Single-particle visualization of assembly: I. Dimerization in a planar zone

Single-particle fluorescence microscopy of association/dissociation is required for analysis of biological assembly reactions. Toward achieving this goal, Wang et al. (J. Microsc., 2004, 213 , 101–109) used molten agarose to concentrate thermally diffusing particles in a thin zone of solution next to the surface of a coverglass (plane of concentration). The present study details the first real-time, single-particle analysis of the association/dissociation of thermally diffusing particles in the plane of concentration. The test particles were procapsids of bacteriophage λ (radius = 31 nm). Quantification of thermal motion was developed and used to determine whether co-diffusing particles were bound to each other. The data are explained by (1) the presence of a molten agarose-generated barrier that is 93–155 nm from the coverglass surface, and (2) non-random orientation of procapsid dimers in the plane of concentration.     

INHIBITION OF LISTERIA MONOCYTOGENES BY LACTOCOCCUS LACTIS SUBSP. LACTIS ISOLATED FROM ITALIAN RAW HAM

A total of 168 strains of lactic acid bacteria were isolated from Italian raw ham and screened for antagonistic activity against Listeria monocytogenes by using an agar spot assay. Only one strain of Lactococcus lactis subsp . lactis produced antagonistic effects other than inhibition by low pH and hydrogen peroxide. The proteinaceous nature of the compound produced by L. lactis B10 was demonstrated by its inactivation by proteolytic enzymes. The cell-free culture super-natants (filtered and heat-treated) showed a bactericidal mode of action. Bacteriocin produced by L. lactis B10 was inhibitory to other lactic acid bacteria and one strain of Staphylococcus aureus, but not to the gram-negative bacteria tested .     

Comparison between light and electron microscopy in canine and feline renal pathology: a preliminary study

The aim of this study is to compare the accuracy and clinical use of light and transmission electron microscopy in detecting the early stages of renal pathologies in domestic animals. We examined 30 samples of renal tissue from cats and dogs referred to the Veterinary Hospital of the Department of Animal Pathology for different systemic diseases. The progressions of the kidney pathologies were classified using the scheme system proposed by the International Renal Interest Society. All samples were submitted for conventional histology and ultrastructural examination. Our study shows that electron microscopy is necessary to complete the histological examinations, especially to define early stages of kidney diseases (minimal changes disease, epithelial tubular pathologies, tubular basement membrane and glomerular basement membrane changes). Electron microscopy can be more accurate in defining the level of focal lesion, and permits discrimination between different clinical and pathological alterations such as fibrillary deposits. In conclusion, transmission electron microscopy associated with clinical, histological, histochemical and immunological examinations, is an essential method for diagnosis and prognosis of renal disease.     

Role of PTX3 and complement modulation in the tumor microenvironment

Pentraxin-3 (PTX3), the prototype of long pentraxins, seems to influence complement system (CS) modulation. PTX3 and CS sustain carcinogenesis, enriching tumor microenvironment (TME) with pro-inflammatory molecules promoting angiogenesis in prostate cancer (PC) and renal cell carcinoma (RCC). Furthermore, cancer cells overexpress complement regulatory proteins, such as CD46, CD55 and CD59, which negatively affect complement pathways for support cancer cells survival. This viewpoint aims to elucidate the ambivalent role of PTX3 and the CS in the context of tumor microenvironment (TME).     

WT-1 mRNA expression is modulated by nitric oxide availability and Hsp70 interaction after neonatal unilateral ureteral

Wilms tumor gene 1 (wt-1), a key regulator of mesenchymal-epithelial transformation, is downregulated during congenital obstructive nephropathy, leading to apoptosis. There is a functional interaction between WT-1 and inducible nitric oxide synthase (iNOS). In this regard, we reported that after neonatal unilateral ureteral obstruction, rosuvastatin prevents apoptosis through an increase in nitric oxide bioavailability, which in turn is linked to higher Hsp70 expression. Hence, the goal of this study was to determine whether a nitric oxide/Hsp70 interaction is involved in changes in WT-1 mRNA expression after ureteral obstruction. Neonatal rats submitted to experimental ureteral obstruction were treated with either vehicle or rosuvastatin for 14 days. Decreased nitric oxide and iNOS/Hsp70 expression associated with WT-1 low expression was shown in obstructed kidneys. Apoptosis was induced and it was associated with an increased Bax/BcL2 ratio. Conversely, iNOS/Hsp70 upregulation and an increased WT-1 mRNA expression, without an apoptotic response, were observed in the cortex of obstructed kidneys of rosuvastatin-treated rats. Nitric oxide also modulated Hsp70 and WT-1 mRNA expression in MDCK cells. Finally, in vivo experiments with nitric oxide modulators support our hypothesis that WT-1 mRNA expression is associated with nitric oxide level. Results suggest that rosuvastatin may modulate WT-1 mRNA expression through renal nitric oxide bioavailability, preventing neonatal obstruction-induced apoptosis associated with Hsp70 interaction.     

Identification of SARS-CoV-2 by gold nanoparticles

The SARS-CoV-2 outbreaks highlighted the need for effective, reliable, fast, easy-to-do and cheap diagnostics procedures. We pragmatically experienced that an early positive-case detection, inevitably coupled with a mass vaccination campaign, is a milestone to control the COVID-19 pandemic. Gold nanoparticles (AuNPs) can indeed play a crucial role in this context, as their physicochemical, optics and electronics properties are being extensively used in photothermal therapy (PTT), radiation therapy (RT), drug delivery and diagnostic. AuNPs can be synthesized by several approaches to obtain different sizes and shapes that can be easily functionalized with many kinds of molecules such as antibodies, proteins, probes, and lipids. In addition, AuNPs showed high biocompatibility making them useful tool in medicine field. We thus reviewed here the most relevant evidence on AuNPs as effective way to detect the presence of SARS-CoV-2 antigens. We trust future diagnostic efforts must take this ‘old-fashioned’ nanotechnology tool into consideration for the development and commercialization of reliable and feasible detection kits.     

APPLICATION OF MULTIVARIATE STATISTICAL ANALYSES TO THE STUDY OF FACTORS AFFECTING WHITE WINE VOLATILE COMPOSITION

ABSTRACT

The influence of different storage conditions on the volatile composition of young white wine was evaluated during 1 year of storage. The wine was bottled and stored under different conditions of temperature, position and illumination. During storage, a significant increase in total content esters (mainly due to the increase in ethyl butyrate, ethyl acetate and diethyl succinate) and total content acids was detected. Also total content alcohols and carbonyl compounds decreased during storage. Storage time, temperature and illumination have a significant effect on esters content, whereas carbonyl compounds are affected by temperature, and alcohols content is affected by illumination. Stepwise linear discriminant analysis was applied to the experimental data. The results showed that the samples were well classified as a function of storage temperature. On the other hand, a certain trend was observed when the wine samples were classified according to storage time. The samples corresponding to two and four months of storage were well differentiated from the rest.

PRACTICAL APPLICATIONS

From a sensory point of view, the aroma influences greatly the quality of wines. The loss of aromatic characteristics in young white wine, as well as browning, take place over a variable period of time which ranges from one month to several years, depending on wine type and storage conditions. Assessment of possible factors affecting the useful lifespan of young white wine is of great interest for the wine making industry. Knowing the chemical composition of wine, specifically aromas, and its evolution relating to different storage and preservation conditions is an important tool in quality control.