 patients) or osteoporosis diagnosed by densitometry (9 patients) with 50 age-matched controls. The influence of baseline remodeling level on alendronate efficacy was studied. Bone remodeling markers (CTX and bALP) did not significantly differ between patients and controls and were correlated in both groups. There was no correlation between these markers, vitamin D and PTH levels. Twenty-one patients underwent repeat densitometry after 1 year of alendronate (70 mg/week). Mean annual BMD increase, spine +4.1 ± 3.9%, and hip +1.5 ± 1.2% showed no correlation with baseline CTX. Bone remodeling is very heterogeneous and formation and resorption remain biologically coupled in both idiopathic male osteoporosis and controls. Baseline remodeling level does not affect the action of alendronate on BMD.

Modulation of electrolyte homeostasis by dietary nitrogen intake in growing goats

In goats, the combination of dietary N and Ca reduction caused hypocalcaemia and further changes in Ca homeostasis. The aim of the present study was to characterise the effects of dietary N reduction under normocalcaemia on mineral and bone metabolism in young goats. Young male goats of the Saanen breed were fed a diet reduced in N (8 %) for about 7 weeks (ten animals per group) and were compared with goats fed with an adequate N (14 %) diet. When N intake was reduced in young goats, plasma urea concentrations as well as renal elimination of urea were reduced. This was inversely related to creatinine in plasma and urine, which increased during a dietary N reduction as a function of reduced renal activity to save urea during N scarcity. During this decrease in renal function, associated with declined insulin-like growth factor 1 concentrations, a reduction in calcidiol and calcitriol concentrations could be observed. Meanwhile, carboxyterminal cross-linked telopeptide of type I collagen values and activity of total alkaline phosphatase were both elevated, indicating some bone remodelling processes taking place during a reduced N diet in young goats. The concentrations of inorganic phosphate (Pi) and total Ca were changed in several body fluids, indicating that Pi and Ca homeostasis was perturbed in goats fed a reduced N diet. Therefore, more research is needed to find the balance between reduction of environmental N pollution by reducing dietary N in ruminant feeding and maintaining the animal's health.

Long-term effects of intermittent equine parathyroid hormone fragment (ePTH-1-37) administration on bone metabolism in healthy horses

Intermittent administration of parathyroid hormone (PTH) is an anabolic therapy for osteoporotic conditions in humans. This study evaluated the effects of equine PTH fragment (ePTH-1-37) administration on bone metabolism in 12 healthy horses. Six horses each were treated once daily for 120days with subcutaneous injections of 0.5μg/kg ePTH-1-37 or placebo. Blood was collected to determine ionized calcium (Ca(++)), total Ca (Ca(T)), inorganic phosphorus, serum equine osteocalcin (eOC), carboxy-terminal telopeptide of type I collagen (ICTP), bone-specific alkaline phosphatase, and carboxy-terminal cross-linked telopeptide of type I collagen. Bone mineral density (BMD) was determined with dual X-ray absorptiometry of the metacarpus and calcaneus. Significantly higher blood Ca(++) and plasma Ca(T) concentrations were measured 5h after ePTH-1-37 administration compared to placebo. Higher serum eOC concentrations were found for ePTH-1-37 treatment at days 90 (P<0.05) and 120 (P=0.05). Significantly higher serum ICTP levels were observed with ePTH-1-37 treatment at days 60 and 90. For both study groups, BMD increased significantly in the calcaneus. Long-term use of ePTH-1-37 seemed to have no negative effects on bone metabolism in healthy horses. The absence of undesirable side effects is the premise to ensure safety for further clinical investigations in horses with increased bone resorption processes.

Effects of amlodipine on bone metabolism in male albino Wistar rats

Amlodipine (dihydropyridine-type calcium channel blocker) is a widely used agent for the treatment of hypertension in human and veterinary medicine but detailed information about its effects on bone metabolism are missing. Therefore, the aim of our study was to investigate the effect of amlodipine on bone metabolism in male albino Wistar rats. Amlodipine (0.3 mg/100 g body weight; gavage) was administered to 8 rats for 8 weeks. Control group (n = 8) received aqua pro inj. (0.2 ml/100 g body weight; gavage). Bone marker concentrations of carboxy-terminal cross-linking telopeptide of type I collagen (CTX-I) and aminoterminal propeptide of procollagen type I in serum, and of bone alkaline phosphatase (BALP) in both serum and bone homogenate were measured by enzyme immunoassay. We investigated the expression of bone morphogenetic protein 2 (BMP-2) in proximal tibia using Western blotting, and bone mineral density was measured by Dual-energy X-ray Absorptiometry in lumbar and caudal vertebrae and in femoral areas. Mechanical properties of the femurs were measured by three-point bending of the shaft and compression testing of the femoral neck. After 8 weeks of amlodipine administration there was a significant decrease in serum concentrations of BALP (p= 0.0009) and CTX-I (p= 0.003), and the content of BALP in bone homogenate (p= 0.026) compared to the control. In addition, Western blot analysis indicated increased BMP-2 protein concentration after amlodipine administration. Our findings suggest that amlodipine has a retarding influence on bone metabolism in rats by decreasing bone turnover, which probably in consequence increases expression of BMP-2.

The use of biochemical markers of bone remodeling in multiple myeloma: a report of the International Myeloma Working Group

Lytic bone disease is a frequent complication of multiple myeloma (MM). Lytic lesions rarely heal and X-rays are of limited value in monitoring bone destruction during anti-myeloma or anti-resorptive treatment. Biochemical markers of bone resorption (amino- and carboxy-terminal cross-linking telopeptide of type I collagen (NTX and CTX, respectively) or CTX generated by matrix metalloproteinases (ICTP)) and bone formation provide information on bone dynamics and reflect disease activity in bone. These markers have been investigated as tools for evaluating the extent of bone disease, risk of skeletal morbidity and response to anti-resorptive treatment in MM. Urinary NTX, serum CTX and serum ICTP are elevated in myeloma patients with osteolytic lesions and correlate with advanced disease stage. Furthermore, urinary NTX and serum ICTP correlate with risk for skeletal complications, disease progression and overall survival. Bone markers have also been used for the early diagnosis of bone lesions. This International Myeloma Working Group report summarizes the existing data for the role of bone markers in assessing the extent of MM bone disease and in monitoring bone turnover during anti-myeloma therapies and provides information on novel markers that may be of particular interest in the near future.

Genitourinary prolapse and joint hypermobility are associated with altered type I and III collagen metabolism

The aim of this study was to determine whether benign joint hypermobility (BJH) is associated with urogenital prolapse and altered collagen metabolism. 43 postmenopausal women with previous vaginal hysterectomy operated due to genitourinary prolapse were recruited. Each patient was also evaluated for joint hypermobility. The collagen metabolism was studied measuring serum concentrations of type I and III procollagen aminoterminal propeptides and trivalently cross-linked carboxyterminal telopeptide of type I collagen. Clinical joint hypermobility was found in 35% patients. Women with joint hypermobility had higher concentration of aminoterminal propeptide for type I procollagen and the values were statistically significant (P < 0.0178). Recurrent prolapse was found in 47% of the patients with BJH as compared to non-hypermobile group (25%). In this subgroup the results were statistically significant (P < 0.0085) for type III collagen. Also, the mean serum concentration for type III procollagen was significantly increased above the reference limit. Women with joint hypermobility have more recurrent genital prolapse as compared to women with normal joint mobility. Plain hypermobility was associated with higher concentrations for type I procollagen. Patients with recurrent prolapse and joint hypermobility have significantly high concentrations for type III procollagen.

Salivary MMP‐8, TIMP‐1, and ICTP as markers of advanced periodontitis

Salivary matrix metalloproteinase (MMP)-8 and -14, tissue inhibitor of matrix metalloproteinase (TIMP)-1, and pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP) were analysed aiming to detect potential markers of advanced periodontitis in saliva. In addition, we compared two MMP-8 detection methods, a time-resolved immunofluorometric assay (IFMA) and an enzyme-linked immunoassay (ELISA), to differentiate periodontitis subjects from controls. Concentrations of MMP-8, MMP-14, TIMP-1, and ICTP were analysed from salivary specimens of 165 subjects, including 84 subjects having at least 14 teeth with periodontal pocket (pocket depth > or =4 mm) and 81 subjects without pocket depth as their controls. Salivary MMP-8 detection by IFMA differentiated periodontitis subjects from controls more strongly than by ELISA. Salivary MMP-8, TIMP-1, and ICTP concentrations were higher in periodontitis subjects than those in controls. When only smokers were included in the analysis these differences were lost. The MMP-8/TIMP-1 ratio and the combination of MMP-8 and ICTP differentiated periodontitis and control groups even in smoker subjects. Salivary MMP-8, TIMP-1, ICTP, and especially their ratios and combinations are potential candidates in the detection of advanced periodontitis. Differentiating periodontitis and control subjects with salivary MMP-8 detection is dependent on the selected techniques.

Effects of a reduced nitrogen diet on calcitriol levels and calcium metabolism in growing goats

For monogastric animals, changes in dietary protein content modulate calcium (Ca) metabolism by changing parathyroid hormone and calcitriol concentrations. However, the effects of dietary nitrogen (N) restriction on Ca metabolism are not known in ruminants. Since ruminants express endogenous recycling mechanisms very efficiently to save N, it is known that these recycling mechanisms protect ruminants against N depletion in times of dietary N restriction. Therefore, consequences on Ca metabolism induced by reduction of dietary N supply as observed in monogastric animals should not occur in ruminants. Due to this specific metabolic feature, a reduction of dietary N intake can be used to diminish environmental N pollution. The aim of the present study was to determine the consequences of a reduced N intake on Ca homeostasis and respective regulatory hormone concentrations in ruminants. Growing goats fed with a reduced N diet showed a decrease in ionised calcium (Ca 2+) and total Ca concentrations while bone resorption marker carboxyterminal cross-linked telopeptide of type I collagen increased in plasma. Unexpectedly, despite hypocalcemia, concentrations of calcitriol were decreased in the animals of the N reduction group whereas calcidiol levels were not affected. From this data, it can be concluded that the Ca metabolism of growing goats can be modulated by changes of dietary N content like in monogastric animals.

Combination of radiological and biochemical methods to assess bone mineral density of mandible in fully edentulous patients after chemotherapy: a 5-year prospective study

Background: Osteoporosis is of concern in breast cancer patients who are undergoing chemotherapy. This study compared the bone mineral density (BMD) index of the mandible and hip hinge between patients who were undergoing chemotherapy or breast cancer, and fully edentulous Chinese patients without cancer over a period of 5 years. Method: 120 fully edentulous patients with an average age of 69 who had undergone mastectomy for grade two or three non-metastatic invasive breast ductal carcinoma. This was followed by administration of 5-fluorouracil, cyclophosphamide, and doxorubicin. The 118 fully edentulous cancer-free patients were included as a control group. The first assessment point was 6 months after chemotherapy treatment. The BMD and panoramic and side views of the mandible were measured by γ-ray and the BMD of left hip hinge was measured using dual energy X-ray absorptiometry. The serum and urine level of bone-specific alkaline phosphatase (BAP), carboxyterminal cross-linked telopeptide of type I collagen (ICTP), as well as liver and renal function tests were determined. These examinations were performed annually for 5 years. Result: The cancer patients demonstrated a statistically significant (p < 0.05) increase in bone resorption of mandible and hip, and an increase in BAP and ICTP levels when compared with the control group. Although data were collected annually there was no statistical significance for the first 3 years. Conclusion: Breast cancer patients undergoing chemotherapy displayed significant resorption of mandibular bones compared with the healthy control, which might result in difficulties in fitting dentures, as it would cause pain and mucosal friction. Thus, concurrent therapy to decrease mandibular bone loss and special considerations in dentures are warranted for these patients.

The effect of prior bisphosphonate therapy on the subsequent BMD and bone turnover response to strontium ranelate

Strontium ranelate is an effective treatment for osteoporosis in treatment-naive women. In the United Kingdom, bisphosphonates are often used first line. Prior bisphosphonate use may blunt the bone mineral density (BMD) response to strontium ranelate by reducing strontium uptake into the bone. Sixty bisphosphonate-naive women and 60 women discontinuing bisphosphonates were recruited. All women commenced strontium ranelate and calcium/vitamin D. BMD and bone turnover markers were recorded for 12 months. After 12 months, the bisphosphonate-naive group's BMD increased by 5.6% (p < .001) at the spine, 3.4% (p < .001) at the total hip, and 4.0% (p < .001) at the heel. By comparison, the prior bisphosphonate group had a 2.1% (p = .002) increase at the spine but no change at the hip or heel. At all time points, BMD was significantly greater in the bisphosphonate-naive group. In the prior bisphosphonate group, there was no significant change in BMD during the first 6 months at the spine, but between months 6 and 12 there was a parallel gain in BMD (0.027 versus 0.020 g/cm(2), p = .40). The baseline difference in bone markers was no longer significant by 3 months for bone-specific alkaline phosphatase (BSAP) and 6 months for procollagen type 1 amino-terminal propeptide (P1NP) and carboxy-terminal cross-linking telopeptide of type I collagen (CTX). More women in the prior bisphosphonate group suffered a vertebral fracture (2 versus 8 women, p = .047). After bisphosphonates, bone turnover remains suppressed for up to 6 months, with blunting of the BMD response to strontium ranelate during this time. After 6 months, BMD increases in the spine but not at the hip or heel.

Effects of alendronate treatment on serum levels of osteoprotegerin and total receptor activator of nuclear factor κB in women with postmenopausal osteoporosis

Bisphosphonates are potent inhibitors of bone resorption that are used as effective therapeutic agents for the management of osteoporosis and other bone diseases. The osteoprotegerin (OPG)-receptor activator of nuclear factor kappaB (RANKL) system plays an important role in the regulation of bone metabolism and vascular biology. The effects of bisphosphonate treatment in OPG-RANKL system have not been fully elucidated. The aims of the study were to evaluate the effects of alendronate treatment (70 mg once/wk) on serum concentrations of OPG, total RANKL, and biochemical markers of bone turnover in untreated women with postmenopausal osteoporosis and to determine the correlation between changes in bone mineral density and changes in serum OPG, total RANKL, and bone turnover markers. The study was a single group pretest/posttest design including a total number of 46 participants. Serum OPG and total RANKL serum levels were determined before and after 3, 6, and 12 months of treatment with alendronate. We also measured serum carboxyterminal cross-linked telopeptide of type I collagen, osteocalcin, and bone-specific alkaline phosphatase. The main outcome measures are the changes in OPG and total RANKL serum levels after alendronate treatment. Serum OPG changes were not significant at 3 and 6 months (-1.6% and -1%), but at 12 months, there was a significant reduction of 6.5% (P < 0.01). Total RANKL serum levels increased during treatment: 23% at 3 months, 25% at 6 months, and 52% at 12 months (P < 0.001 for all comparisons). Basal levels of OPG, total RANKL, and bone turnover markers were not correlated, and we did not find correlations between changes in these parameters after treatment. We conclude that the determination of total RANKL integrates the free RANKL and the fraction bound to OPG. The apparent decrease in the serum levels of OPG might reflect an increase in OPG binding to RANKL, which results in a beneficial effect on bone.