scholarly journals Efficacy of Zoledronic Acid in Patients with Systemic Osteoporosis and Problem of «Non Respondents» to the Treatment

2015 ◽  
Vol 22 (4) ◽  
pp. 39-43
Author(s):  
S. S Rodionova ◽  
Yu. V Buklemishev

Prospective study of zolendronic acid efficacy was performed in 112 patients with systemic osteoporosis. Study results confirmed the presence of patients who did not response to the treatment: in 15.7 % of observations reduction of mineral bone density (BMD) continued to progress. No significant differences in initial deviations of resorption and bone formation markers, peculiarities of calcium homeostasis were detected in “non respondents”. At the same time by the 12th month after treatment initiation the relationship between BMD increase with preservation of marked decrease of resorption marker (deoxypyridinoline) and bone formation marker (osteocalcin) was noted, that pointed out the expediency of prognostic model creation. Evaluation of the influence of certain risk factors (age, results of blood and urine biochemical tests, data of densitometry including the results of femoral neck BMD in some patients) using discriminant analysis showed that 81.5% of patients were correctly referred to the groups of patients who responded and not responded to treatment. Out of all initially studied parameters the most significant were 7 that in 78.6% of cases (method sensitivity) enabled to identify the patients with negative treatment effect and in 82.1% of cases (method specificity) - with positive treatment effect.

1993 ◽  
Vol 3 (1) ◽  
pp. 2-28 ◽  
Author(s):  
Larry G. Matson ◽  
Zung Vu Tran

Many researchers have investigated the effects of induced metabolic alkalosis, by ingestion of sodium bicarbonate, on anaerobic exercise performance. But the results have been inconsistent and often contradictory. The purpose of this review was to synthesize the varied findings using a meta-analytic approach. Twenty-nine investigations met our inclusion criteria. Results show that, ingestion clearly results in a more alkaline extracellular environment. The dosage, however, was only moderately related to the increase in pH and HCO3-. Overall, performance was enhanced but the range of effect sizes was large, -0.12 to 2.87. In studies that measured time to exhaustion, there was a mean 27±20% increase in duration. The treatment effect, however, was only weakly related to the degree of induced alkalosis. But in comparing the 19 studies that showed a positive treatment effect with the 16 that showed no effect, the former were associated with a greater increase in pH following ingestion of a somewhat larger dosage, and a greater decrease in pH with exercise.


Author(s):  
Dean Karlan ◽  
Jacob Appel

This chapter focuses on low participation rates. Low participation rates squeeze the effective sample size for a test, making it more difficult, statistically, to identify a positive treatment effect. There are two moments in which low participation rates can materialize: during the intake process to a study or intervention, or after random assignment to treatment or control. Low participation during the intake process often occurs when marketing a program to the general public. Researchers working in the field with partner organizations often face inflexible constraints in trying to cope with low participation during intake. The second type of low participation—that which occurs after subjects have been randomly assigned to treatment or control—is a more daunting problem and is less likely solvable than low participation at the intake phase.


2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Syazrah Salam ◽  
Orla Gallagher ◽  
Fatma Gossiel ◽  
Arif Khwaja ◽  
Richard Eastell

Abstract Background and Aims Renal osteodystrophy is common in advanced chronic kidney disease (CKD) patients and is characterized by abnormal bone turnover and mineralization. Parathyroid hormone (PTH) increases bone turnover through osteoblast and osteoclast activation. Osteoprotegerin (OPG) is a decoy receptor of receptor activator of nuclear factor kappa-β ligand and thus, inhibits osteoclast maturation. Meanwhile, sclerostin is an inhibitor of the Wnt signalling pathway and thus, inhibits osteoblast maturation. We aimed to assess the relationship between these bone regulatory markers and bone turnover as assessed by bone histomorphometry and bone turnover markers (BTMs). Method We recruited 43 CKD patients with eGFR<30ml/min/1.73m2 or on dialysis. Fasting serum samples were analysed using Immunodiagnostic Systems automated assays (Boldon, UK) for intact PTH (iPTH) and BTMs such as bone alkaline phosphatase (bALP) and intact procollagen type 1 N-terminal propeptide (intact PINP) which are bone formation markers, and tartrate-resistant acid phosphatase 5b (TRAP5b) which is a bone resorption marker. OPG and sclerostin were analysed using manual ELISA by Biomedica (Vienna, Austria). Trans-iliac bone biopsy was performed after tetracycline labelling. Bone samples were analysed using quantitative histomorphometry. Normal bone turnover was defined as bone formation rate/bone surface (BFR/BS) of 18 - 38µm3/µm2/year. Spearman rank correlation was used to test the relationship between the variables. Results Median BFR/BS was 32.12 (IQR 17.76 – 48.25) um3/um2/year. 26% of patients had low and 40% had high bone turnover. iPTH and OPG were positively correlated with BFR/BS (rho = 0.42, p<0.01 and rho = 0.36, p<0.05 respectively). Sclerostin was not correlated with BFR/BS. Furthermore, sclerostin did not correlate with bALP and intact PINP whereas OPG correlated with TRAP5b (rho = 0.43, p<0.01). iPTH correlated with bALP (rho = 0.62, p<0.001), intact PINP (rho = 0.62, p<0.001) and TRAP5b (rho = 0.50, p = 0.001). Conclusion Circulating levels of iPTH and OPG were modestly associated with bone turnover but sclerostin was not. There are likely to be bone regulators other than iPTH, OPG and sclerostin which regulate bone turnover in renal osteodystrophy.


Author(s):  
E.J. Pegg

Objective: Current treatments have only a modest effect on impairment in Alzheimer’s Dementia (AD) and there is no treatment currently licensed for Mild Cognitive Impairment (MCI). Oxidative stress is postulated to play a role in the pathogenesis of AD and MCI and this provides a rationale for treatment with antioxidant supplements. The aim of this review is to evaluate the effect of antioxidant supplements in people with AD and MCI. Methods: A systematic review of published randomised controlled trials was carried out. 4 electronic databases were searched. Studies were included if they compared the use of a placebo with the following antioxidant supplements in people with AD or MCI: Vitamin e, vitamin c, selenium, alpha lipoic acid, phenols, zinc, curcumin, beta carotene, coenzyme Q10, melatonin. The primary outcome measure was cognitive impairment. Secondary outcome measures included functional impairment, behavioural disturbance and safety. Results: 10 trials were identified which met the inclusion criteria. Outcome data was not suitable for meta-analysis. 5 studies reported a small positive treatment effect on cognition and 1 reported a negative effect. 2 reported a positive treatment effect on functional ability and 1 on behaviour. There were no consistent adverse effects found overall however two studies raised concern of possible worsening of cognition in certain circumstances. Conclusions: The findings of this systematic review do not support the use of antioxidant supplements to slow cognitive, functional or behavioural deterioration in people with AD or MCI. However the majority of included studies had a high or unknown risk of bias. In the one study which had a low overall risk of bias, there was evidence that antioxidant supplements may have a positive effect on functional decline in AD. The overall risk of harm associated with short term antioxidant supplementation appears to be low however caution is warranted. Further studies evaluating the role of oxidative stress in the pathogenesis of AD are suggested.


2011 ◽  
Vol 34 (5) ◽  
pp. 267 ◽  
Author(s):  
Mari Takano ◽  
Kazuhiro Okano ◽  
Yuki Tsuruta ◽  
Tetsuri Yamashita ◽  
Yoshihisa Echida ◽  
...  

Background: New bone metabolic markers have become available clinically for evaluating chronic kidney disease mineral and bone disorders (CKD-MBD). The aim of this study was to correlate these new bone metabolic markers with conventional markers in regular hemodialysis (HD) patients. Methods: One hundred forty three HD patients underwent cross-sectional assessment. Two bone formation markers, bone-specific alkaline phosphatase (BAP) and osteocalcin (OC), and one bone resorption marker, amino-terminal telopeptides of type 1 collagen (NTx), were selected for study. Results: Both circulating OC and NTx levels showed positive correlations with serum intact parathyroid hormone (iPTH) levels. The levels of NTx and OC showed a strongly positive correlation, although they are known to be markers of different aspects of bone metabolism: bone formation and resorption. Patients with high iPTH (≥300pg/mL) had significantly higher levels of all the three bone markers compared with patients with low or normal iPTH . Conclusion: Serum OC and NTx levels may be useful markers of serum iPTH levels for evaluating bone turnover in HD patients and may eventually prove useful in the management of patients with CKD-MBD.


2012 ◽  
Vol 30 (5_suppl) ◽  
pp. 144-144
Author(s):  
Chadi Nabhan ◽  
Leonard G. Gomella ◽  
Todd DeVries ◽  
James Boyd Whitmore ◽  
Mark Walter Frohlich ◽  
...  

144 Background: Sipuleucel-T is an autologous cellular immunotherapy approved for the treatment of asymptomatic or minimally symptomatic metastatic castrate resistant prostate cancer (mCRPC). Our previous analyses on the effect of salvage crossover treatment with a product constructed from previously frozen cells (APC8015F) on OS in the control arms of mCRPC studies of sipuleucel-T suggested a positive treatment effect with salvage therapy (George DJ et al. JCO 2011;29:abstr 139). To quantify how treatment with APC8015F might have impacted the OS of the IMPACT study, we performed an exploratory analysis adjusting for the potential bias that salvage APC8015F might have had in estimating the OS advantage of sipuleucel-T. Methods: After objective disease progression, patients (pts) in the control arm were offered 3 infusions of APC8015F, an autologous immunotherapy made from cells cryopreserved at the time of control generation. A rank-preserving structural failure time (RPSFT) model, as previously described, was applied to adjust the sipuleucel-T treatment effect. Results: In the 512-pt IMPACT study, there was a 4.1-month median improvement in OS (25.8 vs 21.7 months) for sipuleucel-T compared to control (HR=0.78; 95% CI: 0.61, 0.98; p=0.032). 109/171 (64%) of control pts received APC8015F; other post-progression interventions were balanced. Median OS was 23.8 months for control pts receiving APC8015F and 11.6 months for control pts not receiving APC8015F. Using the RPSFT model, and assuming APC8015F was equally as effective as sipuleucel-T, the estimate of median OS for control was 18.0 months (HR=0.60, 95% CI: 0.41, 0.95), representing a 7.8-month median improvement in OS in favor of sipuleucel-T. Results from extensions of the RPFST model, where APC8015F is assumed to have less treatment effect than sipuleucel-T, will be presented. Conclusions: Adjusting for a positive effect of APC8015F in the control arm resulted in a sipuleucel-T OS treatment benefit in the IMPACT study ranging from 4.1 to 7.8 months. These results support a greater treatment effect of sipuleucel-T than reported in the IMPACT study and should be factored into future studies without APC8015F crossover.


2020 ◽  
Vol 29 (10) ◽  
pp. 2945-2957 ◽  
Author(s):  
Alexandra Christine Graf ◽  
Dominic Magirr ◽  
Alex Dmitrienko ◽  
Martin Posch

An important step in the development of targeted therapies is the identification and confirmation of sub-populations where the treatment has a positive treatment effect compared to a control. These sub-populations are often based on continuous biomarkers, measured at baseline. For example, patients can be classified into biomarker low and biomarker high subgroups, which are defined via a threshold on the continuous biomarker. However, if insufficient information on the biomarker is available, the a priori choice of the threshold can be challenging and it has been proposed to consider several thresholds and to apply appropriate multiple testing procedures to test for a treatment effect in the corresponding subgroups controlling the family-wise type 1 error rate. In this manuscript we propose a framework to select optimal thresholds and corresponding optimized multiple testing procedures that maximize the expected power to identify at least one subgroup with a positive treatment effect. Optimization is performed over a prior on a family of models, modelling the relation of the biomarker with the expected outcome under treatment and under control. We find that for the considered scenarios 3 to 4 thresholds give the optimal power. If there is a prior belief on a small subgroup where the treatment has a positive effect, additional optimization of the spacing of thresholds may result in a large benefit. The procedure is illustrated with a clinical trial example in depression.


2000 ◽  
Vol 61 (3) ◽  
pp. 166-169 ◽  
Author(s):  
Antti Ahokas ◽  
Marjatta Aito ◽  
Ranan Rimón

1978 ◽  
Vol 47 (1) ◽  
pp. 243-250 ◽  
Author(s):  
Morris B. Holbrook

In contrast to its effect on most perceptual tasks, verbal uncertainty might be expected to facilitate the detection of typographical errors in proofreading. Experimental treatments consisted of messages differing in their levels of verbal uncertainty. In two proofreading tasks, 104 subjects searched for typographical errors systematically introduced into these passages of text. Task I showed a significant positive treatment effect of verbal uncertainty on recognition of errors and a significant positive correlation, across words, between subjective uncertainty and detection of typographical errors. The results for Task II were more equivocal and suggested the need for further research.


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