Effect of administration of anti-bursal extract or perfusate serum on the antibody production in chickens

Antisera to bursal extracts or perfusates were prepared and the influence of such sera on antibody production in chickens was investigated by the injection of antisera during the embryonic stage. Antisera to cyclophosphamide treated bursal extracts or bursal perfusates were injected on the 15th day of embryogenesis. The level of antibodies produced by chickens treated by these antisera was equal to the controls but IgG antibodies were totally absent. These results suggested that the administration of these antisera inhibited the differentiation of IgM antibody producing cells.     

Acute-phase protein response in pigs experimentally infected with Haemophilus parasuis

The acute-phase protein (APP) response to an infection caused by Haemophilus parasuis, the etiological agent of Glässer's disease in pigs, was characterized measuring serum concentrations of pig major acute-phase protein (pig MAP), haptoglobin (HPT), C-reactive protein (CRP) and apolipoprotein A-I (ApoA-I) in colostrum-deprived pigs. They were divided into six experimental groups: non-immunized control group (I); immunized with a non-commercial bacterin (II); with an OMP-vaccine (III); with a sublethal dose (IV); and with two commercial bacterins (V and VI). All groups were challenged intratracheally with 5 × 10⁹ CFU of H. parasuis 37 days after immunisation. The highest levels of the positive APPs (pig MAP, HPT and CRP) and the lowest levels of the negative APPs (ApoA-I) were observed in the animals that died as a consequence of the infection, both those in the non-inmunized and in the immunized groups. However, the surviving animals (all of them in groups II, V and VI, two pigs in group III, and three in group IV) showed a minor variation in APP response, mainly on day 1 post-challenge (p.c.), and then tended to recover the initial values. APP response was still less pronounced in the groups of pigs previously immunized with bacterins. In conclusion, APP response can reflect Glässer-disease ongoing, showing a correlation between the severity and duration of the clinical signs and lesions and the magnitude of changes in the APP levels.     

The diagnosis of enzootic bovine leukosis

This paper reviews the clinical and virological diagnostic procedures for enzootic bovine leukosis (EBL). The clinical diagnosis must be always confirmed by a specific laboratory test for Bovine Leukaemia Virus (BLV). Many virological tests were proposed. The sensitivity of all the diagnostic methods is sufficient to do an early detection of a BLV infection on an individual base. Advantages of the highly sensitive methods like RIA and ELISA appear when the samples to be tested have naturally very low antibody titers (individual milk, bulk milk, pooled sera).     

Modulated expression of ion transporters may be responsible for manganese deficiency in brittle leaf disease affected date palm (Phoenix dactylifera L.) trees

Date palm (Phoenix dactylifera L.) is an economically important and widely cultivated palm from the Arecaceae family. In Tunisia, date orchards are being decimated by a disease called brittle leaf disease of unknown origin. In this study we carried comparative mineral element analysis in healthy and affected trees from three oases. The identification of three metal transporter families (NRAMP, ZIP and MTP), making use of whole genome sequences of date palm. We identified 32 gene models for the three ion transporter families. Phylogenetic analysis led to the identification of putative orthologs of Arabidopsis and rice landmark genes. The expression patterns of gene models from each family were investigated in brittle leaf disease affected date palm trees from the three investigated oases, results showed that the expression of putative manganese transporters was modulated by the disease and especially in affected roots.     

Implantation of Rous sarcoma virus transformed cells in the hamster: effect of various parameters

The effect of inoculation of allogeneic hamster cells transformed by Rous sarcoma virus on tumour growth, in the hamster is described. Inoculation of low doses (10(2)-10(4)) of live cells was followed by the apparition and the growth of sub-cutaneous sarcomas. Repeated injections of irradiated or glutaraldehyde-treated cells which induce immune reactions led only to partial protection since they did not totally prevent tumour growth, after challenge with strong doses (5 X 10(4)) of live transformed cells. Inoculation route did not influence tumour growth, whatever the nature of injected cells. The interest of using irradiated or glutaraldehyde-treated transformed cells in tumour immunity should be emphasised.     

两种索绪尔批判思考——读时枝诚记与本维尼斯特

索绪尔是二十世纪最杰出的语言学家,他引领了语言学研究的哥白尼式革命并创立了结构主义语言学。索绪尔语言学理论不仅对语言学研究意义重大,而且也对二十世纪人文社会学科提供了丰富的哲学暗示。然而同对索绪尔的拥簇一样,对索绪尔的批评也从未停止。对索绪尔批评最具代表性的观点来自于日本著名语言学家时枝诚记和法国著名语言学家本维尼斯特。从二者对索绪尔的批判中可以看出学界对索绪尔思想中一些重要概念的分歧,这对推动索绪尔研究有着重要的意义。     

A new strain of white spot syndrome virus affecting Litopenaeus vannamei in Indian shrimp farms

White spot syndrome virus (WSSV)‐infected shrimp samples collected from grow‐out ponds located at Nellore, Andhra Pradesh, India, showed WSSV negative and positive by PCR using primer sets specific to ORF119 and VP28 gene of WSSV, respectively. This indicated the deletion of genetic fragments in the genome of WSSV. The WSSV isolate along with lab strain of WSSV was subjected to next‐generation sequencing. The sequence analysis revealed a deletion of 13,170 bp at five positions in the genome of WSSV‐NS (new strain) relative to WSSV‐TH and WSSV‐LS (lab strain). The PCR analysis using the ORF's specific primer sets revealed the complete deletion of 10 ORFs in the genome of WSSV‐NS strain. The primer set was designed based on sequence covering ORF161/162/163 to amplify a product of 2,748 bp for WSSV‐LS and 402 bp for WSSV‐NS. Our surveillance programme carried out since 2002 revealed the replacement of WSSV‐LS by WSSV‐NS in Indian shrimp culture system.     

Integral Management Zones: A novel strategy for marine bivalve production in the Gulf of California,Mexico

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Isolation and characterization of Aeromonas schubertii from diseased snakehead, Channa maculata (Lacepède)

Pure bacterial cultures were isolated from diseased snakeheads, Channa maculata (Lacepède), suffering high mortality in a farm in Zhongshan, southern China. Three isolates, namely ZS20100725, ZS20100725-1 and ZS20100725-2, were identified as Aeromonas schubertii. All the isolates showed high 16S rRNA sequence similarities with A. schubertii. The isolates exhibited strong virulence to snakeheads in experimental challenges with LD(50) ranging between 1.4 × 10(4) and 6.4 × 10(6) CFU g(-1). Two of the isolates were positive for haemolysin, elastase, lipase and lecithinase by phenotypic determination, which was further confirmed by PCR amplification of the haemolysin and elastase genes. In sterile liquid medium, the best growth conditions of strain ZS20100725 were 30 °C, pH 7 and 0.5% salinity (w/v). Antibiotic susceptibility tests showed that strain ZS20100725 was susceptible to cefoxitin, cefoperazone and chloramphenicol. Furthermore, histopathology of diseased snakeheads infected with A. schubertii showed necrosis and congestion in liver, kidney and spleen and also damage to the cardiac muscle, intestine and gills.     

Conservation of a permanent hypersaline lake: management options evaluated from decadal variability of Coleofasciculus chthonoplastes microbial mats

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