Efficacy of selected adjuvants for protecting Spodoptera litura nucleopolyhedrovirus from sunlight inactivation

Efficacy of selected adjuvants for protecting Spodoptera litura nucleopolyhedrovirus (SpltNPV) from sunlight inactivation was tested in direct sunlight exposure bioassays and in the field on virus-treated Brassica chinensis var parachinensis plants. All adjuvants, except palm oil, gave significant protection to the virus after 16 h of sunlight exposure, as shown by the larval mortalities. Cumulative mortalities after 14 days show that the virus + Tinopal treatment and the virus not to sunlight treatment attained 100% mortality, while the virus in riboflavin treatment and the crude brown sugar treatment caused mortality of less than 30%. However, the LT₅₀ value of virus + Tinopal was 1.2 times lower than the unexposed virus. All virus-treated plants in the field trials had higher yields and lower damage indices than the control plants. Unlike the results from direct sunlight exposure bioassays, adjuvants, including virus + Tinopal LPW, did not significantly enhance efficacy of the virus against early instars of S. litura in the field. The unformulated virus was as effective as virus + Tinopal LPW and Nurelle-D in protecting the plants from infestation. Thus, in a well-planned pest management program, SpltNPV, without any adjuvant, can be used effectively for controlling S. litura on B. chinensis var parachinensis.     

RT-PCR Assays for Seven Serotypes of Epizootic Haemorrhagic Disease Virus & Their Use to Type Strains from the Mediterranean Region and North America

Epizootic haemorrhagic disease virus (EHDV) infects wild ruminants, causing a frequently fatal haemorrhagic disease. However, it can also cause bluetongue-like disease in cattle, involving significant levels of morbidity and mortality, highlighting a need for more rapid and reliable diagnostic assays. EHDV outer-capsid protein VP2 (encoded by genome-segment 2 [Seg-2]) is highly variable and represents the primary target for neutralising antibodies generated by the mammalian host. Consequently VP2 is also the primary determinant of virus “serotype”, as identified in virus neutralisation tests (VNT). Although previous reports have indicated eight to ten EHDV serotypes, recent serological comparisons and molecular analyses of Seg-2 indicate only seven EHDV “types”. Oligonucleotide primers were developed targeting Seg-2, for use in conventional RT-PCR assays to detect and identify these seven types. These assays, which are more rapid and sensitive, still show complete agreement with VNT and were used to identify recent EHDV isolates from the Mediterranean region and North America.     

The relationship between serum prolactin levels and disease activity in patients with Behcet's disease

The aim of this study was to determine the serum levels of prolactin in patients with Behcet's disease and to evaluate its correlation with disease activity. Serum prolactin levels were measured by a chemiluminescence method in 32 patients with Behcet's disease and compared with 20 age-and sex-matched healthy controls. The patients with Behcet's disease were subdivided into two groups according to disease activity: active (18 patients; 13 men and five women, average age 34.0 +/- 6.5 (28-48) years), and inactive (14 patients; 10 men and four women, average age 32.7 +/- 3.1 (22-49 years). Patients with active Behcet's disease had higher serum prolactin levels than the inactive and control groups. Prolactin levels in patients with active Behcet's disease differed significantly from the healthy control subjects (p < 0.05) only, but not the inactive group. Four patients out of 32 (12.5%) Behcet's disease patients showed mild hyperprolactinemia. All four of these cases were from the active Behcet's disease group. Prolactin levels were correlated with ESR (p < 0.05) and CRP (p < 0.05) levels in the active BD group, but not in the inactive BD and control groups. Our results suggest a possible role for this immunoregulatory hormone in the disease expression and pathogenesis of Behcet's disease.     

Enhancing the affinity of SEB-binding peptides by repeating their sequence

The utilization of peptide ligands in biosensors and bioassays is dependent on achieving high affinity of these peptides toward their targets. In a previous report, we identified 12-mer peptides that could selectively bind to Staphylococcal enterotoxin B (SEB) using a phage-display library. In this study, we explore for new modification approaches to enhance the affinity of two different SEB-binding peptides. In order to identify the binding regions of selected peptides, the charged residues and the ones, critical for the structure of peptide, were replaced with alanine. However, a specific binding region could not be suggested as all mutant peptides have lost their affinities toward SEB completely. The modifications for the affinity enhancement were done by repeating the 12-mer peptide sequences. A 10-fold increase was observed in the binding affinity of one of the two-repeated peptides, while this modification did not affect the affinity of the other tested peptide. The peptide, with enhanced affinity, was further modified as three repeats; however the affinity of the peptide decreased. The structural basis of the affinity difference between modified peptides was examined by molecular dynamics simulation. The results showed that the conformational differences hold the key for affinity of peptides modified by repeating the sequence. This high affinity peptide with increased affinity is a promising molecular recognition agent to be used in the detection of SEB to be utilized in biosensing systems.     

Preferential CEBP binding to T:G mismatches and increased C-to-T human somatic mutations

DNA cytosine methylation in mammals modulates gene expression and chromatin accessibility. It also impacts mutation rates, via spontaneous oxidative deamination of 5-methylcytosine (5mC) to thymine. In most cases the resulting T:G mismatches are repaired, following T excision by one of the thymine DNA glycosylases, TDG or MBD4. We found that C-to-T mutations are enriched in the binding sites of CCAAT/enhancer binding proteins (CEBP). Within a CEBP site, the presence of a T:G mismatch increased CEBPβ binding affinity by a factor of >60 relative to the normal C:G base pair. This enhanced binding to a mismatch inhibits its repair by both TDG and MBD4 in vitro. Furthermore, repair of the deamination product of unmethylated cytosine, which yields a U:G DNA mismatch that is normally repaired via uracil DNA glycosylase, is also inhibited by CEBPβ binding. Passage of a replication fork over either a T:G or U:G mismatch, before repair can occur, results in a C-to-T mutation in one of the daughter duplexes. Our study thus provides a plausible mechanism for accumulation of C-to-T human somatic mutations.     

Comparative analysis of realistic CT-scan and simplified human airway models in airflow simulation

Efforts to model the human upper respiratory system have undergone many phases. Geometrical proximity to the realistic shape has been the subject of many research projects. In this study, three different geometries of the trachea and main bronchus were modelled, which were reconstructed from computed tomography (CT) scan images. The geometrical variations were named realistic, simplified and oversimplified. Realistic refers to the lifelike image taken from digital imaging and communications in medicine format CT scan images, simplified refers to the reconstructed image based on natural images without realistic details pertaining to the rough surfaces, and oversimplified describes the straight wall geometry of the airway. The characteristics of steady state flows with different flow rates were investigated, simulating three varied physical activities and passing through each model. The results agree with previous studies where simplified models are sufficient for providing comparable results for airflow in human airways. This work further suggests that, under most exercise conditions, the idealised oversimplified model is not favourable for simulating either airflow regimes or airflow with particle depositions. However, in terms of immediate analysis for the prediction of abnormalities of various dimensions of human airways, the oversimplified techniques may be used.     

Cryopreservation of protocorm-like bodies (PLBs) of <Emphasis Type="Italic">Phalaenopsis bellina</Emphasis> (Rchb.f.) christenson by encapsulation-dehydration

Protocorm-like bodies (PLBs) of Phalaenopsis bellina were successfully cryopreserved by the encapsulation-dehydration approach. Various stages in obtaining successful cryopreservation using this method were optimized. Encapsulated PLBs precultured in half-strength MS medium supplemented with 0.75 M sucrose for 3 days exhibited the highest viability in terms of 2,3,5-triphenyltetrazoliumchloride (TTC) reduction. The amount of sucrose in the PLBs after incubation in different concentrations of sucrose for different periods of time determined by HPLC. The highest sucrose concentration was 7 mg/g of PLBs for the PLBs treated with 0.75 M sucrose for 3 days as compared to the control which had only 1 mg/g sucrose. After sucrose preculture, the PLBs were subjected to desiccation using one of two methods. Desiccation using silica gel was more efficient in reducing PLBs moisture content. After 6 h of desiccation, PLBs desiccated using laminar air flow had 43.5% moisture content while for those desiccated using silica gel had 32% moisture content. PLBs desiccated to different moisture contents were plunged into LN. After storage in LN the encapsulated PLBs were re-warmed. Two weeks after re-warming PLBs viability was determined by TTC reduction and re-growth assessed. Encapsulated PLBs precultured with 0.75 M sucrose for 3 days followed by desiccated using silica gel for 5 h resulting in a moisture content of 39% lead to the highest post re-warming viability in terms of TTC reduction (46.6% of control PLBs) and 30% re-growth.     

Diet-induced obesity suppresses ghrelin in rat gastrointestinal tract and serum

The aims of the present study were to examine ghrelin expression in serum and gastrointestinal tract (GIT) tissues, and to measure tissue ghrelin levels and obesity-related alterations in some serum biochemical variables in rats with diet-induced obesity (DIO). The study included 12 male rats, 60 days old. The rats were randomly allocated to two groups (n = 6). Rats in the DIO group were fed a cafeteria-style diet to induce obesity, while those in the control group were fed on standard rat pellets. After a 12 week diet program including an adaptation period all rats were decapitated, tissues were individually fixed, ghrelin expression was examined by immunohistochemistry , and tissue and serum ghrelin levels were measured by radioimmunoassay. Serum biochemical variables were measured using an autoanalyzer. When the baseline and week 12 body mass index and GIT ghrelin expression were compared between DIO and control rats, BMI had increased and ghrelin expression decreased due to obesity. The RIA results were consistent with these findings. Serum glucose, LDL cholesterol, and total cholesterol levels were elevated and HDL cholesterol significantly decreased in the DIO group. A comparison of GIT tissues between the control and obese groups demonstrated that ghrelin was decreased in all tissues of the latter. This decrease was brought about a decline in the circulating ghrelin pool. This suggests that rather than being associated with a change in a single tissue, obesity is a pathological condition in which ghrelin expression is changed in all tissues.     

Comparision of some models for estimation of reflectance of hypericum leaves under stress conditions

Lack of water resources and high water salinity levels are among the most important growth-restricting factors for plants species of the world. This research investigates the effect of irrigation levels and salinity on reflectance of Saint John’s wort leaves (Hypericum perforatum L.) under stress conditions (water and salt stress) by multiple linear regression (MLR), artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS). Empirical and heuristics modeling methods were employed in this study to relate stress conditions to leaf reflectance. It was found that the constructed ANN model exhibited a high performance than multiple regression and ANFIS in estimating leaf reflectance accurately.     

Do leafy green vegetables and their ready-to-eat [RTE] salads carry a risk of foodborne pathogens?

Over the past 10 years, there is an increasing demand for leafy green vegetables and their ready-to-eat (RTE) salads since people changed their eating habits because of healthier lifestyle interest. Nevertheless fresh leafy green vegetables and their RTE salads are recognized as a source of food poisoning outbreaks in many parts of the world. However, this increased proportion of outbreaks cannot be completely explained by increased consumption and enhanced surveillance of them. Both in Europe and in the USA, recent foodborne illness outbreaks have revealed links between some pathogens and some leafy green vegetables such as mostly lettuces and spinaches and their RTE salads since fresh leafy green vegetables carry the potential risk of microbiological contamination due to the usage of untreated irrigation water, inappropriate organic fertilizers, wildlife or other sources that can occur anywhere from the farm to the fork such as failure during harvesting, handling, processing and packaging. Among a wide range of pathogens causing foodborne illnesses, Escherichia coli O157:H7, Salmonella spp., and Listeria monocytogenes are the most common pathogens that contaminate leafy green vegetables. Children, the elderly, pregnant women and immunocompromised people are the most at risk for developing complications from foodborne illness as a result of eating contaminated leafy greens or their RTE salads. These outbreaks are mostly restaurant associated or they sometimes spread across several countries by international trade routes. This review summarizes current observations concerning the contaminated leafy green vegetables and their RTE salads as important vehicles for the transmission of some foodborne pathogens to humans.