Conditioning adhesive contacts between the neutrophils and the endotheliocytes by Staphylococcus aureus

We have developed a model for evaluating the integral intercellular interactions in the “endotheliocyte‐neutrophil” system and have shown the high variability of adhesion contacts in different donors associated with different expression profiles of neutrophils. Two methods (forсe spectroscopy‐spectroscopy and scanning ion‐conductance microscopy) showed a decrease in the rigidity of the membrane‐cytoskeletal complex of neutrophils under the influence of Staphylococcus aureus 2879 M. Adding this strain to the “endotheliocyte‐neutrophil” system caused a statistically significant decrease in the adhesion force and adhesion work, which indicates a change in the expression profile and physicochemical properties of membranes of both types of interacting cells (neutrophils and endotheliocytes).     

New advances on the Aurignacian in the central Iberian Mediterranean basin

This study aims to obtain a chronological and cultural framework of the Evolved Aurignacian in the central Iberian Mediterranean basin and find agreement between this framework and other sequences of the Iberian southeast. Over the last few years, there has been remarkable progress in the research of the Evolved Aurignacian sites in the Valencian area, making a review of the main characteristics of the technocomplex on a regional scale necessary. The recent fieldwork carried out in Cova de les Malladetes (Valencia) and in Cova de les Cendres (Alicante) have been key to understanding the lithic, osseous and ornament assemblages ascribed to the Evolved Aurignacian. Several Bayesian modelled ages have been constructed from the large dataset of chronological dates obtained at Malladetes and Cendres, as well as in other sites. The Bayesian models have allowed us to chronologically place the characteristics of the analysed assemblages. The present research supports the importance of the Aurignacian as the first technocomplex of the Upper Palaeolithic in this area of the Iberian Peninsula.     

Lung tissue engineering and preservation of alveolar microstructure using a novel casting method

Abstract

We used a rat model to decellularize and seed alveolar cells on a three-dimensional lung scaffold to preserve alveolar microarchitecture. We verified the preservation of terminal respiratory structure by casting and by scanning electron microscopy (SEM) of the casts after decellularization. Whole lungs were obtained from 12 healthy Sprague-Dawley rats, cannulated through the trachea under sterile conditions, and decellularized using a detergent-based method. Casting of both natural and decellularized lungs was performed to verify preservation of the inner microstructure of scaffolds for further cell seeding. Alveolar cell seeding was performed using green fluorescent protein (GFP) lung cells and non-GFP lung cells, and a peristaltic pump. We assessed cell seeding using histological and immunohistochemical staining, and enzymatic evaluation. All cellular components were removed completely from the scaffolds, and histological staining and SEM of casts were used to verify the preservation of tissue structure. Tensile tests verified conservation of biomechanical properties. The hydroxyproline content of decellularized lungs was similar to native lung. Histological and immunohistochemical evaluations showed effective cell seeding on decellularized matrices. Enzymatic measurement of trypsin and alpha 1 antitrypsin suggested the potential functional properties of the regenerated lungs. Casts produced by our method have satisfactory geometrical properties for further cell seeding of lung scaffolds. Preservation of micro-architecture and terminal alveoli that was confirmed by SEM of lung casts increases the probability of an effective cell seeding process.     

In vitro and in vivo antimicrobial efficacy of essential oils and individual compounds against Phytophthora parasitica var. nicotianae

Aim

To evaluate the antimicrobial effects of essential oils (EOs) from cassia, basil, geranium, lemongrass, cumin and thyme, as well as their major components, against Phytophthora parasitica var. nicotianae; to investigate morphological changes in hyphae and sporangia in response to treatment with cinnamaldehyde; and to further evaluate potential biocontrol capacities against tobacco black shank under greenhouse conditions.

Methods and Results

The results revealed that the extent of mycelial growth inhibition was primarily dependent on the composition and concentration of the EOs and the structure of individual compounds. Cinnamaldehyde had a significantly higher inhibitory effect on mycelial growth, formation of sporangia, and production and germination of zoospores in P. parasitica var. nicotianae in vitro, achieving complete inhibition of these phenotypes at 72, 36, 36 and 18 mg l^?1, respectively. Scanning electron microscopic observations revealed that cinnamaldehyde can cause considerable morphological degenerations of hyphae and sporangia such as cytoplasmic coagulation, shrivelled mycelia and sporangia aggregates and swelling and lysis of mycelia and sporangia walls. In vivo assays with cinnamaldehyde demonstrated that this compound afforded protective effect against tobacco black shank under greenhouse conditions in susceptible tobacco plants.

Conclusions

The results of in vitro and in vivo bioassays, together with SEM imaging of the microstructure of P. parasitica var. nicotianae supported the possibility of using cinnamaldehyde as a potent natural biofungicide in the greenhouse.

Significance and Impact of the Study

This study provides a theoretical basis for the potential use of cinnamaldehyde as commercial agents or lead compounds that can be exploited as commercial biofungicides in the protection of tobacco plants from P. parasitica var. nicotianae infection.     

Elimination of Aspergillus fumigatus conidia from the airways of mice with allergic airway inflammation

Background

Aspergillus fumigatus conidia can exacerbate asthma symptoms. Phagocytosis of conidia is a principal component of the host antifungal defense. We investigated whether allergic airway inflammation (AAI) affects the ability of phagocytic cells in the airways to internalize the resting fungal spores.

Methods

Using BALB/c mice with experimentally induced AAI, we tested the ability of neutrophils, macrophages, and dendritic cells to internalize A. fumigatus conidia at various anatomical locations. We used light microscopy and differential cell and conidium counts to determine the ingestion potential of neutrophils and macrophages present in bronchoalveolar lavage (BAL). To identify phagocyte-conidia interactions in conducting airways, conidia labeled with tetramethylrhodamine-(5-(and-6))-isothiocyanate were administered to the oropharyngeal cavity of mice. Confocal microscopy was used to quantify the ingestion potential of Ly-6G⁺ neutrophils and MHC II⁺ antigen-presenting cells located in the intraepithelial and subepithelial areas of conducting airways.

Results

Allergen challenge induced transient neutrophil recruitment to the airways. Application of A. fumigatus conidia at the acute phase of AAI provoked recurrent neutrophil infiltration, and consequently increased the number and the ingestion potential of the airway neutrophils. In the absence of recurrent allergen or conidia provocation, both the ingestion potential and the number of BAL neutrophils decreased. As a result, conidia were primarily internalized by alveolar macrophages in both AAI and control mice at 24 hours post-inhalation. Transient influx of neutrophils to conducting airways shortly after conidial application was observed in mice with AAI. In addition, the ingestion potential of conducting airway neutrophils in mice with induced asthma exceeded that of control mice. Although the number of neutrophils subsequently decreased, the ingestion capacity remained elevated in AAI mice, even at 24 hours post-conidia application.

Conclusions

Aspiration of allergen to sensitized mice enhanced the ingestion potential of conducting airway neutrophils. Such activation primes neutrophils so that they are sufficient to control dissemination of non-germinating A. fumigatus conidia. At the same time, it can be a reason for the development of sensitivity to fungi and subsequent asthma exacerbation.     

Phylogenetics and seed morphology of African Nymphoides (Menyanthaceae)

We evaluated the boundaries among Nymphoides (Menyanthaceae) species in Africa, a region where the genus has received relatively little attention. We gathered morphological data from seeds using light and scanning electron microscopy, and we conducted molecular phylogenetic analyses using nuclear sequence data from the internal transcribed spacer (ITS) region. Morphological and molecular features distinguished six species and affirmed their respective geographic ranges. No African specimens were attributable to Nymphoides indica, even though this paleotropical species previously had been understood to grow in Africa. We establish the new combination Nymphoides senegalensis (G. Don) Tippery, based on an established African basionym, to accommodate the specimens formerly identified as N. indica. Phylogenetic analyses resolved two distinct clades containing African species. The majority of African species are closely related to neotropical species, with which they share similar petal ornamentation. The morphologically distinct N. ezannoi shares floral and phylogenetic similarity with species from North America and Asia. Results presented here support prior hypotheses that allopolyploid species in the Americas may have originated from one or more parental lineages in Africa. Seed morphological characters remain some of the most reliable features for identifying species, particularly for herbarium specimens lacking observable floral characters.     

Oxidized albumin. The long way of a protein of uncertain function

Background

Proteins are extremely reactive to oxidants and should represent a potential target of instable reactive oxygen. This may represent a problem for plasma proteins since they may be directly modified in vivo in a compartment where antioxidant enzymatic systems are scarcely represented. On the other hand, it is possible that some plasma components have evolved over time to guarantee protection, in which case they can be considered as anti-oxidants.

Scope of review

To present and discuss main studies which addressed the role of albumin in plasma antioxidant activity mainly utilizing in vitro models of oxidation. To present some advances on structural features of oxidized albumin deriving from studies carried out on in vitro models as well as albumin purified in vivo from patients affected by clinical conditions characterized by oxidative stress.

Major conclusions

There are different interaction with HOCl and chloramines. In the former case, HOCl produces an extensive alteration of ²³⁸Trp and ¹⁶²Tyr, ⁴²⁵Tyr, ⁴⁷Tyr, while thiol groups are only partially involved. Chloramines are extremely reactive with the unique free SH group of albumin (³⁴Cys) with the formation of sulfenic and sulfinic acid as intermediates and sulfonic acid as end-product. Oxidized albumin has a modified electrical charge for the addition of an acidic residue and presents α-helix and random coil reorganization with subtle changes in domain orientation.

General significance

Albumin, is the major antioxidants in plasma with a concentration (0.8 mM) higher than other antioxidants by an exponential factor. Functional and protective roles in the presence of oxidative stress must be defined. This article is part of a Special Issue entitled Serum Albumin.