Cell shape regulates subcellular organelle location to control early Ca2+ signal dynamics in vascular smooth muscle cells.

The shape of the cell is connected to its function; however, we do not fully understand underlying mechanisms by which global shape regulates a cell's functional capabilities. Using theory, experiments and simulation, we investigated how physiologically relevant cell shape changes affect subcellular organization, and consequently intracellular signaling, to control information flow needed for phenotypic function. Vascular smooth muscle cells going from a proliferative and motile circular shape to a contractile fusiform shape show changes in the location of the sarcoplasmic reticulum, inter-organelle distances, and differential distribution of receptors in the plasma membrane. These factors together lead to the modulation of signals transduced by the M3 muscarinic receptor/Gq/PLCß pathway at the plasma membrane, amplifying Ca2+ dynamics in the cytoplasm, and the nucleus resulting in phenotypic changes, as determined by increased activity of myosin light chain kinase in the cytoplasm and enhanced nuclear localization of the transcription factor NFAT. Taken together, our observations show a systems level phenomenon whereby global cell shape affects subcellular organization to modulate signaling that enables phenotypic changes.

[Flank pain caused by a renal artery dissection]. / Flankpijn door een nierarteriedissectie.

BACKGROUND: A spontaneous renal artery dissection is a very rare diagnosis. The clinical presentation can vary and its course can be atypical. There are no guidelines available regarding treatment; however, the options are a conservative (medication) or interventional (radiological or surgical) approach. CASE DESCRIPTION: A 45-year-old man presented to the emergency department with hypertensive urgency after earlier episodes of flank pain. The cause appeared to be a spontaneous bilateral renal artery dissection with infarction. After a multidisciplinary consultation, the decision was made to manage the patient conservatively since symptoms had subsided, blood pressure was acceptable and renal function remained stable. Eventually, kidney function restored to normal and CT images showed almost complete recovery of the previously damaged renal parenchyma. CONCLUSION: This case demonstrates that in the event of renal artery dissection, a conservative medication policy may be a good option in clinically stable patients with non-deteriorating renal function. Timely recognition and adequate follow-up are important to prevent serious complications, such as renal ischaemia or renal infarction that could necessitate a nephrectomy.

Effect and mechanism of hydrocortisone on organ function in patients with severe burns.

INTRODUCTION: In patients with severe burns, resuscitation with large volumes of fluid is needed, partly because of an increase in capillary leakage. Corticosteroids might be beneficial by diminishing capillary leakage. This study aimed to assess in severely burned nonseptic patients whether hydrocortisone (HC) improved outcome and diminished capillary leakage. METHODS: Retrospective analyses of a prospectively collected database were performed, including 39 patients (age 52 [35-62] years, 72% male). Patients were divided based on HC therapy. First, in patients in whom HC was started late, that is when deteriorating (late; 5-12 days postburn) data before and after start of HC were compared. Second, patients in whom HC was started day 0 or 1 postburn (upfront; within 48 hours) were compared with patients who did not receive HC (control). Outcome was assessed as organ dysfunction by Denver Multiple Organ Failure (MOF) score and Sequential Organ Failure Assessment (SOFA) score. As markers for capillary leakage and hydration state, proteinuria, B-type natriuretic peptide (BNP), and fluid administration were assessed. Follow-up was 20 days postburn. Possible adverse effects including mortality were recorded. Repeated measurement regression analyses were performed using MLwiN. RESULTS: In the late group, Denver MOF and SOFA scores significantly decreased after HC (P<.001). Proteinuria tended to decrease (P=.13), BNP increased on the days HC was used (P<.001), and amounts of fluids diminished (P<.001). In the upfront vs control group, Denver MOF and SOFA scores (P<.001) decreased more quickly. Proteinuria (P=.006) and administered fluids decreased more rapidly (P<.001). Mortality rate, numbers of positive blood cultures, incidence of pneumonia, and graft loss were similar in all groups. CONCLUSIONS: Hydrocortisone treatment in severe burned patients without sepsis might improve organ dysfunction possibly because of a reduction in capillary leakage, as reflected by a decrease of proteinuria, an increase of BNP, and diminished fluid resuscitation volumes.

F-actin remodeling defects as revealed in primary immunodeficiency disorders.

Primary immunodeficiencies (PIDs) are a heterogeneous group of immune-related diseases. PIDs develop due to defects in gene-products that have consequences to immune cell function. A number of PID-proteins is involved in the remodeling of filamentous actin (f-actin) to support the generation of a contact zone between the antigen-specific T cell and antigen presenting cell (APC): the immunological synapse (IS). IS formation is the first step towards T-cell activation and essential for clonal expansion and acquisition of effector function. We here evaluated PIDs in which aberrant f-actin-driven IS formation may contribute to the PID disease phenotypes as seen in patients. We review examples of such contributions to PID phenotypes from literature, and highlight cases in which PID-proteins were evaluated for a role in f-actin polymerization and IS formation. We conclude with the proposition that patient groups might benefit from stratifying them in distinct functional groups in regard to their f-actin remodeling phenotypes in lymphocytes.

Increased prevalence of gastrointestinal viruses and diminished secretory immunoglobulin a levels in antibody deficiencies.

PURPOSE: Gastrointestinal disease occurs frequently in antibody deficiencies. This study aims to explore the relation between gastrointestinal infections and mucosal homeostasis in patients with antibody deficiencies. METHODS: We performed an observational study including 54 pediatric antibody deficient patients (48 % CVID, 41 % CVID-like, 11 % XLA) and 66 healthy controls. Clinical symptom scores and stool samples were collected prospectively. Stool samples were evaluated for bacteria, parasites, viruses, secretory IgA- and for calprotectin levels. Results were compared between patients and controls. RESULTS: 24 % of antibody deficient patients versus 9 % of healthy controls tested positive for gastrointestinal viruses (p = 0.028). Fecal calprotectin levels were significantly higher in virus positive patients compared to virus negative patients (p = 0.002). However, in controls, fecal calprotectin levels were similar between virus positive and virus negative controls. Moreover, gastrointestinal virus positive patients had low serum IgA levels in 13/14 cases (94 %) versus 40/62 (62 %) patients in the virus negative patient group (p = 0.04). The virus positive patient group also displayed significantly lower secretory IgA levels in stool (median 13 ug/ml) than patients without gastrointestinal viruses detected or healthy controls (median 155 ug/ml) (p = 0.046). CONCLUSION: We here report an increased prevalence of gastrointestinal viruses and gastrointestinal complaints in antibody deficient patients. Patients that tested positive for gastrointestinal viruses showed diminished serum- and secretory IgA levels, and only in patients, virus positivity was associated with signs of mucosal inflammation. These findings suggest that particularly patients with low IgA are at risk for longstanding replication of gastrointestinal viruses, which may eventually result in CVID-related enteropathy.

c-Myc-dependent transcriptional regulation of cell cycle and nucleosomal histones during oligodendrocyte differentiation.

Oligodendrocyte progenitor cells (OPCs) have the ability to divide or to growth arrest and differentiate into myelinating oligodendrocytes in the developing brain. Due to their high number and the persistence of their proliferative capacity in the adult brain, OPCs are being studied as potential targets for myelin repair and also as a potential source of brain tumors. This study addresses the molecular mechanisms regulating the transcriptional changes occurring at the critical transition between proliferation and cell cycle exit in cultured OPCs. Using bioinformatic analysis of existing datasets, we identified c-Myc as a key transcriptional regulator of this transition and confirmed direct binding of this transcription factor to identified target genes using chromatin immunoprecipitation. The expression of c-Myc was elevated in proliferating OPCs, where it also bound to the promoter of genes involved in cell cycle regulation (i.e. Cdc2) or chromosome organization (i.e. H2afz). Silencing of c-Myc was associated with decreased histone acetylation at target gene promoters and consequent decrease of gene transcripts. c-Myc silencing also induced a global increase of repressive histone methylation and premature peripheral nuclear chromatin compaction while promoting the progression towards differentiation. We conclude that c-Myc is an important modulator of the transition between proliferation and differentiation of OPCs, although its decrease is not sufficient to induce progression into a myelinating phenotype.

Volume control in treatment-resistant congestive heart failure: role for peritoneal dialysis.

Chronic congestive heart failure (HF) has a rising prevalence and increasing impact on health care systems. Current treatment consists of diuretics, renin-angiotensin-aldosterone system blockers, and restriction of salt and fluids. This strategy is often hampered by a drop in effective circulating volume and hence renal perfusion and function, triggering harmful counter regulatory mechanisms. Slow ultrafiltration by peritoneal dialysis (PD) might be an effective treatment strategy to relieve fluid overload without compromising cardiac output and thereby renal function. In this review, we discuss the (patho)physiological mechanisms of the cardiorenal interaction and the current literature on PD strategies in congestive HF.

Continuously delivered ovarian steroids do not alter dendritic spine density or morphology in macaque dorsolateral prefrontal cortical neurons.

Aged ovariectomized (OVX) female monkeys, a model for menopause in humans, show a decline in spine density in the dorsolateral prefrontal cortex (dlPFC) and diminished performance in cognitive tasks requiring this brain region. Previous studies in our laboratory have shown that long-term cyclic treatment with 17ß-estradiol (E) produces an increase in spine density and in the proportion of thinner spines in layer III pyramidal neurons in the dlPFC of both young and aged OVX rhesus monkeys. Here we used 3D reconstruction of Lucifer yellow-loaded neurons to investigate whether clinically relevant schedules of hormone therapy would produce similar changes in prefrontal cortical neuronal morphology as long-term cyclic E treatment in young female monkeys. We found that continuously delivered E, with or without a cyclic progesterone treatment, did not alter spine density or morphology in the dlPFC of young adult OVX rhesus monkeys. We also found that the increased density of thinner spines evident in the dlPFC 24h after E administration in the context of long-term cyclic E therapy is no longer detectable 20days after E treatment. When compared with the results of our previously published investigations, our results suggest that cyclic fluctuations in serum E levels may cause corresponding fluctuations in the density of thin spines in the dlPFC. By contrast, continuous administration of E does not support sustained increases in thin spine density. Physiological fluctuations in E concentration may be necessary to maintain the morphological sensitivity of the dlPFC to E.

Impact of the physical environment of psychiatric wards on the use of seclusion.

BACKGROUND: The physical environment is presumed to have an effect on aggression and also on the use of seclusion on psychiatric wards. Multicentre studies that include a broad variety of design features found on psychiatric wards and that control for patient, staff and general ward characteristics are scarce. AIMS: To explore the effect of design features on the risk of being secluded, the number of seclusion incidents and the time in seclusion, for patients admitted to locked wards for intensive psychiatric care. METHOD: Data on the building quality and safety of psychiatric as well as forensic wards (n = 199) were combined with data on the frequency and type of coercive measures per admission (n = 23 868 admissions of n = 14 834 patients) on these wards, over a 12-month period. We used non-linear principal components analysis (CATPCA) to reduce the observed design features into a smaller number of uncorrelated principal components. Two-level multilevel (logistic) regression analyses were used to explore the relationship with seclusion. Admission was the first level in the analyses and ward was the second level. RESULTS: Overall, 14 design features had a significant effect on the risk of being secluded during admission. The 'presence of an outdoor space', 'special safety measures' and a large 'number of patients in the building' increased the risk of being secluded. Design features such as more 'total private space per patient', a higher 'level of comfort' and greater 'visibility on the ward', decreased the risk of being secluded. CONCLUSIONS: A number of design features had an effect on the use of seclusion and restraint. The study highlighted the need for a greater focus on the impact of the physical environment on patients, as, along with other interventions, this can reduce the need for seclusion and restraint.

Differences in seclusion rates between admission wards: does patient compilation explain?

Comparison of seclusion figures between wards in Dutch psychiatric hospitals showed substantial differences in number and duration of seclusions. In the opinion of nurses and ward managers, these differences may predominantly be explained by differences in patient characteristics, as these are expected to have a large impact on these seclusion rates. Nurses assume more admissions of severely ill patients are related to higher seclusion rates. In order to test this hypothesis, we investigated differences in patient and background characteristics of 718 secluded patients over 5,097 admissions on 29 different admission wards over seven Dutch psychiatric hospitals. We performed an extreme group analysis to explore the relationship between patient and ward characteristics and the wards' number of seclusion hours per 1,000 admission hours. In a multivariate and a multilevel analysis, various characteristics turned out to be related to the number of seclusion hours per 1,000 admission hours as well as to the likelihood of a patient being secluded, confirming the nurses assumptions. The extreme group analysis showed that seclusion rates depended on both patient and ward characteristics. A multivariate and multilevel analyses revealed that differences in seclusion hours between wards could partially be explained by ward size next to patient characteristics. However, the largest deal of the difference between wards in seclusion rates could not be explained by characteristics measured in this study. We concluded ward policy and adequate staffing may, in particular on smaller wards, be key issues in reduction of seclusion.

Apheresis and transplant of hematopoietic progenitor cells (HPC) from allogeneic donors of age above 60 years.

Over the immediate past 4 years, our program has collected hematopoietic progenitor cells by apheresis from 48 individuals aged 61 and over (range 61-71 years of age). We have retrospectively analyzed the collection and transplant results associated with employing these donors, and have compared them with 175 donors aged 60 or less who were collected during the same time period. We have found no significant difference in venous access (P = 0.208), rate of post-transplant engraftment of neutrophils (P = 0.117) and platelets (P = 0.692), or in rate and grade of acute GVHD (P = 0.806). However, we have found that these older donors have a significantly lower mobilization of CD34 + cells as reflected in lower absolute counts of circulating CD34 + cells pre-apheresis (P = 0.016). This, in turn, results in lower CD34 + cell yields in apheresis products (P < 0.001), trending towards requiring more apheresis procedures (22.9 vs 13.7%, P = 0.095) to collect sufficient CD34 + cells for transplantation. We conclude that it is practical when necessary to employ donors aged 60 and above, as well as safe for both donor and intended recipient. However, concern over reduced CD34 + cell mobilization may be sufficient grounds to seek younger donors when possible.

Methodological issues in monitoring the use of coercive measures.

PURPOSE: In many European countries, initiatives have emerged to reduce the use of seclusion and restraint in psychiatric institutions. To study the effects of these initiatives at a national and international level, consensus on definitions of coercive measures, assessment methods and calculation procedures of these coercive measures are required. The aim of this article is to identify problems in defining and recording coercive measures. The study contributes to the development of consistent comparable measurements definitions and provides recommendations for meaningful data-analyses illustrating the relevance of the proposed framework. METHODS: Relevant literature was reviewed to identify various definitions and calculation modalities used to measure coercive measures in psychiatric inpatient care. Figures on the coercive measures and epidemiological ratios were calculated in a standardized way. To illustrate how research in clinical practice on coercive measures can be conducted, data from a large multicenter study on seclusion patterns in the Netherlands were used. RESULTS: Twelve Dutch mental health institutes serving a population of 6.57 million inhabitants provided their comprehensive coercion measure data sets. In total 37 hospitals and 227 wards containing 6812 beds were included in the study. Overall seclusion and restraint data in a sample of 31,594 admissions in 20,934 patients were analyzed. Considerable variation in ward and patient characteristics was identified in this study. The chance to be exposed to seclusion per capita inhabitants of the institute's catchment areas varied between 0.31 and 1.6 per 100.000. Between mental health institutions, the duration in seclusion hours per 1000 inpatient hours varied from less than 1 up to 18h. The number of seclusion incidents per 1000 admissions varied between 79 up to 745. The mean duration of seclusion incidents of nearly 184h may be seen as high in an international perspective. CONCLUSION: Coercive measures can be reliably assessed in a standardized and comparable way under the condition of using clear joint definitions. Methodological consensus between researchers and mental health professionals on these definitions is necessary to allow comparisons of seclusion and restraint rates. The study contributes to the development of international standards on gathering coercion related data and the consistent calculation of relevant outcome parameters.

B-type natriuretic peptide and interdialytic fluid retention are independent and incremental predictors of mortality in hemodialysis patients.

AIM: Management of fluid homeostasis remains a major challenge in hemodialysis patients. We aimed to establish whether the cardiac strain marker B-type natriuretic peptide (BNP) could help to identify hypervolemic patients at increased risk of death. METHODS: BNP levels were determined before dialysis in the entire HD population at our institution (n = 57). IDWG and BNP were stratified above or below 1.5 kg or the median value, respectively. All patients were prospectively followed for 35 months. The influence of IDWG and BNP on mortality was assessed with a Cox proportional hazards model, adjusted for each other, as well as for demographics, comorbidities, cardiac function, residual diuresis, dialysis duration and efficiency and complications of renal failure. RESULTS: Median BNP was 303 (135 - 692) and 21 (36%) patients displayed an average IDWG below 1.5 kg. During follow up a total of 25 (44%) patients died, 5 (26%) in the low IDWG group and 20 (53%) in the high IDWG group (adjusted hazard ratio (adjusted HR) 5.31 95% CI (1.47 - 19.1), p = 0.011). In the low BNP group 7 (25%) patients died and in the high BNP Group 18 (62%) patients died (adjusted HR 3.53 95 CI (1.37 - 9.09), p = 0.009). When both factors were considered simultaneously, patients with low BNP and low IDWG had an 11 times lower risk of death compared to patients with high BNP and high IDWG (HR. 0.08 95% CI (0.01 - 0.6129, p = 0.015). CONCLUSIONS: BNP and IDWG are independent and incremental predictors of mortality in HD patients. These findings suggest that BNP guided fluid management could improve survival in these patients.

Interactive effects of age and estrogen on cortical neurons: implications for cognitive aging.

In the past few decades it has become clear that estrogen signaling plays a much larger role in modulating the cognitive centers of the brain than previously thought possible. We have developed a nonhuman primate (NHP) model to investigate the relationships between estradiol (E) and cognitive aging. Our studies of cyclical E treatment in ovariectomized (OVX) young and aged rhesus monkeys have revealed compelling cognitive and synaptic effects of E in the context of aging. Delayed response (DR), a task that is particularly dependent on integrity of dorsolateral prefrontal cortex (dlPFC) area 46 revealed the following: (1) that young OVX rhesus monkeys perform equally well whether treated with E or vehicle (V), and (2) that aged OVX animals given E perform as well as young adults with or without E, whereas OVX V-treated aged animals display significant DR impairment. We have analyzed the structure of layer III pyramidal cells in area 46 in these same monkeys. We found both age and treatment effects on these neurons that are consistent with behavioral data. Briefly, reconstructions of pyramidal neurons in area 46 from these monkeys showed that cyclical E increased the density of small, thin spines in both young and aged monkeys. However, this effect of E was against a background of age-related loss of small, thin spines, leaving aged V-treated monkeys with a particularly low density of these highly plastic spines, and vulnerable to cognitive decline. Our current interpretation is that E not only plays a critically important role in maintaining spine number, but also enables synaptic plasticity through a cyclical increase in small highly plastic spines that may be stabilized in the context of learning. Interestingly, recent studies demonstrate that chronic E is less effective at inducing spinogenesis than cyclical E. We have begun to link certain molecular attributes of excitatory synapses in area 46 to E effects and cognitive performance in these monkeys. Given the importance of synaptic estrogen receptor α (ER-α) in rat hippocampus, we focused our initial studies on synaptic ER-α in area 46. Three key findings have emerged from these studies: (1) synaptic ER-α is present in axospinous synapses in area 46; (2) it is stable across treatment and age groups (which is not the case in rat hippocampus); and (3) the abundance and distribution of synaptic ER-α is a key correlate of individual variation in cognitive performance in certain age and treatment groups. These findings have important implications for the design of hormone treatment strategies for both surgically and naturally menopausal women. This article is part of a Special Issue entitled: Neuroactive Steroids: Focus on Human Brain.

High prevalence of short-chain acyl-CoA dehydrogenase deficiency in the Netherlands, but no association with epilepsy of unknown origin in childhood.

Short-chain acyl-CoA dehydrogenase deficiency (SCADD) is an autosomal recessive inborn error of metabolism, most frequently associated with developmental delay and/or epilepsy. Most SCADD patients carry common SCAD-encoding gene ( ACADS) variants or these variants in combination with a rare ACADS mutation, in the Netherlands predominantly the c.1058C>T. Epilepsy in childhood often remains unexplained and patients with epilepsy related to SCADD may remain undiagnosed because studies for SCADD are often not performed. To test this hypothesis and to further estimate the extent of the Dutch SCADD population, we performed a study on blood spot samples in 131 paediatric patients with epilepsy and 909 anonymous newborns and investigated the presence of the 2 common ACADS variants and the rare c.1058C>T mutation. Overall, the 2 common ACADS variants and the rare c.1058C>T mutation were detected in either homozygous or compound heterozygous forms in 9.2% of the epilepsy and 7.5% of the reference group. A birth prevalence of SCADD with a mutation/variant genotype in the Netherlands as high as >1:1,000 was calculated. This is in contrast with the low number of patients diagnosed clinically and supports the hypothesis that SCADD is clinically irrelevant. Furthermore our study does not support an association between SCADD and epilepsy.

Inflammation, immunological reaction and role of infection in pulmonary hypertension.

Inflammation underlies a wide variety of physiological and pathological processes. Acute inflammation is the initial response of the body to harmful stimuli. Chronic inflammation, by contrast, is a prolonged, dysregulated and maladaptive response that involves active inflammation, tissue destruction and attempts at tissue repair. Over the past few years, such persistent inflammation has been shown to be associated with pulmonary hypertension (PH). Substantial advances in basic and experimental science have illuminated the role of inflammation and the underlying cellular and molecular mechanisms that contribute to PH. This review summarizes the experimental and clinical evidence for inflammation in various types of PH. In addition, it assesses the current state of knowledge regarding the inducers/triggers of chronic inflammation and infection, as well as the inflammatory mediators and cells that are involved in PH. Infiltration of inflammatory cells, such as dendritic cells, macrophages, mast cells, T-lymphocytes and B-lymphocytes, in the vascular lesions and an elevation of serum/tissue concentrations of proinflammatory cytokines and chemokines and their contribution to pulmonary vascular remodelling are reported in detail. We review the data supporting the use of inflammatory markers as prognostic and predictive factors in PH. Finally, we consider how new insights into inflammation in PH may identify innovative therapeutic strategies.