Two complementary fluorimetric assays for the determination of aminoquinoline binding and uptake by human erythrocytes in vitro

We provide two simple low-cost and low-tech procedures to measure with good precision and accuracy the binding and internalization into human erythrocytes of chloroquine and other aminoquinolines. The methods are based on the high fluorescence of the quinoline ring and are complementary. Method A evaluates residual drugs in the supernatants of treated erythrocytes, whereas method B quantifies the total uptake by whole cells and the fraction bound to the membranes. Drug uptake is dose dependent and related to the number of erythrocytes. These assays could be useful when studying the cell interaction of quinoline-type compounds not available in the radioactive form.     

Syncytia formation by SARS‐CoV‐2‐infected cells

In the supporting information of the article, the authors noticed that there was an error in Movie EV1. The right panel (SARS‐CoV‐2 + IFITM1) showed the same PI channel data (red) as the middle panel (SARS‐CoV‐2). This mistake occurred during the assembly of the merged movie file and does not change the interpretation of the data. A corrected version of the movie is herewith updated.     

Neuronal membrane dynamics as fine regulator of sphingolipid composition

Sphingolipid metabolism is an intricate network of several interdependent and co-regulated pathways. In addition to the mainstream biosynthetic and catabolic pathways, several processes, even if less important in contributing to the final tissue sphingolipid composition from the quantitative point of view, might become relevant when sphingolipid metabolism is for any reason dysregulated and concur to the onset of neuronal pathologies. The main subcellular sites involved in the mainstream metabolic pathway are represented by the Golgi apparatus (for the biosynthesis) and by the lysosomes (for catabolism). On the other hand, the minor collateral pathways are associated with the plasma membrane and membranes of other organelles, and likely play important roles in the local regulation of membrane dynamics and contribute to maintain a perfect membrane organization functional to the physiology of the cell. In this review, we will consider few aspects of the sphingolipid metabolic pathway depending by the dynamic of the membranes that seems to become relevant in neurodegenerative diseases.     

Update on the presence of taste buds on the laryngeal surface of the epiglottis]

Previous investigations have ascertained, according to the results obtained by Bradley et al. (1980) in the sheep, that the laryngeal surface of the epiglottis of goat and bovine is always provided with numerous taste buds. These observations have verified in other ruminant species, as the moufflon and the buffalo, the validity of the above-named datum and have ascertained that it is always inconstant in the other animal species considered (wild boar, coypu). These taste buds show a typical structure (diameter of the outer taste pore varying from 2.7 to 4.2 micron, width of the chemoreceptors varying from 30 to 60 micron and length from 27.5 to 57.5 micron). Moreover, the normal structure of the above-named taste buds is also testified by the arrangement of their innervation and particularly by the integrity of the synaptic contacts. The results of the present research have permitted a critical and more severe examination of the probable functional role of those laryngeal receptors. In fact, in the ruminants they may protect the deep airways precluding to food particles the larynx in the phase of food regurgitation.     

Comparison of cyclohexanone monooxygenase as an isolated enzyme and whole cell biocatalyst for the enantioselective oxidation of 1,3-dithiane

Both whole cells of recombinant Escherichia coli TOP10, overexpressing cyclohexanone monooxygenase (CHMO) and isolated cyclohexanone monooxygenase, were used to carry out the enantioselective oxidation of 1,3-dithiane (1) to (R)-1,3-dithiane-1-oxide (2). The two biocatalysts were evaluated under various experimental conditions (e.g., shaken flask or bioreactor; non-bound or resin-adsorbed substrate; different substrate concentrations) in terms of volumetric productivity and enantioselectivity. While productivity was similar in the two cases (up to 0.58 g L⁻¹ h⁻¹), the optical purity of the product was much higher with the isolated enzyme (up to 98% e.e.) than with the whole cell biocatalyst (up to 85% e.e.).