Urease activity in the gastrointestinal tract of the European hare (<Emphasis Type="Italic">Lepus europaeus</Emphasis>)

The intensity of urea recycling in the wild herbivorous European hare has been investigated. The intensity of urease activity in the gastrointestinal tract has been selected as a convenient quantitative measure of nitrogen recycling. High urease activity was detected in the large intestine; it was higher than the previously detected activity in other mammals with postgastric fermentation: pigs, rats, and rabbits. The strong seasonal dynamics of urease activity has been noted: it increases during winter diet consumption, which is poor in available nitrogen.     

A robust method of determination of high concentrations of peptides and proteins

In this paper, we pioneer application of a unique method of protein determination by coloring peptide bonds for analysis of a variety of biomolecules with different grades of purity (e.g., oligopeptides, membrane, and glycol proteins). We demonstrated that the calibration curve for all studied molecules is universal and linear within 0.1 to 1.2 mg protein content range. The assay thus can be used to analyze peptides without preliminary dilutions and calibration in up to 1 g/ml solutions of peptides, which is crucial for many biotechnological processes, such as development of coatings, scaffolds, and biocompatible materials.     

Silicon Dioxide Thin Film Mediated Single Cell Nucleic Acid Isolation

A limited amount of DNA extracted from single cells, and the development of single cell diagnostics make it necessary to create a new highly effective method for the single cells nucleic acids isolation. In this paper, we propose the DNA isolation method from biomaterials with limited DNA quantity in sample, and from samples with degradable DNA based on the use of solid-phase adsorbent silicon dioxide nanofilm deposited on the inner surface of PCR tube.     

The Potato Nucleotide-binding Leucine-rich Repeat (NLR) Immune Receptor Rx1 Is a Pathogen-dependent DNA-deforming Protein

Plant nucleotide-binding leucine-rich repeat (NLR) proteins enable cells to respond to pathogen attack. Several NLRs act in the nucleus; however, conserved nuclear targets that support their role in immunity are unknown. Previously, we noted a structural homology between the nucleotide-binding domain of NLRs and DNA replication origin-binding Cdc6/Orc1 proteins. Here we show that the NB-ARC (nucleotide-binding, Apaf-1, R-proteins, and CED-4) domain of the Rx1 NLR of potato binds nucleic acids. Rx1 induces ATP-dependent bending and melting of DNA in vitro, dependent upon a functional P-loop. In situ full-length Rx1 binds nuclear DNA following activation by its cognate pathogen-derived effector protein, the coat protein of potato virus X. In line with its obligatory nucleocytoplasmic distribution, DNA binding was only observed when Rx1 was allowed to freely translocate between both compartments and was activated in the cytoplasm. Immune activation induced by an unrelated NLR-effector pair did not trigger an Rx1-DNA interaction. DNA binding is therefore not merely a consequence of immune activation. These data establish a role for DNA distortion in Rx1 immune signaling and define DNA as a molecular target of an activated NLR.     

A 10-year experience in the treatment of intraabdominal cerebrospinal fluid pseudocysts

The aim of this retrospective study was to assess a ten-year experience in the treatment of rare complications of ventriculoperitoneal shunting--intraabdominal cerebrospinal fluid pseudocysts. At this time there are no data about incidence, clinical course and treatment of these complications in Croatia. Cerebrospinal fluid (CSF) abdominal pseudocyst is an uncommon but important complication of ventriculoperitoneal shunts. Retrospective data were obtained from 5 children with abdominal CSF pseudocysts, treated between 1996 and 2007. The incidence of intraabdominal CSF pseudocysts in our study is 2.9%. All patients were girls ranged in age from 4 to 12 years old (mean 8.8 years). In most cases etiology of hydrocephalus was congenital, idiopathic. Abdominal pain and distension were the most frequent clinical finding (4/5). Although infection has been reported as responsible for pseudocyst formation, we did not found it in our series. Laparotomy with cyst wall excision and catheter replacement was performed in 2/5 cases, and only cyst fluid aspiration with catheter replacement in 3/5 cases. Recurrence of the abdominal cyst was observed in one girl who was in terminal stadium of anaplastic ependymoma. It is our opinion that only catheter replacement and cyst fluid evacuation, as one of the treatment modalities, may be successful, even in large CSF intraperitoneal pseudocysts.     

Sus Scrofa immune tissues as a new source of bioactive substances for skin wound healing

Influence of a new protein-peptide complex on promoting skin wound healing in male BALB/c mice was studied. Protein-peptide complex, extracted from Sus scrofa immune organs, was percutaneously administered using two methods: by lecithin gel-like liquid crystals and by liquid microemulsion. On the fifth day, wound closure in mice with a linear wound model become faster in group (less 2 days comparison to other ones), which was treated with lecithin liquid crystals carrying the protein-peptide complex. This promoting healing can be caused by resorption of bioactive high-molecular compounds the animal skin. In mice with the linear wound model, the tensile strength of the scars were respectively higher both in mice, treated using lecithin liquid crystals with protein-peptide complex, and in mice, treated using microemulsion containing protein-peptide complex, by 215.4% and 161.5% relative to the animals, which did not receive bioactive substances for wound treatment. It was associated with the regeneratory effects of tissue- and species-specific protein-peptide complexes, including α-thymosin Sus scrofa (C3VVV8_PIG, m/z 3802.8) and other factors, which were described as parts of the new extracted complex. This reveals that percutaneous administration of the complex reliably activates local regenerative processes in animals.     

Crybb2 coding for βB2-crystallin affects sensorimotor gating and hippocampal function

βB2-crystallin (gene symbol: Crybb2/CRYBB2) was first described as a structural protein of the ocular lens. This gene, however, is also expressed in several regions of the mammalian brain, although its function in this organ remains entirely unknown. To unravel some aspects of its function in the brain, we combined behavioral, neuroanatomical, and physiological analyses in a novel Crybb2 mouse mutant, O377. Behavioral tests with male O377 mutants revealed altered sensorimotor gating, suggesting modified neuronal functions. Since these mouse mutants also displayed reduced hippocampal size, we concentrated further investigations on the hippocampus. Free intracellular Ca²⁺ levels were increased and apoptosis was enhanced in the hippocampus of O377 mutants. Moreover, the expression of the gene encoding calpain 3 (gene symbol Capn3) was elevated and the expression of genes coding for the NMDA receptor subunits was downregulated. Additionally, the number of parvalbumin-positive interneurons was decreased in the hippocampus but not in the cortex of the mutants. High-speed voltage-sensitive dye imaging demonstrated an increased translation of input-to-output neuronal activity in the dentate gyrus of this Crybb2 mutant. These results point to an important function of βB2-crystallin in the hippocampal network. They indicate pleiotropic effects of mutations in the Crybb2 gene, which previously had been considered to be specific to the ocular lens. Moreover, our results are the first to demonstrate that βB2-crystallin has a role in hippocampal function and behavioral phenotypes. This model can now be further explored by future experiments.