Thermal requirements for growth,survival and aerobic performance of weatherfish larvae Misgurnus fossilis

Thermal requirements of larval weatherfish Misgurnus fossilis were investigated in terms of growth, survival and aerobic performance. Growth and survival of M. fossilis larvae acclimated to five temperatures (11, 15, 19, 23 and 27° C) were measured over 25 days. In the upper temperature treatments (19, 23 and 27° C), survival of larvae was stable throughout the entire rearing period (>75%), whereas 11 and 15° C resulted in severe declines in survival (to <10%). Growth of larvae (expressed as dry mass and total length) was highest at 19 and 23° C, but significantly decreased at 27° C. Routine metabolic rate of 3 days post‐hatch larvae was estimated as oxygen consumption rate (?O₂) during acute exposure (30 min to 1 h) to seven temperatures (11, 15, 19, 23, 27, 31 and 35° C). Larval oxygen uptake increased with each consecutive temperature step from 11 to 27° C, until a plateau was reached at temperatures >27° C. All larvae of the 35° C regime, however, died within the ?O₂ measurement period. M. fossilis larvae show greater than expected tolerance of high temperatures. On the other hand, low temperatures that are within the range of likely habitat conditions are critical because they might lead to high mortality rates when larvae are exposed over periods >10 days. These findings help to improve rearing conditions and to identify suitable waters for stocking and thus support the management of re‐introduction activities for endangered M. fossilis.     

Comparison of verdeluz orange G and modified Gallego stains

Tumors of the oral cavity include combinations of hard and soft tissues that may be difficult to identify using routine hematoxylin and eosin (H & E) staining. Although combination stains can demonstrate hard and soft tissues, trichrome stains, such as VanGieson and Masson, cannot differentiate dental hard tissues, such as dentin, cementum and osteoid. Modified Gallegos (MGS) and verdeluz orange G-acid fuchsin (VOF) stains can differentiate components of teeth. We used 10 tissue sections of decalcified bone and 10 pathologic tissue sections that contained different calcified tissues including peripheral ossifying fibroma, odontoma, central ossifying fibroma and cemento-ossifying fibroma. Sections were stained with H & E, VOF or MGS. H and E stained both hard tissues pink. VOF stained bone purple-red, cementum red and collagen blue. MGS stained bone green-blue, cementum red and collagen blue. VOF staining intensity and differentiation was better than MGS staining. VOF staining demonstrated hard tissue components distinctly and exhibited good contrast with the surrounding connective tissue. VOF also is a simple, single step, rapid staining procedure.     

Anatomically based lower limb nerve model for electrical stimulation

Background  

Functional Electrical Stimulation (FES) is a technique that aims to rehabilitate or restore functionality of skeletal muscles using external electrical stimulation. Despite the success achieved within the field of FES, there are still a number of questions that remain unanswered. One way of providing input to the answers is through the use of computational models.     

Pulmonary hypertension in patients with chronic kidney disease on dialysis and without dialysis: results of the PEPPER-study

Pulmonary hypertension (PH) is common in patients with dialysis-dependent chronic kidney disease and is an independent predictor of mortality. However, specific hemodynamics of the pulmonary circulation, changes induced by hemodialysis and characterization into pre- or postcapillary PH have not been evaluated in patients with chronic kidney disease. We assessed consecutive patients with end-stage chronic kidney disease in WHO FC ≥ II with dyspnea unexplained by other causes on hemodialysis (group 1, n = 31) or without dialysis (group 2, n = 31) using right heart catheterization (RHC). In group 1, RHC was performed before and after dialysis. In end-stage chronic kidney disease, prevalence of precapillary PH was 13% (4/31), and postcapillary PH was discovered in 65% (20/31). All four cases of precapillary PH were unmasked after dialysis. In group 2, two cases of precapillary PH were detected (6%), and postcapillary PH was diagnosed in 22 cases (71%). This is the first study examining a large cohort of patients with chronic kidney disease invasively by RHC for the prevalence of PH. The prevalence of precapillary PH was 13% in patients with end-stage kidney disease. That suggests careful screening for precapillary PH in this selected patient population. RHC should be performed after hemodialysis.     

The 37-kDa/67-kDa laminin receptor acts as the cell-surface receptor for the cellular prion protein.

Recently, we identified the 37-kDa laminin receptor precursor (LRP) as an interactor for the prion protein (PrP). Here, we show the presence of the 37-kDa LRP and its mature 67-kDa form termed high-affinity laminin receptor (LR) in plasma membrane fractions of N2a cells, whereas only the 37-kDa LRP was detected in baby hamster kidney (BHK) cells. PrP co-localizes with LRP/LR on the surface of N2a cells and Semliki Forest virus (SFV) RNA transfected BHK cells. Cell-binding assays reveal the LRP/LR-dependent binding of cellular PrP by neuronal and non-neuronal cells. Hyperexpression of LRP on the surface of BHK cells results in the binding of exogenous PrP. Cell binding is similar in PrP(+/+) and PrP(0/0) primary neurons, demonstrating that PrP does not act as a co-receptor of LRP/LR. LRP/LR-dependent internalization of PrP is blocked at 4 degrees C. Secretion of an LRP mutant lacking the transmembrane domain (aa 86-101) from BHK cells abolishes PrP binding and internalization. Our results show that LRP/LR acts as the receptor for cellular PrP on the surface of mammalian cells.     

Einige beobachtungen über die höhenstufen-differenzierung der mähwiesen in der mediterranen quercus ilex-stufe von montpellier

Ohne Zusammenfassung     

Demonstration of alternative splicing of a pre-mRNA expressed in the blood stage form of Plasmodium falciparum.

By screening of a lambda gt11 library from Plasmodium falciparum genomic DNA with an antiserum raised against a 41-kDa protein band, which was shown to confer protective immunity to monkeys, the phage clone 41-3 was identified. The entire 41-3 gene was isolated, and its coding regions were determined by amplification and sequencing of 41-3 specific mRNA fragments. The 41-3 gene has a complex structure consisting of nine exons, encoding 375 amino acids in total with a calculated molecular weight of 43,400. Provided that the N-terminal hydrophobic residues function as signal sequence which is cleaved off, the molecular weight of the 41-3 protein decreases to 41,200 and could therefore be considered to be a component of the protective Mr = 41,000 protein band. Indeed, a 41-kDa protein could be detected by Western blot analysis using antisera raised against different recombinant expression products of the 41-3 gene. We furthermore demonstrate an alternative splice process for the mRNA precursor transcribed from the 41-3 gene to yield at least three distinct mRNAs. The major splice product carries all exons E1 to E9, whereas at least two minor 41-3 mRNA species can be identified which show deletions in the region between exons E5 and E7. The possible role of this differential splice process for the parasite is discussed.     

High-level expression and characterization of a glycosylated covalently linked dimer of the prion protein

There is evidence that prion protein dimers may be involved in the formation of the scrapie prion protein, PrP(Sc), from its normal (cellular) form, PrP(c). Recently, the crystal structure of the human prion protein in a dimeric form was reported. Here we report for the first time the overexpression of a human PrP dimer covalently linked by a FLAG peptide (PrP::FLAG::PrP) in the methylotrophic yeast Pichia pastoris. FLAG-tagged human PrP (aa1-aa253) (huPrP::FLAG) was also expressed in the same system. Treatment with tunicamycin and endoglycosidase H showed that both fusion proteins are expressed as various glycoforms. Both PrP proteins were completely digested by proteinase K (PK), suggesting that the proteins do not have a PrP(Sc) structure and are not infectious. Plasma membrane fractionation revealed that both proteins are transported to the plasma membrane of the cell. The glycosylated proteins might act as powerful tools for crystallization trials, PrP(c)/PrP(Sc) conversion studies and other applications in the life cycle of prions.     

Identification of the heparan sulfate binding sites in the cellular prion protein

Data from cell culture and animal models of prion disease support the separate involvement of both heparan sulfate proteoglycans and copper (II) ions in prion (PrP) metabolism. Though direct interactions between prion protein and heparin have been recorded, little is known of the structural features implicit in this interaction or of the involvement of copper (II) ions. Using biosensor and enzyme-linked immunosorbent assay methodology we report direct heparin and heparan sulfate-binding activity in recombinant cellular prion protein (PrP(c)). We also demonstrate that the interaction of recombinant PrP(c) with heparin is weakened in the presence of Cu(II) ions and is particularly sensitive to competition with dextran sulfate. Competitive inhibition experiments with chemically modified heparins also indicate that 2-O-sulfate groups (but not 6-O-sulfate groups) are essential for heparin recognition. We have also identified three regions of the prion protein capable of independent binding to heparin and heparan sulfate: residues 23-52, 53-93, and 110-128. Interestingly, the interaction of an octapeptide-spanning peptide motif amino acids 53-93 with heparin is enhanced by Cu(II) ions. Significantly, a peptide of this sequence is able to inhibit the binding of full-length prion molecule to heparin, suggesting a direct role in heparin recognition within the intact protein. The collective data suggest a complex interaction between prion protein and heparin/heparan sulfate and has implications for the cellular and pathological functions of prion proteins.