98 research outputs found

    Wireless Power Transfer to Biomedical Implants Using a Class-E Inverter and a Class-DE Rectifier

    Get PDF
    In this article, we propose a strategy for the design of a wireless power transfer system consisting of a class-E inverter, a half-bridge class-DE rectifier, and two coupled coils. The system is optimized for maximum power transfer efficiency. The design is validated via a case study, for which a wireless power transfer link to a neuroprosthesis was designed. After circuit simulations, a prototype was realized and measured. There is a good agreement between the calculated, simulated and measured voltages and currents. The prototype delivers 80 mW, 7 V to a biomedical implant at 6.78 MHz, the transfer efficiency is 52 to 68%, depending on the alignment. The end-to-end efficiency, with the controller and gate driver also taken into account, is 39 to 57%. Electromagnetic and thermal simulations were performed to verify compliance with relevant safety regulations on specific absorption rate (SAR) levels, magnetic field strength, and heat generation in the implant, for separation distances between the coils of 8 to 15 mm, and transverse misalignment from 0 to 15 mm.</p

    Muscle Function in Moderate to Severe Asthma:Association With Clinical Outcomes and Inflammatory Markers

    Get PDF
    BackgroundPatients with severe asthma have been shown to have low muscle mass, but the clinical consequences are unknown.ObjectiveIn a clinical cohort of patients with moderate to severe asthma, we aimed to assess muscle mass and strength and their relation with functional and clinical outcomes, as well as with systemic inflammatory markers.MethodsMuscle mass and strength were assessed by the fat-free mass index (FFMI), creatinine excretion in a 24-hour urine sample, and handgrip strength test. Functional outcomes included pulmonary function tests and the 6-minute walking distance, whereas clinical outcomes were assessed with questionnaires on asthma control, quality of life, and health care use. Associations of muscle mass and strength with asthma outcomes were assessed with multivariable regression analyses.ResultsA total of 114 patients participated (36% male; mean age, 51.9 ± 14.4 years; body mass index, 27.7 ± 5.7 kg/m2). According to predefined criteria, 16% had a low FFMI and 8% a low urinary creatinine excretion, which did not differ between categories of asthma severity. Both lower FFMI and urinary creatinine excretion were associated with lower values of FEV1 and 6-minute walking distance, whereas a lower handgrip strength was related to worse asthma control, poorer quality of life, and a higher probability of emergency visits (all P &lt; .05). Except for higher leukocytes in relation to lower FFMI, we did not find associations between systemic inflammatory markers and muscle function.ConclusionsThis study demonstrates that low muscle mass is prevalent in patients with moderate to severe asthma and, along with low muscle strength, is associated with poorer clinical and functional outcomes. Our results encourage longitudinal studies into muscle function as a potential target for treatment to improve asthma outcomes

    Dietary Inflammatory Index and clinical outcome measures in adults with moderate to severe asthma

    Get PDF
    BACKGROUND: Diet is increasingly recognized as a modifiable factor in lung health, predominantly due to the immunomodulatory effects of nutrients. The Dietary Inflammatory Index (DII) is a score developed to express the inflammatory potential of a diet.OBJECTIVE: We aimed to assess the association of the DII and food groups, with clinical, functional and inflammatory asthma outcomes in adults with asthma.METHODS: Patients with moderate to severe asthma were included in this cross-sectional study between June 2019 and October 2021, and completed a 3-day food diary, to calculate the DII and intake of food groups (i.e. fruits, whole grains, processed meats and sugar-sweetened beverages). Functional outcomes included pulmonary function tests and the 6-minute walking distance, while clinical outcomes were assessed using questionnaires on asthma control, quality of life, and healthcare utilization. Inflammatory markers were exhaled nitric oxide and blood leukocytes, eosinophils and interleukin-6. Multivariable regression analyses were used to examine the association of DII and food groups with asthma outcomes.RESULTS: A total of 109 patients participated (35% male, mean±SD age 51.8 ± 14.2 years, BMI 27.4 ± 5.3 kg/m 2). Overall, 62% had a DII score &gt;0, indicating a pro-inflammatory diet, which was not related to asthma severity. A more pro-inflammatory diet was consistently associated to lower FVC (%pred), but inconsistent results were observed with respect to airway obstruction. Neither the DII nor food groups were associated with clinical outcomes. Except for higher levels of exhaled nitric oxide in relation to an anti-inflammatory diet, we found no associations between inflammatory markers and the DII. CONCLUSION: Results from this cross-sectional study among patients with moderate to severe asthma do not support the hypothesis that a pro-inflammatory diet is associated with worse asthma outcomes, although limitations in study design and dietary intake estimation should be considered. Future well-designed experimental studies are needed to assess whether targeting the inflammatory potential of diet could lead to better outcomes in adults with asthma.</p

    Dietary Inflammatory Index and clinical outcome measures in adults with moderate to severe asthma

    Get PDF
    BACKGROUND: Diet is increasingly recognized as a modifiable factor in lung health, predominantly due to the immunomodulatory effects of nutrients. The Dietary Inflammatory Index (DII) is a score developed to express the inflammatory potential of a diet.OBJECTIVE: We aimed to assess the association of the DII and food groups, with clinical, functional and inflammatory asthma outcomes in adults with asthma.METHODS: Patients with moderate to severe asthma were included in this cross-sectional study between June 2019 and October 2021, and completed a 3-day food diary, to calculate the DII and intake of food groups (i.e. fruits, whole grains, processed meats and sugar-sweetened beverages). Functional outcomes included pulmonary function tests and the 6-minute walking distance, while clinical outcomes were assessed using questionnaires on asthma control, quality of life, and healthcare utilization. Inflammatory markers were exhaled nitric oxide and blood leukocytes, eosinophils and interleukin-6. Multivariable regression analyses were used to examine the association of DII and food groups with asthma outcomes.RESULTS: A total of 109 patients participated (35% male, mean±SD age 51.8 ± 14.2 years, BMI 27.4 ± 5.3 kg/m 2). Overall, 62% had a DII score &gt;0, indicating a pro-inflammatory diet, which was not related to asthma severity. A more pro-inflammatory diet was consistently associated to lower FVC (%pred), but inconsistent results were observed with respect to airway obstruction. Neither the DII nor food groups were associated with clinical outcomes. Except for higher levels of exhaled nitric oxide in relation to an anti-inflammatory diet, we found no associations between inflammatory markers and the DII. CONCLUSION: Results from this cross-sectional study among patients with moderate to severe asthma do not support the hypothesis that a pro-inflammatory diet is associated with worse asthma outcomes, although limitations in study design and dietary intake estimation should be considered. Future well-designed experimental studies are needed to assess whether targeting the inflammatory potential of diet could lead to better outcomes in adults with asthma.</p

    Dietary Inflammatory Index and clinical outcome measures in adults with moderate to severe asthma

    Get PDF
    BACKGROUND: Diet is increasingly recognized as a modifiable factor in lung health, predominantly due to the immunomodulatory effects of nutrients. The Dietary Inflammatory Index (DII) is a score developed to express the inflammatory potential of a diet.OBJECTIVE: We aimed to assess the association of the DII and food groups, with clinical, functional and inflammatory asthma outcomes in adults with asthma.METHODS: Patients with moderate to severe asthma were included in this cross-sectional study between June 2019 and October 2021, and completed a 3-day food diary, to calculate the DII and intake of food groups (i.e. fruits, whole grains, processed meats and sugar-sweetened beverages). Functional outcomes included pulmonary function tests and the 6-minute walking distance, while clinical outcomes were assessed using questionnaires on asthma control, quality of life, and healthcare utilization. Inflammatory markers were exhaled nitric oxide and blood leukocytes, eosinophils and interleukin-6. Multivariable regression analyses were used to examine the association of DII and food groups with asthma outcomes.RESULTS: A total of 109 patients participated (35% male, mean±SD age 51.8 ± 14.2 years, BMI 27.4 ± 5.3 kg/m 2). Overall, 62% had a DII score &gt;0, indicating a pro-inflammatory diet, which was not related to asthma severity. A more pro-inflammatory diet was consistently associated to lower FVC (%pred), but inconsistent results were observed with respect to airway obstruction. Neither the DII nor food groups were associated with clinical outcomes. Except for higher levels of exhaled nitric oxide in relation to an anti-inflammatory diet, we found no associations between inflammatory markers and the DII. CONCLUSION: Results from this cross-sectional study among patients with moderate to severe asthma do not support the hypothesis that a pro-inflammatory diet is associated with worse asthma outcomes, although limitations in study design and dietary intake estimation should be considered. Future well-designed experimental studies are needed to assess whether targeting the inflammatory potential of diet could lead to better outcomes in adults with asthma.</p

    Modulation by epidermal growth factor of the basal 1,25(OH)2D3 receptor level and the heterologous up-regulation of the 1,25(OH)2D3 receptor in clonal osteoblast-like cells

    Get PDF
    The effects of epidermal growth factor (EGF) on basal 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) receptor level and on parathyroid hormone (PTH)-induced 1,25-(OH)2D3 (OH)2D3 receptor up-regulation were studied in the phenotypically osteoblastic cell line UMR 106. EGF in concentrations exceeding 0.1 ng/ml reduced the number of 1,25(OH)2D3 binding sites without changing the binding affinity. Maximal reduction was 30% at about 1 ng/ml. This reduction was independent of a change in cAMP content. EGF dose-dependently attenuated both PTH-induced 1,25(OH)2D3 receptor up-regulation and PTH-stimulated cAMP production without and effect on the ED50 of the PTH effects. For both PTH responses the IC50 and the maximal effective dose were similar, 0.1 ng/ml an 1 ng/ml EGF, respectively. Reduction was first seen at 0.01 ng/ml EGF. At this concentration. EGF reduced PTH-stimulated 1,25-(OH)2D3 receptor binding without an inhibition of the cAMP response. Time-course studies with 1 ng/ml EGF revealed that at 2 h preincubation EGF reduced the heterologous up regulation by PTH, and maximal inhibition was seen after 4 h. In contrast, PTH-stimulated cAMP production was just significantly inhibited only after 6 h, with 60% inhibition after 24 h preincubation. The effects of prostaglandin E2 and forskolin on both 1,25(OH)2D3 binding and cAMP production were inhibited in a similar fashion. On the other hand, dibutyryl cAMP- and 3-isobutyl-1-methylxanthinestimulated 1,25(OH)2D3 binding were not affected by EGF. Taken together, our results demonstrate that EGF reduces both the basal number of 1,25(OH)2D3 binding sites and the heterologous up-regulation of the 1,25(OH)2D3 receptor. The current data suggest that EGF reduces heterologous upregulation of the 1,25(OH)2D3 receptor independent of as well as dependent on the cAMP messenger system. The EGF effect is not primarily located at the PTH receptor, at cAMP phosphodiesterase, or at protein kinase A level

    Subclinical hypothyroidism is an independent risk factor for atherosclerosis and myocardial infarction in elderly women: the Rotterdam Study

    Get PDF
    BACKGROUND: Overt hypothyroidism has been found to be associated with cardiovascular disease. Whether subclinical hypothyroidism and thyroid autoimmunity are also risk factors for cardiovascular disease is controversial. OBJECTIVE: To investigate whether subclinical hypothyroidism and thyroid autoimmunity are associated with aortic atherosclerosis and myocardial infarction in postmenopausal women. DESIGN: Population-based cross-sectional study. SETTING: A district of Rotterdam, The Netherlands. PARTICIPANTS: Random sample of 1149 women (mean age +/- SD, 69.0 +/- 7.5 years) participating in the Rotterdam Study. MEASUREMENTS: Data on thyroid status, aortic atherosclerosis, and history of myocardial infarction were obtained at baseline. Subclinical hypothyroidism was defined as an elevated thyroid-stimulating hormone level (>4.0 mU/L) and a normal serum free thyroxine level (11 to 25 pmol/L [0.9 to 1.9 ng/dL]). In tests for antibodies to thyroid peroxidase, a serum level greater than 10 IU/mL was considered a positive result. RESULTS: Subclinical hypothyroidism was present in 10.8% of participants and was associated with a greater age-adjusted prevalence of aortic atherosclerosis (odds ratio, 1.7 [95% CI, 1.1 to 2.6]) and myocardial infarction (odds ratio, 2.3 [CI, 1.3 to 4.0]). Additional adjustment for body mass index, total and high-density lipoprotein cholesterol level, blood pressure, and smoking status, as well as exclusion of women who took beta-blockers, did not affect these estimates. Associations were slightly stronger in women who had subclinical hypothyroidism and antibodies to thyroid peroxidase (odds ratio for aortic atherosclerosis, 1.9 [CI, 1.1 to 3.6]; odds ratio for myocardial infarction, 3.1 [CI, 1.5 to 6.3]). No association was found between thyroid autoimmunity itself an

    Diet quality, food intake and incident adult-onset asthma:a Lifelines Cohort Study

    Get PDF
    PURPOSE: Dietary factors have been suggested as drivers of the rising prevalence of adult-onset asthma, but evidence is inconclusive, possibly due to the complex interrelation with obesity. We aim to explore the relation of diet quality and food intake with incident adult-onset asthma in normal weight and overweight adults of the prospective population-based Lifelines Cohort Study.METHODS: Incident adult-onset asthma was defined as self-reported asthma at ± 4-year follow-up, in adults free of airway disease at baseline. Diet quality scores and food group intake were assessed at baseline. Log-binomial regression analyses were used to estimate adjusted relative risks (RR) between dietary intake (per portion) and incident adult-onset asthma, in categories of BMI (cutoff: 25 kg/m 2). RESULTS: 477 incident asthma cases (75% female, 62% overweight) and 34,698 controls (60% female, 53% overweight) were identified. Diet quality-assessed by the Lifelines Diet Score and Mediterranean Diet Score-was not associated with incident adult-onset asthma in the two BMI groups. Although the dietary intake of several food groups differed between cases and controls, after adjustment for confounders only few remained associated with adult-onset asthma, including red and processed meat (RR: 0.93 per 15 g intake; 95% CI 0.86-0.99) in the normal weight group and intake of cheese (RR 1.09 per 20 g intake; 95% CI 1.00-1.17) and vegetables (RR 1.10 per 50 g intake; 95% CI 1.00-1.21) in the overweight group.CONCLUSION: The results of this study question the role of food as a 'simple' predictor of adult-onset asthma and call for an integrative approach, including a range of modifiable lifestyle factors and further asthma phenotyping.</p

    Fibrinolysis during liver transplantation is enhanced by using solvent/detergent virus-inactivated plasma (ESDEP)

    Get PDF
    After the introduction of solvent/detergent-treated plasma (ESDEP) in our hospital, an increased incidence of hyperfibrinolysis was observed (75% vs 29%; P = 0.005) compared with the use of fresh frozen plasma for liver transplantation. To clarify this increased incidence, intraoperative plasma samples of patients treated with fresh frozen plasma or ESDEP were analyzed in a retrospective observational study. During the anhepatic phase, plasma levels of D-dimer (6.58 vs 1.53 microg/mL; P = 0.02) and fibrinogen degradation products (60 vs 23 mg/L; P = 0.018) were significantly higher in patients treated with ESDEP. After reperfusion, differences increased to 23.5 vs 4.7 microg/mL (D-dimer, P = 0.002) and 161 vs 57 mg/L (fibrinogen degradation products, P = 0.001). The amount of plasma received per packed red blood cell concentrate, clotting tests, and levels of individual clotting factors did not show significant differences between the groups. alpha(2)-Antiplasmin levels, however, were significantly lower in patients receiving ESDEP during the anhepatic phase (0.37 vs 0.65 IU/mL; P < 0.001) and after reperfusion (0.27 vs 0.58 IU/mL; P = 0.001). Analysis of alpha(2)-antiplasmin levels in ESDEP alone showed a reduction to 0.28 IU/mL (normal >0.95 IU/mL) because of the solvent/detergent process. Therapeutic consequences for the use of ESDEP in orthotopic liver transplantation are discussed in view of an increased incidence of hyperfibrinolysis caused by reduced levels of alpha(2)-antiplasmin in the solvent/detergent-treated plasma. IMPLICATIONS: The use of solvent/detergent virus-inactivated plasma is of increasing importance in the prevention of human immunodeficiency virus and hepatitis C virus transmission. Since the use of this plasma during orthotopic liver transplantation has increased, the incidence of hyperfibrinolysis was observed. Clotting analysis of the patients revealed small alpha(2)-antiplasmin concentrations because of the solvent/detergent process
    • …
    corecore