Antibody to testicular cells in the serum of normal mice

The mixed hemadsorption hybrid antibody (MHA.HA) test was applied successfully to the detection of antigens on the surface of testicular cells separated into sub-populations by velocity sedimentation at unit gravity in the staput apparatus. Normal serum from mice of all strains tested, both male and female, was found to contain a natural autoantibody that reacts with testicular cells of all mice tested, but not with sperm or other cells. This autoantibody is detectable at an age of 4–6 weeks in females, and reaches a plateau at about 10 weeks of age. The corresponding antigen is denoted TCDA, because it is evidently a Testicular Cell Differentiation Antigen. Microscopy of the cells forming rosettes in the MHA.HA test confirmed that the TCDA⁺ cells belong to the gametogenetic series. Because females as well as males produce the autoantibody we presume that TCDA is also present on female gametic cells although it was not feasible to test this adequately. The anti-TCDA autoantibody is not related to the natural autoantibody against sperm, which according to MHA.HA test occurs in the serum of males but not of virgin females.Abbreviations used in this paper are as follows MHA.HA mixed hemadsorption hybrid antibody - TC testicular cells - TCDA testicular cells differentiation antigen - BALB BALB/c - BSA bovine serum albumin - Sp sperm - SpA sperm antigen - Ig immunoglobulin - PBS phosphate-buffered saline - NMS normal mouse serum - FBS fetal bovine serum - SRBC sheep red blood cells     

Transient kinetic studies support refinements to the chemical and kinetic mechanisms of aminolevulinate synthase

5-Aminolevulinate synthase catalyzes the pyridoxal 5'-phosphate-dependent condensation of glycine and succinyl-CoA to produce carbon dioxide, CoA, and 5-aminolevulinate, in a reaction cycle involving the mechanistically unusual successive cleavage of two amino acid substrate alpha-carbon bonds. Single and multiple turnover rapid scanning stopped-flow experiments have been conducted from pH 6.8-9.2 and 5-35 degrees C, and the results, interpreted within the framework of the recently solved crystal structures, allow refined characterization of the central kinetic and chemical steps of the reaction cycle. Quinonoid intermediate formation occurs with an apparent pK(a) of 7.7 +/- 0.1, which is assigned to His-207 acid-catalyzed decarboxylation of the alpha-amino-beta-ketoadipate intermediate to form an enol that is in rapid equilibrium with the 5-aminolevulinate-bound quinonoid species. Quinonoid intermediate decay occurs in two kinetic steps, the first of which is acid-catalyzed with a pK(a) of 8.1 +/- 0.1, and is assigned to protonation of the enol by Lys-313 to generate the product-bound external aldimine. The second step of quinonoid decay defines k(cat) and is relatively pH-independent and is assigned to opening of the active site loop to allow ALA dissociation. The data support important refinements to both the chemical and kinetic mechanisms and indicate that 5-aminolevulinate synthase operates under the stereoelectronic control predicted by Dunathan's hypothesis.     

Prion infection influences murine endogenous retrovirus expression in neuronal cells

Prions as causative agents of transmissible spongiform encephalopathies have been well investigated in experimental and modelling work. However, little is known about the molecular pathogenesis of prion-induced encephalopathies, the role of co-factors, and the interaction of prions with cellular components. We investigated the influence of prion infection on expression of murine endogenous retroviruses (ERVs), which compose approximately 10% of the mouse genome. Hypothalamic neuronal cells (GT1) and neuroblastoma cells (N2a) were examined. Both cell lines can be persistently infected with mouse adapted prion strains, i.e., RML. Using a mammalian retrovirus-specific DNA microarray and quantitative PCR methods, we compared the expression profiles of ERVs in prion-infected, uninfected, and anti-prion compound-treated murine neuronal cell lines, including clonal cell populations. The results suggest that prion infection influences ERV expression in neuronal cell lines, that this influence is cell line-specific, ERV-specific, and responsive to anti-prion compound treatment.     

Metalloproteases Secreted by <Emphasis Type="Italic">Actinobacillus suis</Emphasis>

Actinobacillus suis secretes metalloproteases into its medium. These secreted proteins, when concentrated by precipitation with 70% (NH₄)₂SO₄ or methanol, displayed proteolytic activity at >200 kDa molecular mass bands in 10% polyacrylamide gels copolymerized with bovine casein (1%). They showed activity in a broad pH range (from pH 5 to pH 10) and were inhibited by 20 mM EDTA or EGTA, but could be reactivated by calcium. They were found heat stable at 40°C, 50°C, 60°C, and 70°C, but their activity diminished at 80°C or higher. They degraded pig and bovine IgG and cross-reacted with a polyclonal serum against a high molecular mass secreted protease from A. pleuropneumoniae. Extracellular proteases could play a role in diseases caused by A. suis.     

Mapping structural differences between 30S ribosomal subunit assembly intermediates

Under appropriate conditions, functional Escherichia coli 30S ribosomal subunits assemble in vitro from purified components. However, at low temperatures, assembly stalls, producing an intermediate (RI) that sediments at 21S and is composed of 16S ribosomal RNA (rRNA) and a subset of ribosomal proteins (r-proteins). Incubation of RI at elevated temperatures produces a particle, RI*, of similar composition but different sedimentation coefficient (26S). Once formed, RI* rapidly associates with the remaining r-proteins to produce mature 30S subunits. To understand the nature of this transition from RI to RI*, changes in the reactivity of 16S rRNA between these two states were monitored by chemical modification and primer extension analysis. Evaluation of this data using structural and biochemical information reveals that many changes are r-protein-dependent and some are clustered in functional regions, suggesting that this transition is an important step in functional 30S subunit formation.     

Importance of randomization in microarray experimental designs with Illumina platforms

Measurements of gene expression from microarray experiments are highly dependent on experimental design. Systematic noise can be introduced into the data at numerous steps. On Illumina BeadChips, multiple samples are assayed in an ordered series of arrays. Two experiments were performed using the same samples but different hybridization designs. An experiment confounding genotype with BeadChip and treatment with array position was compared to another experiment in which these factors were randomized to BeadChip and array position. An ordinal effect of array position on intensity values was observed in both experiments. We demonstrate that there is increased rate of false-positive results in the confounded design and that attempts to correct for confounded effects by statistical modeling reduce power of detection for true differential expression. Simple analysis models without post hoc corrections provide the best results possible for a given experimental design. Normalization improved differential expression testing in both experiments but randomization was the most important factor for establishing accurate results. We conclude that lack of randomization cannot be corrected by normalization or by analytical methods. Proper randomization is essential for successful microarray experiments.     

Carnivores from Los Rincones,a leopard den in the highest mountain of the Iberian range (Moncayo,Zaragoza, Spain)

Carnivores are a common element in Pleistocene fossil assemblages. However, they are not so abundant in terms of the numbers of remains. Here, we present a palaeontological study of the carnivores from the Late Pleistocene (MIS 3) of Los Rincones (Spain), one of the few deposits accumulated by leopards. One hundred and ten leopard remains have been recovered. This carnivore is not the only inhabitant of the cave, and 175 remains belonging to Ursus arctos have also been recovered, making it one of the sites with the greatest number of brown bear remains in the Iberian Peninsula. The large number of leopard remains has allowed us to make a detailed morphological and biometrical study that has enabled us to classify the remains within the subspecies Panthera pardus spelaea. The European Ice Age leopard inhabited Europe during Upper Pleistocene and it presents some similarities with Panthera uncia. A study of the scarce remains of Canis lupus indicates that this was similar in size to Canis lupus maximus; the scarcity of the remains prevents us from assigning our remains to this subspecies. A study of the brown bear remains indicates that it is similar to other populations in the north of the Iberian Peninsula with this chronology.     

Topical Olive Oil Is Not Inferior to Hyperoxygenated Fatty Aids to Prevent Pressure Ulcers in High-Risk Immobilised Patients in Home Care. Results of a Multicentre Randomised Triple-Blind Controlled Non-Inferiority Trial

Pressure ulcers represent a major current health problem and produce an important economic impact on the healthcare system. Most of studies to prevent pressure ulcers have been carried out in hospital contexts, with respect to the use of hyperoxygenated fatty acids and to date, no studies have specifically examined the use of olive oil-based substances.

Methods and Design

Main objective: To assess the effectiveness of the use of olive oil, comparing it with hyperoxygenated fatty acids, for immobilised home-care patients at risk of suffering pressure ulcers. Design: Non-inferiority, triple-blind, parallel, multicentre, randomised clinical trial. Scope: Population attending Primary Healthcare Centres in Andalusia (Spain). Sample: 831 immobilised patients at risk of suffering pressure ulcers.

Results

The follow-up period was 16 weeks. Groups were similar after randomization. In the per protocol analysis, none of the body areas evaluated presented risk differences for pressure ulcers incidence that exceeded the 10% delta value established. Sacrum: Olive Oil 8 (2.55%) vs HOFA 8 (3.08%), ARR 0.53 (-2.2 to 3.26) Right heel: Olive Oil 4 (1.27%) vs HOFA 5 (1.92)%, ARR0.65 (-1.43 to 2.73). Left heel: Olive Oil 3 (0.96%) vs HOFA 3 (1.15%), ARR0.2 (-1.49 to 1.88). Right trochanter: Olive Oil 0 (0%) vs HOFA 4 (1.54%), ARR1.54 (0.04 to 3.03). Left trochanter: Olive Oil 1 (0.32%) vs HOFA 1 (0.38%), ARR0.07 (-0.91 to 1.04). In the intention to treat analysis the lower limit of the established confidence interval was never exceeded.

Discussion

The results obtained confirmed that the use of topical extra-virgin olive oil to prevent PU in the home environment, for immobilised patients at high risk, is not inferior to the use of HOFA. Further studies are needed to investigate the mechanism by which olive oil achieves this outcome.

Trial Registration

Clinicaltrials.gov NCT01595347