359 research outputs found
Mathematical modelling of the pathogenesis of multiple myeloma-induced bone disease
Multiple myeloma (MM) is the second most common haematological malignancy and results in destructive bone lesions. The interaction between MM cells and the bone microenvironment plays an important role in the development of the tumour cells and MM-induced bone disease and forms a 'vicious cycle' of tumour development and bone destruction, intensified by suppression of osteoblast activity and promotion of osteoclast activity. In this paper, a mathematical model is proposed to simulate how the interaction between MM cells and the bone microenvironment facilitates the development of the tumour cells and the resultant bone destruction. It includes both the roles of inhibited osteoblast activity and stimulated osteoclast activity. The model is able to mimic the temporal variation of bone cell concentrations and resultant bone volume after the invasion and then removal of the tumour cells and explains why MM-induced bone lesions rarely heal even after the complete removal of MM cells. The behaviour of the model compares well with published experimental data. The model serves as a first step to understand the development of MM-induced bone disease and could be applied further to evaluate the current therapies against MM-induced bone disease and even suggests new potential therapeutic targets
The first biosimilar approved for the treatment of osteoporosis
To demonstrate the clinical comparability between RGB-10 (a biosimilar teriparatide) and the originator, a comparative pharmacokinetic trial was conducted. The study was successful in establishing bioequivalence. Marketing authorisation for RGB-10 (Terrosa®) was granted by the European Medicines Agency in 2017.Teriparatide, the first bone anabolic agent, is the biologically active fragment of human parathyroid hormone. The imminent patent expiry of the originator will open the door for biosimilars to enter the osteology market, thereby improving access to a highly effective, yet prohibitively expensive therapy.Subsequent to establishing comparability on the quality and non-clinical levels between RGB-10, a biosimilar teriparatide, and its reference product (Forsteo®), a randomised, double-blind, 2-way cross-over comparative study (duration: four days) was conducted in 54 healthy women (ages: 18 to 55 years) to demonstrate the pharmacokinetic/pharmacodynamic (PK/PD) equivalence and comparable safety of these products. Extents of exposure (AUC0-tlast) and peak exposure (Cmax), as measured by means of ELISA, were evaluated as co-primary PK endpoints, and serum calcium levels, as measured using standard automated techniques, were assessed for PD effects. Safety was monitored throughout the study.The 94.12% CIs for the ratio of the test to the reference treatments, used due to the two-stage design (85.20-98.60% and 85.51-99.52% for AUC0-tlast and Cmax, respectively), fell within the 80.00-125.00% acceptance range. The calcium PD parameters were essentially identical with geometric mean ratios (GMRs) of 99.93% and 99.87% for AUC and Cmax, respectively. Analysis of the safety data did not reveal any differences between RGB-10 and its reference.Based on the high level of similarity in the preclinical data and the results of this clinical study, marketing authorisation for RGB-10 (Terrosa®) was granted by the European Medicines Agency (EMA) in 2017
Attitudes towards treatment among patients suffering from sleep disorders. A Latin American survey
BACKGROUND: Although sleep disorders are common, they frequently remain unnoticed by the general practitioner. Few data are available about the willingness and reasons of patients with sleep disturbances to seek for medical assistance. METHODS: The results of a cross-sectional community-based multinational survey in three major Latin American urban areas, i.e. Buenos Aires, Mexico City and Sao Paulo, are reported. Two-hundred subjects suffering sleep disturbances and 100 non-sufferers were selected from the general population in each city (total number: 600 sufferers vs. 300 non-sufferers). A structured interview was conducted, sleep characteristics, feelings about sleep disturbances and strategies to cope with those problems being recorded. Data were analyzed by employing either t-test or analysis of variance (ANOVA) to the Z-transformed proportions. RESULTS: 22.7 ± 3.5 % (mean ± SEM) of subjects reported to suffer from sleep disturbances every night. About 3 out of 4 (74.2 ± 2.0 %) considered their disorder as mild and were not very concerned about it. Only 31 ± 2 % of sufferers reported to have sought for medical help. Although 45 ± 2 % of sufferers reported frequent daily sleepiness, trouble to remember things, irritability and headaches, they did not seek for medical assistance. Among those patients who saw a physician with complaints different from sleep difficulties only 1 out of 3 (33 ± 2 % of patients) were asked about quality of their sleep by the incumbent practitioner. Strategies of patients to cope with sleep problems included specific behaviors (taking a warm bath, reading or watching TV) (44 ± 1.6 %), taking herbal beverages (17 ± 1.2 %) or taking sleeping pills (10 ± 1.1 %). Benzodiazepines were consumed by 3 ± 0.6 % of sufferers. CONCLUSION: Public educational campaigns on the consequences of sleep disorders and an adequate training of physicians in sleep medicine are needed to educate both the public and the general practitioners about sleep disorders
Cue-target contingencies modulate voluntary orienting of spatial attention: dissociable effects for speed and accuracy
Voluntary orienting of spatial attention is typically investigated by visually presented directional cues, which are called predictive when they indicate where the target is more likely to appear. In this study, we investigated the nature of the potential link between cue predictivity (the proportion of valid trials) and the strength of the resulting covert orienting of attention. Participants judged the orientation of a unilateral Gabor grating preceded by a centrally presented, non-directional, color cue, arbitrarily prompting a leftwards or rightwards shift of attention. Unknown to them, cue predictivity was manipulated across blocks, whereby the cue was only predictive for either the first or the second half of the experiment. Our results show that the cueing effects were strongly influenced by the change in predictivity. This influence differently emerged in response speed and accuracy. The speed difference between valid and invalid trials was significantly larger when cues were predictive, and the amplitude of this effect was modulated at the single trial level by the recent trial history. Complementary to these findings, accuracy revealed a robust effect of block history and also a different time-course compared with speed, as if it mainly mirrored voluntary processes. These findings, obtained with a new manipulation and using arbitrary non-directional cueing, demonstrate that cue-target contingencies strongly modulate the way attention is deployed in space
International Osteoporosis Foundation and European Calcified Tissue Society Working Group. Recommendations for the screening of adherence to oral bisphosphonates
Background
Low adherence to oral bisphosphonates is a common problem that jeopardizes the efficacy of treatment of osteoporosis. No clear screening strategy for the assessment of compliance is widely accepted in these patients.
Methods
The International Osteoporosis Foundation and the European Calcified Tissue Society have convened a working group to propose a screening strategy to detect a lack of adherence to these drugs. The question to answer was whether the bone turnover markers (BTMs) PINP and CTX can be used to identify low adherence in patients with postmenopausal osteoporosis initiating oral bisphosphonates for osteoporosis. The findings of the TRIO study specifically address this question and were used as the basis for testing the hypothesis.
Results
Based on the findings of the TRIO study, specifically addressing this question, the working group recommends measuring PINP and CTX at baseline and three months after starting therapy to check for a decrease above the least significant change (decrease of more than 38% for PINP and 56% for CTX). Detection rate for the measurement of PINP is 84%, for CTX 87% and, if variation in at least one is considered when measuring both, the level of detection is 94.5%.
Conclusions
If a significant decrease is observed the treatment can continue but if no decrease occurs the clinician should reassess to identify problems with the treatment, mainly low adherence</p
Improvement of trochanteric bone quality in an osteoporosis model after short-term treatment with parathyroid hormone: a new mechanical test for trochanteric region of rat femur
Preventive drugs in the last year of life of older adults with cancer: Is there room for deprescribing?
BACKGROUND: The continuation of preventive drugs among older patients with advanced cancer has come under scrutiny because these drugs are unlikely to achieve their clinical benefit during the patients' remaining lifespan. METHODS: A nationwide cohort study of older adults (those aged ≥65 years) with solid tumors who died between 2007 and 2013 was performed in Sweden, using routinely collected data with record linkage. The authors calculated the monthly use and cost of preventive drugs throughout the last year before the patients' death. RESULTS: Among 151,201 older persons who died with cancer (mean age, 81.3 years [standard deviation, 8.1 years]), the average number of drugs increased from 6.9 to 10.1 over the course of the last year before death. Preventive drugs frequently were continued until the final month of life, including antihypertensives, platelet aggregation inhibitors, anticoagulants, statins, and oral antidiabetics. Median drug costs amounted to 700-213 (IQR, 490) for preventive therapies. Compared with older adults who died with lung cancer (median drug cost, 61-13; 95% confidence interval, 22) or gynecological cancers (adjusted median difference, 18-$36). There was no decrease noted with regard to the cost of preventive drugs throughout the last year of life. CONCLUSIONS: Preventive drugs commonly are prescribed during the last year of life among older adults with cancer, and often are continued until the final weeks before death. Adequate deprescribing strategies are warranted to reduce the burden of drugs with limited clinical benefit near the end of life
Trabecular Reorganization in Consecutive Iliac Crest Biopsies when Switching from Bisphosphonate to Strontium Ranelate Treatment
BACKGROUND: Several agents are available to treat osteoporosis while addressing patient-specific medical needs. Individuals' residual risk to severe fracture may require changes in treatment strategy. Data at osseous cellular and microstructural levels due to a therapy switch between agents with different modes of action are rare. Our study on a series of five consecutively taken bone biopsies from an osteoporotic individual over a six-year period analyzes changes in cellular characteristics, bone microstructure and mineralization caused by a therapy switch from an antiresorptive (bisphosphonate) to a dual action bone agent (strontium ranelate). METHODOLOGY/PRINCIPAL FINDINGS: Biopsies were progressively taken from the iliac crest of a female patient. Four biopsies were taken during bisphosphonate therapy and one biopsy was taken after one year of strontium ranelate (SR) treatment. Furthermore, serum bone markers and dual x-ray absorptiometry measurements were acquired. Undecalcified histology was used to assess osteoid parameters and bone turnover. Structural indices and degree of mineralization were determined using microcomputed tomography, quantitative backscattered electron imaging, and combined energy dispersive x-ray/µ-x-ray-fluorescence microanalysis. CONCLUSIONS/SIGNIFICANCE: Microstructural data revealed a notable increase in bone volume fraction after one year of SR treatment compared to the bisphosphonate treatment period. Indices of connectivity density, structure model index and trabecular bone pattern factor were predominantly enhanced indicating that the architectural transformation from trabecular rods to plates was responsible for the bone volume increase and less due to changes in trabecular thickness and number. Administration of SR following bisphosphonates led to a maintained mineralization profile with an uptake of strontium on the bone surface level. Reactivated osteoclasts designed tunneling, hook-like intratrabecular resorption sites. The appearance of tunneling resorption lacunae and the formation of both mini-modeling units and osteon-like structures within increased plate-like cancellous bone mass provides additional information on the mechanisms of strontium ranelate following bisphosphonate treatment, which may deserve special attention when monitoring a treatment switch
Health problems and help-seeking in a nationwide sample of operational Norwegian ambulance personnel
Background
To estimate the prevalence of anxiety and depression symptoms, and their association with professional help-seeking, among operational ambulance personnel and a general working population, and to study the symptoms of musculoskeletal pain and disturbed sleep among ambulance personnel.
Methods
The results of a comprehensive nationwide questionnaire survey of operational ambulance personnel (n = 1180) were compared with the findings of a population-based Norwegian health study of working people (n = 31,987). The questionnaire included measures of help-seeking, the Hospital Anxiety and Depression Scale, the Subjective Health Complaints Questionnaire, the Karolinska Sleep Questionnaire and the Need for Recovery after Work Scale.
Results
Compared with those in the reference population, the mean of level anxiety symptoms in the ambulance sample was lower for men (3.5 vs. 3.9, P < 0.001) and women (4.0 vs. 4.4, P < 0.05), and the mean level of depression symptoms in ambulance workers was lower for men (2.3 vs. 2.8, P < 0.05) but not for women (2.9 vs. 3.1, P = 0.22). A model adjusted for anxiety and depression symptoms indicated that ambulance personnel had lower levels of help-seeking except for seeing a chiropractor (12% vs. 5%, P < 0.01). In the ambulance sample, symptoms of musculoskeletal pain were most consistently associated with help-seeking. In the adjusted model, only symptoms of disturbed sleep were associated with help-seeking from a psychologist/psychiatrist (total sample = 2.3%). Help-seeking was more often reported by women but was largely unaffected by age.
Conclusion
The assumption that ambulance personnel have more anxiety and depression symptoms than the general working population was not supported. The level of musculoskeletal pain and, accordingly, the level of help-seeking from a chiropractor were higher for ambulance workers. More research should address the physical strains among ambulance personnel
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