BGP Measurement Research Articles

Effects of parecoxib of bone mineral density and osteocalcin of rats and intervention of ketamine

Objective To study the effects of parecoxib on bone metabolism of rats at different time points,and intervention of ketamine.Methods Thirty-two SD rats were randomly divided into four groups:control group,ketamine group,parecoxib group,ketamine + parecoxib group.The treatments were given once every 12 h for three days.After being finished doses for seven days,fourteen days and thirty-five days,bone mineral density (BMD) & osteocalcin (BGP) measurements would be separately taken.Results Result of seven-day BMD measurement:It was not statistically significant between the different groups (F =I.802,P ＞ 0.05).Result of fourteen-day BMD measurement:It was not statistically significant between the different groups (F =2.699,P ＞ 0.05).Result of thirty-five-day BMD measurement:Each of them were 0.1444 ±0.0036,0.1426 ± 0.0024,0.1377 ± 0.0005 and 0.1308 ± 0.0066,It was showed statistically significant between the different groups (F =15.258,P ＜ 0.05).By comparison,It was showed statistically significant between the different of precoxib group and others;It was showed statistically significant between the different of ketamine group and others,too;Meanwhile,It was not statistically significant between control group and ketamine group.Result of seven-day BGP measurement:Each of them were 222.500 ± 9.607,229.830 ±6.795,226.830 ± 12.828 and 115.830 ± 11.125,It was showed statistically significant between the different of ketamine group and others (F =172.335,P ＜ 0.05).Result of fourteen-day BGP measurement:Each of them were 229.830 ±5.193,221.670 ± 16.884,85.500 ± 15.592 and 223.670 ±34.256,It was showed statistically significant between the different of precoxib group and others (F =67.768,P ＜0.05).Result of thirty-five-day BGP measurement:Each of them were 231.170 ± 72.486,221.000 ±51.166,100.500 ± 14.053 and 101.500 ± 8.643,It was showed statistically significant between the different precoxib group& ketamine group and control group & ketamine group (F =15.420,P ＜0.05).Conclusion The use of parecoxib weakened BMD and BGP,and had an adverse impact on symphysis.The process may be accelerated after using ketamine. Key words: Parecoxib; Bone mineral density; Bone gla protein; Ketamine

Identifying BGP routing table transfers

BGP routing updates collected by monitoring projects such as RouteViews and RIPE have been a vital source to our understanding of the global routing system. However the collected BGP data contains both the updates generated by actual route changes, and the updates of BGP routing table transfers resulted from BGP session resets between operational routers and the data collection stations. Since the latter is caused by measurement artifact, it is important to accurately separate out the latter from the former. In this paper, we present the design and evaluation of the minimum collection time (MCT) algorithm. Given a BGP update stream, MCT can identify the start and duration of each routing table transfer in the stream with high accuracy. We evaluated MCT performance by using three months of BGP data from all RIPE collectors. Our results show that out of the total 1664 BGP resets with 166 monitors, MCT can identify BGP routing table transfers with over 95% accuracy, and pinpoint the exact starting time of the detected table transfers in 83% of such cases. Accurate detection of BGP table transfers enables users to separate out real BGP routing changes and measurement artifacts, and can be used to measure and diagnose the BGP session failures.

Route oracle

Many network-management problems in large backbone networks need the answer to a seemingly simple question: where does a given IP packet, entering the network at a particular place and time, leave the network to continue on its path to the destination? Answering this question at scale and in real time is challenging for several reasons: (i) a destination IP address could match several IP prefixes, (ii) the longest-matching prefix may change over time, (iii) the number of IP prefixes and routing protocol messages is very large, and (iv) network-management applications often require answers to this question for a large number of destination IP addresses in real time. In this paper, we present an efficient algorithm for tracking prefix-match changes for ranges of IP addresses. We then present the design, implementation, and evaluation of the Route Oracle tool that answers queries about routing changes on behalf of network management applications. Our design of Route Oracle includes several performance optimizations, such as pre-processing of BGP update messages, and parallelization of query processing. Experiments with BGP measurement data from a large ISP backbone demonstrate that our system answers queries in real time and at scale.

Interest of biochemical markers of bone turnover for long-term prediction of new vertebral fracture in postmenopausal osteoporotic women

Objective: To analyse the interest of baseline levels and short-term (3-months) changes in serum osteocalcin (BGP), serum bone-specific alkaline phosphatase (BALP) and urinary C-telopeptide of type I collagen/creatinine ratio (U-CTX) to predict 3-years changes in bone mineral density (BMD) and spinal deformity index (SDI) in postmenopausal osteoporotic women. Methods: Data were derived from a cohort of 603 osteoporotic women corresponding to the placebo arm of a 3-years prospective, double-blind study. Results: Baseline values of BALP, BGP and U-CTX were negatively and significantly correlated with baseline spinal BMD. Significant correlations were also observed between the changes in BMD observed after 36 months at the spine and baseline BALP ( r=0.20, P=0.0001), BGP ( r=0.09, P=0.05) and U-CTX ( r=−0.11, P=0.02). At 3 years, 71 women (15.9%) showed an increase in their SDI, corresponding to the occurrence of at least one new vertebral deformity. Baseline values of the four bone turnover markers (BTM) were not significantly related to the occurrence of new vertebral deformities. However, when considering the changes in the BTM observed after 3-months of follow-up, BGP ( P=0.003) and U-CTX ( P=0.047) were identified as significant predictors of an increase of SDI. The associated odds ratios (95% confidence interval (CI)) were 10.922 (2.218–53.78) for unit changes of log BGP and 1.369 (1.003–1.867) for unit changes of log U-CTX. The relative risk (RR) (IC 95%) of having a new vertebral fracture over 36 months was 0.31 (0.15–0.65) when being in the lowest quartile of 3-months changes in BGP as compared with the highest. Conclusion: We conclude that two sequential measurements of BGP and U-CTX performed at 3-months intervals could be of interest to identify postmenopausal osteoporotic women with the highest risk to present new vertebral deformities.

Serum Levels of Osteocalcin and Type I Procollagen in Children with Celiac Disease

Bone metabolism may be disturbed in children with celiac disease. Two markers of bone turnover were used: the level of osteocalcin (BGP) and the level of carboxylterminal peptide of type I procollagen (PICP). BGP and PICP were measured by radioimmunoassays in 18 untreated children with celiac disease (mean age: 22.9 +/- 15.6 months) and in 15 control subjects (mean age 28.5 +/- 21 months). All the patients were rechecked after 1 month and again after 3 months from beginning of a gluten-free diet (GFD). Compared with controls at diagnosis our patients had significantly lower serum levels of BGP and PICP (p = 0.003 and p = 0.018 by Student's t test, respectively). These levels increased markedly during the 1st 3 months of GFD. The alteration in calcium phosphate homeostasis caused by celiac disease directly affects the synthesis of both components of the connective matrix of bone. Measurements of BGP and PICP provide a reliable and rapidly obtainable index of normalization of the processes of bone growth which can be achieved with a GFD.

Serum Levels of Osteocalcin and Type I Procollagen in Children with Celiac Disease

Background:Bone metabolism may be disturbed in children with celiac disease.Methods:Two markers of bone turnover were used: the level of osteocalcin (BGP) and the level of carboxylterminal peptide of type I procollagen (PICP). BGP and PICP were measured by radioimmunoassays in 18 untreated children with celiac disease (mean age: 22.9 ± 15.6 months) and in 15 control subjects (mean age 28.5 ± 21 months). All the patients were rechecked after 1 month and again after 3 months from beginning of a gluten‐free diet (GFD).Results:Compared with controls at diagnosis our patients had significantly lower serum levels of BGP and PICP (p = 0.003 and p = 0.018 by Student's t test, respectively). These levels increased markedly during the 1st 3 months of GFD.Conclusions:The alteration in calcium phosphate homeostasis caused by celiac disease directly affects the synthesis of both components of the connective matrix of bone. Measurements of BGP and PICP provide a reliable and rapidly obtainable index of normalization of the processes of bone growth which can be achieved with a GFD.

Biochemical markers of bone and collagen turnover in acromegaly or Cushing's syndrome.

We evaluated serum bone Gla-protein (osteocalcin, BGP), carboxyterminal propeptide of type I procollagen (PICP) and aminoterminal propeptide of type III procollagen (PIIINP) in 15 patients with active acromegaly (6M aged 27-54, 4 PMF aged 39-51, 5MP aged 54-65 years), 12 with active Cushing's syndrome [(CS) 2M of 32 and 42 years; 4PMF aged 25-40; 6MF aged 50-64)] and controls evenly matched for age, sex and menstrual status. Patients with acromegaly were evaluated before and at regular intervals on octreotide treatment (50-150 micrograms t.i.d., s.c.); the duration of the follow-up was 5-49 months (median 28). Endocrine evaluation included measurements of serum GH, IGF-I, BGP, PICP and PIINP. In a case-control analysis, acromegalic patients showed increased BGP (14.3 +/- 2.1 vs 8.3 +/- 2.1 ng/ml p < 0.001) and PIIINP concentrations (4.8 +/- 1.4 vs 3.1 +/- 0.7 micrograms/l, p < 0.02). During octreotide treatment we observed a roughly parallel decline of GH, IGF-I and BGP. BGP and log-transformed 24-h mean GH concentrations were positively correlated (r = 0.48, p < 0.001) as was the case for BGP and IGF-I (r = 0.43, p < 0.001). Also PIIINP correlated with log-transformed GH (r = 0.58, p < 0.001) and IGF-I (r = 0.35, p < 0.05). Serum PICP did not differ in the two groups (152 +/- 55 vs 120 +/- 55 micrograms/l, NS) and did not correlate either with GH or IGF-I. Patients with CS were evaluated measuring serum and urinary cortisol (UFC), ACTH, BGP, PICP, PIIINP.(ABSTRACT TRUNCATED AT 250 WORDS)

The diagnostic and prognostic value of serum bone Gla protein (osteocalcin) in patients with recurrent breast cancer.

Serum bone Gla protein (S-BGP), a marker of bone metabolism, was measured in 60 patients included in a staging programme for recurrent breast cancer. Other diagnostic procedures comprised S-alkaline phosphatase (S-AP), bone scan (B-scan), bilateral iliac crest bone marrow biopsies, and radiological bone survey. The sites of recurrence were bone (61%), bone marrow (46%), soft tissue (52%), lung (13%), pleura (11%), liver (4%), and brain (2%). Radiology and bone biopsy served as key diagnoses as to the presence or absence of bone metastases. The diagnostic efficiency of B-scan and S-AP was greater than that of S-BGP, and the result of BGP measurement was associated with neither extent nor number of bone metastases. However, the BGP values were significantly lower in patients who had visceral metastases, and the median duration of survival after recurrence was 13 months for patients with low S-BGP levels (= < 2.0 nmol l-1), compared to 18 months for patients with medium S-BGP values (2.0-2.9 nmol l-1), and 25 months for patients with high values (> 3.0 nmol l-1) (p = 0.19). Analyses of the simultaneous effect of univariate prognostic factors were performed using the Cox proportional hazards model. S-alkaline phosphatase (S-AP) and S-BGP were the only significant, independent prognostic factors.

Osteocalcin: a potential marker of metastatic bone disease and response to treatment

Serum osteocalcin (BGP) is an osteoblast product that probably reflects the rate of bone formation. It is a potential marker of skeletal metastases and, to investigate this, BGP was measured by radioimmunoassay in the serum of normal subjects and patients with breast or prostate cancer. Significantly higher levels were found in patients with metastatic bone disease in comparison to both normal subjects ( P < 0.001) and patients with non-metastatic cancer ( P < 0.05 for breast cancer and <0.001 for prostate cancer). The range of values was wide. Levels were higher in sclerotic than lytic bone metastases ( P < 0.01) and lower in patients with hypercalcaemia ( P < 0.001). Serial measurements of BGP were made in 53 patients with skeletal metastases from breast cancer receiving systemic therapy. At 1 month BGP rose by >0.5 ng/ml in 15 16 responding patients compared with 7 23 patients with progressive disease ( P < 0.01). Responding patients also showed a rise in the bone isoenzyme of alkaline phosphatase and a paradoxical deterioration in the bone scan appearance, both reflecting a flare in osteoblast activity. The early increase in responding patients was followed by a gradual decrease over subsequent months as the osteoblast reaction induced by systemic therapy subsided. We conclude that BGP measurements reflect a wide variability of bone formation rates in metastatic bone disease. Bone formation was usually increased, particularly when metastases were sclerotic in appearance, but in patients with hypercalcaemia the low BGP levels suggest uncoupling of bone resorption and formation. Serial measurements of BGP may be useful in monitoring response to treatment.

The effect of aging on bone formation in rats: biochemical and histological evidence for decreased bone formation capacity.

Ectopic bone formation by subcutaneously implanted demineralized bone matrix powder (DBM) was assessed biochemically and histologically in Fischer 344 rats of different ages. The total calcium accumulated in implants was greatly depressed in older rats, as was the rate of 45Ca deposition. High alkaline phosphatase activity appeared later in the 10- and 16-month-old rats compared with 1-month-old rats, and the magnitude of the alkaline phosphatase activity was decreased in 16-month-old rats. The accumulation of the bone-specific vitamin K-dependent bone protein (bone gla protein, BGP) was decreased in the implants in older rats. Histological examination of the implants confirms the decreased ability of aged animals to produce bone in response to DBM. Measurements of total calcium, alkaline phosphatase, and BGP at the site of demineralized bone matrix implants clearly demonstrates that bone formation decreases dramatically with increasing age. Significant differences in total calcium can be detected even between 1-month-old and 3-month-old rats. Serum BGP shows a marked decrease (47%) between 1-month- and 3-month-old rats, a decrease not paralleled by a similar decrease in BGP present in calvarial or tibial bone.