Transplacental infection of porcine fetuses following experimental challenge inoculation with encephalomyocarditis virus.   总被引：2，自引：0，他引：2  

W T Christianson  H S Kim  I J Yoon  H S Joo 《American journal of veterinary research》1992,53(1):44-47

Ten multiparous sows were inoculated between 46 and 50 days of gestation with a fetal swine isolate of encephalomyocarditis virus (EMCV) to investigate the ability of the virus to cause transplacental infection and fetal death. Four sows (group 1) were inoculated IM with EMCV MN-25 that had been passaged 4 times on baby hamster kidney-21 line cell monolayers. Two sows were euthanatized at postinoculation (PI) day 23, and the other 2 sows at PI day 44. An additional 6 sows (group 2) were inoculated IM with the same virus that had been passaged 5 additional times in pigs. Two sows were euthanatized at 14 days, and the remaining 4 sows at PI day 28. Clinical signs were not observed in any of the sows, whereas all sows seroconverted to EMCV. In group 1, only 2 of 50 fetuses were mummified. Virus was not recovered, although EMCV antibodies were detected in the 2 mummified fetuses. In group 2, the 2 sows that were euthanatized at PI day 14 had 26 normal fetuses and there was no evidence of fetal infection. However, in the 4 sows euthanatized at PI day 28, 20 of 48 fetuses were mummified, hemorrhagic, or edematous. Encephalomyocarditis virus was recovered from 21 of 48 fetuses. Transplacental infection and fetal deaths in pregnant sows was achieved following infection with EMCV passaged in pigs.  相似文献   

In utero infection of swine fetuses with infectious bovine rhinotracheitis virus (bovine herpesvirus-1)   总被引：1，自引：0，他引：1  

H S Joo  S A Dee  T W Molitor  B J Thacker 《American journal of veterinary research》1984,45(10):1924-1927

The pathogenesis of infectious bovine rhinotracheitis (IBR) virus (bovine herpesvirus-1) was studied in porcine fetuses after in utero inoculation. Laparotomies were performed on 8 seronegative pregnant sows at 34 to 86 days of gestation, and all fetuses in 1 uterine horn of each sow were exposed to IBR virus via inoculation into the amniotic sacs. Fetuses in the other horn served as controls. Clinical signs of infection were not observed in the sows, except for 2 sows that aborted at postinoculation days (PID) 11 and 15. Fetuses of the remaining 6 sows were collected at slaughter on PID 15 to 28. Fetuses were examined for gross abnormalities, presence of IBR virus in tissues, and the formation of neutralizing antibodies to IBR virus. Of 33 inoculated fetuses from 6 sows, 10 were mummified, 11 were hemorrhagic and/or edematous, and 12 were alive. Necrotic lesions were observed on the skin and in the liver of dead and live fetuses. Virus was recovered from 29 of 33 inoculated fetuses. Infectious bovine rhinotracheitis virus was isolated from fetal skin, liver, lungs, kidney, spleen, stomach contents, brain, amniotic fluid, and placenta. Virus was isolated from 4 of 11 fetuses recovered from 1 aborting sow. Antibodies to IBR virus were not detected in sera from the sows. However, antibodies were detected in 6 of 15 fetuses inoculated at 63 to 86 days of gestation and collected at slaughter at 86 to 112 days of gestation. The youngest fetus with detectable IBR antibody was estimated to be 74 days of gestation by measuring crown-rump length of the fetus.  相似文献   

Antibody responses of guinea-pigs, rabbits and pigs to inactivated porcine parvovirus vaccines   总被引：3，自引：0，他引：3  

H S Joo  T W Molitor  A D Leman 《Veterinary microbiology》1984,9(1):27-33

Antibody responses were compared in guinea-pigs, rabbits and pigs following vaccination with inactivated porcine parvovirus (PPV) vaccines. Mean PPV hemagglutination inhibition (HI) antibody titers of 52, 56 and 36 at 1 week after first vaccination and 896, 640 and 512 at 2 weeks after second vaccination were detected in guinea-pigs, rabbits and pigs, respectively. PPV vaccines prepared with greater concentrations of virus, as determined by hemagglutination (HA) units, and of aluminum hydroxide gel adjuvant, induced higher HI antibody titers in guinea-pigs. Optimal concentrations for inducing consistently high antibody titers consisted of vaccine virus with a HA titer of 256/0.1 ml and gel adjuvant at a final concentration of 50%. A second vaccination at 4 weeks compared to 2 or 3 weeks after first vaccination resulted in higher mean HI titers. These data provide preliminary information on the use of guinea-pigs or rabbits as laboratory animal models for testing the potency of PPV vaccines.  相似文献   

The effect on reproductive performance of porcine parvovirus infection in a susceptible pig herd     

C R Donaldson-Wood  H S Joo  R H Johnson 《The Veterinary record》1977,100(12):237-239

An acute episode of reproductive failure occurred following natural introduction of porcine parvovirus to a susceptible herd of 48 breeding sows. Serological data gave a close estimate of the time that infection spread through the herd, and enabled a correct forecast of the reproductive failure that followed. Severe fetal mummification was seen over a three-week period. Epidemiological data is presented strongly linking in utero parvovirus infection with the mummification that occurred, and the significance of this data is discussed in connection with the present knowledge of transplacental porcine parvovirus infection.  相似文献   

Isolation and characterization of porcine circovirus type-2 from sera of stillborn fetuses   总被引：3，自引：0，他引：3       下载免费PDF全文

MacDonald W. Farnham  Young Ki Choi  Sagar M. Goyal    Han Soo Joo 《Canadian journal of veterinary research》2003,67(2):108-113

In order to examine an association between porcine circovirus type-2 (PCV2) infection and reproductive failure in pigs, sera (n = 171) from stillborn fetuses were collected from 3 different farms with prolonged histories of reproductive problems. These sera were tested for the presence of antibodies to PCV2 using an immunoperoxidase monolayer assay. Of the 171 sera tested, 28 had PCV2 antibody titers of ≥ 1:16. When these 28 samples were tested by a polymerase chain reaction assay, 13 were found to contain PCV2 viral DNA. Of these 13 samples containing both PCV2 antibodies and viral DNA, 9 yielded PCV2 on virus isolation. Amino acid sequences comprising open reading frame 2 of PCV2 from 2 of these isolates were compared to PCV2 isolates from cases of post-weaning multi-systemic wasting syndrome (PMWS). The amino acid sequences of the 2 isolates from stillborn pigs were shown to be nearly identical to each other, as well as to other PCV2 isolates associated with reproductive failure. When compared with PMWS isolates, the isolates from the stillborn fetuses showed differences of at least 2 amino acids. These results confirm previous findings that transplacental infection of PCV2 occurs in the field and that stillbirths in pigs may be associated with PCV2 infections. At present, the significance of minor differences in amino acid sequences is not known.  相似文献   

Evaluation of transmission of swine influenza type A subtype H1N2 virus in seropositive pigs     

Choi YK  Goyal SM  Joo HS 《American journal of veterinary research》2004,65(3):303-306

OBJECTIVE: To examine clinical signs, virus infection and shedding, and transmission of swine influenza virus (SIV) subtype H1N2 among seropositive pigs. ANIMALS: Eighteen 3-week-old pigs with maternal antibodies against SIV subtypes H1N1, H3N2, and H1N2. PROCEDURE: Ten pigs (principal) were inoculated intranasally with subtype H1N2 and 2 groups of contact pigs (n = 4) each were mixed with principal pigs on day 7 (group 1) or 28 (group 2). Two principal pigs each were necropsied on days 4, 14, 21, 28, and 42 days after inoculation. Four pigs in each contact group were necropsied 35 and 14 days after contact. Virus excretion was evaluated after inoculation or contact. Lung lesions and the presence of SIV in various tissues were examined. RESULTS: Mild coughing and increased rectal temperature were observed in principal pigs but not in contact pigs. Nasal virus shedding was detected in all principal pigs from day 2 for 3 to 5 days, in group 1 pigs from day 2 for 4 to 9 days after contact, and in group 2 pigs from day 4 for 2 to 6 days after contact. Trachea, lung, and lymph node specimens from infected pigs contained virus. Antibody titers against all 3 subtypes in all pigs gradually decreased. CONCLUSIONS AND CLINICAL RELEVANCE: Protection from viral infection and shedding was not observed in pigs with maternal antibodies, but clinical disease did not develop. Vaccination programs and good management practices should be considered for control of SIV subtype H1N2 infection on swine farms.  相似文献   

RGO/Nylon-6 composite mat with unique structural features and electrical properties obtained from electrospinning and hydrothermal process     

Hem Raj Pant  Bishweshwar Pant  Chan Hee Park  Han Joo Kim  Dong Su Lee  Leonard D. Tijing  Bo Sang Hwang  Hak Yong Kim  Cheol Sang Kim 《Fibers and Polymers》2013,14(6):970-975

In this work, the reduced graphene oxide (RGO) sheets were effectively uploaded through nylon-6 fibers using combined process of electrospinning and hydrothermal treatment. Good dispersion of graphene oxide (GO) with nylon-6 solution could allow to upload GO sheets through nylon-6 fibers and facilitate the formation of spider-wave-like nano-nets during electrospinning. GO sheets present on/into nylon-6 spider-wave-like nano-nets were further reduced to RGO using hydrothermal treatment. The impregnated GO sheets into nylon-6 nanofibers and their reduction during hydrothermal treatment were confirmed by FE-SEM, TEM, FT-IR and Raman spectra. The electrical characteristics of pristine nylon-6, GO/nylon-6 and RGO/nylon-6 nanofibers were investigated and it was found that RGO/nylon-6 composite mat had better electrical conductivity than others. The formation of spider-wave-like nano-nets as well as indirect route of incorporation of RGO sheets on electrospun nylon-6 mat may open a new direction for future graphene/polymer electronics.  相似文献   

Rehabilitating Abandoned Pastures in Panama: Control of the Invasive Exotic Grass,Saccharum spontaneum L., Using Artificial Shade Treatments     

Taek Joo Kim  Florencia Montagnini  Daisy Dent 《Journal of Sustainable Forestry》2013,32(3):192-203

ABSTRACT

The exotic grass, Saccharum spontaneum L., has invaded abandoned agricultural lands in the Panama Canal Watershed for decades. The grass aggressively competes with regenerating tree seedlings preventing natural forest regeneration. To estimate effectual light level for controlling the grass, the growth of S. spontaneum was measured under a range of artificial shading conditions. Five shade treatment subplots–light intensities of 100% (full sunlight), 50, 25, 15, and 5%–were established at each of eight plots in land adjacent to the Panama Canal Watershed. Each site was cleared of S. spontaneum and then the regrowth was harvested. The regrowth of the grass was harvested and measured four times every one and half months for six months. The biomass of S. spontaneum was significantly less in lower light conditions than in full sunlight. The results showed that comparing growth of the grass at each harvest date, except for the first harvest date, there were significant differences between full sunlight and light intensities of 5, 15 and 25%. When compared by different harvest dates for each light level, only full sunlight showed a significant difference in biomass of the grass. The study demonstrates that shading is an effective method for controlling S. spontaneum. The results can be applied to developing reforestation strategies for abandoned lands occupied by S. spontaneum.  相似文献   

Potential of indigenous Bacillus spp. as probiotic feed supplements in an extruded low‐fish‐meal diet for juvenile olive flounder,Paralichthys olivaceus     

Kai‐Min Niu  Sanaz Khosravi  Damini Kothari  Woo‐Do Lee  Bong‐Joo Lee  Sang‐Gu Lim  Sang‐Woo Hur  Sang‐Min Lee  Soo‐Ki Kim 《Journal of the World Aquaculture Society》2021,52(1):244-261

A 12‐week feeding trial was designed to assess the probiotic potential of indigenous Bacillus amyloliquefaciens and/or Bacillus subtilis singly or in combination with Bacillus licheniformis in an extruded feed for olive flounder (Paralichthys olivaceus) juveniles. A high fish meal (FM) diet (control) and a low‐FM diet containing an alternative protein blend (30% FM replacement, FM30) were formulated. Three other experimental diets were prepared by inclusion of B. amyloliquefaciens (BA), B. subtilis (BS), or a mixture of B. amyloliquefaciens, B. subtilis, and B. licheniformis (BASL) into FM30 diet, with a final concentration of 10⁶ CFU/g diet. Results indicated that the FM30 diet was well tolerated by flounder, and the overall performance was not affected by dietary treatments. Lysozyme activity and total immunoglobulin level were significantly reduced in flounders when fed with the FM30 diet compared with the BASL and BA diets, respectively. The Bacillus additives neither enriched the relative abundance of the corresponding Bacillus spp. in the relevant gut microbiota of olive flounder nor modulated the presumptive gene functions of the gut microbiome. Despite the absence of growth‐promoting effect, the tested probiotics could still be economically viable for use as immunostimulants in commercial flounder diets with partial FM replacement.  相似文献   

Embryonic development and hatchability of red‐spotted grouper (Epinephelus akaara) ♀ × giant grouper (E. lanceolatus) ♂ hybrid at three incubation temperatures     

Choong Hwan Noh  Min Joo Kang  Sung Jin Yoon 《Aquaculture Research》2019,50(11):3477-3481

  相似文献