132 research outputs found

    Comparative assessment of in vitro and in silico methods for aerodynamic characterization of powders for inhalation

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    In vitro assessment of dry powders for inhalation (DPIs) aerodynamic performance is an inevitable test in DPI development. However, contemporary trends in drug development also implicate the use of in silico methods, e.g., computational fluid dynamics (CFD) coupled with discrete phase modeling (DPM). The aim of this study was to compare the designed CFD-DPM outcomes with the results of three in vitro methods for aerodynamic assessment of solid lipid microparticle DPIs. The model was able to simulate particle-to-wall sticking and estimate fractions of particles that stick or bounce off the inhaler’s wall; however, we observed notable differences between the in silico and in vitro results. The predicted emitted fractions (EFs) were comparable to the in vitro determined EFs, whereas the predicted fine particle fractions (FPFs) were generally lower than the corresponding in vitro values. In addition, CFD-DPM predicted higher mass median aerodynamic diameter (MMAD) in comparison to the in vitro values. The outcomes of different in vitro methods also diverged, implying that these methods are not interchangeable. Overall, our results support the utility of CFD-DPM in the DPI development, but highlight the need for additional improvements in these models to capture all the key processes influencing aerodynamic performance of specific DPIs

    LH prevents cisplatin-induced apoptosis in oocytes and preserves female fertility in mouse

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    Premature ovarian failure and female infertility are frequent side effects of anticancer therapies, owing to the extreme sensitivity of the ovarian reserve oocytes to the damaging effects of irradiation and chemotherapy on DNA. We report here a robust protective effect of luteinizing hormone (LH) on the primordial follicle pool of prepubertal ovaries against the cisplatin (Cs)-induced apoptosis. In vitro LH treatment of prepubertal ovarian fragments generated anti-apoptotic signals by a subset of ovarian somatic cells expressing LH receptor (LHR) through cAMP/PKA and Akt pathways. Such signals, reducing the oocyte level of pro-apoptotic TAp63 protein and favoring the repair of the Cs-damaged DNA in the oocytes, prevented their apoptosis. Noteworthy, in vivo administration to prepubertal female mice of a single dose of LH together with Cs inhibited the depletion of the primordial follicle reserve caused by the drug and preserved their fertility in reproductive age, preventing significant alteration in the number of pregnancy and of delivered pups. In conclusion, these findings establish a novel ovoprotective role for LH and further support the very attracting prospective to use physiological 'fertoprotective' approaches for preventing premature infertility and risks linked to precocious menopause in young patients who survived cancer after chemotherapy

    Single and Combined Effects of Acute and Chronic Non-Thermal Stressors on Rat Interscapular Brown Adipose Tissue Metabolic Activity

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    The aim of this study was to examine whether the thermogenic potential of rat interscapular brown adipose tissue (IBAT) changes in response to acute and/or chronic exposure to non-thermal stressors (immobilization and isolation), by measuring the uncoupling protein 1 (UCP-1) content, MAO-A, SOD and CAT activities, as well as the number of IBAT sympathetic noradrenaline-containing nerve fibers. Both acute immobilization (2 h) and chronic isolation (21 days), as well as their combined effects, significantly increased the IBAT UCP-1 content in comparison to non-stressed animals. When applied individually, stressors increased the number of sympathetic fibers in comparison to controls, whereas in combination they decreased it. The activity of IBAT monoamine oxidase-A (MAO-A) decreased under the influence of each stressor independent of its type or duration. SOD activity coincided with MAO-A decrement, whereas CAT activity had an opposite pattern of changes. We conclude that acute and chronic exposure to non-thermal stressors, immobilization and isolation, respectively, affect the metabolic potential of rat IBAT, judging by the increase in UCP-1 content and sympathetic outflow. However, when acute immobilization was applied as a novel stressor to previously chronically isolated animals, an increase in the UCP-1 content was accompanied by a lower IBAT sympathetic outflow, suggesting that IBAT metabolic function under various stress condition is not solely dependent on SNS activity

    Temporal Responses of a Low-Energy Meal Replacement Plan or Exercise Training on Cardiovascular Function and Fibro-Inflammatory Markers in People with Type 2 Diabetes—A Secondary Analysis of the “Diabetes Interventional Assessment of Slimming or Training to Lessen Inconspicuous Cardiovascular Dysfunction” Study

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    Background: This study assesses the temporal responses of cardiovascular function, fibro-inflammation, and glucometabolic profiles in asymptomatic adults with type 2 diabetes, following a low-energy meal replacement plan (MRP) or exercise training. Methods: Secondary analysis of DIASTOLIC: a randomised, open-label, blinded-endpoint trial of 12 weeks MRP (~810 kcal/day) or exercise training. Cardiac magnetic resonance, plasma fibroinflammatory, and metabolic markers were undertaken at baseline, 4, and 12 weeks. Results: Out of 24 participants in the MRP group and 22 in exercise training, 18 and 11 completed all three visits. MRP resulted in early (0–4 weeks) improvement in insulin resistance (HOMA-IR: 10.82 to 4.32), decrease in FABP-4 (4.87 ± 0.19 to 5.15 ± 0.32 mg/L), and improvement in left ventricular remodelling LV mass: volume (0.86 ± 0.14 to 0.78 ± 0.11), all with large effect sizes. MMP8 levels increased moderately at 4–12 weeks. Peak early diastolic strain rate (cPEDSR) initially decreased, then improved. Exercise training led to minor improvements in insulin resistance and MMP-8 levels, with no significant changes in cPEDSR or LV remodelling. Conclusions: MRP resulted in early improvements in insulin resistance, cardiac remodelling, and inflammation, but with an initial decrease in diastolic function, improving by 12 weeks. Exercise training showed minor early benefits in insulin resistance and inflammation, but no significant cardiac changes

    An example of secondary fault activity along the North Anatolian Fault on the NE Marmara Sea Shelf, NW Turkey

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    Seismic data on the NE Marmara Sea Shelf indicate that a NNE-SSW-oriented buried basin and ridge system exist on the sub-marine extension of the Paleozoic Rocks delimited by the northern segment of the North Anatolian Fault (NS-NAF), while seismic and multi-beam bathymetric data imply that four NW-SE-oriented strike-slip faults also exist on the shelf area. Seismic data indicate that NW-SE-oriented strike-slip faults are the youngest structures that dissect the basin-ridge system. One of the NW-SE-oriented faults (F1) is aligned with a rupture of the North Anatolian Fault (NAF) cutting the northern slope of the Cinarcik Basin. This observation indicates that these faults have similar characteristics with the NS-NAF along the Marmara Sea. Therefore, they may have a secondary relation to the NAF since the principle deformation zone of the NAF follows the Marmara Trough in that region. The seismic energy recorded on these secondary faults is much less than that on the NAF in the Marmara Sea. These faults may, however, produce a large earthquake in the long term

    Ivan Djaja (Jean Giaja)<sup>1</sup>and the Belgrade school of physiology

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    Summary The founder of physiology studies in the Balkans and the pioneer of research on hypothermia, Ivan Djaja (Jean Giaja) was born 1884 in L'Havre. Giaja gained his PhD at the Sorbonne in 1909. In 1910 he established the first Chair of Physiology in the Balkans and organized the first Serbian Institute for Physiology at the School of Philosophy of the University of Belgrade. He led this Institute for more than 40 subsequent years. His most notable papers were in the field of thermoregulation and bioenergetics. Djaja became member of the Serbian and Croatian academies of science and doctor honoris causa of Sorbonne. In 1952 for the seminal work on the behavior of deep cooled warm blooded animals he became associate member of the National Medical Academy in Paris. In 1955 the French Academy of Sciences elected him as associate member in place of deceased Sir Alexander Fleming. Djaja died in 1957 during a congress held in his honor. He left more than 200 scientific and other papers and the golden DaVincian credo "Nulla dies sine experimento". His legacy was continued by several generations of researchers, the most prominent among them being Stefan Gelineo, Radoslav Andjus and Vojislav Petrović. © 2011 Institute of Physiology

    Ivan Djaja (Jean Giaja) and the Belgrade School of Physiology

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    The founder of physiology studies in the Balkans and the pioneer of research on hypothermia, Ivan Djaja (Jean Giaja) was born 1884 in L’Havre. Giaja gained his PhD at the Sorbonne in 1909. In 1910 he established the first Chair of Physiology in the Balkans and organized the first Serbian Institute for Physiology at the School of Philosophy of the University of Belgrade. He led this Institute for more than 40 subsequent years. His most notable papers were in the field of thermoregulation and bioenergetics. Djaja became member of the Serbian and Croatian academies of science and doctor honoris causa of Sorbonne. In 1952 for the seminal work on the behavior of deep cooled warm blooded animals he became associate member of the National Medical Academy in Paris. In 1955 the French Academy of Sciences elected him as associate member in place of deceased Sir Alexander Fleming. Djaja died in 1957 during a congress held in his honor. He left more than 200 scientific and other papers and the golden DaVincian credo “Nulla dies sine experimento”. His legacy was continued by several generations of researchers, the most prominent among them being Stefan Gelineo, Radoslav Andjus and Vojislav Petrović.</jats:p

    Vasopressin modulates hypothalamo-pituitary activity by paracrine action during acute and chronic immobilization stress in rats

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    The aim of the study was to examine changes in corticotropin releasing hormone (CRH), vasopressin (VP), adrenocorticotropin (ACTH) as well as VP3 receptor protein concentration in the hypothalamus and the pituitary of rats exposed to acute (3 h) and chronically repeated (3 h daily for 7 days) immobilization stress. Our results show that, unlike the increase in ACTH, there were no changes in serum VP despite the significant changes in this hormone and its receptor concentrations in the hypothalamus and pituitary (HP). This suggests that VP regulates HP activity by predominantly acting in a paracrine manner under the examined stress condition
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