Search results for "XOS"

TEM observations on symbionts ofJoenia annectens(Flagellata Hypermastigida)

2001

Transmission electron microscopy was used to evaluate the ultrastructural morphology of some other symbiotic prokaryotes of Joenia annectens, an intestinal flagellate of the termite Kalotermes flavicollis. Three morphotypes are predominant and recognizable from their morphological characteristics. One morphotype is represented by spirochaetes that are mainly external and cover the flagellate, helping its movement. Rod-shaped bacteria, which represent the second morphotype, are also attached to the surface among the spirochaetes. Rod-shaped bacteria and some spirochaetes may enter the cell surface of Joenia annectens as a consequence of phagocytosis, remaining enclosed in an envelope of plas…

The flagellates of the termite Hodotermopsis sjoestedti with special reference to Hoplonympha, Holomastigotes and Trichomonoides trypanoides n. comb.

2004

Abstract The termite Hodotermopsis sjoestedti harbours a symbiotic fauna of protists comprising at least 11 genera and a much larger number of species. Two oxymonad genera, Pyrsonympha and Dinenympha, are mixed with nine parabasalid genera, two trichomonads, Trichomitopsis termopsidis and Trichomonoides trypanoides n. comb., four spirotrichonymphid genera/species: Spirotrichonympha, Microjoenia, Holomastigotes lanceolata n. sp., Holomastigotes elongatum and three trichonymphid genera/species; Hoplonympha natator, Eucomonympha, Trichonympha. Hoplonympha natator has two anterior symmetrical bundles of ∼60 basal bodies/flagella separated by two parabasal plates. The cell surface is crenelated …

Gut microbiota changes in rainbow trout, Oncorhynchus mykiss (Walbaum), during organic acid feed supplementation and Yersinia ruckeri infection

2013

Gut microbiota (GM) composition of vertebrates are considered to influence health parameters including immunological parameters in the host but knowledge of these issues in fish are sparse. We have performed a 45 day experimental study elucidating effects of dietary supplementation of organic acids (Mera Cid) and immunostimulants on the GM composition of rainbow trout Oncorhynchus mykiss (Walbaum) and investigated its association with blood parameters and disease resistance (against enteric red mouth disease (ERM) caused the bacterium Yersinia ruckeri). A total of 640 fish received either 1) basic fish feed without organic acids or immunostimulants, 2) fish feed with immunostimulants (β6glu…

role of CML exosomes in the crosstalk between chronic myelogenous leukaemia and bone marrow-derived cells

2012

Exosomes are small membrane vesicles (30–100 nm) derived from the luminal membranes of multivesicular bodies and constitutively released by fusion with the cell membrane (1). Exosomes mediate local and systemic cell communication through the presence of cytokines, growth factors and others molecules. It is well recognized that bone marrow–derived cells (BMDCs) are crucial for the generation of a suitable microenvironment for the primary tumor and the development of metastasis through a process called pre-metastatic niche formation. Secreted factors are known contributors to BMDC recruitment to both the primary tumor and to pre-metastatic niches (2) and in particular exosomes may have a role…

Role of exosomes released by colon cancer stem cells in the modulation of tumor microenvironment.

2014

Targeting of the Peritumoral Adipose Tissue Microenvironment as an Innovative Antitumor Therapeutic Strategy

2022

The tumor microenvironment (TME) plays a key role in promoting and sustaining cancer growth. Adipose tissue (AT), due to its anatomical distribution, is a prevalent component of TME, and contributes to cancer development and progression. Cancer-associated adipocytes (CAAs), reprogrammed by cancer stem cells (CSCs), drive cancer progression by releasing metabolites and inflammatory adipokines. In this review, we highlight the mechanisms underlying the bidirectional crosstalk among CAAs, CSCs, and stromal cells. Moreover, we focus on the recent advances in the therapeutic targeting of adipocyte-released factors as an innovative strategy to counteract cancer progression.

Hsp60 from cancer cells can reach near and distant targets: A proposal for a multistage pathway

2011

Cancer cells have means to influence other cells in their vicinity and distant, and in this signal-delivering mechanisms the chaperonin Hsp60 plays a role, which is currently being recognized as potentially crucial for the growth and dissemination of at least certain types of tumors. In order to arrive at its destination, Hsp60, a typical resident of mitochondria in normal and tumor cells, leaves the organelle and reaches the blood. In the latter, Hsp60 can travel and arrive at targets situated far away from its origin. The details of the route followed by Hsp60 and their molecular mechanisms have not yet been fully elucidated. We investigated Hsp60 levels and secretion in normal and tumor …

The Structure and Metabolism of Carbohydrates

1994

Compared with the variety of carbohydrates in plants, relatively few sugars or sugar derivatives are regularly found in animals either free or as components of more complex compounds. However, it is possible that sugars originating from plants in the diet are transiently retained in animals and distort the normal sugar spectrum. Approximately a dozen sugars and sugar derivatives are regularly found in animals: the pentoses d-ribose and 2-deoxy-d-ribose; the hexoses d-glucose, d-galactose, d-mannose, d-fructose and l-fucose; the uronic acids d-glucuronic acid and l-iduronic acid; and the hexosamines d-glucosamine and d-galactosamine. In addition, d-erythrose, d-ribulose, d-xylulose and d-sed…

Allelic variants of hexose transporter Hxt3p and hexokinases Hxk1p/Hxk2p in strains ofSaccharomyces cerevisiaeand interspecies hybrids

2015

The transport of sugars across the plasma membrane is a critical step in the utilization of glucose and fructose by Saccharomyces cerevisiae during must fermentations. Variations in the molecular structure of hexose transporters and kinases may affect the ability of wine yeast strains to finish sugar fermentation, even under stressful wine conditions. In this context, we sequenced and compared genes encoding the hexose transporter Hxt3p and the kinases Hxk1p/Hxk2p of Saccharomyces strains and interspecies hybrids with different industrial usages and regional backgrounds. The Hxt3p primary structure varied in a small set of amino acids, which characterized robust yeast strains used for the p…

Enzyme molecular mechanism as a starting point to design new inhibitors: a theoretical study of O-GlcNAcase.

2011

O-Glycoprotein 2-acetamino-2-deoxy-β-d-glucopyranosidase (O-GlcNAcase) hydrolyzes O-linked 2-acetamido-2-deoxy-β-d-glucopyranoside (O-GlcNAc) residues from post-translationally modified serine/threonine residues of nucleocytoplasmic protein. The chemical process involves substrate-assisted catalysis, where two aspartate residues have been identified as the two key catalytic residues of O-GlcNAcase. In this report, the first step of the catalytic mechanism used by O-GlcNAcase involving substrate-assisted catalysis has been studied using a hybrid quantum mechanical/molecular mechanical (QM/MM) Molecular Dynamics (MD) calculations. The free energy profile shows that the formation of the oxazol…