Mice deficient in involucrin, envoplakin, and periplakin have a defective epidermal barrier

The cornified envelope is assembled from transglutaminase cross-linked proteins and lipids in the outermost epidermal layers and is essential for skin barrier function. Involucrin, envoplakin, and periplakin form the protein scaffold on which the envelope assembles. To examine their combined function, we generated mice deficient in all three genes. The triple knockouts have delayed embryonic barrier formation and postnatal hyperkeratosis (abnormal accumulation of cornified cells) resulting from impaired desquamation. Cornified envelopes form but are ultrastructurally abnormal, with reduced lipid content and decreased mechanical integrity. Expression of proteases is reduced and the protease inhibitor, serpina1b, is highly upregulated, resulting in defective filaggrin processing and delayed degradation of desmoglein 1 and corneodesmosin. There is infiltration of CD4⁺ T cells and a reduction in resident γδ⁺ T cells, reminiscent of atopic dermatitis. Thus, combined loss of the cornified envelope proteins not only impairs the epidermal barrier, but also changes the composition of T cell subpopulations in the skin.     

Digestion versus abrasion features in rodent bones

The origin of most fossil small mammal assemblages is predation by avian or mammalian predators. Bone corrosion by gastric juices observed in these fossils is direct evidence of digestion, and traits of digestion indicate the type of predator involved. However, certain features observed in digested bones, such as rounding and polishing, are similar to the rounding and polishing produced by other processes, particularly abrasion, in which predation is not involved. Misidentification of digestion has major repercussions in palaeoenvironmental and palaeoclimatic interpretations as well as interpretations of biostratigraphy and potential reworking. Digestion is directional and progressive process, primarily affecting the most mineralized tissues (enamel) advancing from the tips to the centre of the anatomical element. In contrast, abrasion identically affects any type of osseous tissue homogeneously rounding the entire skeletal element. Microscopically, digested bones display a distinctive chemical corrosion (‘tornlike’ appearance), whilst abraded bones appear smooth with microstriations and pitting microwear. Here, we present the results of a series of experiments designed to establish new and clear criteria to distinguish bone rounding and polishing caused by digestion from that originating from abrasion.     

Elevated CO2 and water-availability effect on gas exchange and nodule development in N2-fixing alfalfa plants

N₂-fixing alfalfa plants were grown in controlled conditions at different CO₂ levels (350 μmol mol^?1 versus 700 μmol mol^?1) and water-availability conditions (WW, watered at maximum pot water capacity versus WD, watered at 50% of control treatments) in order to determine the CO₂ effect (and applied at two water regimes) on plant growth and nodule activity in alfalfa plants. The CO₂ stimulatory effect (26% enhancement) on plant growth was limited to WW plants, whereas no CO₂ effect was observed in WD plants. Exposure to elevated CO₂ decreased Rubisco carboxylation capacity of plants, caused by a specific reduction in Rubisco (EC 4.1.1.39) concentration (11% in WW and 43% in WD) probably explained by an increase in the leaf carbohydrate levels. Plants grown at 700 μmol mol^?1 CO₂ maintained control photosynthetic rates (at growth conditions) by diminishing Rubisco content and by increasing nitrogen use efficiency. Interestingly, our data also suggest that reduction in shoot N demand (reflected by the TSP and especially Rubisco depletion) affected negatively nodule activity (malate dehydrogenase, EC 1.1.1.37, and glutamate-oxaloacetate transaminase, EC 2.6.1.1, activities) particularly in water-limited conditions. Furthermore, nodule DM and TSS data revealed that those nodules were not capable to overcome C sink strength limitations.     

Maintenance of C sinks sustains enhanced C assimilation during long-term exposure to elevated [CO2] in Mojave Desert shrubs

During the first few years of elevated atmospheric [CO(2)] treatment at the Nevada Desert FACE Facility, photosynthetic downregulation was observed in desert shrubs grown under elevated [CO(2)], especially under relatively wet environmental conditions. Nonetheless, those plants maintained increased A (sat) (photosynthetic performance at saturating light and treatment [CO(2)]) under wet conditions, but to a much lesser extent under dry conditions. To determine if plants continued to downregulate during long-term exposure to elevated [CO(2)], responses of photosynthesis to elevated [CO(2)] were examined in two dominant Mojave Desert shrubs, the evergreen Larrea tridentata and the drought-deciduous Ambrosia dumosa, during the eighth full growing season of elevated [CO(2)] treatment at the NDFF. A comprehensive suite of physiological processes were collected. Furthermore, we used C labeling of air to assess carbon allocation and partitioning as measures of C sink activity. Results show that elevated [CO(2)] enhanced photosynthetic performance and plant water status in Larrea, especially during periods of environmental stress, but not in Ambrosia. δ(13)C analyses indicate that Larrea under elevated [CO(2)] allocated a greater proportion of newly assimilated C to C sinks than Ambrosia. Maintenance by Larrea of C sinks during the dry season partially explained the reduced [CO(2)] effect on leaf carbohydrate content during summer, which in turn lessened carbohydrate build-up and feedback inhibition of photosynthesis. δ(13)C results also showed that in a year when plant growth reached the highest rates in 5 years, 4% (Larrea) and 7% (Ambrosia) of C in newly emerging organs were remobilized from C that was assimilated and stored for at least 2 years prior to the current study. Thus, after 8 years of continuous exposure to elevated [CO(2)], both desert perennials maintained their photosynthetic capacities under elevated [CO(2)]. We conclude that C storage, remobilization, and partitioning influence the responsiveness of these desert shrubs during long-term exposure to elevated [CO(2)].     

ESR evidence for sequential divalent cation binding in higher plant cell walls

Electron spin resonance linewidth measurements have been made on intact cell walls exchanged with various combinations of Mn²⁺ and Ca²⁺. These experiments were performed to find the Mn²⁺ nearest-neighbor distance and thereby determine whether carboxylate-Mn²⁺ complexes potentiate ion association at adjacent sites on cell wall polyuronides. Our results show that as the fraction of available binding sites occupied by Mn²⁺ increased from 2% to 27%, the nearest-neighbor distance parameter decreased only from 14 to 11 Å. These distances are close to polyuronide interanionic spacings. The small change in the distance parameter with concentration is evidence for sequential rather than random binding. Competitive ion-exchange with Ca²⁺ was found to reduce the Mn²⁺ spin-spin line broadening at similar total bound Mn²⁺ concentrations. This is expected only if Ca²⁺ competes at adjacent sites. The data presented offer strong support for the hypothesis that carboxylate groups near already occupied sites have a greater affinity for divalent cations than other sites along the polyuronide main chain.     

Identification of protein and mannoprotein antigens of Candida albicans of relevance for the serodiagnosis of invasive candidiasis.

Antigens from Candida albicans blastoconidia and germ tubes were identified by two-dimensional electrophoresis and Western blotting and characterized by microsequencing, reactivity with concanavalin A, and a panel of human sera. Antigens identified included a polydispersed area in the acidic high-molecular-mass regions of blastoconidium and germ-tube extracts, and 16 antigens varying in molecular masses and isoelectric points (pIs). The majority of the detected antigens, especially those in the polydispersed region, showed mannosyl groups, as determined by concanavalin A reactivity. Antibodies present in sera from patients with invasive candidiasis showed high reactivity with a number of antigens not detected with sera from blood donors. Eight of the 16 antigens could be identified by reactivity with monoclonal antibodies or by microsequencing. Five antigens showed homology with five enzymes previously described as antigens in C. albicans: enolase, phosphoglycerate kinase, malate dehydrogenase, and two isoforms of the fructose biphosphate aldolase. However, to our knowledge, this is the first report of the immunogenic activity of a kexin precursor, a mitochondrial complex I chaperone, and a diacylglycerol kinase catalytic domain from C. albicans. Antigens described in this study may be of potential interest for the serodiagnosis of invasive candidiasis.     

Acute effects of different external compression with blood flow restriction on force-velocity profile during squat and bench press exercises

The aim was to compare the acute effects of bench press (BP) and squat (SQ) exercises with blood flow restriction (BFR) (40%, 60%, 80% and 100% of the complete arterial occlusion pressure (AOP)) and without BFR (CON) on the mean propulsive (Vel_MED) and maximum (Vel_MAX) bar velocity. Fourteen healthy, physically active males (age, 23.6 ± 4.1 years; height, 1.85 ± 0.11 m; body weight 85.4 ± 4.1 kg) took part in the study. There was one set for each testing condition (CON, 40%, 60%, 80% and 100%) with 6 repetitions for BP and 6 repetitions for SQ, at 60% of 1RM, and 3 minutes of recovery between sets. The results showed statistically significant differences of the sets with 80% BFR vs. CON (mean difference [MD] = 0.035 m · s^-1, p < 0.05, ES = 0.52 [1.02–0.03]) and 100% BFR sets vs. CON (MD = 0.074, p < 0.001, ES = 1.08 [1.79–0.38]) for BP. In the SQ exercise, statistically significant differences were found between 100% BFR vs. CON (DM = 0.031 m · s^-1, p < 0.05), vs. 100% BFR 40% (MD = 0.04 m · s^-1, p < 0.05). Trend analysis showed a statistically significant linear trend (F[1,9] = 34.9, p < 0.001, F[1,13] = 27.32, p < 0.001) for the Vel_MED in relation to the different levels of BFR. In conclusion, our results showed that BFR levels above ˜80% AOP (BP) and ˜100% AOP (SQ) produce a Vel_MED improvement at 60% 1RM.     

Selection and implantation of yeast strains of genus Saccharomyces at a winery regulated by Appellation Contrôlée "Chacolí de Vizcaya/Bizkaiko Txakolina"

The white wine Chacolía de Vizcaya/Bizkaiko Txakolina is characteristic from The Basque Country region and regulated under Appellation Contr?lée standards (BOPV 14/6/94). The objective of this study was the identification and selection of autochthonous yeast strains, to improve the conditions used to maintain the typical characteristics of this region wines. Yeasts identified as Saccharomyces bayanus isolated around these fields from 1996 to 1998, were subjected to a selective procedure based on enological characteristics and fermentative behaviour. Three of the selected strains were used to inoculate, at winery scale, two grape juice varieties accepted by the Appellation Contr?lée (Hondarrabi Zuri and Folle Blanche). The inoculated strains on the respective vinifications was followed by restriction fragment length polymorphism of mitochondrial DNA (REAmt) method with AluI enzyme, due to their specificity, short outcome, and technological simplicity compared with other molecular typing methods such as: chromosomal karyotyping analyzed by pulsed field gel electrophoresis, Random Amplified Polymorphic DNA-PCR (RAPD-PCR) and restriction fragment length polymorphism using the infrequently cutting enzyme SfiI (REA infrequent). This study demonstrated that strains with different phenotypic traits could show indistinguishable restriction patterns with REAmt, but could be discriminated using other typing methods such as RAPD-PCR, which although showing low reproducibility could be used as complementary to REAmt. Our results demonstrate that in spite of using autochthonous selected strains, the inoculation of musts with a particular strain do not guarantee its predominance and driving fermentation features. Of all yeast strains studied, strain no. 2 showed the best results in sensory testing and at the implantation process. Therefore, it could be used with commercial purposes for the production of Chacolí de Vizcaya/Bizkaiko Txakolina, especially when using musts from Folle Blanche.