Finding the best antibody dilution by repeated immunostaining of the same tissue section

One can find the optimal antibody dilution for immunostaining by repeated staining on the same tissue section by using a less dilute antibody for each attempt. Using secondary antibody and horseradish peroxidase conjugated to a dextran polymer, a section stained repeatedly with several dilutions of antibody appears as good as a section stained with only the last dilution.     

Barley microgreen incorporation in diet-controlled diabetes and counteracted aflatoxicosis in rats

Increased environmental pollution and unhealthy lifestyle are blamed for escalated chronic diseases. Exposure to aflatoxins was recently suggested to have a role in the increased incidence of type 2 diabetes mellitus. Diet modification and consumption of different functional food are now gaining attention, especially in diabetes management. This study investigates the effect of a diet containing barley microgreen against diabetes induced by streptozotocin with or without aflatoxin administration in rats. Barley microgreen was rich in 3′-Benzyloxy-5,6,7,4′-tetramethoxyflavone (48.8% of total) followed by 5β,7βH,10α-Eudesm-11-en-1α-ol (18.46%). Streptozotocin injection and/or aflatoxin administration significantly elevated glucose level, decreased insulin level, decreased β-cell function, deteriorated liver and kidney function parameters, and induced oxidative stress in the liver. Histopathology revealed irregular small-sized islets and decreased area % of insulin-positive beta cells in the pancreas, hepatic degeneration, nephropathy, and neuropathy in diabetic and/or aflatoxin administered rats compared to control. Barley microgreen diet fed to diabetic rats with or without aflatoxin alleviated all evaluated parameters. Barley microgreen diet also ameliorated the toxic effect of aflatoxin. In conclusion, exposure to aflatoxin aggravated diabetes and its complication. The incorporation of barley microgreen in the diet was able to control type 2 diabetes mellitus and the improved outcomes observed with barley microgreen treatments involved or occurred in conjunction with improved biomarkers of oxidative stress.     

Biodamage on Phylladoderma leaves from the Upper Permian of the Pechora Basin

A new insect damage type on leaves Phylladoderma arberi Zalessky, 1913 from the Upper Permian of the Pechora Basin (Adz’va River, Russia) is described. These are punctures about 120 μm in diameter surrounded by circular spots with a dark rim. We suppose that these feeding traces were made by palaeodictyopteroid nymphs.     

Development of Search Strategy for Peptide Inhibitors of Immune Checkpoints

Current strategy for the blockade of molecules inhibiting T-cell immunity, the immune checkpoints (ICP), such as CTLA-4, PD-1, and B7-H1(PD-L1), using monoclonal antibodies (mAbs), showed significant clinical effects in cancer immunotherapy. In this kind of therapy, antibodies do not kill tumor cells directly, but block inhibitory signals for T lymphocytes, resulting in activation of the immune response cascade that eliminate malignant cells and lead to tumor degradation. However, the mAb preparations have some limitations, and the development of new low-molecular-weight antagonists (for example, peptides) is an important issue. In this study, we used peptide microarrays and phage display libraries to search for peptides that interact with the immune checkpoints. We found peptides that specifically bind CTLA-4, PD-1, B7-1, B7-2 and B7-H1(PD-L1) which play important role in the regulation of the immune responses. These synthetic peptides can be applied to the development of new immunomodulating drugs for cancer immunotherapy.     

Membrane mechanics can account for fusion pore dilation in stages.

Once formed, fusion pores rapidly enlarge to semi-stable conductance values. The membranes lining the fusion pore are continuous bilayer structures, so variations of conductance in time reflect bending and stretching of membranes. We therefore modeled the evolution of fusion pores using the theory of the mechanics of deforming homogeneous membranes. We calculated the changes in length and width of theoretical fusion pores according to standard dynamical equations of motion. Theoretical fusion pores quickly achieve semi-stable dimensions, which correspond to energy minima located in a canyon between energy barriers. The height of the barrier preventing pore expansion diminishes along the dimensions of length and width. The bottom of the canyon slopes gently downward along increasing length. As a consequence, theoretical fusion pores slowly lengthen and widen as the dimensions migrate along the bottom of the canyon, until the barrier vanishes and the pore rapidly enlarges. The dynamics of growth is sensitive to tension, spontaneous curvature, bending elasticity, and mobilities. This sensitivity can account for the quantitative differences in pore evolution observed in two experimental systems: HA-expressing cells fusing to planar bilayer membranes and beige mouse mast cell degranulation. We conclude that the mechanics of membranes could cause the phenomenon of stagewise growth of fusion pores.     

Elastic stability of chains of magnetosomes in magnetotactic bacteria

Electron micrographs of magnetotactic bacteria reveal that chains of magnetosomes are often bent. This is surprising inasmuch as straight chains are actually the most favourable arrangement for magnetonavigation achieving the maximum value of the bacterial net magnetic moment. In order to answer the question of what causes the chains to bend, we calculated the stability limit of straight magnetosome chains by taking into account elastic and magnetic forces. For several scenarios, the threshold values of external forces leading to elastic instability were computed. From our calculations and observations on freeze-dried cells, we conclude that, under normal conditions, magnetosome chains are straight or only slightly bent, whereas shrinkage during preparation may cause severe artifacts such as kinks or zig-zag structures in the chains. Received: 10 February 1997 / Accepted: 9 April 1997     

Outer membranes of a lipopolysaccharide-protein complex (LPS-17 kDa protein) as chemical tularemia vaccines

Abstract Immunisation with outer membranes of Francisella tularensis induced an efficient protection in guinea pigs against challenge with the virulent strains 503 or 144/713 (type B biovar holarctica ), both clinical isolates, and prevented the development of typical signs of infection in hamadryads (baboons), challenged with the virulent strain Schu (type A, biovar tularensis ) of F. tularensis . Immunisation with a lipopolysaccharide protein complex isolated from the outer membranes afforded protection in CBA mice against challenge with strain 503. Another LPS-protein complex obtained by the simple mixture of LPS preparations from strain 503 and a 17-kDa membrane protein from the avirulent R-variant of the vaccine strain 15 also demonstrated protective properties against experimental tularemia in mice.     

On the taxonomic position of the genus <Emphasis Type="Italic">Parapryg</Emphasis> (Homoptera,Fulgoroidea) and classification of Protorthoptera and related groups

Parapryg alogus Aristov et Rasnitsyn, 2014 (terminal Permian of European Russia) is transferred from Prygidae (Cnemidolestida) to Surijokocixiidae (Homoptera, Fulgoroidea). Some characters and approaches used in classification of Protorthoptera and related groups are briefly discussed.