Pharmacological doses of melatonin impede cognitive decline in tau‐related Alzheimer models,once tauopathy is initiated,by restoring the autophagic flux

Alterations in autophagy are increasingly being recognized in the pathogenesis of proteinopathies like Alzheimer's disease (AD). This study was conducted to evaluate whether melatonin treatment could provide beneficial effects in an Alzheimer model related to tauopathy by improving the autophagic flux and, thereby, prevent cognitive decline. The injection of AAV‐hTau^P301L viral vectors and treatment/injection with okadaic acid were used to achieve mouse and human ex vivo, and in vivo tau‐related models. Melatonin (10 μmol/L) impeded oxidative stress, tau hyperphosphorylation, and cell death by restoring autophagy flux in the ex vivo models. In the in vivo studies, intracerebroventricular injection of AAV‐hTau^P301L increased oxidative stress, neuroinflammation, and tau hyperphosphorylation in the hippocampus 7 days after the injection, without inducing cognitive impairment; however, when animals were maintained for 28 days, cognitive decline was apparent. Interestingly, late melatonin treatment (10 mg/kg), starting once the alterations mentioned above were established (from day 7 to day 28), reduced oxidative stress, neuroinflammation, tau hyperphosphorylation, and caspase‐3 activation; these observations correlated with restoration of the autophagy flux and memory improvement. This study highlights the importance of autophagic dysregulation in tauopathy and how administration of pharmacological doses of melatonin, once tauopathy is initiated, can restore the autophagy flux, reduce proteinopathy, and prevent cognitive decline. We therefore propose exogenous melatonin supplementation or the development of melatonin derivatives to improve autophagy flux for the treatment of proteinopathies like AD.     

Residual cholesterol synthesis and simvastatin induction of cholesterol synthesis in Smith-Lemli-Opitz syndrome fibroblasts

Smith-Lemli-Opitz syndrome (RSH/SLOS) is an autosomal recessive, malformation syndrome caused by mutations in the 3beta-hydroxysterol delta7-reductase gene (DHCR7). DHCR7 catalyzes the reduction of 7-dehydrocholesterol (7DHC) to cholesterol. We report the mutation analysis and determination of residual cholesterol synthesis in 47 SLOS patients, and the effects of treatment of SLOS skin fibroblasts with simvastatin. Using deuterium labeling we have quantified the amount of synthesized cholesterol and 7DHC in homozygote, heterozygote, and control fibroblast cell lines. In SLOS fibroblasts, the fraction of synthesized cholesterol to total sterol synthesis ranged from undetectable to over 50%. This establishes that different mutant alleles encode enzymes with varying degrees of residual activity. There was a correlation between increased phenotypic severity and decreased residual cholesterol synthesis (r(2)=0.45, p<0.0001). Simvastatin treatment of SLOS fibroblasts with residual DHCR7 enzymatic activity decreased 7DHC levels and increased cholesterol synthesis. This increase in cholesterol synthesis is due to increased expression of a mutant allele with residual function. Determination of residual enzymatic activity for specific DHCR7 mutant alleles will help in understanding the processes underlying the broad phenotypic spectrum found in this disorder and will be useful in identifying patients who may benefit from simvastatin therapy.     

The soluble tumor necrosis factor receptor I is an early predictor of local infective complications after colorectal surgery

The clinical implications of increased cytokine levels after major surgery remain unclear. In this study, systemic concentration of a spectrum of cytokines, including interleukins IL-6, IL-8, IL-10, IL-1ra, and soluble tumor necrosis factor receptor-I (sTNF-RI) was examined in patients with and without postoperative septic complications following colorectal surgery. Although there were no significant changes in IL-1, TNF-, and IL-8 serum levels during the observation period, there was a significant rise in IL-6, IL-1ra, and sTNF-RI concentrations in the entire group of patients between postoperative day 1 and 14. There were no differences between the group without and with local complications when IL-6, IL-1ra, and IL-10 were examined. The serum levels of sTNF-RI, IL-1ra, and IL-6 were found to be sensitive indicators of the pro- and anti-inflammatory response to the surgical trauma, but only sTNF-RI turned out to be a sensitive early marker of local septic postoperative complications in patients with colorectal carcinoma.     

The kinetics of mast cells in lymph nodes of immunized mice

Normal mouse peritoneal exudate cells (PEC), consisting of 90–95 per cent macrophages, were used to augment haemagglutination in microtrays. Antibody titres were augmented 1000-fold when 10⁶ PEC/ml were mixed with sheep erythrocytes (SRBC) and added to serial dilutions of mouse anti-SRBC sera. This method has certain advantages over conventional antiglobulin augmented haemagglutination. It is thought that augmented haemagglutination by PEC is mediated by macrophage receptors for cytophilic antibodies or by a non-specific surface mechanism.     

Spatial and seasonal variability of the mass concentration and chemical composition of PM2.5 in Poland

The seasonal changes in ambient mass concentrations and chemical composition of fine particulate matter (PM_2.5) were investigated in three locations in Poland. The analyses included PM_2.5-bound hazardous benzo(a)pyrene (BaP), As, Ni, Cd, and Pb. The samples of PM_2.5 were collected daily in Katowice (southern Poland, urban background site), Gdańsk, and Diabla Góra (northern Poland, urban and regional background sites, respectively) during 1-year-long campaign in 2010. Based on monthly ambient concentrations of PM_2.5-bound carbon (organic and elemental), water-soluble ions (Na⁺, NH₄ ⁺, K⁺, Mg²⁺, Ca²⁺, Cl^?, NO₃ ^?, SO₄ ^2?), and elements As, Ni, Cd, Pb, Ti, Al, Fe, the chemical mass closure of PM_2.5 was checked for each of the four seasons of the year and for the heating and non-heating periods at each site. Also, the annual concentrations of PM_2.5 were determined and the annual PM_2.5 mass closure checked. At each measuring point, the PM_2.5 concentrations were high compared to its Polish yearly permissible value, 25 μg/m³, and its concentrations elsewhere in Europe. The highest annual PM_2.5 concentration, 43 μg/m³, occurred in Katowice; it was twice the annual PM_2.5 concentration in Gdańsk, and thrice the one in Diabla Góra. The high annual averages were due to very high monthly concentrations in the heating period, which were highest in the winter. PM_2.5 consisted mainly of carbonaceous matter (elemental carbon (EC) + organic matter (OM), the sum of elemental carbon, EC, and organic matter, OM; its annual mass contributions to PM_2.5 were 43, 31, and 33 % in Katowice, Gdansk, and Diabla Góra, respectively), secondary inorganic aerosol (SIA), the Na_Cl group, and crustal matter (CM)—in the decreasing order of their yearly mass contributions to PM_2.5. OM, EC, SIA, Na_Cl, and CM accounted for almost 81 % of the PM_2.5 mass in Katowice, 74 % in Gdańsk, and 90 % in Diabla Góra. The annual average toxic metal contribution to the PM_2.5 mass was not greater than 0.2 % at each site. In Katowice and Gdańsk, the yearly ambient BaP concentrations were high (15.4 and 3.2 ng/m³, respectively); in rural Diabla Góra, the concentrations of BaP were almost equal to 1 ng/m³, the Polish BaP annual limit. The great seasonal fluctuations of the shares of the component groups in PM_2.5 and of the concentrations of PM_2.5 and its components are due to the seasonal fluctuations of the emissions of PM and its precursors from hard and brown coal combustion for energy production, growing in a heating season, reaching maximum in winter, and decreasing in a non-heating period. In Gdańsk, northern Poland, especially in the spring and autumn, sea spray might have affected the chemical composition of PM_2.5. The greatest hazard from PM_2.5 occurs in Katowice, southern Poland, in winter, when very high concentrations of PM_2.5 and PM_2.5-related carbonaceous matter, including BaP, are maintained by poor natural ventilation in cities, weather conditions, and the highest level of industrialization in Poland. In less industrialized northern Poland, where the aeration in cities is better and rather gaseous than solid fuels are used, the health hazard from ambient PM_2.5 is much lower.     

The chicken chorioallantoic membrane model in biology,medicine and bioengineering

The chicken chorioallantoic membrane (CAM) is a simple, highly vascularized extraembryonic membrane, which performs multiple functions during embryonic development, including but not restricted to gas exchange. Over the last two decades, interest in the CAM as a robust experimental platform to study blood vessels has been shared by specialists working in bioengineering, development, morphology, biochemistry, transplant biology, cancer research and drug development. The tissue composition and accessibility of the CAM for experimental manipulation, makes it an attractive preclinical in vivo model for drug screening and/or for studies of vascular growth. In this article we provide a detailed review of the use of the CAM to study vascular biology and response of blood vessels to a variety of agonists. We also present distinct cultivation protocols discussing their advantages and limitations and provide a summarized update on the use of the CAM in vascular imaging, drug delivery, pharmacokinetics and toxicology.     

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.     

Functionalization of α-hydroxyphosphonates as a convenient route to N-tosyl-α-aminophosphonates

Direct conversion of the α-hydroxyl group by para-toluenesulfonamide to yield α-(N-tosyl)aminophosphonates is reported. α-Aminophosphonates 23a,b–37a,b were obtained from the corresponding α-hydroxyphosphonates 6a,b–21a,b in the presence of K₂CO₃, via the retro-Abramov reaction of the appropriate aldehydes, 1–5. The subsequent formation of imines with simultaneous addition of diethyl phosphite provided access to the α-sulfonamide phosphonates 23a,b–37a,b with better diastereoselectivity than in the case of the Pudovik reaction. The mechanism for this transformation is proposed herein. When Cbz N-protected aziridine 9a,b and phenylalanine analogue 12a,b were exploited, intramolecular substitution was observed, leading to the corresponding epoxide 38 as the sole product, or oxazolidin-2-one 39 as a minor product. Analogous substitution was not observed in the case of proline 18a,b and serine 21a,b derivatives.

The reaction mechanism and diastereoselectivity of the direct transformation of α-hydroxyphosphonates 6a,b–21a,b by para-toluenesulfonamide, yielding α-(N-tosyl)aminophosphonates 23a,b–37a,b under K₂CO₃ conditions are presented.