Arrhythmogenic right ventricular cardiomyopathy in two pairs of monozygotic twins

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inheritant disease with an autosomal dominant mode of transmission with incomplete penetrance and variable expression. Linkage analysis in affected families succeeds in identifying 9 loci determining 9 subtypes of the disease. Genotype phenotype correlation is unclear and the influence of various environmental factors is discussed. OBJECTIVES: Genotype phenotype correlation in 2 pairs of monozygotic twins with ARVC and the role of environmental factors are analyzed. PATIENTS AND METHODS: Among 40 pts with ARVC and their 195 relatives there were 2 pairs of monozygotic twins: brothers, age 47 y; and sisters, age 48 y. History, ECG, Holter monitoring, 2D and Doppler Echo, and MRI were analyzed. RESULTS: Twin brothers: ARVC was diagnosed in the proband after the episode of VT with LBBB morphology (enlarged right ventricle, focal hypokinesia of apex, MR evidence of adipose tissue in RV wall). Identical morphology of RV was seen in asymptomatic twin brother. The patient presenting arrhythmia has been rowing for 4 years. Twin sisters: diagnosis was done during family screening. Both were asymptomatic. RV morphology typical for ARVC was found discrete in one of them (bulges adipose tissue in the RV apex); the latter showed changes suggesting RV abnormality (mild segmental dilatation of infundibulum, adipose tissue in a free wall of the RV). No differences in previous viral infections and sports involvement were observed. CONCLUSIONS: 1. Clinical picture of ARVC in monozygotic twins is not identical. 2. Strenuous effort may be a factor triggering the arrhythmia in pts with ARVC.     

Cardiac status after childhood growth hormone treatment of Turner syndrome

CONTEXT: In Turner syndrome (TS), GH treatment is well established. Data on cardiac status after discontinuation of treatment are scarce. This study aimed to assess biventricular size and function in TS at least 6 months after discontinuation of GH treatment. METHODS: TS patients and healthy women prospectively underwent cardiac magnetic resonance imaging. Ventricular two-dimensional tomographic cine data were acquired to obtain biventricular volume, mass, and ejection fraction. Atrioventricular valve flow measurements were performed using a two-dimensional flow-sensitized sequence. Flow velocity curves were calculated and indices of biventricular diastolic filling were derived. RESULTS: Thirty-one patients [mean (sd) age 20 (2) yr, body surface area 1.75 (0.15) m(2), 5 (2) yr after GH discontinuation] and 23 normal control women [age 21 (2) yr, body surface area 1.80 (0.13) m(2)] were included. Compared with controls, patients had smaller mean end-diastolic volumes [right ventricle (RV), 84 (11) ml/m(2) vs. 79 (10), P = 0.02; left ventricle (LV), 81 (10) vs. 72 (9), P < 0.001], end-systolic volumes [RV 38 (7) ml/m(2) vs. 36 (6), P = 0.04; LV 34 (5) vs. 29 (4), P < 0.001], and stroke volumes [RV 46 (6) ml/m(2) vs. 43 (6), P = 0.03; LV, 47 (7) vs. 44 (4), P = 0.02]. Patients had a higher mean heart rate [79 (13) beats/min vs. 71 (10), P < 0.05]. Biventricular ejection fraction, mass, cardiac output, and diastolic filling pattern were comparable. CONCLUSION: After discontinuation of GH treatment TS patients showed no myocardial hypertrophy and well-preserved biventricular function. Ventricular volumes were smaller in Turner patients, compared with controls, whereas mean heart rate was higher. These last observations may be part of the natural development in TS and not linked to GH treatment, which at this point we consider safe.     

Towards potent but less toxic nanopharmaceuticals – lipoic acid bioconjugates of ultrasmall gold nanoparticles with an anticancer drug and addressing unit

Modification of ultrasmall gold nanoparticles (AuNPs) with the lipoic acid derivative of folic acid was found to enhance their accumulation in the cancer cell, as compared to AuNPs without addressing units. The application of lipoic acid enabled the control of the gold nanoparticle functionalities leading to enhanced solubility and allowing for attachment of both the folic acid and the cytotoxic drug, doxorubicin. More robust attachment of doxorubicin to the nanoparticle through the amide bond resulted in toxicity comparable with that of the drug alone, opening a new perspective for designing more potent, but less toxic nanopharmaceuticals. The increased uptake was accompanied by pronounced nuclear accumulation and observable cytotoxicity. Doxorubicin binding via covalent amide bonds enhanced stability of the whole drug vehicle and provided much better control over doxorubicin release in the cell environment, as compared to physical adsorption or pH sensitive bonding commonly used for anthracycline carriers. Confocal microscopy revealed that the bond was stable in the cytoplasm for 22 h. The ability to slow down the rate of drug release may be crucial for the application in sustained anticancer drug delivery. Biological analyses performed using MTT assay and confocal microscopy confirmed that the ultrasmall AuNPs with the lipoic acid derivative of folic acid exhibit relatively low cytotoxicity, however when loaded with a chemotherapeutic, they cause a significant reduction in the cell viability.

Modification of ultrasmall gold nanoparticles (AuNPs) with the lipoic acid derivative of folic acid was found to enhance their accumulation in the cancer cell, as compared to AuNPs without addressing units.     

New synthetic pathway leading to oxospirochlorins

In this work we propose a completely new approach for the synthesis of spirochlorin derivatives based on the use of an imino-keto intermediate formed in situ from 2-amino-5,10,15,20-tetraphenylporphyrins and inverse electron demand Diels–Alder (iEDDA) cycloaddition with 3,6-di-2-pyridyl-1,2,4,5-tetrazine. The mechanism of reaction was analyzed employing theoretical methods by comparing the difference in energy of Frontier Molecular Orbitals (FMO) for appropriate reagents. Ground-state molecular electrostatic (ESP) potential maps were employed as additional tools allowing explanation of the reactivity of substrates. The new class of spirochlorin compounds was fully characterized by means of mass spectrometry, IR, liquid and solid state NMR and X-ray crystallography. Correlation between molecular structure and optical properties for the obtained title compounds is discussed.

Oxospirochlorins – novel analogs of porphyrinoids were synthesized and characterized by various methods including X-ray, NMR spectroscopy and mass spectrometry.     

Non-invasive mechanical ventilation improves walking distance but not quadriceps strength in chronic respiratory failure

BACKGROUND: In patients with chronic respiratory failure (CRF) nocturnal mechanical ventilation (NMV) confers increased exercise tolerance. The hypothesis tested in the present study was that the increased exercise performance is associated with increased quadriceps strength. METHODS: In 28 patients with CRF due to chronic obstructive pulmonary disease and restrictive thoracic disease (post-tuberculosis-sequelae, scoliosis and obesity-hypoventilation) NMV was started. Before and after 2-month NMV the exercise tests, namely shuttle and 6-min walking distance, were performed. Furthermore, quadriceps strength was measured as the twitch tension elicited by magnetic stimulation the femoral nerve (TwQ) and the maximum voluntary contraction force (MVC). RESULTS: After 2 months therapy with NMV there was significant clinical and blood gas improvement. NMV significantly improved the walking distance by approximately 18% but there was no improvement in TwQ or MVC, the data could exclude a 15% improvement in TwQ with 82% confidence. CONCLUSION: The strength of quadriceps does not change after 2 months of effective NMV in patients with CRF despite a marked increase in endurance time. Factors other than quadriceps strength account for the improved performance.     

Elevated soluble intercellular adhesion molecule-1 levels in obesity: relationship to insulin resistance and tumor necrosis factor-alpha system activity.

Intercellular adhesion molecule-1 (ICAM-1) is 1 of the possible factors linking obesity and diabetes with cardiovascular disease, however, the mechanism of the increase in ICAM-1 concentration in obesity remains unclear. Therefore, the aim of the present study was to assess plasma soluble ICAM-1 (sICAM-1) levels in obese subjects with normal glucose tolerance and to evaluate whether those levels may be related to insulin resistance and tumor necrosis factor-alpha (TNFalpha) system activity. The study was performed in 8 lean and 15 obese subjects. Anthropometric and biochemical parameters were measured, and insulin sensitivity was evaluated using the euglycemic hyperinsulinemic clamp technique (insulin infusion, 50 mU x kg(-1) x h(-1)). Obese subjects were markedly more hyperinsulinemic and insulin resistant and had higher plasma soluble TNF receptor 2 (sTNFR2) and sICAM-1 levels. sICAM-1 was related positively to body mass index (BMI), waist-to-hip ratio (WHR), percent of body fat, glycated hemoglobin (HbA(1c)), plasma insulin and triglycerides (TG), TNFalpha, and sTNFR2 and negatively to insulin sensitivity. Multiple regression analysis showed that only sTNFR2 and insulin sensitivity were independent predictors of sICAM-1 concentrations and were responsible for 66% of sICAM-1 variability. We conclude that an increase in plasma sICAM-1 concentration in obesity is related to TNFalpha system activation and insulin resistance.     

Anti-VEGF agents confer survival advantages to tumor-bearing mice by improving cancer-associated systemic syndrome

The underlying mechanism by which anti-VEGF agents prolong cancer patient survival is poorly understood. We show that in a mouse tumor model, VEGF systemically impairs functions of multiple organs including those in the hematopoietic and endocrine systems, leading to early death. Anti-VEGF antibody, bevacizumab, and anti-VEGF receptor 2 (VEGFR-2), but not anti-VEGFR-1, reversed VEGF-induced cancer-associated systemic syndrome (CASS) and prevented death in tumor-bearing mice. Surprisingly, VEGFR2 blockage improved survival by rescuing mice from CASS without significantly compromising tumor growth, suggesting that “off-tumor” VEGF targets are more sensitive than the tumor vasculature to anti-VEGF drugs. Similarly, VEGF-induced CASS occurred in a spontaneous breast cancer mouse model overexpressing neu. Clinically, VEGF expression and CASS severity positively correlated in various human cancers. These findings define novel therapeutic targets of anti-VEGF agents and provide mechanistic insights into the action of this new class of clinically available anti-VEGF cancer drugs.     

The human JC polyomavirus (JCPyV): virological background and clinical implications

JC polyomavirus (JCPyV) was the first of now 12 PyVs detected in humans, when in 1964, PyV particles were revealed by electron microscopy in progressive multifocal leukoencephalopathy (PML) tissues. JCPyV infection is common in 35–70% of the general population, and the virus thereafter persists in the renourinary tract. One third of healthy adults asymptomatically shed JCPyV at approximately 50 000 copies/mL urine. PML is rare having an incidence of <0.3 per 100 000 person years in the general population. This increased to 2.4 per 1000 person years in HIV‐AIDS patients without combination antiretroviral therapy (cART). Recently, PML emerged in multiple sclerosis patients treated with natalizumab to 2.13 cases per 1000 patients. Natalizumab blocks α4‐integrin‐dependent lymphocyte homing to the brain suggesting that not the overall cellular immunodeficiency but local failure of brain immune surveillance is a pivotal factor for PML. Recovering JCPyV‐specific immune control, e.g., by starting cART or discontinuing natalizumab, significantly improves PML survival, but is challenged by the immune reconstitution inflammatory syndrome. Important steps of PML pathogenesis are undefined, and antiviral therapies are lacking. New clues might come from molecular and functional profiling of JCPyV and PML pathology and comparison with other replicative pathologies such as granule cell neuronopathy and (meningo‐)encephalitis, and non‐replicative JCPyV pathology possibly contributing to some malignancies. Given the increasing number of immunologically vulnerable patients, a critical reappraisal of JCPyV infection, replication and disease seems warranted.     

Reproducibility of quantitative plaque measurement in advanced coronary artery disease

BackgroundThe ability to characterize and to quantify the extent of coronary artery disease has the potential to improve the prognostic capability of coronary computed tomography angiography. Although reproducible techniques have been described in those with mild coronary disease, this has yet to be assessed in patients with advanced disease.MethodsTwenty patients with known multivessel disease underwent repeated computed tomography coronary angiography, 2 weeks apart. Coronary artery segments were analysed using semi-automated software by two trained observers to determine intraobserver, interobserver and interscan reproducibility.ResultsOverall, 149 coronary arterial segments were analysed. There was excellent intraobserver and interobserver agreement for all plaque volume measurements (Lin’s coefficient 0.95 to 1.0). There were no substantial interscan differences (P ?> ?0.05 for all) for total (2063 ?± ?1246 ?mm³, mean of differences ?35.6 ?mm³), non-calcified (1795 ?± ?910 ?mm³, mean of differences ?4.3 ?mm³), calcified (298 ?± ?425 ?mm³, mean of differences ?31.3 ?mm³) and low-attenuation (13 ?± ?13 ?mm³, mean of differences ?2.6 ?mm³) plaque volumes. Interscan agreement was highest for total and noncalcified plaque volumes. Calcified and low-attenuation plaque (?236.6 to 174 ?mm³ and -15.8 to 10.5 ?mm³ respectively) had relatively wider 95% limits of agreement reflecting the lower absolute plaque volumes.ConclusionIn the presence of advanced coronary disease, semi-automated plaque quantification provides excellent reproducibility, particularly for total and non-calcified plaque volumes. This approach has major potential to assess change in disease over time and optimize risk stratification in patients with established coronary artery disease.