The new HNO donor, 1-nitrosocyclohexyl acetate, increases contractile force in normal and β-adrenergically desensitized ventricular myocytes

Contractile dysfunction and diminished response to β-adrenergic agonists are characteristics for failing hearts. Chemically donated nitroxyl (HNO) improves contractility in failing hearts and thus may have therapeutic potential. Yet, there is a need for pharmacologically suitable donors. In this study we tested whether the pure and long acting HNO donor, 1-nitrosocyclohexyl acetate (NCA), affects contractile force in normal and pathological ventricular myocytes (VMs) as well as in isolated hearts. VMs were isolated from mice either subjected to isoprenaline-infusion (ISO; 30 μg/g per day) or to vehicle (0.9% NaCl) for 5 days. Sarcomere shortening and Ca²⁺ transients were simultaneously measured using the IonOptix system. Force of contraction of isolated hearts was measured by a Langendorff-perfusion system. NCA increased peak sarcomere shortening by + 40-200% in a concentration-dependent manner (EC₅₀ ∼55 μM). Efficacy and potency did not differ between normal and chronic ISO VMs, despite the fact that the latter displayed a markedly diminished inotropic response to acute β-adrenergic stimulation with ISO (1 μM). NCA (60 μM) increased peak sarcomere shortening and Ca²⁺ transient amplitude by ∼200% and ∼120%, respectively, suggesting effects on both myofilament Ca²⁺ sensitivity and sarcoplasmic reticulum (SR) Ca²⁺ cycling. Importantly, NCA did not affect diastolic Ca²⁺ or SR Ca²⁺ content, as assessed by rapid caffeine application. NCA (45 μM) increased force of contraction by 30% in isolated hearts. In conclusion, NCA increased contractile force in normal and β-adrenergically desensitized VMs as well as in isolated mouse hearts. This profile warrants further investigations of this HNO donor in the context of heart failure.     

Surface expression of CXCR4 in unrestricted somatic stem cells and its regulation by growth factors

Umbilical cord blood‐derived USSCs (unrestricted somatic stem cells) have recently been considered as a potential source for stem cell therapy and transplantation due to their characteristics such as easy accessibility, low immunogenicity, self‐renewing and multilineage differentiation potential. Stem cell homing is a key factor in successful transplantation, which is regulated by CXCR4 in stem cells. In this study, we evaluated the expression of CXCR4 in USSCs different passages. Moreover, the effect of VEGF (vascular endothelial growth factor) and IGF‐1 (insulin‐like growth factor 1) on its expression was assessed. It was shown that the expression of CXCR4 in USSCs decreased with the increase in passage number. It was also revealed that VEGF increased surface expression and mRNA level of CXCR4 in USSCs, while IGF‐1 decreased its expression. When VEGF and IGF‐1 were administered simultaneously, CXCR4 expression was increased, but the expression level was less than VEGF alone. Finally, it was shown that over‐expression of CXCR4 enhanced the migratory capacity of USSCs. The increase of CXCR4 expression, here caused by VEGF in USSCs, can improve the efficacy of stem cell therapy and transplantation after long‐term culture of stem cells before clinical use.     

A Review of the Chemistry and Biological Activities of Natural Colorants,Dyes, and Pigments: Challenges,and Opportunities for Food,Cosmetics, and Pharmaceutical Application

Natural pigments are important sources for the screening of bioactive lead compounds. This article reviewed the chemistry and therapeutic potentials of over 570 colored molecules from plants, fungi, bacteria, insects, algae, and marine sources. Moreover, related biological activities, advanced extraction, and identification approaches were reviewed. A variety of biological activities, including cytotoxicity against cancer cells, antioxidant, anti-inflammatory, wound healing, anti-microbial, antiviral, and anti-protozoal activities, have been reported for different pigments. Considering their structural backbone, they were classified as naphthoquinones, carotenoids, flavonoids, xanthones, anthocyanins, benzotropolones, alkaloids, terpenoids, isoprenoids, and non-isoprenoids. Alkaloid pigments were mostly isolated from bacteria and marine sources, while flavonoids were mostly found in plants and mushrooms. Colored quinones and xanthones were mostly extracted from plants and fungi, while colored polyketides and terpenoids are often found in marine sources and fungi. Carotenoids are mostly distributed among bacteria, followed by fungi and plants. The pigments isolated from insects have different structures, but among them, carotenoids and quinone/xanthone are the most important. Considering good manufacturing practices, the current permitted natural colorants are: Carotenoids (canthaxanthin, β-carotene, β-apo-8′-carotenal, annatto, astaxanthin) and their sources, lycopene, anthocyanins, betanin, chlorophyllins, spirulina extract, carmine and cochineal extract, henna, riboflavin, pyrogallol, logwood extract, guaiazulene, turmeric, and soy leghemoglobin.     

ROS-Mediated Antitumor Activity,Apoptosis, and Molecular Docking Studies of Platinum(II) Coordination Complexes Bearing 2-(Diphenylphosphino)pyridine Ligands

Platinum-based drugs have been widely used in cancer treatment. However, their severe side effects have limited their use. So, researchers have been striving to find compounds with fewer side effects and greater efficacy, to overcome these drawbacks. Here, the cytotoxicity of platinum(II) complexes containing 2-(diphenylphosphino)pyridine ligands have been studied on human lung (A549), ovarian (SKOV3), breast (MCF-7) cancer, and normal breast (MCF-10A) cell lines. The most potent compound exhibits a marked cell growth-inhibitory effect against ovarian and lung cancer cells with IC₅₀ values of 9.41 and 5.58 μM, respectively, which were significantly better than that observed for cisplatin (19.02, and 8.64 μM). Additionally, all complexes achieved significantly lower cytotoxicity towards MCF-10A. To investigate the interaction of complexes with DNA, an electrophoresis mobility shift assay was conducted, which indicated that complexes bind to DNA and affect its electrophoretic mobility. An analysis of apoptosis in A549 cells supported the conclusion that they inhibits cell proliferation via induction of apoptosis in a concentration-dependent manner. Molecular docking was also used to investigate the interactions of compounds with different DNA structures. These compounds have the ability to be a suitable pharmaceutical compound with further investigations in the field of cancer research.     

Cellulose nanocrystals from celery stalk as quercetin scaffolds: A novel perspective of human holo-transferrin adsorption and digestion behaviours

In this study, cellulose nanocrystals (CNCs) were synthesized from celery stalks to be used as the platform for quercetin delivery. Additionally, CNCs and CNCs–quercetin were characterized using the results of scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and zeta potential, while their interactions with human holo-transferrin (HTF) were also investigated. We examined their interaction under physiological conditions through the exertion of fluorescence, resonance light scattering, synchronized fluorescence spectroscopy, circular dichroism, three-dimensional fluorescence spectroscopy, and fluorescence resonance energy transfer techniques. The data from SEM and TEM exhibited the spherical shape of CNCs and CNCs–quercetin and also, a decrease was detected in the size of quercetin-loaded CNCs from 676 to 473 nm that indicated the intensified water solubility of quercetin. The success of cellulose acid hydrolysis was confirmed based on the XRD results. Apparently, the crystalline index of CNCs–quercetin was reduced by the interaction of CNCs with quercetin, which also resulted in the appearance of functional groups, as shown by FTIR. The interaction of CNCs–quercetin with HTF was also demonstrated by the induced quenching in the intensity of HTF fluorescence emission and Stern–Volmer data represent the occurrence of static quenching. Overall, the effectiveness of CNCs as quercetin vehicles suggests its potential suitability for dietary supplements and pharmaceutical products.     

Erythrocyte membrane modifying agents and the inhibition of Plasmodium falciparum growth: structure-activity relationships for betulinic acid analogues

The natural triterpene betulinic acid and its analogues (betulinic aldehyde, lupeol, betulin, methyl betulinate and betulinic acid amide) caused concentration-dependent alterations of erythrocyte membrane shape towards stomatocytes or echinocytes according to their hydrogen bonding properties. Thus, the analogues with a functional group having a capacity of donating a hydrogen bond (COOH, CH(2)OH, CONH(2)) caused formation of echinocytes, whereas those lacking this ability (CH(3), CHO, COOCH(3)) induced formation of stomatocytes. Both kinds of erythrocyte alterations were prohibitive with respect to Plasmodium falciparum invasion and growth; all compounds were inhibitory with IC(50) values in the range 7-28 microM, and the growth inhibition correlated well with the extent of membrane curvature changes assessed by transmission electron microscopy. Erythrocytes pre-loaded with betulinic acid or its analogues and extensively washed in order to remove excess of the chemicals could not serve as hosts for P. falciparum parasites. Betulinic acid and congeners can be responsible for in vitro antiplasmodial activity of plant extracts, as shown for Zataria multiflora Boiss. (Labiatae) and Zizyphus vulgaris Lam. (Rhamnaceae). The activity is evidently due to the incorporation of the compounds into the lipid bilayer of erythrocytes, and may be caused by modifications of cholesterol-rich membrane rafts, recently shown to play an important role in parasite vacuolization. The established link between erythrocyte membrane modifications and antiplasmodial activity may provide a novel target for potential antimalarial drugs.     

Delayed epidermal permeability barrier formation and hair follicle aberrations in Inv-Cldn6 mice

Homozygous mice overexpressing Claudin-6 (Cldn6) exhibit a perturbation in the epidermal differentiation program leading to a defective epidermal permeability barrier (EPB) and dehydration induced death ensuing within 48 h of birth [Turksen, K., Troy, T.C., 2002. Permeability barrier dysfunction in transgenic mice overexpressing claudin 6. Development 129, 1775-1784]. Their heterozygous counterparts are also born with an incomplete EPB; however, barrier formation continues after birth and normal hydration levels are achieved by postnatal day 12 allowing survival into adulthood. Heterozygous Inv-Cldn6 mice exhibit a distinct coat phenotype and histological analysis shows mild epidermal hyperkeratosis. Expression of K5 and K14 is aberrant, extending beyond the basal layer into the suprabasal layer where they are not co-localized suggesting that their expression is uncoupled. There is also atypical K17 and patchy K15 expression in the basal layer with no K6 expression in the interfollicular epidermis; together with marked changes in late differentiation markers (e.g. profilaggrin/filaggrin, loricrin, transglutaminase 3) indicating that the normal epidermal differentiation program is modified. The expression compartment of various Cldns is also perturbed although overall protein levels remained comparable. Most notably induction of Cldn5 and Cldn8 was observed in the Inv-Cldn6 epidermis. Heterozygous Inv-Cldn6 animals also exhibit subtle alterations in the differentiation program of the hair follicle including a shorter anagen phase, and altered hair type distribution and length compared to the wild type; the approximately 20% increase in zig-zag hair fibers at the expense of guard hairs and the approximately 30% shorter guard hairs contribute to coat abnormalities in the heterozygous mice. In addition, the transgenic hair follicles exhibit a decreased expression of K15 as well as some hair-specific keratins and express Cldn5 and Cldn18, which are not detectable in the wild type. These data indicate that Cldn6 plays a role in the differentiation processes of the epidermis and hair follicle and supports the notion of a link between Cldn regulation and EPB assembly/maintenance as well as the hair cycle.     

An improved method for extraction of high-quality total RNA from oil seeds

Biotechnology Letters - Seeds of oilseed plants that contain large amounts of oil, polysaccharides, proteins and polyphenols are not amenable to conventional RNA isolation protocols. The presence...     

Synthesis and characterization of new Pd(II) complexes of <Emphasis Type="SmallCaps">l</Emphasis>-ethylphenylalanate

Complex (S,S)-[Pd{C₆H₄(CH₂CHNH₂CO₂CH₂CH₃)}(μ-Br)]₂ (3) was prepared following the method by Vicente and Saura-Llamas (Organometallics 26:2768–2776, 2007), by the reaction of l-ethylphenylalanate and Pd(OAc)₂ in 1:1 molar ratio under acetonitrile heating conditions and subsequently treating with NaBr. In addition, the cleavage of halogeno-bridge of the complex 3 via nucleophilic attack of some neutral ligands such as triphenylphosphine, pyridine, 2,4,6-trimethylpyridine and piperidine were investigated and the corresponding complexes (S)-[Pd{C₆H₄(CH₂CHNH₂CO₂CH₂CH₃)(Y)(Br)}] (4a–f) were obtained in moderate yields. The six-member orthopalladated complexes were characterized by ¹H-NMR, ³¹P-NMR, FT-IR and elemental analysis techniques.     

Automated Detection of Actinic Keratoses in Clinical Photographs

Background

Clinical diagnosis of actinic keratosis is known to have intra- and inter-observer variability, and there is currently no non-invasive and objective measure to diagnose these lesions.

Objective

The aim of this pilot study was to determine if automatically detecting and circumscribing actinic keratoses in clinical photographs is feasible.

Methods

Photographs of the face and dorsal forearms were acquired in 20 volunteers from two groups: the first with at least on actinic keratosis present on the face and each arm, the second with no actinic keratoses. The photographs were automatically analysed using colour space transforms and morphological features to detect erythema. The automated output was compared with a senior consultant dermatologist’s assessment of the photographs, including the intra-observer variability. Performance was assessed by the correlation between total lesions detected by automated method and dermatologist, and whether the individual lesions detected were in the same location as the dermatologist identified lesions. Additionally, the ability to limit false positives was assessed by automatic assessment of the photographs from the no actinic keratosis group in comparison to the high actinic keratosis group.

Results

The correlation between the automatic and dermatologist counts was 0.62 on the face and 0.51 on the arms, compared to the dermatologist’s intra-observer variation of 0.83 and 0.93 for the same. Sensitivity of automatic detection was 39.5% on the face, 53.1% on the arms. Positive predictive values were 13.9% on the face and 39.8% on the arms. Significantly more lesions (p<0.0001) were detected in the high actinic keratosis group compared to the no actinic keratosis group.

Conclusions

The proposed method was inferior to assessment by the dermatologist in terms of sensitivity and positive predictive value. However, this pilot study used only a single simple feature and was still able to achieve sensitivity of detection of 53.1% on the arms.This suggests that image analysis is a feasible avenue of investigation for overcoming variability in clinical assessment. Future studies should focus on more sophisticated features to improve sensitivity for actinic keratoses without erythema and limit false positives associated with the anatomical structures on the face.