Risk Factors Associated with Incident Vertebral Fractures in Steroid-treated Males with Duchenne Muscular Dystrophy.

PURPOSE: Prevention of fractures is an unmet need in glucocorticoid (GC)-treated Duchenne muscular dystrophy. This study explored factors associated with incident vertebral fractures (VFs) to inform future fracture prevention efforts. METHODS: VFs were evaluated prospectively at study baseline and 12 months on lateral spine radiographs in participants aged 4 to 25 years with Duchenne muscular dystrophy. Clinical factors were analyzed for their association with the change in Spinal Deformity Index (sum of the Genant-defined VF grades from T4 to L4) between baseline and 12 months. RESULTS: Thirty-eight males were evaluated (mean ± SD age at baseline 11.0 ± 3.6 years; mean ± SD GC duration at baseline 4.1 ± 3.1 years; 74% ambulatory). Nine of 38 participants (24%) had 17 incident VFs, of which 3/17 VFs (18%) were moderate/severe. Participants with 12-month incident VF had lower mean ± SD baseline lumbar spine areal bone mineral density Z-scores (-2.9 ± 1.0 vs -1.9 ± 1.1; P = .049) and lower total body less head areal bone mineral density Z-scores (-3.1 ± 1.2 vs -1.6 ± 1.7; P = .036). Multivariable linear regression showed that at least 1 VF at baseline (P < .001), a higher number of antecedent non-VF (P < .001), and greater bone age delay at baseline (P = .027) were significant predictors of an increase in the Spinal Deformity Index from baseline to 12 months. CONCLUSION: The observation that ≥ 1 prevalent VF and/or non-VF were the strongest predictors of incident VFs at 12 months supports the need for prevention of first fractures in this high-risk setting. Bone age delay, a marker of GC exposure, may assist in the prioritization of patients in efforts to prevent first fractures.

RANKL Inhibition Reduces Cardiac Hypertrophy in mdx Mice and Possibly in Children with Duchenne Muscular Dystrophy.

Cardiomyopathy has become one of the leading causes of death in patients with Duchenne muscular dystrophy (DMD). We recently reported that the inhibition of the interaction between the receptor activator of nuclear factor κB ligand (RANKL) and receptor activator of nuclear factor κB (RANK) significantly improves muscle and bone functions in dystrophin-deficient mdx mice. RANKL and RANK are also expressed in cardiac muscle. Here, we investigate whether anti-RANKL treatment prevents cardiac hypertrophy and dysfunction in dystrophic mdx mice. Anti-RANKL treatment significantly reduced LV hypertrophy and heart mass, and maintained cardiac function in mdx mice. Anti-RANKL treatment also inhibited NFκB and PI3K, two mediators implicated in cardiac hypertrophy. Furthermore, anti-RANKL treatment increased SERCA activity and the expression of RyR, FKBP12, and SERCA2a, leading possibly to an improved Ca2+ homeostasis in dystrophic hearts. Interestingly, preliminary post hoc analyses suggest that denosumab, a human anti-RANKL, reduced left ventricular hypertrophy in two patients with DMD. Taken together, our results indicate that anti-RANKL treatment prevents the worsening of cardiac hypertrophy in mdx mice and could potentially maintain cardiac function in teenage or adult patients with DMD.

Mitigating the Denosumab-Induced Rebound Phenomenon with Alternating Short- and Long-Acting Anti-resorptive Therapy in a Young Boy with Severe OI Type VI.

Osteogenesis imperfecta (OI) type VI, a recessively inherited form of OI caused by mutations in SERPINF1, is a severe form distinguished by osteomalacia on bone histomorphometry. We describe a boy with severe OI type VI who was initially treated with intravenous (IV) zoledronic acid (ZA) at 1.4 years of age; however, a year later he transitioned to denosumab 1 mg/kg sub-cutaneously every three months in an effort to decrease fracture rates. After two years on denosumab, he presented with symptomatic hypercalcemia due to the denosumab-induced, hyper-resorptive rebound phenomenon. Laboratory parameters at the time of the rebound were as follows: elevated serum ionized calcium (1.62 mmol/L, N 1.16-1.36), elevated serum creatinine due to hypercalcemia-induced muscle catabolism (83 µmol/L, N 9-55), and suppressed parathyroid hormone (PTH) (< 0.7 pmol/L, N 1.3-5.8). The hypercalcemia was responsive to low-dose IV pamidronate, with a rapid decline in serum ionized calcium, and otherwise normalization of the aforementioned parameters within 10 days. To benefit from the powerful, albeit short-term, anti-resorptive effect of denosumab without further rebound episodes, he was treated thereafter with denosumab 1 mg/kg alternating every three months with IV ZA 0.025 mg/kg. Five years later, he remained on dual alternating anti-resorptive therapy without further rebound episodes, and an overall improvement in his clinical status. This novel pharmacological approach of alternating short- and long-term anti-resorptive therapy every three months has not previously been described. Our report suggests this strategy may be an effective method for prevention of the rebound phenomenon in select children for whom denosumab may be beneficial.

Risk factors associated with prevalent vertebral fractures in Duchenne muscular dystrophy.

Patients with Duchenne muscular dystrophy (DMD) have a high fracture burden due to progressive myopathy and steroid-induced osteoporosis. This study in males with DMD showed that markers of systemic glucocorticoid exposure including shorter stature, greater bone age delay, and lower lumbar spine bone mineral density were associated with spine fragility. INTRODUCTION: Fragility  fractures are frequent in DMD. The purpose of this study was to identify clinical factors associated with prevalent vertebral fractures (VF) in boys, teens/young adults with Duchenne muscular dystrophy (DMD). METHODS: This was a cross-sectional study of males aged 4-25 years with DMD. VF were evaluated using the modified Genant semi-quantitative method on T4-L4 lateral spine radiographs. Areal bone mineral density (aBMD) was measured at the lumbar spine (LS) and used to estimate volumetric BMD (vBMD). Clinical factors were analyzed for their association with the Spinal Deformity Index (SDI, the sum of the Genant grades). RESULTS: Sixty participants were enrolled (mean age 11.5 years, range 5.4-19.5). Nineteen participants (32%) had a total of 67 VF; 23/67 VF (34%) were moderate or severe. Participants with VF were shorter (mean height Z-score ± standard deviation: - 3.1 ± 1.4 vs. - 1.8 ± 1.4, p = 0.001), had longer glucocorticoid exposure (mean duration 6.0 ± 3.3 vs. 3.9 ± 3.3 years, p = 0.027), greater bone age (BA) delay (mean BA to chronological age difference - 3.2 ± 3.4 vs. - 1.3 ± 1.2 years, p = 0.035), and lower LSaBMD Z-scores (mean - 3.0 ± 1.0 vs. - 2.2 ± 1.2, p = 0.023). There was no difference in LSvBMD Z-scores. Multivariable Poisson regression showed that every 0.1 mg/kg/day increment in average glucocorticoid daily dose was associated with a 1.4-fold SDI increase (95% confidence interval: 1.1-1.7, p = 0.013). Greater BA delay (p < 0.001), higher weight Z-score (p = 0.004), decreased height Z-score (p = 0.025), and lower LSvBMD Z-score (p = 0.025) were also associated with SDI increase. CONCLUSION: Readily measurable clinical variables were associated with prevalent VF in males with glucocorticoid-treated DMD. These variables may be useful to identify candidates for primary osteoporosis prevention after glucocorticoid initiation.

Dominant osteogenesis imperfecta with low bone turnover caused by a heterozygous SP7 variant.

Mutations in SP7 (encoding osterix) have been identified as a rare cause of recessive osteogenesis imperfecta ('OI type XII') and in one case of dominant juvenile Paget's disease. We present the first description of young adult siblings with OI due to a unique heterozygous mutation in SP7. The phenotype was characterized by fragility fractures (primarily of the long bone diaphyses), poor healing, scoliosis, and dental malocclusion. Both siblings had very low cortical volumetric bone mineral density on peripheral quantitative computed tomography of the radius (z-scores -6.6 and - 6.7 at the diaphysis), porous cortices, and thin cortices at the radial metaphysis. Histomorphometry demonstrated thin cortices and low bone turnover with reduced osteoblast function. Both siblings were heterozygous for a missense variant affecting a highly conserved zinc finger domain of osterix (c.1019A > C; p.Glu340Ala) on DNA sequencing. Co-transfection of plasmids carrying the SP7 mutation with DLX5 and a luciferase reporter demonstrated that this variant impacted gene function (reduced transcription co-activation compared to wild-type SP7). The low cortical density and cortical porosity seen in our patients are consistent with previous reports of individuals with SP7 mutations. However, the low bone turnover in our patients contrasts with the high turnover state seen in previously reported patients with SP7 mutations. This report indicates that dominant variants in SP7 can give rise to OI. The predominant feature, low cortical density, is common in patients with other SP7 mutations, however other features appear to depend on the specific variant.

A real-world experience of subcutaneous and transvenous implantable cardiac defibrillators-comparison with the PRAETORIAN study.

Background: PRAETORIAN is the first randomized controlled trial that demonstrated the noninferiority of subcutaneous ICD (S-ICD) in comparison with transvenous ICD (TV-ICD). We retrospectively reviewed electronic records of patients with ICD implanted over the past 6 years, with the primary objective to compare our real-world single tertiary center experience with the randomized data from the PRAETORIAN study. Methods: Seventy S-ICD patients were compared with 197 TV-ICD patients, from July 2014 to June 2020 retrospectively, over a median period of 1304 days (296-2451 days). Primary composite endpoints included inappropriate shocks and device-related malfunctions. Results: Patients with S-ICD implantation were younger than those who received TV-ICD (mean, 49.7 years vs 63.9 years, p < .001). About 31.4% of S-ICDs were implanted for secondary prevention, and 58.6% of S-ICD patients had ischemic cardiomyopathy (ICM) with a median left ventricular ejection fraction of 32.5% (range: 10-67%). S-ICDs and TV-ICD had statistically similar inappropriate shocks (4.3% vs 4.6%, p = .78), device-related complications (11.4% vs 9.1%, p = .93), and the overall primary endpoints (15.7% vs 13.7%, p = .68). The findings remained the same even after age and gender adjustments and time-dependent analysis. Conclusion: Although single-center experience with a small number of S-ICD patients, results of the PRAETORIAN study has been replicated in our real-world experience of S-ICD and TV-ICD implantations across diverse etiologies, indications, and age groups confirming the comparable performance of S-ICD and TV-ICD when implanted in selected patients.

Sodium bisulfite pyrosequencing revealed that developmental exposure to environmental contaminant mixtures does not affect DNA methylation of DNA repeats in Sprague-Dawley rats.

Hypomethylation of DNA repeats has been linked to diseases and cancer predisposition. Human studies suggest that higher blood concentrations of environmental contaminants (EC) correlate with levels of hypomethylation of DNA repeats in blood. The objective of this study was to examine the effect of in utero and/or lactational exposure to EC on the methylation of DNA repeats (LINE-1 and identifier element) in Sprague-Dawley rat pups at birth, at postnatal day (PND) 21, and in adulthood (PND78-86). From gestation day 0 to PND20, dams were exposed to a mixture "M" of polychlorinated biphenyls (PCB), pesticides, and methylmercury (MeHg), at 0.5 or 1 mg/kg/d (0.5M and M). At birth, some control (C) and M litters were cross-fostered to create the following in utero/postnatal exposure groups: C/C, M/C, C/M, M/M. Additional dams received 1.8 ng/kg/d of a mixture of aryl-hydrocarbon receptor (AhR) agonists (non-ortho-PCB, PC-dibenzodioxins, and PC-dibenzofurans) without or with 0.5M (0.5MAhR). Measurements of EC residue levels confirmed differences in their accumulation across treatments, age, and tissues. Although induction of hepatic detoxification enzyme activities (cytochrome P-450) demonstrated biological effects of treatments, the assessment of methylation in DNA repeats by sodium bisulfite pyrosequencing of liver, spleen, and thymus samples revealed no marked treatment-related effects but significant tissue- and age-related methylation differences. Further studies are required to determine whether absence of significant observable treatment effects on methylation of DNA repeats in the rat relate to tissue, strain, or species differences.

Direct detection of endogenous MicroRNAs and their post-transcriptional modifications in cancer serum by capillary electrophoresis-mass spectrometry.

MicroRNA molecules (miRNAs) are a class of small, single-stranded, non-coding RNA molecules that regulate cellular messenger RNA and their corresponding proteins. Extracellular miRNAs circulate in the bloodstream inside exosomes or in complexes with proteins and lipoproteins. The miRNA sequences and their quantitative levels are used as unique signatures associated with cancer diagnosis and prognosis after anticancer treatment. MicroRNAs are modified through a series of processing events after transcription like 5'-end phosphorylation, 3'- end adenylation or uridylation, terminal nucleotide deletion. The problem is that existing bioanalytical methods such as microarrays and a quantitative polymerase chain reaction are sensitive, but not capable of identifying the post-transcriptional modifications of miRNA. Here we report a capillary electrophoresis-mass spectrometry (CE-MS) method, which performs a multiplex, direct analysis of miRNAs from biological samples. Using the CE-MS method, we detected two endogenous human circulating miRNAs, a 23-nucleotide long 5'-phosporylated miRNA with 3'-uridylation (iso-miR-16-5p), and a 22-nucleotide long 5'-phosporylated miRNA (miR-21-5p) isolated from B-cell chronic lymphocytic leukemia serum. The CE separation and following MS analysis provides label-free quantitation and reveals modifications of miRNAs. MicroRNA profiling of serum samples with CE-MS has the potential to be a versatile and minimally invasive bioassay that could lead to better clinical diagnostics and disease treatment.

Protein electrocatalysis for direct sensing of circulating microRNAs.

MicroRNAs (miRNAs) are potentially useful biomarkers for diagnosis, classification, and prognosis of many diseases, including cancer. Herein, we developed a protein-facilitated electrocatalytic quadroprobe sensor (Sens(PEQ)) for detection of miRNA signature of chronic lymphocytic leukemia (CLL) in human serum. The developed signal-ON sensor provides a compatible combination of two DNA adaptor strands modified with four methylene blue molecules and electrocatalysis using glucose oxidase in order to enhance the overall signal gain. This enhanced sensitivity provided the response necessary to detect the low-abundant serum miRNAs without preamplification. The developed Sens(PEQ) is exquisitely sensitive to subtle π-stack perturbations and capable of distinguishing single base mismatches in the target miRNA. Furthermore, the developed sensor was employed for profiling of three endogenous miRNAs characteristic to CLL, including hsa-miR-16-5p, hsa-miR-21-5p, and hsa-miR-150-5p in normal healthy serum, chronic lymphocytic leukemia Rai stage 1 (CLL-1), and stage 3 (CLL-3) sera, using a non-human cel-miR-39-3p as an internal standard. The sensor results were verified by conventional SYBR green-based quantitative reverse-transcription polymerase chain reaction (RT-qPCR) analysis.

A young pregnant woman with spontaneous carotid artery dissection--unknown mechanisms.

Spontaneous carotid artery dissection in pregnancy has not been reported before. We present a case of a 31-year-old Caucasian woman who was 11 weeks pregnant and presented with neck pain, headache, vomiting and left side Horner's syndrome. Subsequent investigations with MR angiography confirmed spontaneous left internal carotid artery dissection.

Conformational Dynamics of DNA G-Quadruplex in Solution Studied by Kinetic Capillary Electrophoresis Coupled On-line with Mass Spectrometry.

G-quadruplex-forming DNA/RNA sequences play an important role in the regulation of biological functions and development of new anticancer and anti-aging drugs. In this work, we couple on-line kinetic capillary electrophoresis with mass spectrometry (KCE-MS) to study conformational dynamics of DNA G-quadruplexes in solution. We show that peaks shift and its widening in KCE can be used for measuring rate and equilibrium constants for DNA-metal affinity interactions and G-quadruplex formation; and ion mobility mass spectrometry (IM-MS) provides information about relative sizes, absolute molecular masses and stoichiometry of DNA complexes. KCE-MS separates a thrombin-binding aptamer d[GGTTGGTGTGGTTGG] from mutated sequences based on affinity to potassium, and reveals the apparent equilibrium folding constant (K F≈150 µm), folding rate constant (k on≈1.70×10(3) s(-1) m(-1)), unfolding rate constant (k off≈0.25 s(-1)), half-life time of the G-quadruplex (t 1/2≈2.8 s), and relaxation time (τ≈3.9 ms at physiological 150 mm [K(+)]). In addition, KCE-MS screens for a GQ-stabilizing/-destabilizing effect of DNA binding dyes and an anticancer drug, cisplatin.

Four-way junction formation promoting ultrasensitive electrochemical detection of microRNA.

MicroRNAs (miRNAs) represent a class of biomarkers that are frequently deregulated in cancer cells and have shown a great promise for cancer classification and prognosis. Here, we endeavored to develop a DNA four-way junction based electrochemical sensor (4J-SENS) for ultrasensitive miRNA analysis. The developed sensor can be operated within the dynamic range from 10 aM to 1 fM and detect as low as 2 aM of miR-122 (∼36 molecules per sample), without PCR amplification. Furthermore, the 4J-SENS was employed to profile endogenouse hsa-miR-122 in healthy human and chronic lymphocyitc leukemia (CLL) patient serum, and the results were validated by qPCR analysis.

Quantitative analysis of microRNA in blood serum with protein-facilitated affinity capillary electrophoresis.

MicroRNAs play an important role in gene regulation and disease etiology and are blood-based biomarkers of diseases. Here, we describe a protein-facilitated affinity capillary electrophoresis (ProFACE) method for ultra-sensitive direct miRNA detection as low as 300,000 molecules in 1 mL of blood serum, using single-stranded DNA binding protein (SSB) and double-stranded RNA binding protein (p19) as separation enhancers. This method utilizes either the selective binding of SSB to a fluorescent single-stranded DNA/RNA probe or the binding of p19 to miRNA-RNA probe duplex.

Three-mode electrochemical sensing of ultralow microRNA levels.

MicroRNAs (miRNAs) are an emerging class of biomarkers that are frequently deregulated in cancer cells and have shown great promise for cancer classification and prognosis. In this work, we developed a three-mode electrochemical sensor for detection and quantitation of ultralow levels of miRNAs in a wide dynamic range of measured concentrations. The sensor facilitates three detection modalities based on hybridization (H-SENS), p19 protein binding (P-SENS), and protein displacement (D-SENS). The combined three-mode sensor (HPD-SENS) identifies as low as 5 aM or 90 molecules of miRNA per 30 µL of sample without PCR amplification, and can be operated within the dynamic range from 10 aM to 1 µM. The HPD sensor is made on a commercially available gold nanoparticles-modified electrode and is suitable for analyzing multiple miRNAs on a single electrode. This three-mode sensor exhibits high selectivity and specificity and was used for sequential analysis of miR-32 and miR-122 on one electrode. In addition, the H-SENS can recognize miRNAs with different A/U and G/C content and distinguish between a fully matched miRNA and a miRNA comprising either a terminal or a middle single base mutation. Furthermore, the H- and P-SENS were successfully employed for direct detection and profiling of three endogenous miRNAs, including hsa-miR-21, hsa-miR-32, and hsa-miR-122 in human serum, and the sensor results were validated by qPCR.

Quantitative analysis of microRNA in blood serum with protein-facilitated affinity capillary electrophoresis.

MicroRNAs (miRNAs) are small (∼22 nt) regulatory RNAs that are frequently deregulated in cancer and have shown promise as tissue- and blood-based biomarkers for cancer classification and prognostication. Here we present a protein-facilitated affinity capillary electrophoresis (ProFACE) assay for rapid quantification of miRNA levels in blood serum using single-stranded DNA binding protein (SSB) and double-stranded RNA binding protein (p19) as separation enhancers. The method utilizes either the selective binding of SSB to a single-stranded DNA/RNA probe or the binding of p19 to miRNA-RNA probe duplex. For the detection of ultralow amounts of miRNA without polymerase chain reaction (PCR) amplification in blood samples we apply off-line preconcentration of synthetic miRNA-122 from serum by p19-coated magnetic beads followed by online sample stacking in the ProFACE assay. The detection limit is 0.5 fM or 30 000 miRNA molecules in 1 mL of serum as a potential source of naïve miRNAs.

Predictors of short term mortality in heart failure - insights from the Euro Heart Failure survey.

OBJECTIVE: To identify factors associated with short term mortality in hospitalised patients with heart failure. BACKGROUND: Hospitalisation is frequent in patients with heart failure and is associated with a high mortality. METHODS: The Euro Heart Failure survey collected data from patients with suspected heart failure. We searched this data for predictors of short term mortality. RESULTS: Of 10,701 patients, 1404 (13%) died within 12 weeks of admission. On univariate analysis, increasing age, hyponatraemia, renal impairment, hyperkalaemia, anaemia, severe mitral regurgitation, severe LV systolic dysfunction(LVSD), increasing QRS and female sex carried adverse prognosis. ACEI, beta-blockers, nitrates, anti-thrombotic and lipid lowering drugs were associated with a better prognosis. On multivariable analysis the following provided independent prognostic information: increasing age (OR per SD=1.5, 95% CI 1.4-1.6), severe LVSD (1.8, 1.5-2.1), serum creatinine (1.2, 1.2-1.3), sodium (0.9, 0.8-0.9), Hb (0.9, 0.8-0.9) and treatment with ACEI (0.5, 0.5-0.6), beta-blockers (0.7, 0.6-0.8), statins (0.6, 0.5-0.7), calcium channel blockers (0.7, 0.6-0.8), warfarin (0.5, 0.4-0.6), heparin (1.7, 1.4-1.9), anti-platelet drugs (0.6, 0.5-0.6) and need for inotropes (5.5, 4.6-6.6). A simple risk score (range 0-11) identified cohorts with a 12 week mortality ranging from 2% to 44%. CONCLUSIONS: Simple and readily available clinical variables and a risk score based on medical history and routine tests that all patients admitted with heart failure have, can identify patients with good, intermediate and high short term mortality.

The timing of development and subsequent clinical course of heart failure after a myocardial infarction.

AIMS: Myocardial infarction (MI) is a common cause of heart failure (HF), which may develop early and persist or resolve, or develop late. The cumulative incidence, persistence, and resolution of HF after MI are poorly described. The aim of this study is to describe the natural history and prognosis of HF after an MI. METHODS AND RESULTS: Patients with a death or discharge diagnosis of MI in 1998 were identified from records of hospitals providing services to a local community of 600 000 people. Records were scrutinized to identify the development of HF, defined as signs and symptoms consistent with that diagnosis and treated with loop diuretics. HF was considered to have resolved if diuretics could be stopped without recurrent symptoms. Totally, 896 patients were identified of whom 54% had died by December 2005. During the index admission, 199 (22.2%) patients died, many with HF, and a further 182 (20.3%) patients developed HF that persisted until discharge, of whom 121 died subsequent to discharge. Of 74 patients with transient HF that resolved before discharge, 41 had recurrent HF and 38 died during follow-up. After discharge, 145 (33%) patients developed HF for the first time, of whom 76 died during follow-up. Overall, of 281 deaths occurring after discharge, 235 (83.6%) were amongst inpatients who first developed HF. CONCLUSION: The development of HF precedes death in most patients who die in the short- or long-term following an MI. Prevention of HF, predominantly by reducing the extent of myocardial damage and recurrent MI, and subsequent management could have a substantial impact on prognosis.

Prevalence of ECG abnormalities in an international survey of patients with suspected or confirmed heart failure at death or discharge.

BACKGROUND: Most patients suspected of having heart failure (HF) will get a 12-lead electrocardiogram (ECG) but its utility for excluding HF or assisting in its management has rarely been investigated. METHODS: The EuroHeart Failure survey identified 11,327 patients hospitalised with a suspected diagnosis of HF from 115 hospitals in 24 countries. ECGs were obtained from 9315 patients, of whom 5934 had cardiac imaging tests. The utility of the ECG was assessed for excluding or diagnosing major structural heart disease (MSHD) or major left ventricular systolic dysfunction (MLVSD) and for therapeutic decision making. FINDINGS: MSHD was present in 70% and MLVSD in 54% of patients overall but in only 21% and 5%, respectively, if the ECG was entirely normal. However, <2% of patients had a normal ECG. No single ECG characteristic identified a probability <25% of MSHD or <20% of MLVSD. Patients with QRS width >or=120 ms or anterior pathological Q-waves had a probability >80% of MSHD and >70% of MLVSD. Diagnostic models suggested that electrocardiographic criteria alone were not accurate for the diagnosis or exclusion of important heart disease in this population. However, 2468 patients (42%) had an electrocardiographic finding that should be used to guide the choice of therapy. CONCLUSIONS: A normal ECG is rare in patients with suspected HF but has limited diagnostic value in this setting. The ECG has an important role in guiding therapy.