Impact of Bacillus popilliae,Rickettsiella popilliae and entomopathogenic nematodes on a population of the scarabaeid,Cyclocephala hirta

Larvae of the scarabaeid, Cyclocephala hirta, are major pests of turfgrass in California. A field test was conducted against third instars that included the following treatments: untreated control; chemical insecticide (bendiocarb); milky disease bacterium (Bacillus popilliae); and entomopathogenic nematodes (Steinernema feltiae and Heterorhabditis bacteriophora). There were no significant differences in population reduction among the treatments, but the larval population in all plots showed a dramatic decline. The C. hirta population had a natural occurrence of milky disease and blue disease caused by Rickettsiella popilliae. The prevalence of blue disease during the course of the study averaged < 10% but that of milky disease averaged about 20%. More significantly, the soil from all treatment plots when bioassayed for B. popilliae showed that 67–90% of the larvae became infected with this bacterium. None of the larvae became infected with the blue disease organism. We conclude that B. popilliae was occurring in epizootic proportions in our field tests and was a significant mortality factor in causing the decline of the C. hirta population.     

Effect of anticoagulants in vitro on the viability of lymphocytes and content of free fatty acids in plasma

Summary These authors attempted to test the effect of anticoagulants on lymphocytes viability by reproducing the procedure used for lymphocyte isolation for various immunologic tests in which blood specimens are allowed to stay at room temperature for 2 h before lymphocytes are isolated. Blood was obtained with three different anticoagulants i.e. heparin, citrate, and CPDA (citrate, phosphate, dextrose, and adenine). Plasma was lyophilized and extracted with ethanol. Dried ethanol extracts were suspended in medium (RPMI 1640+10% fetal bovine serum) and incubated with a lymphocyte cell line (MOLT-4). After 24 h of incubation the viability of cells was examined. The following death rates of the cells were observed: heparin −63±4.6% (mean±SEM), citrate −27±6.7%, and CPDA 6.2±0.6% (P<0.0005). A significant correlation was found between these results and changes in the concentrations of free fatty acids in the extracts. These results emphasize the importance of choosing the right anticoagulant when the viability of lymphocytes is obligatory.     

A simplified screening test for the diagnosis of allergy.

The Quidel allergy screen is a relatively rapid (less than 2 hours) multiallergen dipstick method for detecting specific immunoglobin E antibodies in serum. It was developed to answer the need of primary physician nonspecialists in allergy for a convenient in-office screening test for diagnosing allergy. The new test was evaluated against the benchmark diagnostic skin tests and the radioallergosorbent serologic tests for sensitivity, specificity, accuracy, and technical feasibility in an office setting. It was found that while the Quidel allergy screen lacks the specificity of the standard tests, its overall sensitivity, as defined by the percentage of patients with positive skin reactions who also tested positive with the Quidel screen (68%), its ease of use, and its rapidity warrant its consideration as a screening tool for confirming a possible case of allergy.     

Choose your partner: Chromosome pairing in yeast meiosis

Premeiotic association of homologous chromosomes in the yeast, Saccharomyces cerevisiae has been shown, by means of fluorescent in situ hybridization (FISH)^(1,2). Time course and mutant studies show that the premeiotic associations are disrupted upon entry into meiosis, to be reestablished shortly before synapsis. The data are consistent with a model in which multiple, unstable interactions bring homologues together, prior to stable joining by recombination⁽³⁾.     

The Prognostic Value of Serum Biomarkers in Localized Bone Sarcoma

OBJECTIVE: Certain biomarkers such as the C-reactive protein, serum albumin, and the neutrophils to lymphocyte ratio are of prognostic significance regarding survival in different types of cancers. Data from sarcoma patients are sparse and mainly derived from soft tissue sarcoma and/or metastatic cases. Adjusting for confounders such as comorbidity and age is an essential safeguard against erroneous conclusions regarding the possible prognostic value of these biomarkers. The aim of this study was to assess the prognostic value of a battery of pretreatment biomarkers in the serum of patients with localized bone sarcomas and to adjust for potential confounders. MATERIAL AND METHODS: All patients diagnosed with localized intermediate and high-grade bone sarcoma during 1994 to 2008 were extracted from the Aarhus Sarcoma Registry. The serum levels of albumin, C-reactive protein, hemoglobin, neutrophils, lymphocytes, and sodium were collected from the patient records. The prognostic values of overall and disease-specific mortality were tested for each individual biomarker as well as for the Glasgow prognostic score (GPS) and for a new composite score incorporating five biomarkers (Aarhus composite biomarker score: ACBS). Adjustments were made for comorbidity as well as other possible prognostic factors, such as size, histological type, margin, chemotherapy, and soft tissue extension, using the Cox proportional hazard model. RESULTS: A total of 172 patients with high- or intermediate-grade localized bone sarcoma were included. Of these patients, 63 were diagnosed with chondrosarcoma and 109 patients with Ewing/osteosarcoma. The median age was 55 years for chondrosarcoma and 19 years for Ewing/osteosarcoma patients. The overall 5-year mortality was 31% [95% confidence interval (CI): 21-44] and 41% (95% CI: 33-51), whereas the 5-year disease-specific mortality was 21% (95% CI: 12-34) and 39% (95% CI: 31-49) for chondrosarcoma and Ewing/osteosarcoma, respectively. Comorbidities were present in 12% of the Ewing/osteosarcoma patients and in 24% of the chondrosarcoma patients. After adjustment for comorbidity and other confounders, it was found that elevated levels of CRP, low hemoglobin, low sodium, high GPS, and high ACBS were associated with increased overall mortality. Furthermore, elevated levels of CRP, low hemoglobin, high GPS, and high ACBS were associated with increased disease-specific mortality. CONCLUSION: Elevated levels of CRP, low hemoglobin, high GPS, and high ACBS were all independent prognostic factors for both overall and disease-specific mortality. ACBS is a new three-level score of five biomarkers, but its value has to be confirmed in an independent data set.     

State-of-the art data normalization methods improve NMR-based metabolomic analysis

Extracting biomedical information from large metabolomic datasets by multivariate data analysis is of considerable complexity. Common challenges include among others screening for differentially produced metabolites, estimation of fold changes, and sample classification. Prior to these analysis steps, it is important to minimize contributions from unwanted biases and experimental variance. This is the goal of data preprocessing. In this work, different data normalization methods were compared systematically employing two different datasets generated by means of nuclear magnetic resonance (NMR) spectroscopy. To this end, two different types of normalization methods were used, one aiming to remove unwanted sample-to-sample variation while the other adjusts the variance of the different metabolites by variable scaling and variance stabilization methods. The impact of all methods tested on sample classification was evaluated on urinary NMR fingerprints obtained from healthy volunteers and patients suffering from autosomal polycystic kidney disease (ADPKD). Performance in terms of screening for differentially produced metabolites was investigated on a dataset following a Latin-square design, where varied amounts of 8 different metabolites were spiked into a human urine matrix while keeping the total spike-in amount constant. In addition, specific tests were conducted to systematically investigate the influence of the different preprocessing methods on the structure of the analyzed data. In conclusion, preprocessing methods originally developed for DNA microarray analysis, in particular, Quantile and Cubic-Spline Normalization, performed best in reducing bias, accurately detecting fold changes, and classifying samples.

     

Epstein-Barr virus (EBV) receptors, complement receptors, and EBV infectibility of different lymphocyte fractions of human peripheral blood. II. Epstein-Barr virus studies.

In B-cell fractions isolated from human peripheral blood, the frequency of surface immunoglobulin-positive and of complement receptor-positive cells showed a good correlation with the frequency of EBV-binding cells, as detected by membrane fluorescence or by a quantitative bioassay for infectious virus in the absorbed supernatant fluid. There was a close relationship between all three parameters mentioned, the frequency of EBNA-positive cells 2 or 3 days after the infection, and the stimulation of cellular DNA synthesis. So-called O-cell fractions remaining after the removal of nylon adherent and E-rosetting cells contained a certain frequency of complement receptor-positive cells and absorbed EBV to a limited extent, but did not respond to EBV infection with EBNA induction or stimulation of DNA synthesis. None of the T-cell fractions absorbed EBV to a detectable extent. This includes the T_ea+ fraction that contained a certain proportion of complement receptor-positive cells. It is concluded that the previously demonstrated relationship between EBV receptors and complement receptors on B-lymphoblastoid lines also holds for peripheral B lymphocytes. In these cells, virus absorption is followed by an intracellular infectious process, signaled by the appearance of EBNA and cellular DNA synthesis. O cells carry complement receptors and absorb EBV to a certain extent, but do not respond with EBNA synthesis or DNA stimulation, presumably due to intracellular restrictions. T cells do not bind EBV, and the complement receptors present on some cells of the T_ea+ fraction do not function as EBV receptors.