338 research outputs found
Evidence and Consequences of the Central Role of the Kidneys in the Pathophysiology of Sympathetic Hyperactivity
Chronic elevation of the sympathetic nervous system has been identified as a major contributor to the complex pathophysiology of hypertension, states of volume overload – such as heart failure – and progressive kidney disease. It is also a strong determinant for clinical outcome. This review focuses on the central role of the kidneys in the pathogenesis of sympathetic hyperactivity. As a consequence, renal denervation may be an attractive option to treat sympathetic hyperactivity. The review will also focus on first results and the still remaining questions of this new treatment option
Adrenaline and hypertension
The questions we hoped to answer by the studies described in this thesis, were:
1 Does adrenaline, when infused intravenously in normotensive subjects leading
to plasma levels in the high physiological range, cause a sustained and
protracted rise in blood pressure, which outlasts the duration of the increments
in circulating adrenaline? And if so, does this effect on blood pressure occurs
at rest or during periods of activation of the sympathetic nervous system? In
view of the data of Vincent et al (43), we hypothesized that the latter would be
the case.
2 If the questions under number 1 are positively answered, does intravenous
administered noradrenaline have the same effect? When the effect of adrenaline is indeed mediated through prejunctional B,-adrenoceptors, we
hypothesized that this would not be the case.
3 Do the pressor responses to standardized sympathetic nervous system
stimulation by cold pressor and isometric exercise testing before, during and
18 hours after cessation of infusions of adrenaline, noradrenaline or dextrose
5% differ? Again we hypothesized that infusion of adrenaline but not
noradrenaline would lead to an amplification of the blood pressure responses.
4 Are the changes in plasma concentrations of adrenaline and noradrenaline
during the infusions of adrenaline and noradrenaline also detectable in
alterations in the amounts of catecholamines and their metabolites excreted in
the urine?
5 Do the infusions of catechOiamines, which lead to alterations in plasma
concentrations within the physiological range, have any effect on urinary
sodium excretion or on plasma levels of several hormones, potassium or
glucose?
6 What is the effect of non-selective and B,-selective B-blockade on the
adrenaline mediated facilitation of noradrenaline release and the adrenaline
induced enhancement of reflex sympathetic nervous system activity
Controversy on the CONVINCE study findings: the PRO take
The CONVINCE study, recently published in the New England Journal of Medicine, reveals a groundbreaking 23% reduction in the relative risk of all-cause mortality among end-stage kidney patients undergoing high convective volume hemodiafiltration. This significant finding challenges the conventional use of high-flux hemodialysis and offers hope for improving outcomes in chronic kidney disease patients. While some controversies surround the study's findings, including concerns about generalizability and the causes of death, it is essential to acknowledge the study's design and its main outcomes. The CONVINCE study, part of the HORIZON 2020 project, enrolled 1360 patients and demonstrated the superiority of hemodiafiltration in reducing all-cause mortality overall, as well as in specific patient subgroups (elderly, short vintage, non-diabetic, and those without cardiac issues). Interestingly, it was shown that hemodiafiltration had a protective effect against infection, including COVID-19. Future research will address sustainability, dose scaling effects, identification of subgroups especially likely to benefit and cost-effectiveness. However, for now, the findings strongly support a broader adoption of hemodiafiltration in renal replacement therapy, marking a significant advancement in the field
Letter on 'European dermatology forum S1-guideline on the diagnosis and treatment of sclerosing diseases of the skin, Part 2: Scleromyxedema, scleredema and nephrogenic systemic fibrosis'
We read with interest the guidelines recently published on sclerosing diseases of the skin (Part 2: Scleromyxedema, scleredema and nephrogenic systemic fibrosis)[1, 2]. However, we are concerned that the guideline recommendations proposed for prevention of nephrogenic systemic fibrosis (NSF) are potentially dangerous. Although we recognise the challenges in constructing comprehensive guidelines, we are concerned that this may be because the guidelines have not involved a multidisciplinary team
Education for the anthropocene : planetary health, sustainable health care, and the health workforce
Over the past few centuries, human activity has wrought dramatic changes in the natural systems
that support human life. Planetary health is a useful concept for health profession education (HPE)
teaching and practice because it situates health within a broader understanding of the interdependent socio-ecological drivers of human and planetary health. It facilitates novel ways of protecting both population health and the natural environment on which human health and wellbeing depends. This paper focuses on the climate crisis as an example of the relationship between
environmental change, healthcare, and education. We analyze how HPE can help decarbonize the
healthcare sector to address both climate change and inequity in health outcomes. Based on the
healthcare practitioner’s mandate of beneficence, we propose simple learning objectives to equip
HPE graduates with the knowledge, skills, and values to create a sustainable health system, using
carbon emission reductions as an example. These learning objectives can be integrated into HPE
without adding unduly to the curriculum load
7 T renal MRI: challenges and promises
The progression to 7 Tesla (7 T) magnetic resonance imaging (MRI) yields promises of substantial increase in signal-to-noise (SNR) ratio. This increase can be traded off to increase image spatial resolution or to decrease acquisition time. However, renal 7 T MRI remains challenging due to inhomogeneity of the radiofrequency field and due to specific absorption rate (SAR) constraints. A number of studies has been published in the field of renal 7 T imaging. While the focus initially was on anatomic imaging and renal MR angiography, later studies have explored renal functional imaging. Although anatomic imaging remains somewhat limited by inhomogeneous excitation and SAR constraints, functional imaging results are promising. The increased SNR at 7 T has been particularly advantageous for blood oxygen level-dependent and arterial spin labelling MRI, as well as sodium MR imaging, thanks to changes in field-strength-dependent magnetic properties. Here, we provide an overview of the currently available literature on renal 7 T MRI. In addition, we provide a brief overview of challenges and opportunities in renal 7 T MR imaging
Hemodynamic and biochemical effects of the AT1 receptor antagonist irbesartan in hypertension
We studied the hemodynamic, neurohumoral, and biochemical effects of the
novel angiotensin type 1 (AT1) receptor antagonist irbesartan in 86
untreated patients with essential hypertension on a normal sodium diet.
According to a double-blind parallel group trial, patients were randomized
to a once-daily oral dose of the AT1 receptor antagonist (1, 25, or 100
mg) or placebo after a placebo run-in period of 3 weeks. Randomization
medication was given for 1 week. Compared with placebo, 24-hour ambulatory
blood pressure did not change with the 1-mg dose, and it fell (mean and
95% confidence interval) by 7.0 (4.2-9.8)/6.1 (3.9-8.1) mm Hg with the
25-mg dose and by 12.1 (8.1-16.2)/7.2 (4.9-9.4) mm Hg with the 100-mg
dose. Heart rate did not change during either dose. With the 25-mg dose,
the antihypertensive effect was attenuated during the second half of the
recording, and wi
Short- and long-term functional effects of percutaneous transluminal angioplasty in hemodialysis vascular access
The efficacy of percutaneous transluminal angioplasty (PTA) is usually
expressed as the angiographic result. Access flow (Qa) measurements offer
a means to quantify the functional effects. This study was performed to
evaluate the short-term functional and angiographic effects of PTA and to
determine the longevity of the functional effects during the follow-up
period. Patients with an arteriovenous graft (AVG) or an arteriovenous
fistula (AVF) who were eligible for PTA (Qa values of <600 ml/min) were
included. Ultrasound-dilution Qa measurements were obtained shortly before
PTA and periodically after PTA, beginning 1 wk after the procedure. The
short-term effects were expressed as the increase in Qa and the reduction
of stenosis. The long-term effects were expressed as patency and the
decrease in Qa after PTA. Ninety-eight PTA procedures for 60 patients (65
AVG and 33 AVF) were analyzed. Qa improved from 371 +/- 17 to 674 +/- 30
ml/min for AVG and from 304 +/- 24 to 638 +/- 51 ml/min for AVF (both P <
0.0001). In 66% (AVG) and 50% (AVF) of cases, Qa increased to levels of
>600 ml/min. The degree of stenosis decreased from 65 +/- 3 to 17 +/- 2%
for AVG and from 72 +/- 5 to 23 +/- 7% for AVF (both P < 0.005). The
reduction of stenosis was not correlated with DeltaQa (r(2) = 0.066).
Six-month unassisted patency rates after PTA were 25% for AVG and 50% for
AVF. The decreases in Qa were 3.7 +/- 0.8 ml/min per d for AVG and 1.8 +/-
0.9 ml/min per d for AVF. Qa values before PTA and DeltaQa were correlated
with the subsequent decrease in Qa (P < 0.005). In conclusion, Qa
increases after PTA but, in a substantial percentage of cases, not to
levels of >600 ml/min. Qa values before PTA and the increase in Qa were
correlated with long-term outcomes, whereas angiographic results were not.
These data, combined with literature data, suggest that there is optimal
timing for PTA
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