A new Ruscinian site in Europe: Baza-1 (Baza basin,Andalusia, Spain)

The Guadix–Baza depression (southeastern Spain) preserves one of the best continental Plio-Pleistocene records of the European continent. The new site, Baza-1, is the first Ruscinian locality with fauna of large vertebrates known in the basin. During the summer seasons of 2001, 2002, 2015 and 2016, systematic excavations were undertaken in the site over an area of 25 m², which provided > 400 fossil remains of Ruscinian mammals. The faunal assemblage is diverse, comprising 17 genera. Rodentia are represented by Ruscinomys sp., Apocricetus barrierei, Debruijnimys julii, Apodemus gorafensis, Castillomys gracilis, Occitanomys cf. brailloni, Paraethomys meini, Paraethomys aff. abaigari, Stephanomys cordii, Trilophomys cf. castroi and Eliomys aff. intermedius. Large mammals are represented by two proboscideans, Anancus arvernensis and Mammut borsoni, the rhino Stephanorhinus sp. cf. S. jeanvireti, the equid cf. Hipparion sp., two bovids, a large sized Alephis sp. and a small-to-middle sized Bovidae indet. (cf. Antilope sp.), and a middle sized deer, Cervinae indet. This record is completed by the presence of a chelonid, Testudinae indet. Biostratigraphic data from micro and macromammals suggest an age for the assemblage between 4 and 4.5 Ma.     

SARS‐CoV‐2 Alpha,Beta, and Delta variants display enhanced Spike‐mediated syncytia formation

Severe COVID‐19 is characterized by lung abnormalities, including the presence of syncytial pneumocytes. Syncytia form when SARS‐CoV‐2 spike protein expressed on the surface of infected cells interacts with the ACE2 receptor on neighboring cells. The syncytia forming potential of spike variant proteins remain poorly characterized. Here, we first assessed Alpha (B.1.1.7) and Beta (B.1.351) spread and fusion in cell cultures, compared with the ancestral D614G strain. Alpha and Beta replicated similarly to D614G strain in Vero, Caco‐2, Calu‐3, and primary airway cells. However, Alpha and Beta formed larger and more numerous syncytia. Variant spike proteins displayed higher ACE2 affinity compared with D614G. Alpha, Beta, and D614G fusion was similarly inhibited by interferon‐induced transmembrane proteins (IFITMs). Individual mutations present in Alpha and Beta spikes modified fusogenicity, binding to ACE2 or recognition by monoclonal antibodies. We further show that Delta spike also triggers faster fusion relative to D614G. Thus, SARS‐CoV‐2 emerging variants display enhanced syncytia formation.     

Isolation of murine sialoglycoprotein using consecutive chromatography

Affinity columns and high performance liquid chromatography were employed consecutively to obtain 89, 65, 46 and 29 kilodalton sialoglycoproteins from mouse erythrocyte ghosts free of the Band 3 protein which traditionally co-purifies with these proteins. The purification scheme involves Concanavalin A, Wheat Germ Agglutinin and/or Limulus lectin Sepharose 4B columns. We have designated these glycophorin-like proteins Sialoglycoproteins 1, 2, 3, and 4, respectively. Sialoglycoprotein 2 can be isolated independently using a Limulus column combination, while Sialoglycoproteins 3 and 4 were isolated separately during high performance liquid chromatography, demonstrating heterogeneity in binding properties between these sialoglycoproteins.     

Transmural potential difference and short circuit current of chicken cecum in vitro

The electrical parameters of the chicken cecum were studied in vitro, in birds fed a commercial NaCl-rich diet. The statistical analysis of data was carried out using a linear model-based method which enabled standardization of concomitant factors that could mask the interpretation of the results. Transmural potential difference (PD) decreased initially reaching stable values at 50 min between 7.9 and 9.0 mV. Short-circuit current (Isc) was stable during incubation, with lower values in the medial (41.8 microA/cm2) than in the distal (58.1 microA/cm2) region of the cecum. The reduction of Na+ concentration in the incubation medium produced a fall in PD and Isc and both were ouabain and amiloride sensitive. This indicates that the current is largely carried by the net Na+ transport.     

Effects of secretagogues on the K+ permeability of mucosal and serosal borders of rabbit colonic mucosa

(1) K⁺ efflux rates from the mucosal and serosal surfaces of sheets of rabbit colonic mucosa have been determined by measuring net K⁺ loss into K⁺-free Ringer solution bathing each side of the tissue. (2) Initially, there is a high rate of K⁺ loss from the tissue, this falls to a lower steady-state rate after 20 min. Loss of K⁺ from the tissue into the serosal bath is 6–8-fold faster than loss to the mucosal bath. (3) A number of intestinal secretagogues, e.g. theophylline, cyclic AMP, carbachol, ionophore A23187, as well as the laxative bisacodyl, raise the K⁺ efflux rate across the mucosal border by 200–300%. In the case of K⁺ efflux induced by carbachol the effect is shown to be dependent on raised levels of intracellular Ca²⁺. Ca²⁺-calmodulin complex does not appear to be be involved in activation of K⁺ efflux across the mucosal border. (4) Amiloride does not block mucosal K⁺ efflux, but tetraethyl-ammonium does inhibit K⁺ efflux across the mucosal border, induced by either bisacodyl or raised intracellular Ca²⁺. (5) The results suggest that laxatives may increase the rate of K⁺ secretion into the colonic lumen by raising the K⁺ permeability of the mucosal border.     

Species specificity in mouse glycophorin

89, 65, 46 and 29 Kd mouse glycophorin proteins identified during polyacrylamide electrophoresis of mouse erythrocytes have been further characterized. These proteins (1) stain positive with Periodic Acid Schiff reagent after sodium hydroxide treatment; (2) labeled using [125I] in intact cells; (3) co-isolated along with integral membrane proteins in the pellet fraction of sodium hydroxide treated ghosts; and (4) demonstrated a molecular weight downshift after neuraminidase treatment during electrophoresis. We have called them mouse Sialoglycoproteins 1, 2, 3 and 4. Immuno-blot analysis revealed distinct species specificity between human and mouse erythrocyte ghosts, and some cross-reactivity between rat and mouse erythrocyte ghosts.     

Iron mobilization in estrogenized male quail

A single diethylstilbestrol (DES) injection (5 mg DES/100 g body wt) was administrated to several lots (three specimens each) of adult male quail (Coturnix coturnix japonica). The birds were sacrificed 24, 48, 72 and 96 hr after the DES injection. A significant increase in liver weight and a clear drop in the hemoglobin concentration were observed after 24 hr. Later, a progressive rise was observed in plasma iron, total iron binding capacity, plasma copper and the phosphoprotein (vitellogenin), which reached highest values after 96 hr. In the liver, the iron showed an initial increase (24 hr), due to a rise in non-ferritin iron followed by a progressive decrease. Ferritin iron increased slowly but was significantly higher after 96 hr. This experimental model on male quail suggests an estrogen response in birds that could be more general and uniform than in mammals.