Search results for " Gradient"
showing 10 items of 575 documents
Isolation of nuclei and downstream processing of cell-type-specific nuclei from micro-dissected mouse brain regions – techniques and caveats
2020
AbstractThe mammalian brain consists of several structurally and functionally distinct regions equipped with an equally complex cell-type system. Due to its relevance in uncovering disease mechanisms, the study of cell-type-specific molecular signatures of different brain regions has increased. The rapid evolution of newer and cheaper sequencing techniques has also boosted the interest in cell-type-specific epigenetic studies. In fact, the nucleus holds most of the cell’s epigenetic information and is quite resistant to tissue dissociation processes as compared to cells. As such, nuclei are continually preferred over cells for epigenetic studies. However, the isolation of nuclei from cells …
Description of an improved method for Blastocystis hominis culture and axenization
1996
An improved method for Blastocystis hominis culture and axenization was developed in the present study. Stool samples were cultured in prereduced Boeck-Drbohlav NHI modified medium (with several modifications) supplemented with antibiotics (0.4% ampicillin, 0.1% streptomycin, 0.0006% amphotericin B). Axenization was performed by the combination of partial purification of B. hominis by Ficoll-metrizoic acid gradient and inoculation in fresh medium containing active antibiotics against remaining bacteria. A total of 25 strains were obtained by this procedure. The time required for axenization ranged between 3 and 5 weeks. The generation time of axenic strains ranged from 6.6 to 12.1 h (mean +…
Effects on lipoprotein subclasses of combined expression of human hepatic lipase and human apoB in transgenic rabbits
2003
Objective— The effects of combined expression of human hepatic lipase (HL) and human apolipoprotein B (apoB) on low-density lipoprotein (LDL) subclasses were examined in rabbits, a species naturally deficient in HL activity. Methods and Results— In apoB-transgenic rabbit plasma, >80% of the protein was found in the 1.006- to 1.050-g/mL fraction. Gradient gel electrophoresis (GGE) of this fraction revealed two distinct species, designated large and small LDL. A denser fraction (d=1.050 to 1.063 g/mL) contained small LDL as well as another discrete LDL subspecies, designated very small LDL. Expression of HL resulted in reductions in protein concentrations in the 1.006- to 1.050-g/mL densi…
Computational fluid dynamics simulation to evaluate aortic coarctation gradient with contrast-enhanced CT
2014
Coarctation of aorta (CoA) is a narrowing of the aorta leading to a pressure gradient (Delta P) across the coarctation, increased afterload and reduced peripheral perfusion pressures. Indication to invasive treatment is based on values of maximal (systolic) trans-coarctation Delta P. A computational fluid dynamic (CFD) approach is herein presented for the non-invasive haemodynamic assessment of Delta P across CoA. Patient-specific CFD simulations were created from contrast-enhanced computed tomography (CT) and appropriate flow boundary conditions. Computed Delta P was validated with invasive intravascular trans-CoA pressure measurements. Haemodynamic indices, including pressure loss coeffic…
3H-cyproterone acetate: binding characteristics to human uterine progestagen receptors
1985
The availability of tritium labeled cyproterone acetate (CPA) facilitated the systematic investigation of the binding characteristics of this compound for human uterine progesterone receptors (PgR). The binding parameters of 3H-CPA are compared to those of 3H-R5020 and 3H-progesterone. The rate constants of association (k1M-1sec-1) to PgR were 7.8 X 10(3) for 3H-R5020, 4.5 X 10(4) for 3H-progesterone and 4.0 X 10(4) for 3H-CPA. The rate constants of dissociation (k-1, sec-1) were 3.6 X 10(-5) for 3H-R5020, 21.3 X 10(-5) for 3H-progesterone and 17.8 X 10(-5) for 3H-CPA. The Kd-values (M), as obtained by titration analysis and subsequent Scatchard plot analysis were 1.2 X 10(-9) for 3H-R5020,…
From Clinical Imaging to Patient-Specific Computational Model: Rapid Adaptation of the Living Heart Human Model to a Case of Aortic Stenosis
2021
Aortic stenosis (AS) is the most common acquired heart valve disease in the developed world. Traditional methods of grading AS have relied on the measurement of aortic valve area and transvalvular pressure gradient. Recent research has highlighted the existence of AS variants that do not meet classic criteria for severe AS such as low-flow, low-gradient AS. With the development of sophisticated multi-scale computational models, investigation into the left ventricular (LV) biomechanics of AS offers new insights into the pathophysiology that may guide treatment decisions surrounding AS. Building upon our prior study entailing LV-aortic coupling where AS conditions were applied to the idealize…
Update on the role of the atherogenic lipoprotein phenotype in cardiovascular prevention
2009
Higher plasma triglyceride levels and decreased HDL-cholesterol concentrations are usually accompanied by the presence of small, dense LDL in the so-called lipid triad or ‘atherogenic lipoprotein phenotype’. This phenotype is highly atherogenic and its prevalence may suggest an even higher overall burden of atherosclerotic disease as compared with that associated with hypercholesterolemia. As stated by the National Cholesterol Education Program Adult Treatment Panel III, there is evidence suggesting each component of this lipid triad is individually atherogenic. However, the relative contribution of each component cannot be easily determined. Therefore, it has been suggested to consider th…
In vivo metabolism of LDL subfractions in patients with heterozygous FH on statin therapy
2004
LDL can be subfractionated into buoyant (1.020-1.029 g/ml(-1)), intermediate (1.030-1.040 g/ml(-1)), and dense (1.041-1.066 g/ml(-1)) LDLs. We studied the rebound of these LDL-subfractions after LDL apheresis in seven patients with heterozygous familial hypercholesterolemia (FH) regularly treated by apheresis (58 +/- 9 years, LDL-cholesterol = 342 +/- 87 mg/dl(-1), triglycerides = 109 +/- 39 mg/dl(-1)) and high-dose statins. Apolipoprotein B (apoB) concentrations were measured in LDL subfractions immediately after and on days 1, 2, 3, 5, and 7 after apheresis. Compartmental models were developed to test three hypotheses: 1) that dense LDLs are derived from the delipidation of buoyant and in…
Gaismas un trokšņa piesārņojuma ietekme uz meža pūces Strix aluco sastopamību gar urbanizācijas gradientu: piemērs no Rīgas Latvijā
2017
Darba mērķis ir noskaidrot, kādi urbānās vides faktori ir svarīgi meža pūces dzīvotnes izvēlē pilsētvidē, vai gaismas un trokšņa piesārņojumam ir būtiska ietekme. Pētījumā izmantotas plaši pieejamas tālizpētes metodes, kas sniedz iespējas šo metodiku pielietot plašos reģionos un veikt datu interpretāciju. Veiktas uzskaites Rīgas administratīvās teritorijas robežās pūču telpiskās izplatības datu iegūšanais. Ar tālizpētes metodēm analizēti gaismas piesārņojuma un zemes virsmas seguma dati. Veikta vispārināto lineāro modeļu analīze meža pūces sastopamības prognozēšanai. Apsekotajās 173 vienībās kostatēti 40 meža pūces atsaukšanās gadījumi. Noskaidrots, ka meža pūces sastopamību urbānā vidē vis…
A new approach to calibrate the thermal conditions in space charge measurements on HVDC mini-cables
2019
The PEA method is currently widespread used for space charge measurements in mini-cables in order to qualify the behavior of semicon-dielectric-semicon compound under electric and thermal stress. The main goal of this research is to quantitatively evaluate the relationship between the thermal boundary conditions applied to cables or mini-cables and the maximum local electric field due to the accumulated space charge. Hitherto, several research groups have obtained thermal gradients over the dielectric's radius heating the conductor by Joule effect due to an induced current. In this paper, a numerical approach is offered to calibrate the heat exchange boundary conditions to apply to a sample…