Kp determination by derivative spectroscopy and Stern Volmer plots of Daunorubicin using a DMPC:SM model system. from A biophysical approach to daunorubicin interaction with model membranes: relevance for the drug's biological activity

Absorption (A) and third-derivative absorption (B) spectra of daunorubicin (40μM) (red line, 0) alone, incubated in DMPC:SM model membrane at 37 °C. Stern–Volmer plots of the probe DPH in the DMPC:SM model at pH 7.4 and 37 °C with increasing daunorubicin concentration

Mercury levels in parturient and newborns from Aveiro region, Portugal

<p>Since the outbreak of methylmercury (MeHg) poisoning in Japan and Iraq, mercury (Hg) is classified as well-established teratogen. The Portuguese region of Aveiro faced some decades ago an environmental Hg contamination due to activities from a chlor-alkali plant. Until now, no apparent evaluation was conducted regarding prenatal exposure to Hg in this area. The main objectives of this study were to: i) assess maternal and fetal exposure to Hg in the Aveiro region using noninvasive biological matrices; ii) examine the influence of variables that may contribute to Hg exposure during pregnancy; and iii) improve knowledge regarding metal accumulation and distribution over the maternal–fetal–placental unit. This study was performed in 50 mother–newborn pairs from the Aveiro district. Total Hg (THg) was quantified in maternal scalp hair, placenta, amniotic membrane, and umbilical cord. Maternal hair presented THg levels with a mean value of 900 ng/g, which is lower than the USEPA and WHO acceptable threshold. Regarding THg levels in placenta and umbilical cord, mean values were similar (decidua basalis: 32.84 ng/g; chorionic plate: 30.18 ng/g; umbilical cord: 30.67 ng/g). The amniotic membrane presented the highest THg levels with a mean concentration of 42.35 ng/g, reaching a maximum of 134.1 ng/g. Further, a significant positive correlation was noted between THg levels found in hair, and all matrices analyzed reinforcing the use of hair in biomonitoring studies with respect to maternal exposure to Hg. In general, levels of THg found in our study were lower than those in previous studies performed in Europe. Consumption of fish rich in selenium and bottled water was negatively correlated with THg levels. Finally, data demonstrated that Hg is capable of crossing the placental barrier and accumulate in placental tissues. Amniotic membrane seemed to play a role in metal detoxification, but further investigations are necessary to examine whether this catabolic process affects Hg accumulation.</p

Response of tagged long-finned pilot whales to KW and CTRL playbacks.

<p>(A) Reaction scores for KW playbacks (N = 5 whales tested twice, n = 10 trials) and CTRL playbacks (N = 3 whales tested twice, n = 6 trials). Positive values: attraction towards the sound source; negative values: avoidance. Dashed lines link the reaction scores of the same subject. (B) Change of group size during KW and CTRL playbacks (for each stimulus type: N = 3 individuals tested twice, n = 6 trials). Positive values: whales aggregating around tagged animal; negative values: whales spreading. Error bars give mean ± SEM.</p

Track of tagged whale gm10_158d.

<p>Each dot corresponds to 1 sighting. Orange: baseline period. Black: control playback (CTRL) period. Magenta: killer whale playback (KW) period. Triangles: position of the sound source, at start and end of playbacks. Dotted lines: projected course of the whale as if the animal had kept its initial direction of horizontal movement.</p

Reaction scores for the 10 KW playback trials (magenta) and the 6 CTRL playback trials (grey) versus the distance between tagged whale and sound source at start of playback.

<p>The 6 different signs represent the 6 tagged whales (▵◊□○X+).</p