Promoting cardiovascular health post‐transplant through early diagnosis and adequate management of hypertension and dyslipidemia

Despite correction of underlying solid organ failure by transplantation, pediatric transplant recipients still have increased mortality rates compared to the general pediatric population, in part due to increased cardiovascular risk. In particular, pediatric kidney and non‐kidney transplant recipients with chronic kidney disease have significant cardiovascular risk that worsens with declining kidney function. Biomarkers associated with future cardiovascular risk such as casual and ambulatory hypertension, dyslipidemia, vascular stiffness and calcification, and left ventricular hypertrophy can be detected throughout the post‐transplant period and in patients with stable kidney function. Among these, hypertension and dyslipidemia are two potentially modifiable cardiovascular risk factors that are highly prevalent in kidney and non‐kidney pediatric transplant recipients. Standardized approaches to appropriate BP measurement and lipid monitoring are needed to detect and address these risk factors in a timely fashion. To achieve sustained improvement in cardiovascular health, clinicians should partner with patients and their caregivers to address these and other risk factors with a combined approach that integrates pharmacologic with non‐pharmacologic approaches. This review outlines the scope and impact of hypertension and dyslipidemia in pediatric transplant recipients, with a particular focus on pediatric kidney transplantation given the high burden of chronic kidney disease‐associated cardiovascular risk. We also review the current published guidelines for monitoring and managing abnormalities in blood pressure and lipids, highlighting the important role of therapeutic lifestyle changes in concert with antihypertensive and lipid‐lowering medications.     

PREDIRCAM eHealth Platform for Individualized Telemedical Assistance for Lifestyle Modification in the treatment of Obesity,Diabetes, and Cardiometabolic Risk Prevention: A Pilot Study (PREDIRCAM 1)

Background

Healthy diet and regular physical activity are powerful tools in reducing diabetes and cardiometabolic risk. Various international scientific and health organizations have advocated the use of new technologies to solve these problems. The PREDIRCAM project explores the contribution that a technological system could offer for the continuous monitoring of lifestyle habits and individualized treatment of obesity as well as cardiometabolic risk prevention.

Methods

PREDIRCAM is a technological platform for patients and professionals designed to improve the effectiveness of lifestyle behavior modifications through the intensive use of the latest information and communication technologies. The platform consists of a web-based application providing communication interface with monitoring devices of physiological variables, application for monitoring dietary intake, ad hoc electronic medical records, different communication channels, and an intelligent notification system. A 2-week feasibility study was conducted in 15 volunteers to assess the viability of the platform.

Results

The website received 244 visits (average time/session: 17 min 45 s). A total of 435 dietary intakes were recorded (average time for each intake registration, 4 min 42 s ± 2 min 30 s), 59 exercises were recorded in 20 heart rate monitor downloads, 43 topics were discussed through a forum, and 11 of the 15 volunteers expressed a favorable opinion toward the platform. Food intake recording was reported as the most laborious task. Ten of the volunteers considered long-term use of the platform to be feasible.

Conclusions

The PREDIRCAM platform is technically ready for clinical evaluation. Training is required to use the platform and, in particular, for registration of dietary food intake.     

No Cytomegalovirus-related Deaths After Non-ablative Stem Cell Allografts

Cytomegalovirus (CMV)-related deaths and data of clinically evident CMV disease were assessed in a group of 47 individuals given allogeneic non-myeloablative hematopoietic stem cell transplants (NST). IgG anti-CMV antibodies were found in 56% of the donors and 76% of the receptors. Prophylactic ganciclovir was given to only 12 of the recipients during 100 days after the graft. There were no CMV-related deaths and clinically overt CMV disease was not found in any individual. The follow up post-transplant period of the patients, ranges between 30 and 810 days (median 242 days), the actuarial median survival (SV) is above 810 days and has not been reached, whereas the 810-days SV is 60%. Eighteen patients (38%) died 30-480 days after the transplant; four failed to engraft and died because of progressive disease; three died as a consequence of graft versus host disease (GVHD), whereas eleven individuals had a relapse of the malignancy and died. It is possible that the reduced bone marrow damage during NST, the prompt recovery of both the hematopoiesis and immune function in this type of allografts and the use of peripheral blood hematopoietic stem cell (HSC) is responsible for the absence of CMV-related deaths and clinical disease despite a high prevalence of CMV infection in these individuals.     

Sexual Risk, Serostatus and Intimate Partner Violence Among Couples During Pregnancy in Rural South Africa

The aim of this study was to describe sexual risk behavior among 239 couples during pregnancy and to examine the relationship of sexual risk behavior with HIV serostatus and intimate partner violence. One-third (31.8 %) of pregnant women and 20.9 % of male partners were HIV positive. HIV risk factors included lack of knowledge of partners’ HIV serostatus, unprotected sexual intercourse and multiple sexual partners. Among men, multivariate logistic regression identified awareness of HIV negative partner status, multiple sexual partners and low levels of partner violence and among women Zulu or Swati ethnicity were associated with unprotected intercourse. HIV positive concordance was associated with protected sex and in multilevel analysis of couples HIV positive status and awareness of the partner’s HIV positive status were associated with protected sex. High levels of HIV risk behaviour was found among couples during pregnancy calling for HIV risk reduction interventions.     

Cascade plasma filtration during the first year after CABG in patients with hyperlipidemia refractory to statins

ObjectiveTo evaluate the effect of a 12-month course of weekly lipid apheresis on vein graft patency after coronary artery bypass grafting (CABG) in patients with hyperlipidemia refractory to statins.MethodsIn a 12-month prospective controlled clinical trial we enrolled 34 male patients (mean age 57 ± 8 years) who passed through successful CABG and low-density lipoprotein cholesterol (LDL-C) level >2.6 mmol/L prior to the operation despite statin treatment. Patients were allocated into 2 groups: active (n = 17, weekly apheresis by cascade plasma filtration (CPF) plus atorvastatin), and control (n = 17, atorvastatin alone). Graft patency was evaluated by multislice computed tomography at 3 months and by angiography at 12 months after an operation.ResultsBoth groups were comparable in clinical and biochemical characteristics. During each CPF procedure, LDL-C level decreased by 64 ± 9%, apoB – by 65 ± 8%, Lp(a) – by 52 ± 15%,; these changes were significant compared to baseline and the control group. Mean net difference in LDL-C level between apheresis and control groups was 1.1 ± 0.3 mmol/L. Vein graft patency at study end was 88.2% (45 of 51) in the apheresis group versus 72.7% (40 of 55) in the control group (p = 0.05). Use of apheresis was associated with decreased vein graft occlusions by 46%: relative risk 0.54; 95% confidence interval 0.27 to 1.02; p = 0.05.ConclusionOur data suggest that the use of lipoprotein apheresis with CPF results in a better vein graft patency during the first year after CABG in patients with hyperlipidemia refractory to statins.     

Design of a superior cytokine antagonist for topical ophthalmic use

IL-1 is a key inflammatory and immune mediator in many diseases, including dry-eye disease, and its inhibition is clinically efficacious in rheumatoid arthritis and cryopyrin-associated periodic syndromes. To treat ocular surface disease with a topical biotherapeutic, the uniqueness of the site necessitates consideration of the agent’s size, target location, binding kinetics, and thermal stability. Here we chimerized two IL-1 receptor ligands, IL-1β and IL-1Ra, to create an optimized receptor antagonist, EBI-005, for topical ocular administration. EBI-005 binds its target, IL-1R1, 85-fold more tightly than IL-1Ra, and this increase translates to an ∼100-fold increase in potency in vivo. EBI-005 preserves the affinity bias of IL-1Ra for IL-1R1 over the decoy receptor (IL-1R2), and, surprisingly, is also more thermally stable than either parental molecule. This rationally designed antagonist represents a unique approach to therapeutic design that can potentially be exploited for other β-trefoil family proteins in the IL-1 and FGF families.The IL-1 cytokines (IL-1α and IL-1β) are master mediators of inflammatory responses (1). IL-1β also regulates immune function through its role in T helper 17 (Th17) cell differentiation and maintenance (2, 3). IL-1 action has been implicated in numerous human diseases, including rheumatoid arthritis, Muckle–Wells syndrome, gout, type 2 diabetes, and stroke (4). Several natural mechanisms directly oppose the actions of IL-1, including a soluble and cell surface decoy receptor (IL-1R2), a natural antagonist (IL-1Ra), and a soluble signaling receptor (IL-1R1) (5). Therapeutics that block IL-1 based on these mechanisms have been developed (6–8).Recently, a nonoptimized formulation of anakinra (methionyl-IL-1Ra; Kineret) was shown to provide clinical benefit in dry-eye disease (DED) (9). Moderate to severe DED is a chronic inflammatory condition of the corneal surface that results in pain, discomfort, and epitheliopathy (as measured by fluorescein staining). Inability to maintain a proper tear film over the cornea (owing to a variety of etiologies) results in desiccating stress, which drives an inflammatory cascade (10, 11). IL-1 plays a central role in the initiation and maintenance of this cascade, as well as in the pain mediated by the corneal neural plexus. IL-1α and IL-1β protein are elevated in the lacrimal gland, tears, and the ocular surface in all forms of dry-eye disease (12), and their mRNA is increased in both humans and in rodent disease models (13, 14). Genetic ablation of IL-1R1, the primary receptor for IL-1α and IL-1β, can block the development of corneal staining in a Sjögren syndrome corneal epitheliopathy model (15), and topically administered anakinra can improve surface epithliopathy in a mouse dry-eye model (14). IL-1β is essential for Th17 cell differentiation and maintenance, and Th17 cells are likely the main effector cells that induce epithelial damage (2, 3). Genetic and pharmacologic studies have shown that IL-1β mediates, and IL-1Ra blocks, normal, inflammatory, and neuropathic pain sensations (16–19).The development of a topical biotherapeutic agent for DED presents a protein engineering challenge, requiring optimization for the biology and topical route of administration. Given the rapid turnover of tear volume (10% min⁻¹) (20), blocking the tissue-associated receptor would be preferred over blocking tear-associated ligands, and the agent’s target affinity should be maximized to minimize clearance and the frequency of dosing. Considering the corneal epithelial barrier, smaller molecules would be preferable, and ideally the agent would have sufficient thermal stability to allow a room temperature formulation, to optimize patient compliance. We considered two designs for small, receptor-targeted agents: improved versions of IL-1Ra (∼17 kDa) and small-format (e.g., single-chain variable fragment) anti–IL-1R1 antibodies. Both designs can be expressed in Escherichia coli, but given the straightforward isolation of anakinra as a soluble protein after E. coli expression, and the fact that the existing clinical data are from the use of anakinra, we focused on improved receptor antagonists. Here we describe the creation of a unique type of chimeric molecule that meets the foregoing criteria.     

BcsA and BcsB form the catalytically active core of bacterial cellulose synthase sufficient for in vitro cellulose synthesis

Cellulose is a linear extracellular polysaccharide. It is synthesized by membrane-embedded glycosyltransferases that processively polymerize UDP-activated glucose. Polymer synthesis is coupled to membrane translocation through a channel formed by the cellulose synthase. Although eukaryotic cellulose synthases function in macromolecular complexes containing several different enzyme isoforms, prokaryotic synthases associate with additional subunits to bridge the periplasm and the outer membrane. In bacteria, cellulose synthesis and translocation is catalyzed by the inner membrane-associated bacterial cellulose synthase (Bcs)A and BcsB subunits. Similar to alginate and poly-β-1,6 N-acetylglucosamine, bacterial cellulose is implicated in the formation of sessile bacterial communities, termed biofilms, and its synthesis is likewise stimulated by cyclic-di-GMP. Biochemical studies of exopolysaccharide synthesis are hampered by difficulties in purifying and reconstituting functional enzymes. We demonstrate robust in vitro cellulose synthesis reconstituted from purified BcsA and BcsB proteins from Rhodobacter sphaeroides. Although BcsA is the catalytically active subunit, the membrane-anchored BcsB subunit is essential for catalysis. The purified BcsA-B complex produces cellulose chains of a degree of polymerization in the range 200–300. Catalytic activity critically depends on the presence of the allosteric activator cyclic-di-GMP, but is independent of lipid-linked reactants. Our data reveal feedback inhibition of cellulose synthase by UDP but not by the accumulating cellulose polymer and highlight the strict substrate specificity of cellulose synthase for UDP-glucose. A truncation analysis of BcsB localizes the region required for activity of BcsA within its C-terminal membrane-associated domain. The reconstituted reaction provides a foundation for the synthesis of biofilm exopolysaccharides, as well as its activation by cyclic-di-GMP.Polysaccharides are essential biopolymers performing diverse biological functions, ranging from energy storage to osmoregulation and cell wall formation. Extracellular polysaccharides, including cellulose, chitin, and alginate, are synthesized inside the cell from nucleotide-activated sugars and are transported across the cell membrane during their synthesis. This remarkable task is performed by membrane-integrated glycosyltransferases (GTs) that couple polymer elongation with translocation (1, 2).Cellulose is a linear polymer of glucose molecules linked via β-1,4 glycosidic linkages (3, 4) and is primarily formed by vascular plants, but also by some algae, protists, and bacteria (4–6). Cellulose is synthesized by cellulose synthase (CesA), a family 2 member of GTs (7) that processively polymerizes UDP-activated glucose via an evolutionarily conserved mechanism (2). CesAs contain eight predicted transmembrane (TM) segments and at least one extended intracellular domain adopting a GT-A fold (2, 8). The intracellular GT-A domain is responsible for donor and acceptor sugar binding, as well as for catalyzing the GT reaction, and the membrane-embedded part forms a TM pore in close juxtaposition with the catalytic site, thereby allowing translocation of the nascent polysaccharide (2).Although most eukaryotic CesAs are believed to form supramolecular complexes that organize the secreted glucans into cable-like structures, i.e., the cellulose microfibrils (9), many Gram-negative bacteria synthesize cellulose as a biofilm component (10, 11). Biofilm formation is stimulated by the bacterial messenger cyclic-di-GMP (c-di-GMP) (12), which affects a diverse group of enzymes via interaction with either covalently or noncovalently attached c-di-GMP-binding domains, such as PilZ (13–15).Bacterial cellulose synthase (Bcs) is a multicomponent protein complex encoded in an operon containing at least three genes, bcsA, B, and C (16, 17). BcsA is the catalytic subunit that synthesizes cellulose and forms the TM pore across the inner membrane and BcsB is a large periplasmic protein that is anchored to the inner membrane via a single C-terminal TM helix. BcsB may guide the polymer across the periplasm toward the outer membrane via two carbohydrate-binding domains (CBDs) (2). BcsA and BcsB are fused into a single polypeptide chain in some species (18). BcsC is predicted to form a β-barrel in the outer membrane, preceded by a large periplasmic domain containing tetratricopeptide repeats likely involved in complex assembly (16). Most cellulose synthase operons also code for a periplasmic cellulase, BcsZ, whose biological function is unknown, yet it appears to enhance cellulose production in vivo (19, 20). Although most biofilm-forming bacteria likely produce amorphous cellulose that is embedded in a 3D matrix of polysaccharides, proteinaceous fibers, and nucleic acids (21), some bacteria produce cellulose microfibrils resembling those synthesized by eukaryotic cells (22). In such bacteria, CesA complexes are linearly arranged along the cell axis, and the CesA operons encode at least one additional subunit, BcsD, that might facilitate the linear organization of the synthases (18).Despite the numerous studies available on a large number of pro- and eukaryotic model systems, revealing the mechanism of cellulose synthesis and translocation has been hampered by difficulties in reconstituting functional CesAs in a purified system, either from eukaryotic or prokaryotic enzymes (23–26). To date, cellulose biosynthetic activities have only been recovered from detergent extracts of native membranes (24–26).To overcome these challenges, we reconstituted an active cellulose synthetic system in vitro from a purified Rhodobacter sphaeroides BcsA-B complex (27). The purified complex efficiently synthesizes amorphous, high-molecular-weight (HMW) cellulose on incubation with UDP-glucose (UDP-Glc) and c-di-GMP, both in a detergent-solubilized state and after reconstitution into proteoliposomes (PLs). We show that cellulose elongation occurs directly from UDP-Glc without lipid-linked intermediates, reveal that c-di-GMP activates the synthase, and demonstrate the strict substrate specificity of BcsA for UDP-Glc. Furthermore, we demonstrate that BcsB is crucial for the catalytic activity of BcsA and localize the region required for cellulose synthesis within BcsB’s C-terminal, membrane-associated domain that packs against the TM region of BcsA.     

Mediterranean diet habits in older individuals: Associations with cognitive functioning and brain volumes

To examine the association between dietary habits, cognitive functioning and brain volumes in older individuals, data from 194 cognitively healthy individuals who participated in the Prospective Investigation of the Vasculature in Uppsala Seniors cohort were used. At age 70, participants kept diaries of their food intake for 1 week. These records were used to calculate a Mediterranean diet (MeDi) score (comprising dietary habits traditionally found in Mediterranean countries, e.g. high intake of fruits and low intake of meat), with higher scores indicating more pronounced MeDi-like dietary habits. Five years later, participants' cognitive capabilities were examined by the seven minute screening (7MS) (a cognitive test battery used by clinicians to screen for dementia), and their brain volumes were measured by volumetric magnetic resonance imaging. Multivariate linear regression analyses were constructed to examine the association between the total MeDi score and cognitive functioning and brain volumes. In addition, possible associations between MeDi's eight dietary features and cognitive functioning and brain volumes were investigated. From the eight dietary features included in the MeDi score, pertaining to a low consumption of meat and meat products was linked to a better performance on the 7MS test (P = 0.001) and greater total brain volume (i.e. the sum of white and gray matter, P = 0.03) when controlling for potential confounders (e.g. BMI) in the analysis. Integrating all dietary features into the total MeDi score explained less variance in cognitive functioning and brain volumes than its single dietary component meat intake. These observational findings suggest that keeping to a low meat intake could prove to be an impact-driven public health policy to support healthy cognitive aging, when confirmed by longitudinal studies. Further, they suggest that the MeDi score is a construct that may mask possible associations of single MeDi features with brain health domains in elderly populations.