Gametogenetic cycle and reproductive effort assessed by two methods in 3 age classes of Pacific oysters, Crassostrea gigas, reared in Normandy     

Juliette Royer  Catherine Seguineau  Kyung-Il Park  Stphane Pouvreau  Kwang-Sik Choi  Katherine Costil 《Aquaculture (Amsterdam, Netherlands)》2008,277(3-4):313-320

Two methods were used to estimate the reproductive output of female Pacific oysters reared in Normandy: histology with image analysis and ELISA (Enzyme-Linked ImmunoSorbent Assay) which allowed the quantification of egg protein. Condition indices, gonad area and gametogenetic stages of the oysters were determined in the entire population (males and females) between May and October 2005. All investigations were performed in 3 age classes: oysters in their first, second or third years (corresponding to spat, half-grown and market-sized oysters, respectively). Both quantitative histology and ELISA provided similar results in terms of reproductive effort (illustrated by the gonado-somatic index, GSI) except during the GSI drop, corresponding to spawning, which was less marked with the ELISA method. Growth depended on oyster age, the sex ratio was well balanced and the reproductive cycle was synchronized in all age classes. In the 3 age classes, most of the oysters were ripe and ready to spawn on August 8, and ten days after the post-spawning stage was observed in 40% of spat oysters and 70% of half-grown and market-sized bivalves. The major difference between age classes was observed in the reproductive investment, with spat having a lower reproductive output. For example, in males and females, the gonad area reached 78–79% in the median animal section at full maturity (August 8) in half-grown and marketable oysters while it attained only 59% in spat. At the same time, GSI in females was, respectively in spat and the 2 oldest age classes, 33% (quantitative histology)–36% (ELISA) and 55% (quantitative histology)–60% (ELISA). The mean assessed gonad weight and fecundities increased with the age of the oysters: 1.3 g and 12 million eggs, 7.8 g and 135 million eggs, and 11.5 g and 146 million eggs in spat, half-grown and market-sized oysters, respectively. Marked differences thus appear between 2 and 3-year-old oysters and spat. As early as their first reproductive cycle, the young oysters not only showed the reproductive features of the species in Normandy, but also a pronounced lower reproductive effort. This lower energy demand could explain their higher survival rate.  相似文献   

Involvement of androgens and growth hormone in the synthesis of vitellogenin in Japanese eel (Anguilla japonica)     

H.C. Kwon  S.H. Choi  Y.U. Kim  S.O. Son  J.Y. Kwon 《Fish physiology and biochemistry》2003,28(1-4):351-352

Immature eels positively responded to estradiol-17β (E₂) injection in terms of vitellogenin (Vg) synthesis but not to growth hormone (GH) or 17α-methyltestosterone (MT) injection. However, injection of MT or GH combined with E₂ strongly increased Vg synthesis. In in vitro experiments, eel hepatocytes treated with E₂, GH, or MT alone did not produce detectable amount of Vg, whereas the combination of E₂ with GH or MT, or both greatly increased Vg synthesis in the hepatocytes.  相似文献   

A recombinant Eimeria protein inducing interferon-gamma production: comparison of different gene expression systems and immunization strategies for vaccination against coccidiosis   总被引：17，自引：0，他引：17  

Lillehoj HS  Choi KD  Jenkins MC  Vakharia VN  Song KD  Han JY  Lillehoj EP 《Avian diseases》2000,44(2):379-389

A rabbit antiserum against an 18- to 27-kD native protein fraction (F3) from Eimeria acervulina merozoites identified a cDNA (3-1E) containing a 1086-base pair insertion with an open reading frame of 170 amino acids (predicted molecular weight, 18,523). The recombinant 3-1E cDNA expressed in Escherichia coli produced a 60-kD fusion protein and a 23-kD protein after factor Xa treatment of the fusion protein. Both proteins were reactive with the F3 antiserum by western blot analysis. A rabbit antiserum against a synthetic peptide deduced from the amino acid sequence of the 3-1E cDNA reacted with a 27-kD recombinant 3-1E protein expressed in Sf9 insect cells and a 20-kD native protein expressed by E. acervulina sporozoites and Eimeria tenella sporozoites and merozoites. By immunofluorescence staining, a monoclonal antibody produced against the recombinant 3-1E protein reacted with sporozoites and merozoites of E. acervulina, E. tenella, and Eimeria maxima. Spleen lymphocytes from E. acervulina-immune chickens showed antigen-specific proliferation and interferon (IFN)-gamma production upon stimulation with the recombinant 3-1E protein, indicating that the protein activates cell-mediated immunity during coccidiosis. Immunization of chickens with either the E. coli- or Sf9-expressed recombinant 3-1E protein with adjuvant, or direct injection of the 3-1E cDNA, induced protective immunity against live E. acervulina. Simultaneous injection of the recombinant 3-1E protein, or the 3-1E cDNA, with cDNAs encoding chicken IFN-gamma or interleukin (IL)-2/15 further enhanced protective immunity. These results indicate that the recombinant E. acervulina 3-1E cDNA or its polypeptide product may prove useful as vaccines against avian coccidiosis.  相似文献   

Role of chicken IL-2 on gammadelta T-cells and Eimeria acervulina-induced changes in intestinal IL-2 mRNA expression and gammadelta T-cells   总被引：14，自引：0，他引：14  

Choi KD  Lillehoj HS 《Veterinary immunology and immunopathology》2000,73(3-4):309-321

  相似文献   

Development and evaluation of indirect ELISA for the detection of antibodies against Japanese encephalitis virus in swine     

Dong-Kun Yang  Byoung-Han Kim  Seong-In Lim  Jun-Hun Kwon  Kyung-Woo Lee  Cheong-Up Choi  Chang-Hee Kweon 《Journal of veterinary science (Suw?n-si, Korea)》2006,7(3):271-275

The Japanese encephalitis virus (JEV) is one of causative agents of reproductive failure in pregnant sows. An indirect enzyme-linked immunosorbent assay (I-ELISA) was examined for its potential use in the rapid monitoring of the JEV, and the results were compared with those from the hemagglutination inhibition (HI) and serum neutralization (SN) tests. The comparative analysis showed that the results of I-ELISA showed a significant correlation with the conventional HI (r = 0.867) and SN tests (r = 0.804), respectively. When the I-ELISA results were compared with the traditional diagnostic assays, the sensitivity of the I-ELISA was 94.3% with the HI test and 93.7% with the SN test, respectively. The specificity was found to be 81.4% and 80.0% with the HI and SN tests, respectively. To determine the applicability of I-ELISA in the field, the serum samples from 720 pigs were collected from 4 regions in Korea between July and August 2004. The results indicated that 21.7% of screened pigs were seropositive for the JEV. The seropositive rates of JEV in the 4 provinces were 12.6% in Gyeonggi, 45.0% in Gyeongnam, 16.7% in Jeonbuk, and 12.2% in Jeju. The I-ELISA methodology developed in this study was shown to have considerable sensitivity and specificity through a comparison with HI and the SN tests. Therefore, it might be one of convenient methods for screening a large number of samples in various fields.  相似文献   

Bayesian Hierarchical Analysis for Multiple Health Endpoints in a Toxicity Study     

Taeryon Choi  Mark J. Schervish  Ketra A. Schmitt  Mitchell J. Small 《Journal of Agricultural, Biological & Environmental Statistics》2010,15(3):290-307

Bayesian hierarchical models are built to fit multiple health endpoints from a dose-response study of a chemical contaminant, perchlorate. Perchlorate exposure results in iodine uptake inhibition in the thyroid, with health effects manifested by changes in blood hormone concentrations and histopathological effects on the thyroid. We propose empirical models to fit blood hormone concentration and thyroid histopathology data for rats exposed to perchlorate in the 90-day study of Springborn Laboratories Inc. (1998), based upon a mechanistic model derived from the assumed toxicological relationships between dose and the various endpoints. All of the models are fit in a Bayesian framework, and predictions about each endpoint in response to dose are simulated based on the posterior predictive distribution. A hierarchical model tries to exploit possible similarities between different combinations of sex and exposure duration, and it allows us to produce more stable estimates of dose-response curves. We also illustrate how the Bayesian model specification allows us to address additional questions that arise after the analysis.  相似文献   

Reductive Dechlorination of Tetrachloroethylene by Green Rusts Modified with Copper     

Jeongyun Choi  Bill Batchelor  Jinwook Chung 《Water, air, and soil pollution》2010,212(1-4):407-417

Reductive dechlorination of tetrachloroethylene (PCE) by green rust modified with copper (GR(Cu)) was investigated using a batch reactor system. Four different forms of GRs (GR-Cl, GR-SO₄, GR-CO₃, and GR-F) were synthesized by partial air oxidation of Fe(OH)₂ and used in reductive dechlorination. The addition of Cu(II) into GRs produced 100-nm particles on the surface of GRs, which were considered to be metallic Cu and transformed a portion of GR to magnetite. Concentration of Fe(II) in the liquid phase increased and concentration of Fe(II) in the solid phase decreased during the modification process and the extent of these changes was dependent on the amount of Cu(II) added. The most reactive of the modified GRs was GR-F(Cu), which reacted with PCE at a rate that was 80 times faster than that of GR-Cl(Cu). The rate of PCE degradation by GR-F(Cu) was strongly dependent on pH with higher rates at higher pH over the range of pH 7.5–11. Increasing concentrations of Cu(II) over the range of 0 to 5 mM increased rate constants. The rate of dechlorination of PCE by GR-F(Cu) showed surface saturation behavior with respect to PCE concentration.  相似文献   

Single-sex education: positive effects     

Park H  Behrman JR  Choi J 《Science (New York, N.Y.)》2012,335(6065):165-6; author reply 166-8

  相似文献   

Comparison of neuroprotective effects of five major lipophilic diterpenoids from Danshen extract against experimentally induced transient cerebral ischemic damage     

Ok Kyu Park  Jung Hoon Choi  Joon Ha Park  In Hye Kim  Bing Chun Yan  Ji Hyeon Ahn  Seung-Hae Kwon  Jae-Chul Lee  Young Sup Kim  Misook Kim  Il-Jun Kang  Jong-Dai Kim  Yun Lyul Lee  Moo-Ho Won 《Fitoterapia》2012

We observed neuroprotective effects of five major lipophilic diterpenes derived from Danshen (Radix Salvia miltiorrhiza) extract, such as cryptotanshinone (CTs), dihydrotanshinone I (DTsI), tanshinone I (TsI), tanshinone IIA (TsIIA) and tanshinone IIB (TsIIB), in the hippocampal CA1 region (CA1) against transient ischemic damage in gerbils. These diterpenes were administered 30 min before ischemia–reperfusion and the animals were sacrificed 4 days after ischemia–reperfusion. In the vehicle-treated-group, cresyl violet positive (CV⁺) cells and neuronal nuclei (NeuN)⁺ neurons were significantly decreased in the CA1. However, in the TsI- and CTs-treated-ischemia-groups, CV⁺ and NeuN⁺ neurons were abundant in the CA1. In the other groups, the number of CV⁺ and NeuN⁺ neurons was less than the TsI- and CTs-treated-ischemia-groups. In addition, gliosis induced by ischemic damage was apparently blocked in the TsI- and CTs-treated-ischemia-groups. These results suggest that TsI and CTs among five major lipophilic diterpenes have strong potentials for neuroprotection against ischemic damage.  相似文献   

Changes in cyclooxygenase-2 immunoreactivity in the hippocampus in a model of streptozotocin-induced type 1 diabetic rats     

Nam SM  Yi SS  Yoo DY  Kim W  Choi JH  Hwang IK  Seong JK  Yoon YS 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(8):977-982

In this study, we investigated diabetic stage dependent cyclooxygenase-2 (COX-2) immunoreactivity in the dentate gyrus in streptozotocin (STZ)-induced type 1 diabetic rats. The animals were sacrificed at 2, 3 and 4 weeks after STZ treatment. Blood glucose levels were increased after STZ treatment. COX-2 immunoreactivity in dentate gyrus was significantly increased in these regions 3 weeks after STZ treatment and restored to its basal level to 4 weeks after STZ treatment. In contrast, COX-2 immunoreactivity was not changed in CA3 region in all groups. These results suggest that STZ-induced type 1 diabetes transiently, but not permanently, decreased synaptic transmission and plasticity 3 weeks after STZ treatment in the dentate gyrus.  相似文献