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1.
Nature ; 627(8003): 321-327, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38480963

ABSTRACT

Overnight fires are emerging in North America with previously unknown drivers and implications. This notable phenomenon challenges the traditional understanding of the 'active day, quiet night' model of the diurnal fire cycle1-3 and current fire management practices4,5. Here we demonstrate that drought conditions promote overnight burning, which is a key mechanism fostering large active fires. We examined the hourly diurnal cycle of 23,557 fires and identified 1,095 overnight burning events (OBEs, each defined as a night when a fire burned through the night) in North America during 2017-2020 using geostationary satellite data and terrestrial fire records. A total of 99% of OBEs were associated with large fires (>1,000 ha) and at least one OBE was identified in 20% of these large fires. OBEs were early onset after ignition and OBE frequency was positively correlated with fire size. Although warming is weakening the climatological barrier to night-time fires6, we found that the main driver of recent OBEs in large fires was the accumulated fuel dryness and availability (that is, drought conditions), which tended to lead to consecutive OBEs in a single wildfire for several days and even weeks. Critically, we show that daytime drought indicators can predict whether an OBE will occur the following night, which could facilitate early detection and management of night-time fires. We also observed increases in fire weather conditions conducive to OBEs over recent decades, suggesting an accelerated disruption of the diurnal fire cycle.


Subject(s)
Darkness , Droughts , Wildfires , Droughts/statistics & numerical data , Ecosystem , North America , Wildfires/statistics & numerical data
2.
Sci Total Environ ; 884: 163849, 2023 Aug 01.
Article in English | MEDLINE | ID: mdl-37137369

ABSTRACT

Landscape fires are a natural component of the Earth System. However, they are of growing global concern due to climate change exacerbating their multiple impacts on biodiversity, ecosystems, carbon storage, human health, economies, and wider society. Temperate regions are predicted to be at greatest risk of increasing fire activity due to climate change, where fires can seriously impact important ecosystems for biodiversity and carbon storage, such as peatlands and forests. There is insufficient literature on the background prevalence, distribution, and drivers of fires in these regions, especially within Europe, to assess and mitigate their risks. Using a global database of fire patches based on the MODIS FireCCI51 product, we address this knowledge gap by quantifying the current prevalence and size of fires in Polesia, a 150,000 km2 area comprising a mosaic of peatland, forest, and agricultural habitats in northern Ukraine and southern Belarus. Between 2001 and 2019, fires burned 31,062 km2 of land, and were most frequent in spring and autumn. Although most fires started in agricultural land, fires disproportionately affected natural and semi-natural land cover types, particularly in protected areas. Over one fifth of protected land burned. Coniferous forests were the most common land cover type in protected areas, but fires mostly occurred in meadows, open peatlands (especially fen and transition mires), and native deciduous forests. These land cover types were highly susceptible to fires under low soil moisture conditions, but the risk of fire was low under average or higher soil moisture conditions. Restoring and maintaining natural hydrological regimes could be an effective nature-based solution to increase the resilience of fire-vulnerable ecosystems and support global biodiversity and carbon storage commitments under the United Nations Framework Conventions on Climate Change and Convention on Biological Diversity.


Subject(s)
Ecosystem , Fires , Humans , Grassland , Forests , Soil , Carbon
3.
Gigascience ; 10(12)2021 12 09.
Article in English | MEDLINE | ID: mdl-34891161

ABSTRACT

BACKGROUND: Fusion genes are typically identified by RNA sequencing (RNA-seq) without elucidating the causal genomic breakpoints. However, non-poly(A)-enriched RNA-seq contains large proportions of intronic reads that also span genomic breakpoints. RESULTS: We have developed an algorithm, Dr. Disco, that searches for fusion transcripts by taking an entire reference genome into account as search space. This includes exons but also introns, intergenic regions, and sequences that do not meet splice junction motifs. Using 1,275 RNA-seq samples, we investigated to what extent genomic breakpoints can be extracted from RNA-seq data and their implications regarding poly(A)-enriched and ribosomal RNA-minus RNA-seq data. Comparison with whole-genome sequencing data revealed that most genomic breakpoints are not, or minimally, transcribed while, in contrast, the genomic breakpoints of all 32 TMPRSS2-ERG-positive tumours were present at RNA level. We also revealed tumours in which the ERG breakpoint was located before ERG, which co-existed with additional deletions and messenger RNA that incorporated intergenic cryptic exons. In breast cancer we identified rearrangement hot spots near CCND1 and in glioma near CDK4 and MDM2 and could directly associate this with increased expression. Furthermore, in all datasets we find fusions to intergenic regions, often spanning multiple cryptic exons that potentially encode neo-antigens. Thus, fusion transcripts other than classical gene-to-gene fusions are prominently present and can be identified using RNA-seq. CONCLUSION: By using the full potential of non-poly(A)-enriched RNA-seq data, sophisticated analysis can reliably identify expressed genomic breakpoints and their transcriptional effects.


Subject(s)
Genomics , RNA, Ribosomal , Gene Fusion , Genome , Sequence Analysis, RNA
4.
Blood Press ; 30(6): 376-385, 2021 12.
Article in English | MEDLINE | ID: mdl-34647513

ABSTRACT

PURPOSE: Blood pressure (BP) reduction after renal sympathetic denervation (RDN) is highly variable. Renal nerve stimulation (RNS) can localize sympathetic nerves. The RNS trial aimed to investigate the medium-term BP-lowering effects of the use of RNS during RDN, and explore if RNS can check the completeness of the denervation. MATERIAL AND METHODS: Forty-four treatment-resistant hypertensive patients were included in the prospective, single-center RNS trial. The primary study endpoint was change in 24-h BP at 6- to 12-month follow-up after RDN. The secondary study endpoints were the acute procedural RNS-induced BP response before and after RDN; number of antihypertensive drugs at follow-up; and the correlation between the RNS-induced BP increase before versus after RDN (delta [Δ] RNS-induced BP). RESULTS: Before RDN, the RNS-induced systolic BP rise was 43(±21) mmHg, and decreased to 9(±12) mmHg after RDN (p < 0.001). Mean 24-h systolic/diastolic BP decreased from 147(±12)/82(±11) mmHg at baseline to 135(±11)/76(±10) mmHg (p < 0.001/<0.001) at follow-up (10 [6-12] months), with 1 antihypertensive drug less compared to baseline. The Δ RNS-induced BP and the 24-h BP decrease at follow-up were correlated for systolic (R = 0.44, p = 0.004) and diastolic (R = 0.48, p = 0.003) BP. Patients with ≤0 mmHg residual RNS-induced BP response after RDN had a significant lower mean 24-h systolic BP at follow-up compared to the patients with >0 mmHg residual RNS-induced BP response (126 ± 4 mmHg versus 135 ± 10 mmHg, p = 0.04). 83% of the patients with ≤0 mmHg residual RNS-induced BP response had normal 24-h BP at follow-up, compared to 33% in the patients with >0 mmHg residual RNS-induced BP response (p = 0.023). CONCLUSION: The use of RNS during RDN leads to clinically significant and sustained lowering of 24-h BP with fewer antihypertensive drugs at follow-up. RNS-induced BP changes were correlated with 24-h BP changes at follow-up. Moreover, patients with complete denervation had significant lower BP compared to the patients with incomplete denervation.


Subject(s)
Hypertension , Kidney , Blood Pressure , Humans , Hypertension/surgery , Kidney/surgery , Prospective Studies , Sympathectomy , Treatment Outcome
5.
BJPsych Open ; 7(1): e19, 2020 Dec 22.
Article in English | MEDLINE | ID: mdl-33349278

ABSTRACT

BACKGROUND: The characteristics of patients who have repeated compulsory psychiatric admissions are largely unknown. AIMS: To investigate the frequency and risk factors for repeated emergency compulsory psychiatric admission (ECPA); and to identify targets for interventions to reduce repeated ECPA. METHOD: Data were collected from a database of electronic patient files (EPFs) held by three psychiatric emergency services (PES) in the Netherlands. Analyses were based on the data for adult patients (aged 18-75 years) with a first PES contact in 2010-2015. Using descriptive statistics and regression analysis, we studied the associations between baseline patient factors and repeated ECPA and time to readmission, within a 2-year follow-up period. RESULTS: We included 6059 patients: 15.6% had two or more ECPAs. In total, 66% of second ECPAs had occurred within 6 months of the first. About 30% of all ECPAs were repeated ECPAs. Two baseline factors were associated with a higher frequency of a second ECPA: history of receiving any mental healthcare treatment, whether in-patient or out-patient or both, and a lower level of self-care. Three were associated with a lower frequency: ethnicity (other than Dutch), older age and suicidality. Lower Global Assessment of Functioning (GAF) scores and housing problems were associated with a shorter time to compulsory readmission and persistent psychiatric problems with a longer time to compulsory readmission. CONCLUSIONS: We found that 15.6% of patients had two or more ECPAs. Two-thirds of the second ECPAs had occurred within 6 months of the first. Like earlier studies, the risk factors we identified suggest that interventions to reduce the risk of repeated compulsory psychiatric admission should seek to improve self-care, general daily functioning and homelessness.

6.
Int J Cancer ; 146(7): 1979-1992, 2020 04 01.
Article in English | MEDLINE | ID: mdl-31411736

ABSTRACT

Removal of colorectal adenomas is an effective strategy to reduce colorectal cancer (CRC) mortality rates. However, as only a minority of adenomas progress to cancer, such strategies may lead to overtreatment. The present study aimed to characterize adenomas by in-depth molecular profiling, to obtain insights into altered biology associated with the colorectal adenoma-to-carcinoma progression. We obtained low-coverage whole genome sequencing, RNA sequencing and tandem mass spectrometry data for 30 CRCs, 30 adenomas and 18 normal adjacent colon samples. These data were used for DNA copy number aberrations profiling, differential expression, gene set enrichment and gene-dosage effect analysis. Protein expression was independently validated by immunohistochemistry on tissue microarrays and in patient-derived colorectal adenoma organoids. Stroma percentage was determined by digital image analysis of tissue sections. Twenty-four out of 30 adenomas could be unambiguously classified as high risk (n = 9) or low risk (n = 15) of progressing to cancer, based on DNA copy number profiles. Biological processes more prevalent in high-risk than low-risk adenomas were related to proliferation, tumor microenvironment and Notch, Wnt, PI3K/AKT/mTOR and Hedgehog signaling, while metabolic processes and protein secretion were enriched in low-risk adenomas. DNA copy number driven gene-dosage effect in high-risk adenomas and cancers was observed for POFUT1, RPRD1B and EIF6. Increased POFUT1 expression in high-risk adenomas was validated in tissue samples and organoids. High POFUT1 expression was also associated with Notch signaling enrichment and with decreased goblet cells differentiation. In-depth molecular characterization of colorectal adenomas revealed POFUT1 and Notch signaling as potential drivers of tumor progression.


Subject(s)
Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , Fucosyltransferases/genetics , Oncogene Proteins/genetics , Adenoma/genetics , Adenoma/metabolism , Adenoma/pathology , Biomarkers, Tumor , Carcinoma/genetics , Carcinoma/metabolism , Carcinoma/pathology , Colorectal Neoplasms/metabolism , Disease Progression , Fucosyltransferases/metabolism , Humans , Oncogene Proteins/metabolism , Reproducibility of Results , Tumor Microenvironment
7.
BMC Psychiatry ; 19(1): 241, 2019 08 05.
Article in English | MEDLINE | ID: mdl-31382937

ABSTRACT

BACKGROUND: On the basis of earlier experiences in Germany and England, we developed an intensive multimodal group programme (FACT Plus) for psychotic-spectrum patients. By combining it with regular Flexible Assertive Community Treatment (FACT) (care as usual), we intended to reduce psychiatric rehospitalizations and mental healthcare costs. METHODS: We included adult patients (>18 years) with a psychotic spectrum disorder who had had at least one psychiatric admission in the 2 years before inclusion. FACT Plus was delivered weekly for 9 months. The intervention group was recruited in northern Rotterdam (the Netherlands), and the control group was recruited in southern Rotterdam. The primary outcome measure was length of stay (LOS) and the secondary outcome measures were mental healthcare costs and compulsory admissions. RESULTS: We included 52 patients in the intervention group and 61 patients in the control group. During the 12-month observation period, the mean LOS per patient was 15.2 (intervention group) and 34.6 (control group). This represents a difference of 19.4 days (56.1%). This result was statistically significant (B = -.859, SE = .497, p = .042) in a regression model correcting for baseline differences between the groups. Mean total mental healthcare costs per patient were €21,098 in the intervention group) versus €25,054 in the control group, a difference of about €4000 per patient (16%). In addition, there were zero compulsory admissions in the intervention group and nine in the control group. CONCLUSIONS: After the addition of FACT Plus to regular FACT, psychiatric LOS was substantially lower in the intervention group than in the control group. This result was accompanied by a limited reduction in mental healthcare costs.


Subject(s)
Community Mental Health Services/methods , Hospitalization/statistics & numerical data , Psychotherapy, Group/methods , Psychotic Disorders/therapy , Adult , Combined Modality Therapy , Female , Humans , Length of Stay , Male , Middle Aged , Netherlands , Program Evaluation , Research Design , Treatment Outcome
8.
BJPsych Open ; 5(3): e32, 2019 May.
Article in English | MEDLINE | ID: mdl-30944047

ABSTRACT

BACKGROUND: Compulsory admission is commonly regarded as necessary and justified for patients whose psychiatric condition represents a severe danger to themselves and others. However, while studies on compulsory admissions have reported on various clinical and social outcomes, little research has focused specifically on dangerousness, which in many countries is the core reason for compulsory admission.AimsTo study changes in dangerousness over time in adult psychiatric patients admitted by compulsory court order, and to relate these changes to these patients' demographic and clinical characteristics. METHOD: In this explorative prospective observational cohort study of adult psychiatric patients admitted by compulsory court order, demographic and clinical data were collected at baseline. At baseline and at 6 and 12 month follow-up, dangerousness was assessed using the Dangerousness Inventory, an instrument based on the eight types of dangerousness towards self or others specified in Dutch legislation on compulsory admissions. We used descriptive statistics and logistic regression to analyse the data. RESULTS: We included 174 participants with a court-ordered compulsory admission. At baseline, the most common dangerousness criterion was inability to cope in society. Any type of severe or very severe dangerousness decreased from 86.2% at baseline to 36.2% at 6 months and to 28.7% at 12 months. Being homeless at baseline was the only variable which was significantly associated with persistently high levels of dangerousness. CONCLUSIONS: Dangerousness decreased in about two-thirds of the patients after court-ordered compulsory admission. It persisted, however, in a substantial minority (approximately one-third).Declaration of interestNone.

9.
Cell ; 176(4): 831-843.e22, 2019 02 07.
Article in English | MEDLINE | ID: mdl-30735634

ABSTRACT

The cancer transcriptome is remarkably complex, including low-abundance transcripts, many not polyadenylated. To fully characterize the transcriptome of localized prostate cancer, we performed ultra-deep total RNA-seq on 144 tumors with rich clinical annotation. This revealed a linear transcriptomic subtype associated with the aggressive intraductal carcinoma sub-histology and a fusion profile that differentiates localized from metastatic disease. Analysis of back-splicing events showed widespread RNA circularization, with the average tumor expressing 7,232 circular RNAs (circRNAs). The degree of circRNA production was correlated to disease progression in multiple patient cohorts. Loss-of-function screening identified 11.3% of highly abundant circRNAs as essential for cell proliferation; for ∼90% of these, their parental linear transcripts were not essential. Individual circRNAs can have distinct functions, with circCSNK1G3 promoting cell growth by interacting with miR-181. These data advocate for adoption of ultra-deep RNA-seq without poly-A selection to interrogate both linear and circular transcriptomes.


Subject(s)
Prostatic Neoplasms/genetics , RNA/genetics , RNA/metabolism , Gene Expression Profiling/methods , Genetic Profile , HEK293 Cells , Humans , Male , MicroRNAs/metabolism , Prostate/metabolism , RNA Splicing/genetics , RNA, Circular , RNA, Untranslated/genetics , Sequence Analysis, RNA/methods , Transcriptome
10.
Clin Res Cardiol ; 108(1): 22-30, 2019 Jan.
Article in English | MEDLINE | ID: mdl-29943270

ABSTRACT

BACKGROUND: Renal nerve stimulation (RNS) is used to localize sympathetic nerve tissue for selective renal nerve sympathetic denervation (RDN). Examination of heart rate variability (HRV) provides a way to assess the state of the autonomic nervous system. The current study aimed to examine the acute changes in HRV caused by RNS before and after RDN. METHODS AND RESULTS: 30 patients with hypertension referred for RDN were included. RNS was performed under general anesthesia before and after RDN. Heart rate (HR) and blood pressure (BP) were continuously monitored. HRV characteristics were assessed 1 min before and after RNS and RDN. RNS before RDN elicited a maximum increase in systolic BP of 45 (± 22) mmHg which was attenuated to 13 (± 12) mmHg (p < 0.001) after RDN. RNS before RDN decreased the sinus cycle length from 1210 (± 201) ms to 1170 (± 203) ms (p = 0.03), after RDN this effect was blunted (p = 0.59). The LF/HF ratio in response to RNS changed from ∆ + 0.448 (± 0.550) before RDN to ∆ - 0.656 (± 0.252) after RDN (p = 0.02). Selecting patients off beta-blockade (n = 11), the RNS-induced changes in HRV components before versus after RDN were more pronounced (LF/HF ratio ∆ + 0.900 ± 1.171 versus ∆ - 0.828 ± 0.519, p = 0.01), whereas changes in HRV parameters in patients on beta-blockade (n = 19) were no longer significant. In patients with diabetes mellitus (n = 7), RNS induced no changes in HRV parameters (LF/HF ratio ∆ - 0.039 ± 0.103 versus ∆ - 0.460 ± 0.491, p = 0.92). CONCLUSION: RNS induces changes in HRV suggesting increased sympathetic activity. Conversely, after RDN, the RNS-induced changes in HRV suggesting a lower sympathetic autonomic balance. These changes were most pronounced in beta-blocker naïve patients and not present in patients with diabetes mellitus. These findings could support RNS-guided RDN to optimize results.


Subject(s)
Heart Rate/physiology , Hypertension/physiopathology , Kidney/innervation , Sympathectomy/methods , Sympathetic Nervous System/surgery , Adolescent , Adult , Aged , Aged, 80 and over , Blood Pressure/physiology , Female , Humans , Hypertension/therapy , Male , Middle Aged , Sympathetic Nervous System/physiopathology , Treatment Outcome , Young Adult
11.
J Pathol ; 246(3): 266-276, 2018 11.
Article in English | MEDLINE | ID: mdl-29968252

ABSTRACT

Consensus molecular subtyping is an RNA expression-based classification system for colorectal cancer (CRC). Genomic alterations accumulate during CRC pathogenesis, including the premalignant adenoma stage, leading to changes in RNA expression. Only a minority of adenomas progress to malignancies, a transition that is associated with specific DNA copy number aberrations or microsatellite instability (MSI). We aimed to investigate whether colorectal adenomas can already be stratified into consensus molecular subtype (CMS) classes, and whether specific CMS classes are related to the presence of specific DNA copy number aberrations associated with progression to malignancy. RNA sequencing was performed on 62 adenomas and 59 CRCs. MSI status was determined with polymerase chain reaction-based methodology. DNA copy number was assessed by low-coverage DNA sequencing (n = 30) or array-comparative genomic hybridisation (n = 32). Adenomas were classified into CMS classes together with CRCs from the study cohort and from The Cancer Genome Atlas (n = 556), by use of the established CMS classifier. As a result, 54 of 62 (87%) adenomas were classified according to the CMS. The CMS3 'metabolic subtype', which was least common among CRCs, was most prevalent among adenomas (n = 45; 73%). One of the two adenomas showing MSI was classified as CMS1 (2%), the 'MSI immune' subtype. Eight adenomas (13%) were classified as the 'canonical' CMS2. No adenomas were classified as the 'mesenchymal' CMS4, consistent with the fact that adenomas lack invasion-associated stroma. The distribution of the CMS classes among adenomas was confirmed in an independent series. CMS3 was enriched with adenomas at low risk of progressing to CRC, whereas relatively more high-risk adenomas were observed in CMS2. We conclude that adenomas can be stratified into the CMS classes. Considering that CMS1 and CMS2 expression signatures may mark adenomas at increased risk of progression, the distribution of the CMS classes among adenomas is consistent with the proportion of adenomas expected to progress to CRC. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.


Subject(s)
Adenoma/genetics , Biomarkers, Tumor/genetics , Carcinoma/genetics , Colorectal Neoplasms/genetics , DNA Copy Number Variations , Gene Dosage , Gene Expression Profiling/methods , Microsatellite Instability , Adenoma/classification , Adenoma/metabolism , Carcinoma/classification , Carcinoma/metabolism , Cell Differentiation , Colorectal Neoplasms/classification , Colorectal Neoplasms/pathology , Consensus , Disease Progression , Genetic Predisposition to Disease , Humans , Neoplasm Staging , Phenotype , Predictive Value of Tests , Reproducibility of Results , Transcriptome
12.
Clin Res Cardiol ; 107(12): 1131-1138, 2018 Dec.
Article in English | MEDLINE | ID: mdl-29845330

ABSTRACT

BACKGROUND: Renal nerve denervation (RDN) is developed as a potential treatment for hypertension. Recently, we reported the use of renal nerve stimulation (RNS) to localize sympathetic nerve tissue for subsequent selective RDN. The effects of RNS on arterial pressure dynamics remain unknown. The current study aimed to describe the acute changes in arterial pressure dynamics response to RNS before and after RDN. METHODS AND RESULTS: Twenty six patients with drug-resistant hypertension referred for RDN were included. RNS was performed under general anesthesia before and after RDN. We continuously monitored heart rate (HR) and invasive femoral blood pressure (BP). Augmentation pressure (AP) and index (Aix), pulse pressure (PP), time to reflected wave, maximum systolic BP and dicrotic notch were calculated. Systolic and diastolic BP at site of maximum response significantly increased in response to RNS (120 ± 16/62 ± 9 to 150 ± 22/75 ± 15 mmHg) (p < 0.001/< 0.001), whereas after RDN no RNS-induced BP change was observed (p > 0.10). RNS increased Aix (29 ± 11 to 32 ± 13%, p = 0.005), PP (59 ± 14 to 75 ± 17 mmHg, p < 0.001), time to reflected wave (63 ± 18 to 71 ± 25 ms, p = 0.004) and time to maximum systolic pressure (167 ± 36 to 181 ± 46 ms, p = 0.004) before RDN, whereas no changes were observed after RDN (p > 0.18). All changes were BP dependent. RNS had no influence on HR or the time to dicrotic notch (p > 0.12).   CONCLUSION: RNS induces temporary rises in Aix, PP, time to maximum systolic pressure and time to reflected wave. These changes are BP dependent and were completely blunted after RDN.


Subject(s)
Electric Stimulation/methods , Hypertension/therapy , Kidney/innervation , Sympathectomy/methods , Aged , Arterial Pressure/physiology , Blood Pressure/physiology , Female , Hemodynamics/physiology , Humans , Male , Middle Aged , Sympathetic Nervous System/surgery , Treatment Outcome
13.
Blood Press ; 27(5): 271-279, 2018 10.
Article in English | MEDLINE | ID: mdl-29653494

ABSTRACT

PURPOSE: Recently we reported the use of renal nerve stimulation (RNS) during renal denervation (RDN) procedures. RNS induced changes in blood pressure (BP) and heart rate are not fully delineated yet. We hypothesized that electrical stimulation of the sympathetic nerve tissue in the renal artery would lead to an increase in BP and vagal stimulation would cause a decrease in BP. We report the different patterns of BP and heart rate responses elicited by RNS prior to RDN. METHODS: 35 patients with drug-resistant hypertension were included. RNS was performed under general anesthesia at four sites in the right and left renal arteries, both before and immediately after RDN. RNS-induced BP and heart rate changes were monitored. RESULTS: A total of 289 RNS sites in 35 patients were analyzed. An increase in systolic BP of >10 mmHg was regarded as a positive BP response to RNS. This pattern of response was observed in 180 sites (62%). 86 RNS sites (30%) showed an indifferent response with BP changes ≤10 mmHg. At 13 sites (4.5%) RNS elicited a decrease in BP up to -8 mmHg. However, 10 RNS sites (3.5%) showed a pronounced vagal response with hypotension and sinus cycle lengths ranging between 4224-10272 milliseconds. These sites were distributed among two patients. CONCLUSION: RNS identified sympathetic and parasympathetic nerve tissue in the renal arteries. RNS can be potentially used to map nerve bundles and guide selective ablation of sympathetic nerve fibers and prevent inadvertent ablation of parasympathetic nerve tissue during RDN.


Subject(s)
Aorta/innervation , Electric Stimulation , Kidney/innervation , Sympathectomy/methods , Aged , Blood Pressure , Female , Heart Rate , Humans , Hypertension , Male , Middle Aged , Renal Artery/innervation , Renal Artery/physiology , Vagus Nerve/physiology
14.
Curr Hypertens Rep ; 20(3): 24, 2018 03 19.
Article in English | MEDLINE | ID: mdl-29556850

ABSTRACT

PURPOSE OF REVIEW: Renal sympathetic denervation (RDN) as treatment option for hypertension has a strong rationale; however, variable effects on blood pressure (BP) have been reported ranging from non-response to marked reductions in BP. The absence of a procedural end point for RDN is one of the potential factors associated with the variable response. Studies have suggested the use of renal nerve stimulation (RNS) to adequately address this issue. This review aims to provide an overview of the clinical and experimental data available regarding the effects of RNS in the setting of RDN. RECENT FINDINGS: Animal studies have shown that high-frequency electrical stimulation of the sympathetic nerves in the adventitia of the renal arteries elicits an increase in BP and leads to an increased norepinephrine spillover as a marker of increased sympathetic activity and these effects of stimulation were attenuated or blunted after RDN. In a human feasibility study using RNS both before and after RDN, similar BP responses were observed. Moreover, in patients with resistant hypertension, RNS-induced changes in BP appeared to be correlated with 24-h BP response after RDN. These data suggest that RNS is a useful tool to identify renal sympathetic nerve fibers in patients with treatment-resistant hypertension undergoing RDN, and to predict the likely effectiveness of RDN treatments. In acute procedural settings both in animal and human models, RNS elicits increase in BP and HR before RDN and these effects are blunted after RDN. Up to now, there is preliminary evidence that the RNS-induced BP changes predict 24-h ABPM outcome at follow-up in patients with resistant hypertension. Of note, studies are small sized and results of large trials comparing conventional RDN to RNS-guided RDN are warranted.


Subject(s)
Blood Pressure/physiology , Electric Stimulation/methods , Hypertension/therapy , Kidney/innervation , Sympathectomy/methods , Animals , Humans , Hypertension/physiopathology , Kidney/physiopathology , Renal Artery/physiopathology , Renal Artery/surgery , Sympathetic Nervous System/physiopathology , Sympathetic Nervous System/surgery
15.
Clin Res Cardiol ; 107(7): 539-547, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29487995

ABSTRACT

BACKGROUND: Hypertension is an important, modifiable risk factor for the development of atrial fibrillation (AF). Even after pulmonary vein isolation (PVI), 20-40% experience recurrent AF. Animal studies have shown that renal denervation (RDN) reduces AF inducibility. One clinical study with important limitations suggested that RDN additional to PVI could reduce recurrent AF. OBJECTIVE: The goal of this multicenter randomized controlled study is to investigate whether RDN added to PVI reduces AF recurrence. METHODS: The main end point is the time until first AF recurrence according to EHRA guidelines after a blanking period of 3 months. Assuming a 12-month accrual period and 12 months of follow-up, a power of 0.80, a two-sided alpha of 0.05 and an expected drop-out of 10% per group, 69 patients per group are required. We plan to randomize a total of 138 hypertensive patients with AF and signs of sympathetic overdrive in a 1:1 fashion. Patients should use at least two antihypertensive drugs. Sympathetic overdrive includes obesity, exercise-induced excessive blood pressure (BP) increase, significant white coat hypertension, hospital admission or fever induced AF, tachycardia induced AF and diabetes mellitus. The interventional group will undergo PVI + RDN and the control group will undergo PVI. RESULTS: Patients will have follow-up for 1 year, and continuous loop monitoring is advocated. CONCLUSION: This randomized, controlled study will elucidate if RDN on top of PVI reduces AF recurrence.


Subject(s)
Atrial Fibrillation/surgery , Catheter Ablation/methods , Hypertension/surgery , Pulmonary Veins/surgery , Renal Artery/innervation , Sympathectomy/methods , Sympathetic Nervous System/surgery , Atrial Fibrillation/diagnosis , Atrial Fibrillation/etiology , Atrial Fibrillation/physiopathology , Catheter Ablation/adverse effects , Clinical Protocols , Europe , Humans , Hypertension/complications , Hypertension/diagnosis , Hypertension/physiopathology , Prospective Studies , Pulmonary Veins/physiopathology , Recurrence , Research Design , Risk Factors , Sympathectomy/adverse effects , Sympathetic Nervous System/physiopathology , Time Factors , Treatment Outcome
16.
J Hypertens ; 36(2): 221-229, 2018 02.
Article in English | MEDLINE | ID: mdl-29045339

ABSTRACT

BACKGROUND: Sympathetic tone is one of the main determinants of blood pressure (BP) variability and treatment-resistant hypertension. The aim of our study was to assess changes in BP variability after renal denervation (RDN). In addition, on an exploratory basis, we investigated whether baseline BP variability predicted the BP changes after RDN. METHODS: We analyzed 24-h BP recordings obtained at baseline and 6 months after RDN in 167 treatment-resistant hypertension patients (40% women; age, 56.7 years; mean 24-h BP, 152/90 mmHg) recruited at 11 expert centers. BP variability was assessed by weighted SD [SD over time weighted for the time interval between consecutive readings (SDiw)], average real variability (ARV), coefficient of variation, and variability independent of the mean (VIM). RESULTS: Mean office and 24-h BP fell by 15.4/6.6 and 5.5/3.7 mmHg, respectively (P < 0.001). In multivariable-adjusted analyses, systolic/diastolic SDiw and VIM for 24-h SBP/DBP decreased by 1.18/0.63 mmHg (P ≤ 0.01) and 0.86/0.42 mmHg (P ≤ 0.05), respectively, whereas no significant changes in ARV or coefficient of variation occurred. Furthermore, baseline SDiw (P = 0.0006), ARV (P = 0.01), and VIM (P = 0.04) predicted the decrease in 24-h DBP but not 24-h SBP after RDN. CONCLUSION: RDN was associated with a decrease in BP variability independent of the BP level, suggesting that responders may derive benefits from the reduction in BP variability as well. Furthermore, baseline DBP variability estimates significantly correlated with mean DBP decrease after RDN. If confirmed in younger patients with less arterial damage, in the absence of the confounding effect of drugs and drug adherence, baseline BP variability may prove a good predictor of BP response to RDN.


Subject(s)
Blood Pressure , Hypertension/surgery , Kidney/innervation , Sympathectomy , Blood Pressure Determination , Europe , Female , Humans , Kidney/surgery , Male , Middle Aged , Treatment Outcome
17.
BMC Psychiatry ; 17(1): 350, 2017 10 24.
Article in English | MEDLINE | ID: mdl-29065870

ABSTRACT

BACKGROUND: Compulsory admissions have a strong effect on psychiatric patients and represent a deprivation of personal liberty. Although the rate of such admissions is tending to rise in several Western countries, there is little qualitative research on the mental health-care process preceding compulsory admission. The objective of the study was to identify crucial factors in the mental health-care process preceding compulsory admission of adult psychiatric patients. METHODS: This retrospective, qualitative multiple-case study was based on the patient records of patients with severe mental illness, mainly schizophrenia and other psychotic disorders. Twenty two patient records were analyzed. Patients' demographic and clinical characteristics were heterogeneous. All were treated by Flexible Assertive Community Treatment teams (FACT teams) at two mental health institutions in the greater Rotterdam area in the Netherlands and had a compulsory admission in a predefined inclusion period. The data were analyzed according to the Prevention and Recovery System for Monitoring and Analysis (PRISMA) method, assessing acts, events, conditions, and circumstances, failing protective barriers and protective recovery factors. RESULTS: The most important patient factors in the process preceding compulsory admission were psychosis, aggression, lack of insight, care avoidance, and unauthorized reduction or cessation of medication. Neither were health-care professionals as assertive as they could be in managing early signs of relapse and care avoidance of these particular patients. CONCLUSION: The health-care process preceding compulsory admission is complex, being influenced by acts, events, conditions and circumstances, failing barriers, and protective factors. The most crucial factors are patients' lack of insight and cessation of medication, and health-care professionals' lack of assertiveness.


Subject(s)
Commitment of Mentally Ill/statistics & numerical data , Community Mental Health Services/organization & administration , Hospitals, Psychiatric/organization & administration , Mental Disorders/therapy , Adult , Female , Humans , Length of Stay , Male , Mental Disorders/psychology , Middle Aged , Netherlands , Qualitative Research , Retrospective Studies , Schizophrenia/therapy
18.
Medicine (Baltimore) ; 96(17): e6611, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28445258

ABSTRACT

Renal sympathetic nerve denervation (RDN) is accepted as a treatment option for patients with resistant hypertension. However, results on decline in ambulatory blood pressure (BP) measurement (ABPM) are conflicting. The high rate of nonresponders may be related to increased systemic vascular stiffness rather than sympathetic overdrive. A single center, prospective registry including 26 patients with treatment resistant hypertension who underwent RDN at the Isala Hospital in the Netherlands. Renal perivascular calcium scores were obtained from noncontrast computed tomography scans. Patients were divided into 3 groups based on their calcium scores (group I: low 0-50, group II: intermediate 50-1000, and group III: high >1000). The primary end point was change in 24-hour ABPM at 6 months follow-up post-RDN compared to baseline. Seven patients had low calcium scores (group I), 13 patients intermediate (group II), and 6 patients had high calcium scores (group III). The groups differed significantly at baseline in age and baseline diastolic 24-hour ABPM. At 6-month follow-up, no difference in 24-hour systolic ABPM response was observed between the 3 groups; a systolic ABPM decline of respectively -9 ±â€Š12, -6 ±â€Š12, -12 ±â€Š10 mm Hg was found. Also the decline in diastolic ambulatory and office systolic and diastolic BP was not significantly different between the 3 groups at follow-up. Our preliminary data showed that the extent of renal perivascular calcification is not associated with the ABPM response to RDN in patients with resistant hypertension.


Subject(s)
Hypertension/surgery , Kidney Diseases/diagnostic imaging , Sympathectomy , Vascular Calcification/diagnostic imaging , Blood Pressure , Blood Pressure Determination , Calcium/metabolism , Computed Tomography Angiography , Female , Follow-Up Studies , Humans , Hypertension/diagnostic imaging , Hypertension/metabolism , Kidney/blood supply , Kidney/diagnostic imaging , Kidney/innervation , Kidney/metabolism , Kidney Diseases/metabolism , Male , Middle Aged , Netherlands , Prospective Studies , Registries , Retrospective Studies , Sympathectomy/adverse effects , Treatment Outcome , Vascular Calcification/metabolism
19.
BMC Genomics ; 18(1): 287, 2017 04 11.
Article in English | MEDLINE | ID: mdl-28399811

ABSTRACT

BACKGROUND: Recently, much progress has been made in the field of gene-expression in early embryogenesis. However, the dynamic behaviour of transcriptomes in individual embryos has hardly been studied yet and the time points at which pools of embryos are collected are usually still quite far apart. Here, we present a high-resolution gene-expression time series with 180 individual zebrafish embryos, obtained from nine different spawns, developmentally ordered and profiled from late blastula to mid-gastrula stage. On average one embryo per minute was analysed. The focus was on identification and description of the transcriptome dynamics of the expressed genes in this embryonic stage, rather than to biologically interpret profiles in cellular processes and pathways. RESULTS: In the late blastula to mid-gastrula stage, we found 6,734 genes being expressed with low variability and rather gradual changes. Ten types of dynamic behaviour were defined, such as genes with continuously increasing or decreasing expression, and all expressed genes were grouped into these types. Also, the exact expression starting and stopping points of several hundred genes during this developmental period could be pinpointed. Although the resolution of the experiment was so high, that we were able to clearly identify four known oscillating genes, no genes were observed with a peaking expression. Additionally, several genes showed expression at two or three distinct levels that strongly related to the spawn an embryo originated from. CONCLUSION: Our unique experimental set-up of whole-transcriptome analysis of 180 individual embryos, provided an unparalleled in-depth insight into the dynamics of early zebrafish embryogenesis. The existence of a tightly regulated embryonic transcriptome program, even between individuals from different spawns is shown. We have made the expression profile of all genes available for domain experts. The fact that we were able to separate the different spawns by their gene-expression variance over all expressed genes, underlines the importance of spawn specificity, as well as the unexpectedly tight gene-expression regulation in early zebrafish embryogenesis.


Subject(s)
Embryonic Development/genetics , Gene Expression Profiling , Gene Expression Regulation, Developmental , Transcriptome , Zebrafish/genetics , Animals , Embryo, Nonmammalian/metabolism , Genetic Variation
20.
J Clin Hypertens (Greenwich) ; 19(4): 371-378, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28296025

ABSTRACT

Renal denervation may be more effective if performed distal in the renal artery because of smaller distances between the lumen and perivascular nerves. The authors reviewed the angiographic results of 97 patients and compared blood pressure reduction in relation to the location of the denervation. No significant differences in blood pressure reduction or complications were found between patient groups divided according to their spatial distribution of the ablations (proximal to the bifurcation in both arteries, distal to the bifurcation in one artery and distal in the other artery, or distal to the bifurcation in both arteries), but systolic ambulatory blood pressure reduction was significantly related to the number of distal ablations. No differences in adverse events were observed. In conclusion, we found no reason to believe that renal denervation distal to the bifurcation poses additional risks over the currently advised approach of proximal denervation, but improved efficacy remains to be conclusively established.


Subject(s)
Blood Pressure/physiology , Kidney/innervation , Renal Artery/surgery , Sympathectomy/methods , Aged , Female , Humans , Hypertension , Kidney/surgery , Male , Middle Aged , Netherlands
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