Cerebral hemodynamics in aging: the interplay between blood pressure, cerebral perfusion, and dementia.

Bespreking proefschrift Jurgen A.H.R. Claassen. Cerebral hemodynamics in aging: the interplay between blood pressure, cerebral perfusion, and dementia

Lojasiewicz exponent of families of ideals, Rees mixed multiplicities and Newton filtrations

We give an expression for the {\L}ojasiewicz exponent of a wide class of n-tuples of ideals $(I_1,..., I_n)$ in \O_n using the information given by a fixed Newton filtration. In order to obtain this expression we consider a reformulation of {\L}ojasiewicz exponents in terms of Rees mixed multiplicities. As a consequence, we obtain a wide class of semi-weighted homogeneous functions $(\mathbb{C}^n,0)\to (\mathbb{C},0)$ for which the {\L}ojasiewicz of its gradient map $\nabla f$ attains the maximum possible value.Comment: 25 pages. Updated with minor change

Impact of prevalent and incident vertebral fractures on utility: results from a patient-based and a population-based sample

Data are scarce on the impact of vertebral fractures (VFX) on utility. The objective of this study was to assess the impact of prevalent and incident VFX on utility in both a patient-based and population-based sample. Data from the Multiple Outcomes of Raloxifene Evaluation (MORE) study (n = 550 for prevalent VFX and n = 174 for incident VFX) and the European Prospective Osteoporosis Study (EPOS) (n = 236) were used. Utility was assessed by the index score of the EQ-5D. In the MORE study, highly statistically significant associations were found between utility and the presence of prevalent VFX (p < 0.001), number of prevalent VFX (p < 0.001), severity of prevalent VFX (p < 0.001), the combination of number and severity of prevalent VFX (p = 0.001) and location of prevalent VFX (p = 0.019). The mean utility was significantly lower among women who suffered an incident VFX (utility = 0.67) than among women who did not (utility = 0.77) (p = 0.005), although utility loss was not significantly different between the two groups (p = 0.142). In EPOS, the combination of number and severity of incident VFX was significantly related to utility (p = 0.030). In conclusion, utility is lower among persons with prevalent and incident VFX, especially in a patient-based sample. Utility loss was not significantly different between women without and with incident VFX

Impact of generic alendronate cost on the cost-effectiveness of osteoporosis screening and treatment

Introduction: Since alendronate became available in generic form in the Unites States in 2008, its price has been decreasing. The objective of this study was to investigate the impact of alendronate cost on the cost-effectiveness of osteoporosis screening and treatment in postmenopausal women. Methods: Microsimulation cost-effectiveness model of osteoporosis screening and treatment for U.S. women age 65 and older. We assumed screening initiation at age 65 with central dual-energy x-ray absorptiometry (DXA), and alendronate treatment for individuals with osteoporosis; with a comparator of "no screening" and treatment only after fracture occurrence. We evaluated annual alendronate costs of $20 through$800; outcome measures included fractures; nursing home admission; medication adverse events; death; costs; quality-adjusted life-years (QALYs); and incremental cost-effectiveness ratios (ICERs) in 2010 U.S. dollars per QALY gained. A lifetime time horizon was used, and direct costs were included. Base-case and sensitivity analyses were performed. Results: Base-case analysis results showed that at annual alendronate costs of $200 or less, osteoporosis screening followed by treatment was cost-saving, resulting in lower total costs than no screening as well as more QALYs (10.6 additional quality-adjusted life-days). When assuming alendronate costs of$400 through $800, screening and treatment resulted in greater lifetime costs than no screening but was highly cost-effective, with ICERs ranging from$714 per QALY gained through $13,902 per QALY gained. Probabilistic sensitivity analyses revealed that the cost-effectiveness of osteoporosis screening followed by alendronate treatment was robust to joint input parameter estimate variation at a willingness-to-pay threshold of$50,000/QALY at all alendronate costs evaluated. Conclusions: Osteoporosis screening followed by alendronate treatment is effective and highly cost-effective for postmenopausal women across a range of alendronate costs, and may be cost-saving at annual alendronate costs of $200 or less. © 2012 Nayak et al

Improvement in health-related quality of life in osteoporosis patients treated with teriparatide

<p>Abstract</p> <p>Background</p> <p>Individuals with osteoporosis and recent vertebral fractures suffer from pain and impaired health-related quality of life (HRQL). To determine whether patients with osteoporosis treated with teriparatide experienced improvement in HRQL and pain symptoms after several months of therapy.</p> <p>Methods</p> <p>We retrospectively studied a sample of osteoporosis patients treated with teriparatide in a Canadian rheumatology practice. We included patients that received teriparatide therapy with baseline and follow-up Mini-Osteoporosis Quality of Life Questionnaire (OQLQ) data. Follow-up data was measured at three or six months. We used a paired Student's t-test to compare baseline and follow-up measurements for each of the questionnaire's ten questions (five domains). Statistical analysis was also repeated to only include patients who suffered a prior vertebral fracture.</p> <p>Results</p> <p>57 patients were included in the study, including 47 women. The mean age was 63.8 years (standard deviation 12.1 years). About sixty five percent (37/57) had previously sustained one or more osteoporotic fractures and about 38.6% (22/57) had suffered a prior vertebral fracture. About 44% (25/57) of individuals were taking one or more types of pain medications regularly prior to starting therapy. At follow-up, significant improvements were observed in the OQLQ domains of pain symptoms. This was seen when all patients on teriparatide were included, and also when only patients with prior vertebral fractures were included. There was also an improvement in emotional functioning, relating to fear of falling at 3 months follow-up (p = 0.019). Respondents also reported improvement in the domain of activities of daily living, relating to vacuuming at 6 months follow-up (p = 0.036), and an improvement in the leisure domain, relating to ease of traveling in the prior vertebral fracture population at 3 months follow-up (p = 0.012). However, there was no significant improvement observed in the domains of physical functioning. Participants also reported a decrease in need for pain medications, with 26% (15/57) requiring analgesics at the time of follow-up.</p> <p>Conclusion</p> <p>Teriparatide use may be associated with improvements in HRQL in osteoporosis patients, in particular alleviation of pain symptoms. These results were especially evident in patients with a history of vertebral fractures. These findings should be confirmed in larger prospective studies with a suitable control group.</p

Review on the influence of process parameters in incremental sheet forming

Incremental sheet forming (ISF) is a relatively new flexible forming process. ISF has excellent adaptability to conventional milling machines and requires minimum use of complex tooling, dies and forming press, which makes the process cost-effective and easy to automate for various applications. In the past two decades, extensive research on ISF has resulted in significant advances being made in fundamental understanding and development of new processing and tooling solutions. However, ISF has yet to be fully implemented to mainstream high-value manufacturing industries due to a number of technical challenges, all of which are directly related to ISF process parameters. This paper aims to provide a detailed review of the current state-of-the-art of ISF processes in terms of its technological capabilities and specific limitations with discussions on the ISF process parameters and their effects on ISF processes. Particular attention is given to the ISF process parameters on the formability, deformation and failure mechanics, springback and accuracy and surface roughness. This leads to a number of recommendations that are considered essential for future research effort

The Dutch Parelsnoer Institute - Neurodegenerative diseases; methods, design and baseline results

Background: The is a collaboration between 8 Dutch University Medical Centers in which clinical data and biomaterials from patients suffering from chronic diseases (so called "Pearls") are collected according to harmonized protocols. The Pearl Neurodegenerative Diseases focuses on the role of biomarkers in the early diagnosis, differential diagnosis and in monitoring the course of neurodegenerative diseases, in particular Alzheimer's disease. Methods: The Pearl Neurodegenerative Diseases is a 3-year follow-up study of patients referred to a memory clinic with cognitive complaints. At baseline, all patients are subjected to a standardized examination, including clinical data and biobank materials, e.g. blood samples, MRI and cerebrospinal fluid. At present, in total more than 1000 patients have been included, of which cerebrospinal fluid and DNA samples are available of 211 and 661 patients, respectively. First descriptives of a subsample of the data (n = 665) shows that patients are diagnosed with dementia (45%), mild cognitive impairment (31%), and subjective memory complaints (24%). Discussion: The Pearl Neurodegenerative Diseases is an ongoing large network collecting clinical data and biomaterials of more than 1000 patients with cognitive impairments. The project has started with data analyses of the baseline characteristics and biomarkers, which will be the starting point of future specific research questions that can be answered by this unique dataset