101,948 research outputs found
Development and validation of a real-time TaqMan PCR assay for the detection of betanodavirus in clinical specimens
No full textDevelopment and validation of a real-time TaqMan PCR assay for the detection of betanodavirus in clinical specimens
Panzarin V, Patarnello P, Mori A, Rampazzo E, Cappellozza E, Bovo G, Cattoli G.
Betanodaviruses are the causal agents of viral encephalo-retinopathy, an infectious disease affecting more than 40 marine fish species, characterized by high morbidity and mortality. Because of its severe impact, robust diagnostic tools are required. The aim of this work was to develop and validate a real-time TaqMan PCR assay to detect betanodaviruses in clinical specimens by amplifying a conserved region of the RNA2 strand. The method proved to be specific and sensitive, being capable of detecting as low as 10 TCID(50)/ml. For clinical validation, samples from 100 marine fish were collected during a natural outbreak of disease and tested by three distinct laboratory methods, namely real-time TaqMan PCR, RT-seminested PCR and virus isolation. The results indicated optimal agreement between tests. The assay that was developed is capable of detecting members of all of the betanodavirus genetic groups currently described and can be considered a valid alternative to the time-consuming and contamination-prone nested PCR
Post-translational control of human hemoglobin synthesis The role of the differential affinity between globin chains in the control of mutated globin gene expression
No full textThe interactions between β-thalassemia and the humen hemoglobin (Hb) α-chain variants, Hb Hasharon, Hb O Indonesia and Hb J Paris, and between α-thalassemia and the β-chain variants, Hb S, Hb C and Hb G San José, which are characterized by preferential decrease of the abnormal Hb level in peripheral blood, have been studied. Both biosynthesis studies in reticulocytes and determination of the relative affinity of abnormal chains for normal complementary chains by in vivo recombination experiments, involving globin chains previously isolated in their native form, have been carried out in order to provide insights on the molecular events following the synthesis of the mutant chains under conditions of complementary chain deficiency. Furthermore, we have measured the relative affinity for complementary chain of βD Los Angeles- and αJ Rovigo-chains, the level of which does not decay in thalassemic carriers, and of αLegnano- and βOsu Christiansborg-chains, which have not yet been observed in association with thalassemias. Our experiments indicated that the differential affinity for β-chains is not always the major post-translational control mechanism which regulates the level of certain α-chain variants in β-thalassemic heterozygotes, and that preferential removal of abnormal chains by proteolytic enzymes is likely to play an important role in most cases. On the other hand, the low affinity of certain variant β-chains for α-chains may offer an explanation for the low level of certain β-chain variants in peripheral blood of non-thalassemic carriers, as well as to their decrease under conditions of relative α-chain deficiency (α-thalassemias). © 1980
Modification of the nutritional parameters and of midgut biochemical and absorptive functions induced by the IGR fenoxycarb in Bombyx mori larvae
No full textFifth instar larvae of B. mori were topically or orally treated with increasing amounts of the Insect Growth Regulator (IGR) fenoxycarb in a single application, in order to determine its
effects on the nutritional parameters, the midgut functional activities and the growth of the silk glands. The IGR affected in a dose-dependent manner the progress of the life cycle of the insect, causing a delay or inhibition of spinning, alteration of the feeding behaviour, decrease of the nutritional parameters, impairment of the growth of the silk glands, and an increased mortality during larval-pupal transformation. Measurement of leucine uptake into midgut brush border membrane vesicles and midgut histochemistry revealed a reduced absorption of leucine by the midgut and a large alteration of a number of midgut enzyme activities as a result of treatments with a high dose of fenoxycarb (2.5 micro g). Treatments with a dose of 2.5 femto g/larva caused an increase in leucine uptake by the midgut, an increased weight of the cocoon shell, and a modification of some
midgut enzyme activities. The lepidopteran midgut appears to be a larval organ that responds promptly to the exposure to fenoxycarb. The epithelial columnar cells modify their absorptive functions, at least with regard to amino acid uptake, as well as their metabolic activity, with a modification of the oxidative status of the cells that is detectable with a single dose of the chemical as low as few fg/larva
Corrigendum to “Timing of autophagy and apoptosis during posterior silk gland degeneration in Bombyx mori” [Arthropod Struct. Dev. 46 (4) (2017) 518–528] (S146780391730035X) (10.1016/j.asd.2017.05.003))
No full textThe authors regret the indication on the scale bars in each Figure was not reported in the published paper and are published below. The length of scale bars in the Figures are as follows: Fig. 1. 200 μm (a, c, e, g, i, k, m), 50 μm (b, d, f, h, j, l, n). Fig. 2. 5 μm (a–c), 500 nm (a′); 1 μm (d), 2 μm (e–g). Fig. 3. 50 μm (a–i). Fig. 4. 50 μm (d–f, j–l), 10 μm (e′), 500 nm (g), 200 nm (h). The authors would like to apologise for any inconvenience caused
Susceptibility of black bullhead Ameiurus melas to a panel of ranavirus isolates
No full textRanaviruses are considered a serious threat to lower vertebrates, including fish, amphibians and reptiles. However, epidemiological data on these agents are lacking, and further investigations are needed to understand the role of carriers and to update the list of susceptible hosts. We carried out various experimental infections under controlled conditions to contribute to the current knowledge on the susceptibility of black bullhead Ameiurus melas to European catfish virus (ECV) and other ranaviruses. A panel of 7 ranavirus isolates was used to challenge duplicate groups of A. melas juveniles maintained in aquaria supplied with running dechlorinated tap water. The experiments were performed at 15 and 25 degrees C. The results confirmed the high susceptibility of A. melas to ECV infection. Furthermore, a significant mortality associated with the typical signs of systemic viral infections was observed in groups challenged with Epizootic haematopoietic necrosis virus (EHNV) at 25 degrees C, and to a lesser extent, at 15 degrees C. No significant mortality was recorded in fish challenged with European sheatfish virus (ESV), Frog virus 3 (FV3), Rana esculenta virus-like (REV-like), Bohle iridovirus (BIV) or short-finned eel virus (SERV)
Proton Spin-Lattice Relaxation in Silkworm Cocoons: Physisorbed Water and Serine Side-Chain Motions
No full textThe molecular dynamic behavior of silkworm cocoons produced by a single Bombyx mori strain was investigated by means of high- and low-resolution solid-state NMR experiments. Cocoons with different moisture content were prepared to study the effects of physisorbed water on their molecular dynamics in the MHz regime, which was probed through the measurement of 1H T1 relaxation times at 25 MHz in the 25-95 °C temperature range. The water content of the different samples was determined from the analysis of 1H free-induction decays. In addition to the rotation of methyl groups, mostly from alanine, and to the reorientation of physisorbed water molecules, already identified in previous works as relaxation sinks, the reorientation of serine side-chains was here found to contribute to 1H T1 above room temperature. The analysis of the trends of 1H T1 versus temperature was carried out in terms of semiempirical models describing the three main motional processes, and indicated that methyl rotation, water reorientation and serine side-chain motions are the most efficient relaxation mechanisms below 0 °C, between 0 and 60 °C, and above 60 °C, respectively. The activation energies were found to decrease passing from serine to water to methyl motions
Modification of the nutritional parameters and of midgut biochemical and absorptive functions induced by the IGR fenoxycarb in Bombyx mori larvae
No full text
Determinaion of 1-deoxynojirimicin (DNJ) in mulberry leaves (Morus app. L.), silkworms and silk by HPLC-TQ-MS
No full textIntroduction
DNJ is a constituent of mulberry leaves and when consumed as part of the diet it showed beneficial properties on health: suppression of high blood glucose levels, antibacterial and antiviral activities [1,2]. In this work DNJ content in different matrices was investigated, the importance lies in the potential uses of these products as food and feed, nutraceutical and medical device.
Methods
Twenty-nine samples of mulberry leaves from an experimental field (CREA-Padova), silk worms larvae and silk cocoons were analyzed by HILIC technique. EtOH:H2O 50% solution and water 60° were employed for leaves extraction. Grinded cocoons and freeze-dried larvae were extracted with EtOH:H2O 50% (at 60°C for cocoons). The detection was performed by using ESI in positive ion MRM mode.
Results
The optimized mass conditions allowed the identification of three usable transitions (one for the quantification of DNJ 164.1146.1, others as qualifier ions 164.1128.1, 164.1110.1). DNJ was detected in all the considered matrices and determined by using its calibration curve (r2=0.9865). In the case of leaves, water infusion resulted less efficient with respect to EtOH:H2O extraction. The mean concentration value in leaves obtained with infusion is 0.073±0.004 mg/g while 2.56±0.3 mg/g for extracts. The mean concentration recovered in larvae is 0.034±0.001 mg/g whereas substantially lower amounts were obtained for silk (3.12*10-5 mg/g).
Conclusions
In this work an efficient HPLC-TQ-MS method was applied to the determination of DNJ in leaves, larvae and silk. The study showed that Morus nigra L. presents the highest content among the tested species and that DNJ is detectable also in larvae and silk. These results could be useful in the further development of herbal supplements and for the potential use of larvae as medicated feed or functional food
Beta-thalassemia in the po delta: Selection, geography, and population structure
No full textThe allele frequencies for beta-thalassemia for 51 localities in the province of Rovigo, and in 25 localities in the province of Ferrara, were studied. It was observed that in the province of Ferrara there is a significant cline of frequencies; these decrease from the coast of the Adriatic Sea toward the west. No such gradient was visible in Rovigo. It was advanced, also on the basis of geography documented by ancient maps, that in the province of Rovigo there were multiple foci of selection for the thalassemia gene, and that in the province of Ferrara selection was stronger in the Oriental part of the area. Examination of the isolation by distance model with these data showed that the Malécot-Morton model fits for the Ferrara data and geography, whereas it does not for Rovig
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