Compliance is an important property of the arterial system and abnormalities in compliance can greatly affect cardiovascular function. The elastic properties of the common carotid artery were therefore studied in 24 normotensive hemodialysis patients and 24 healthy normotensives using a noninvasive technique. The hemodialysis patients and the control subjects were matched for blood pressure. Arterial distension was measured by Doppler analysis of the vessel wall movements and blood pressure was recorded by finger-phlethysmography (Finapres). The vessel wall distensibility (DC: 2.49 +/- 0.23 10(-3)/mm Hg; mean +/- SEM) was significantly reduced and the end diastolic diameter (d: 7.3 +/- 0.3 mm) was significantly increased in younger hemodialysis patients (36.3 +/- 2.0 years) when compared with age-related controls (DC: 3.44 +/- 0.24 10(-3)/mm Hg; d: 6.3 +/- 0.3 mm; mean +/- SEM). In older hemodialysis patients (60.2 +/- 2.3 years), there was no significant difference in vessel wall distensibility (DC: 1.55 +/- 0.15 10(-3)/mm Hg) and vessel diameter (d: 7.8 +/- 0.3 mm) as compared with age-matched controls (DC: 1.77 +/- 0.14 10(-3)/mm Hg; d: 7.2 +/- 0.3 mm). The results show that vessel wall distensibility of the common carotid artery is decreased in younger hemodialysis patients as compared with age-matched healthy subjects. The volume expanded state in hemodialysis patients cannot account for the decreased arterial distensibility, since volume depletion by hemodialysis was not associated with a significant change of arterial distensibility (DC 2.14 +/- 0.44 10(-3)/mm Hg before, DC 2.26 +/- 0.45 10(-3)/mm Hg after ultrafiltration, NS).(ABSTRACT TRUNCATED AT 250 WORDS)
The baseline data from GLORIA-AF phase 2 demonstrate that in newly diagnosed nonvalvular atrial fibrillation patients, NOAC have been highly adopted into practice, becoming more frequently prescribed than VKA in Europe and North America. Worldwide, however, a large proportion of patients remain undertreated, particularly in Asia and North America. (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation [GLORIA-AF]; NCT01468701).
To assess the influence of long-term hemodialysis on arterial compliance, the elastic vessel wall properties of the common carotid artery were determined in 20 normotensive renal transplant recipients (age 44.7 ± 4.1 years) 8-12 weeks after first transplantation and in 10 healthy controls (age 45.9 ± 5.2 years). Arterial distension was measured by using a multigate pulsed Doppler system, blood pressure curve was recorded by fingerplethysmography. 10 patients with a prior long-term hemodialysis of 51 ± 11 months were compared to 10 patients with a prior short hemodialysis of 18 ± 7 months. The patients and controls had been matched in respect of age, sex and blood pressure. In the long and short-term hemodialysis group, the proportion of patients (n = 10) with a history of mild hypertension was similar – mild hypertension for 25 ± 10 months (n = 5) and for 27 ± 9 months (n ≈ 5). In the group with long-term hemodialysis, the cross-sectional compliance and the distensibility coefficient was significantly reduced in comparison to the group with short-term hemodialysis (p < 0.005) and to the control group (p < 0.001). A significant inverse correlation between the hemodialysis period and the distensibility coefficient (r = -0.59; p < 0.005) showed a decrease in arterial compliance with the length of hemodialysis treatment. The results demonstrate that vessel wall elasticity decreases with the length of hemodialysis treatment and is reduced by hemodialysis-dependent factors, which are detached from sustained arterial hypertension. As cause of reduced arterial compliance in long-term hemodialysis hypervolemia, hypercirculation and disturbed calcium-phosphate metabolism is suggested.
The influence of repeated aluminium (Al) administration (0.05 or 0.5 mg 100 g-1 b.w.t. i.p. 5 times weekly for 12 weeks) on the lysosomal enzymes N-acetyl-beta-D-glucosaminidase (beta-NAG) and beta-glucuronidase (beta-Gluc) in serum, liver, spleen and kidneys of adult female rats with intact kidneys, (NR), or following partial nephrectomy (5/6 NX) was investigated. After A1 loading, at the high dose only, the beta-NAG in serum and the free beta-NAG in liver, spleen and kidneys increased. Latent beta-NAG levels decreased in all three organs the effect being dose related. Following A1 loading no elevation in total enzyme activity was observed, with one exception. Depending on A1 doses the spleen of the non-operated animals, the liver of both groups of animals and the serum showed a decrease in beta-Gluc activity. No effect on beta-Gluc activity was observed in the spleen of 5/6 NX animals or in the kidneys of either group of animals. The results confirm that high doses of Al induce toxic effects and damage the lysosomes in the liver, the spleen and the kidneys. The results indicate that the extent of lysosomal damage correlates with dose and duration of Al loading. Repeated administration of Al also interferes selectively with enzyme synthesis.
The effect on renal function following administration of aluminium (i.p., five times weekly (0.05 or 0.5 mg kg-1 body weight) for 12 weeks) to partially nephrectomized (5/6 NX) or intact female rats was examined. The observed loss of concentrating ability, characterized by increased urine volume and an increased sodium excretion, as well as increased renal excretion of p-aminohippurate (demonstrable after low-dose treatment with nephrotoxins) can be interpreted as an initiation of kidney function injury. No distinct differences in response were observed between partially nephrectomized and intact animals.
Meadow pipit migration and orientation was studied by (1) watching visible migration and measuring flight directions with a compass in NW-Germany (1980-1985) and (2) conducting orientation experiments with caged migrants in radial-perch cages (MERKEL & FROMME, 1958). Free-flying pipits migrated SW in autumn and NE in spring in sunny and overcast weather, but on average there was less migration under overcast. In the field migration peaked in the first two morning hours and was almost over by the end of October. Strong migration always corresponded to a minimal scatter of flight directions. In the orientation cages the birds oriented SW in autumn and NNW in spring, but only in sunny weather during the first three morning hours. Activity decreased markedly later in the day (spring), in November compared to September/October and under overcast compared to sunny skies. The more active the birds were, the better was their orientation with respect to the overall mean direction. In general, meaningful orientation in the cages occurred only when migration intensity in the field was maximal. A lack of well-oriented behaviour in the cage is not necessarily caused by an inability to orient, but may be a consequence of low motivation to migrate. A six hour clockshift of experimental birds did not lead to a clear shift of their directional choices, but produced an axial NE-SW orientation in autumn and disorientation is spring. This result does not support the assumption that diurnal migrants orient primarily by means of a sun compass.
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