Antiradical and NO-Inhibiting activities of β-hydroxy(ethoxy) derivatives of nitrous heterocycles

The antiradical and NO-inhibiting activities of β-hydroxy(ethoxy) derivatives of nitrous heterocycles (3-hydroxypyridine, 5-hydroxybenzimodazole, and 6-hydroxy(alkoxy)-benzothiazole) have been studied. The antiradical activity has been studied using a homogeneous hydrophilic chemiluminescent system, and the quenching constants (K _i ) have been determined. For the most reactive compound, 4-methylthiobenzimidazolyl-3-hydroxypyridine, K _i = 4.5 × 10⁵ M⁻¹. The NO-inhibiting activity was estimated on a model of the endotoxin shock of experimental animals using a spin trap of nitric oxide radicals based on complexes of iron with sodium diethyldithiocarbamate. It was found that the compounds at doses of 0.25–1 mmol/kg have both the inhibitory and stimulating action on the production of nitric oxide in the liver of animals. The results obtained suggest that some derivatives of nitrous heterocycles can be used as effective antioxidant preparations.     

Hatching asynchrony and brood reduction influence immune response in Common Kestrel Falco tinnunculus nestlings

The onset of incubation before the end of laying imposes asynchrony at hatching and, therefore, a size hierarchy in the brood. It has been argued that hatching asynchrony might be a strategy to improve reproductive output in terms of quality or quantity of offspring. However, little is known about the mediating effect of hatching asynchrony on offspring quality when brood reduction occurs. Here, we investigate the relationship between phenotypic quality and hatching asynchrony in Common Kestrel Falco tinnunculus nestlings in Spain. Hatching asynchrony did not increase breeding success or nestling quality. Furthermore, hatching asynchrony and brood reduction had different effects on nestlings’ phytohaematogglutinin (PHA)‐mediated immune response and nestling growth. In asynchronous and reduced broods (in which at least one nestling died), nestlings showed a stronger PHA‐mediated immune response and tended to have a smaller body size compared with nestlings raised in synchronous and reduced broods. When brood reduction occurred in broods hatched synchronously, there was no effect on nestling size, but nestlings had a relatively poor PHA‐mediated immune response compared with nestlings raised in asynchronous and reduced broods. We suggest that resources for growth can be directed to immune function only in asynchronously hatched broods, resulting in improved nestling quality, as suggested by their immune response. We also found that males produced a greater PHA‐mediated immune response than females only in brood‐reduced nests without any effect on nestling size or condition, suggesting that females may trade off immune activities and body condition, size or weight. Overall, our results suggest that hatching pattern and brood reduction may mediate resource allocation to different fitness traits. They also highlight that the resolution of immune‐related trade‐offs when brood reduction occurs may differ between male and female nestlings.     

Risk Factors for Death in 632 Patients with Sickle Cell Disease in the United States and United Kingdom

Background

The role of pulmonary hypertension as a cause of mortality in sickle cell disease (SCD) is controversial.

Methods and Results

We evaluated the relationship between an elevated estimated pulmonary artery systolic pressure and mortality in patients with SCD. We followed patients from the walk-PHaSST screening cohort for a median of 29 months. A tricuspid regurgitation velocity (TRV)≥3.0 m/s cuttof, which has a 67–75% positive predictive value for mean pulmonary artery pressure ≥25 mm Hg was used. Among 572 subjects, 11.2% had TRV≥3.0 m/sec. Among 582 with a measured NT-proBNP, 24.1% had values ≥160 pg/mL. Of 22 deaths during follow-up, 50% had a TRV≥3.0 m/sec. At 24 months the cumulative survival was 83% with TRV≥3.0 m/sec and 98% with TRV<3.0 m/sec (p<0.0001). The hazard ratios for death were 11.1 (95% CI 4.1–30.1; p<0.0001) for TRV≥3.0 m/sec, 4.6 (1.8–11.3; p = 0.001) for NT-proBNP≥160 pg/mL, and 14.9 (5.5–39.9; p<0.0001) for both TRV≥3.0 m/sec and NT-proBNP≥160 pg/mL. Age >47 years, male gender, chronic transfusions, WHO class III–IV, increased hemolytic markers, ferritin and creatinine were also associated with increased risk of death.

Conclusions

A TRV≥3.0 m/sec occurs in approximately 10% of individuals and has the highest risk for death of any measured variable.

The study is registered in ClinicalTrials.gov with identifier

{"type":"clinical-trial","attrs":{"text":"NCT00492531","term_id":"NCT00492531"}}NCT00492531     

Preparation and Characterization of <Emphasis Type="Italic">Alphitobius diaperinus</Emphasis> Melanin

Melanin with a high antioxidant and sorption activity comparable to that of synthetic dioxyphenylalanine (DOPA)-melanin was isolated from the biomass of the darkling beetle Alphitobius diaperinus. The pigment was extracted with a solution of potassium hydroxide, followed by precipitation with concentrated hydrochloric acid and hydrolysis of the resulting precipitate with the same acid. The electron paramagnetic resonance (EPR) signal of melanin was characteristic of eumelanins with a spin concentration of 4.9 × 10¹⁷ spin per 1 g of dry weight. The melanin concentration that induced 50% inhibition of peroxidation was 9.2 μg/mL (the analogous concentration of DOPA-melanin was 8.0 μg/mL). The maximum of methylene-blue binding to the beetle melanin was 700 mg of dye per 1 g of dry weight of the preparation. The lipid-free melanin preparation exhibited antiradical activity.     

Binding of iron ions by shielding eye pigments of vertebrates and invertebrates--melanosomes and ommochromes

Melanosomas of eye pigment epithelium tissue of vertebrates, synthetic DOPA-melanin and ommochromas from eye of invertebrates bind effectively bivalent iron ions. Constants of the binding process are calculated. Endogenic iron concentration in melanosomas of the frog eye pigment epithelium is determined. A conclusion is drawn that mechanism of antioxidation action of shielding eye pigments may include Fe2+ ion binding into inactive components.     

Fine‐scale bird monitoring from light unmanned aircraft systems

Unmanned aircraft systems (UAS) are remote‐controlled devices capable of collecting information from difficult‐to‐access places while minimizing disturbance. Although UAS are increasingly used in many research disciplines, their application to wildlife research remains to be explored in depth. Here, we report on the use of a small UAS to monitor temporal changes in breeding population size in a Black‐headed Gull Chroicocephalus ridibundus colony. This method makes it possible to obtain georeferenced data on nest locations without causing colony disturbance, which would not otherwise be possible via direct ground observations.     

Modeling the Entire Human Mortality Curve: A Regulatory Model of Aging

Biophysics - Abstract—Modeling of the human aging process was performed based on the relationship between overall viability and the processes of growth and self-renewal of tissues, which is...     

Opposite effect of lipofuscin granules and melanosomes from human retinal pigment epithelium of eye on photooxidation of cardiolipin

The influence of lipofuscin granules and melanosomes from human retinal pigment epithelium on the light-induced photooxidation of cardiolipin liposomes and the generation of superoxide radicals was studied. Lipofuscin granules were able to stimulate, while melanosomes inhibited, the cardiolipin photooxidation. The visible light irradiation of both melanosomes and lipofuscin granules generated superoxide radicals with mean rates of 1.5 nmole/min/10(7) and 38 nmole/min/10(7) granules, accordingly. However, melanosomes but not lipofuscin granules reacted readily with superoxide radicals. Moreover, the rate constant of degradation of superoxide radicals in the presence of melanosomes was about five orders of magnitude higher than the rate constant of its photogeneration. Therefore, we propose that melanosomes in retinal pigment epithelium cells have a photoprotective role whereas lipofuscin granules may stimulate photodestructive reactions.