Trichinella spiralis (Owen, 1835) Induces Increased Dystrophin Expression in Invaded Cross-striated Muscle.

PURPOSE: Dystrophin and the dystrophin glycoprotein complex serve as a cytoskeletal integrator, critical for muscle membrane stability. The aim of the present study was to clarify the expression of dystrophin protein and mRNA in the skeletal muscle tissue during the muscle phase of trichinellosis in mice. METHODS: Muscle tissue was collected from mice experimentally infected with Trichinella spiralis at days 0, 14 and 40 after infection. The expression of dystrophin in the muscle tissue was investigated by immunohistochemistry with antibodies against three different domains of the protein, and the expression levels of Dys mRNA by real-time PCR. RESULTS: The presence of dystrophin protein was increased in the de-differentiating cytoplasm at the early stage of muscle infection and was persisting also in the mature Nurse cell harbouring the parasite. It was accompanied by significantly elevated expression of Dys mRNA at days 14 and 40 after infection. CONCLUSION: Our findings indicate that dystrophin plays a role in regeneration of the muscle and in the Nurse cell formation and stability for security of the parasite survival.

Novel Triple Stimuli Responsive Interpenetrating Poly(Carboxybetaine Methacrylate)/Poly(Sulfobetaine Methacrylate) Network.

The study reports the synthesis and characterization of novel triple stimuli responsive interpenetrating polymer network (IPN) based on two polyzwitterionic networks, namely of poly(carboxybetaine methacrylate) and poly(sulfobetaine methacrylate). The zwitterionic IPN hydrogel demonstrates the ability to expand or shrink in response to changes in three "biological" external stimuli such as temperature, pH, and salt concentration. The IPN hydrogel shows good mechanical stability. In addition, other important features such as non-cytotoxicity and antibiofouling activity against three widespread bacteria as P. Aeruginosa, A. Baumanii, and K. Pneumoniae are demonstrated. The in vivo behavior of the novel zwitterionic IPN hydrogel suggests that this smart material has very good potential as a biomaterial.

Sonochemically engineered nano-enabled zinc oxide/amylase coatings prevent the occurrence of catheter-associated urinary tract infections.

Catheter-associated urinary tract infections (CAUTIs), caused by biofilms, are the most frequent health-care associated infections. Novel antibiofilm coatings are needed to increase the urinary catheters' life-span, decrease the prevalence of CAUTIs and reduce the development of antimicrobial resistance. Herein, antibacterial zinc oxide nanoparticles (ZnO NPs) were decorated with a biofilm matrix-degrading enzyme amylase (AM) and simultaneously deposited onto silicone urinary catheters in a one-step sonochemical process. The obtained nano-enabled coatings inhibited the biofilm formation of Escherichia coli and Staphylococcus aureus by 80% and 60%, respectively, for up to 7 days in vitro in a model of catheterized bladder with recirculation of artificial urine due to the complementary mode of antibacterial and antibiofilm action provided by the NPs and the enzyme. Over this period, the coatings did not induce toxicity to mammalian cell lines. In vivo, the nano-engineered ZnO@AM coated catheters demonstrated lower incidence of bacteriuria and prevent the early onset of CAUTIs in a rabbit model, compared to the animals treated with pristine silicone devices. The nano-functionalization of catheters with hybrid ZnO@AM coatings appears as a promising strategy for prevention and control of CAUTIs in the clinic.

Accumulation of α-2,6-sialyoglycoproteins in the Muscle Sarcoplasm Due to Trichinella Sp. Invasion.

The sialylation of the glycoproteins in skeletal muscle tissue is not well investigated, even though the essential role of the sialic acids for the proper muscular function has been proven by many researchers. The invasion of the parasitic nematode Trichinella spiralis in the muscles with subsequent formation of Nurse cell-parasite complex initiates increased accumulation of sialylated glycoproteins within the affected area of the muscle fiber. The aim of this study is to describe some details of the α-2,6-sialylation in invaded muscle cells. Asynchronous invasion with infectious T. spiralis larvae was experimentally induced in mice. The areas of the occupied sarcoplasm were reactive towards α-2,6-sialic acid specific Sambucus nigra agglutinin during the whole process of transformation to a Nurse cell.The cytoplasm of the developing Nurse cell reacted with Helix pomatia agglutinin, Arachis hypogea agglutinin and Vicia villosa lectin-B4 after neuraminidase pretreatment.Up-regulation of the enzyme ST6GalNAc1 and down-regulation of the enzyme ST6GalNAc3 were detected throughout the course of this study. The results from our study assumed accumulation of sialyl-Tn-Ag, 6`-sialyl lactosamine, SiA-α-2,6-Gal-ß-1,3-GalNAc-α-Ser/Thr and Gal-ß-1,3-GalNAc(SiA-α-2,6-)-α-1-Ser/Thr oligosaccharide structures into the occupied sarcoplasm. Further investigations in this domain will develop the understanding about the amazing adaptive capabilities of skeletal muscle tissue.

Increased sialylation as a phenomenon in accommodation of the parasitic nematode Trichinella spiralis (Owen, 1835) in skeletal muscle fibres.

The biology of sialic acids has been an object of interest in many models of acquired and inherited skeletal muscle pathology. The present study focuses on the sialylation changes in mouse skeletal muscle after invasion by the parasitic nematode Trichinella spiralis (Owen, 1835). Asynchronous infection with T. spiralis was induced in mice that were sacrificed at different time points of the muscle phase of the disease. The amounts of free sialic acid, sialylated glycoproteins and total sialyltransferase activity were quantified. Histochemistry with lectins specific for sialic acid was performed in order to localise distribution of sialylated glycoconjugates and to clarify the type of linkage of the sialic acid residues on the carbohydrate chains. Elevated intracellular accumulation of α-2,3- and α-2,6-sialylated glycoconjugates was found only within the affected sarcoplasm of muscle fibres invaded by the parasite. The levels of free and protein-bound sialic acid were increased and the total sialyltransferase activity was also elevated in the skeletal muscle tissue of animals with trichinellosis. We suggest that the biological significance of this phenomenon might be associated with securing integrity of the newly formed nurse cell within the surrounding healthy skeletal muscle tissue. The increased sialylation might inhibit the affected muscle cell contractility through decreased membrane ion gating, helping the parasite accommodation process.

The occupation of intestinal epithelium by Trichinella spiralis in BALB/C mice is not associated with local manifestation of apoptosis related factors.

Trichinella spiralis actively passes through the epithelial cells of the intestinal mucosa but morphologically, these cells do not manifest apparent damage. The possible activation of apoptotic mechanisms in the small intestine mucosa after infection with larvae and adults of Trichinella spiralis was explored by immunohistochemistry. Sporadic individual cells of normal intestinal epithelium showed activation of caspase-3, increased expression AIF, or Bax. The larval stage of intestinal trichinellosis was characterized by distortion of cells on the villus tips that were strongly reactive to caspase-3, Bax, and survivin antibodies. There was a transient loss of the survivin expression on the brush border of the epithelial cells at 15-h post infection, which reappeared on the fifth day. Bcl-2 changed its normal apical distribution and re-localized to the basal part of the epithelial cells. No significant changes of expression of the selected apoptosis-related proteins were observed in the intestinal epithelial cells immediately surrounding the worms. The presence of Trichinella affects intestinal epithelial cells, but unlike in muscle cells, invading them does not initiate apoptotic factors activation.

Alcohol based fixatives provide excellent tissue morphology, protein immunoreactivity and RNA integrity in paraffin embedded tissue specimens.

Fixation techniques preserving morphological fidelity, protein antigenicity and integrity of nucleic acids can have a high impact on both basic and applied biomedical sciences and diagnostic pathology. Different types of mouse tissues were fixed with neutral buffered formalin, ethanol supplemented with acetic acid and modified methacarn (methanol-Carnoy) fixative. The alcohol-fixed samples were processed in an Autotechnicon tissue processor or in an incubator. The preservation of tissue morphology was assessed in all specimens and the immunoreactivity was evaluated with antibodies specific for proteins with nuclear, membrane or cytoplasmic localization. RNA was extracted from all groups of fixed hind limb skeletal muscle specimens and was assessed versus unfixed tissue for preservation of its quantity and quality by amplification of gene-specific fragments of different lengths. Both alcohol-based fixatives preserved the tissue architecture and the specificity of immunoreactivity in excellent quality; the trimming approach did not result in detectable differences. Oligonucleotide fragments of length between 108 and 577 base pairs were amplified from all groups of alcohol-fixed skeletal muscle specimens in amounts comparative to the unfixed muscle tissue. We conclude that both alcohol-based fixatives are an excellent tool for storage of tissue samples designed for immunohistochemical and mRNA expression studies when the access to fresh samples is limited.