• Journal of Korean Society of Forest Science
• /
• v.97 no.6
• /
• pp.561-564
• /
• 2008

Pinus densiflora(red pine) stands in Korea have been faced with the serious threat by pine wilt disease caused by Bursaphelenchus xylophilus (nematodes). It is not easy to early detect and prevent the infected trees because those cannot be visually identified during the initial phase of infection. Red pine is usually infected by B. xylophilus from May to July and can be just visually detected in October or November. While the infected trees are wilted, the spectral value of Near Infrared (NIR) is supposed to be decreased. Based on this phenomena, in this paper, the vegetation vitality change of infected trees was analyzed using vegetation indices. Spectral values of Red, Green and NIR had been acquired monthly by a portable NIR camera in the same place of red pine stands infected by pine wilt disease. It could be proven that the vegetation index, or vegetation vitality of damaged trees starts to decrease from June, in the early infecting phase.

• Asian-Australasian Journal of Animal Sciences
• /
• v.23 no.5
• /
• pp.567-572
• /
• 2010

The objective was to assess the concentrations of Vitamins A and E in blood of growing lambs infected or not with gastrointestinal nematodes (GIN) and fed a diet containing clinoptilolite. Twenty-four male lambs were used. A $2{\times}2$ factorial design consisting of two feeding treatments (B and Z) and two levels of parasitic status, infected (I) and uninfected (U) was used. Lambs were randomly assigned to one of four (n = 6), groups: BU (basal-uninfected), BI (basal-infected), ZU (zeolite-uninfected) and ZI (zeoliteinfected). Lambs of groups BI and ZI were infected with a single dose of 15,000 $L_3$ larvae of GIN. Blood samples were collected from individual animals at the start of the experiment and, thereafter, at 15-day intervals. The average blood serum vitamin A and vitamin E, concentration in lambs (mean${\pm}$SD) was 0.25${\pm}$0.090 ${\mu}g/ml$ and 1.59${\pm}$0.769 ${\mu}g/ml$, respectively. Lambs fed Z diet had higher values of vitamin A (p<0.001), but lower values of vitamin E (p<0.01) when compared with those fed B diet.

• Journal of Veterinary Clinics
• /
• v.29 no.1
• /
• pp.58-62
• /
• 2012

To protect aquatic animal health of importing countries from the potential risks associated with exotic diseases introduced through international trade of live aquatic animals, inspection of designated commodities at ports of entry is a critical component of the safeguarding system. The only way to be 100% confident that no fishes in a shipment are infected with a specific agent is to test every fish in the commodity imported with a perfect diagnostic test. For the majority of cases, this is unrealistic since the group of interest may very large particularly for aquatic animals, or imperfect tests are often available. It is, therefore, more common to test a fixed proportion of a group by preplanned sampling schemes. However, decision making based on results of testing the sample can provide quite a chance that infected groups may be misclassified as uninfected, depending on sampling strategy employed. The objective of this study was to determine the possibility that one or more fishes in the group imported being infected but tests negative after inspecting samples. This question is critical to government authorities to examine whether sampling plan is sufficient to achieve the purpose intended for. At fixed population size, the maximum number of infected fishes when all tests negative was decreased as the sampling fraction increased. The probability of including at least one undetected but infected fish in a group for negative tests increased with the number of fish tested or true prevalence. The risk was much lesser where high sensitivity test was assumed; when increasing test sensitivity from 0.9 to 0.99, this risk was dramatically reduced to about a tenth or a fourth for prevalence ranges from 2 to 10%, given sample size ranges from 10 to 200. Based on the preliminary analysis, the author concluded that current sampling plan testing 4-8% of the import proposal for human consumption still can yield high false negative results. Therefore, from the quarantine inspection point of view, an enforced commodity-specific sampling design that accounts for the cost of testing with an imperfect test at the specified design prevalence is urgent.

• The Journal of Korean Society of Virology
• /
• v.29 no.4
• /
• pp.221-233
• /
• 1999

Prospect Hill Virus (PHV) is the well known serotype of hantavirus, a newly established genus in family Bunyaviridae. Extensive studies have upheld the original view of PHV genetics with three genes such as nucleocapsid (N) protein, envelope proteins (G1, G2) and RNA dependent RNA polymerase. In this study, we report the existence of additional gene that is encoded in an overlapping reading frame of the N protein gene within S genome segment of PHV. This gene is expected to encode a nonstructural small (NSs) protein and it seems to be only found in PHV infected cell. The presence and synthesis of NSs protein could be demonstrated in the cell infected with PHV using anti-peptide sera specific to the predicted amino acid sequence deduced from the second open reading frame. Ribosomal synthesis of this protein appears to occur at AUG codon at the 83rd base of S genome segment, downstream of N protein initiation codon. This protein is small in size (10.4 KDa) and highly basic in nature. The expression strategy of NSs protein appears that a signal mRNA is used to translate both N and NSs protein in PHV infected cell. 10 KDa protein in virus infected cell lysates can bind to mimic dsRNA. This fact strongly suggests that NSs protein may be involved in virus replication on late phase of viral life cycle.

• Parasites, Hosts and Diseases
• /
• v.43 no.1 s.133
• /
• pp.1-5
• /
• 2005

The prevalence of parasitic infections was investigated in human immunodeficiency virus (HIV)-infected patients (n = 105) who visited Seoul National University Hospital, Seoul, Korea, during the period from 1995 to 2003. Fecal samples were collected from 67 patients for intestinal parasite examinations, and sputum or bronchoalveolar lavage samples from 60 patients for examination of Pneumocystis carinii. Both samples were obtained from 22 patients. Thirty-three ($31.4\%$) of the 105 were found to have parasitic infections; Cryptosporidium parvum ($10.5\%$; 7/67), Isospora belli ($7.5\%$; 5/67), Clonorchis sinensis ($3.0\%$; 2/67), Giardia lamblia ($1.5\%$; 1/67), Gymnophalloides seoi ($1.5\%$; 1/67), and Pneumocystis carinii ($28.3\%$; 17/60). The hospital records of the 11 intestinal parasite-infected patients showed that all suffered from diarrhea. This study shows that parasitic infections are important clinical complications in HIV-infected patients in the Republic of Korea.

• Parasites, Hosts and Diseases
• /
• v.31 no.2
• /
• pp.83-90
• /
• 1993

We performed bromodeoxyuridine (BrdU) staining to observe the proliferation pattern of epithelial cells on the biliaJy mucosa in Clonorchis sinensis infection. Albino rats were infected with 100 metacercariae each and their livers were processed for histopathological observation after BrdU injection. Five to six sites in the liver of a rat were selected for paraffin section, and stained immunohistochemically to visualize BrdU incorporating cells. The flukes were mainly in the common bile duct and right or left hepatic bile ducts. The proportion of stained epithelial cells in the infected bile ducts where the worms were found on the section was 2.9-10.2% at 1 week after infection. 7.3-12.8% at 2 weeks, 7.3-13.4% at 5 weeks, and 8.4-14.8% at 15 weeks while in the non-infected ducts o to 2.7% cells were stained. The stained cells were mainly at the base of the mucosal layer. It is suggested that mucosal epithelial cells of the bile ducts infected with C. sinensis become hyperplastic mainly by direct and local stimulation of the worms.

• Korean Journal of Veterinary Research
• /
• v.41 no.1
• /
• pp.89-98
• /
• 2001

This study was conducted to detect the toxoplasma specific-DNA in circulating blood and organs collected from slaughtered pigs at slaughtering house and experimentally infected pigs with Toxoplasma gondii tachyzoites by polymerase chain reaction(PCR), and also PCR was applied to diagnose for acute phase of swine toxoplasmosis as a newly developed diagnostic test. The sensitivity of oligonucleotide primer, T-1 & T-2, designed from toxoplasma B1 gene amplification method was compared with Tp parasite detection by mouse inoculation(MI). On the other hand, latex agglutination test(LAT) was conducted to detect the serum antibodies comparing with the detection of toxoplasma by PCR and MI. The results obtained were summarized as follows. PCR was able to determine at the lowest level of $10^0/ml$ T. gondii in blood samples which were blended with a serial diluted T gondii in vitro. On the other hand, $10^2/5g$ of T gondii could detect from a variety of tissues including lung, diaphragm, liver, heart, spleen and brain in vitro. The primer was proved to specifically determine T gondii in blood and tissues in vitro but it did not detect Neospora caninum used as a negative control. DNA of T. gondii was effectively extracted by freezing, thawing and grinding twice both tissues mixed with T gondii in vitro and in experimentally infected pig's tissues. PCR detected specific DNA in the blood of experimentally infected pigs at 108 hrs and 120 hrs post-infection, it was the same time that the pigs showed fever and parasitaemia. In case of tissue, specific DNA was, however, detected only lung from experimentally infected pigs. Even though the duration of acute phase was from 3 to 7 days post-infection, but the latex agglutination test (LAT) results appeared from 8 days post-infection. A comparison of sensitivity in determining T gondii in blood samples between PCR and MI, PCR positive rate ranged from 25 to 33.3%, but that of MI covered from 75 to 100%.

• The Plant Pathology Journal
• /
• v.36 no.1
• /
• pp.106-110
• /
• 2020

Citrus mosaic sadwavirus (CiMV) is a closely related virus with the Satsuma dwarf virus (SDV) along with Navel orange infectious mottling virus (NIMV), Natsudaidai dwarf virus (NDV), and Hyugagatsu virus (HV). The present study found that the typical symptoms of CiMV-infected citrus fruits include the appearance of dark blue speckles or ringspots on fruit rinds and the browning of oil glands in the spots as rind coloring began. As rind coloring progressed, the spots gradually faded, whereas the browning of the oil glands worsened to the point that the tissues surrounding the oil glands became necrotic. In very early satsuma mandarins (Citrus unshiu 'Miyamoto Wase') and 'Setoka' cultivar (C. hybrid 'Setoka') of late-maturity citrus, the symptomatic fruits were eventually dropped. And in early satsuma mandarin (C. unshiu 'Miyakawa Wase'), the peel hardness of the virus-infected fruit (1,618.3 ± 305.5, g-force) was more than twice as hard as that of the healthy fruit (636.5 ± 39.1, g-force). The ratio of flesh weight to total fruit weight was higher for the healthy fruit (77.3 ± 1.7%) than for the infected fruit (70.7 ± 0.6) and peel puffing was more severe in the infected fruit (2.9 ± 0.4 mm) than in the healthy fruit (0.9 ± 0.2 mm). The soluble solids content in infected citrus fruits was less values than the healthy fruit by 0.5-1.5 °Brix. These findings reveal that CiMV infection on citrus trees reduces the fruit quality of citrus.

• Parasites, Hosts and Diseases
• /
• v.52 no.3
• /
• pp.273-280
• /
• 2014

The changing patterns of goblet cell hyperplasia, intestinal epithelial cell turnover, and intestinal motility were studied in ICR and C57BL/6 mice infected with Gymnophalloides seoi (Digenea: Gymnophallidae). Whereas ICR mice retained G. seoi worms until day 7 post-infection (PI), C57BL/6 mice showed a rapid worm expulsion within day 3 PI. Immunosuppression with Depo-Medrol significantly delayed the worm expulsion in C57BL/6 mice. Goblet cell counts were increased in both strains of mice, peaking at day 1 PI in C57BL/6 mice and slowly increasing until day 7 PI in ICR mice. In C57BL/6 mice infected with G. seoi, newly proliferating intestinal epithelial cells were remarkably increased in the crypt, and the increase was the highest at day 1 PI. However, in ICR mice, newly proliferating intestinal epithelial cells increased slowly from day 1 to day 7 PI. Intestinal motility was increased in G. seoi-infected mice, and its chronological pattern was highly correlated with the worm load in both strains of mice. Meanwhile, immunosuppression of C57BL/6 mice abrogated the goblet cell proliferation, reduced the epithelial cell proliferation, and suppressed the intestinal motility. Goblet cell hyperplasia, increased intestinal epithelial cell turnover, and increased intestinal motility should be important mucosal defense mechanisms in G. seoi-infected C57BL/6 mice.

• Korean Journal of Veterinary Research
• /
• v.40 no.4
• /
• pp.729-739
• /
• 2000

Echocardiography, vital signs, microfilaremia, and blood chemistry of 12 Jindo dogs naturally infected with canine heartworms (Dirofilaria immitis) were analysed and compared with those of 5 uninfected control Jindo dogs. Nine of the twelve infected dogs contained microfiaria in the peripheral blood, whereas the presence of adult heartworms in the pulmonary arteries and/or in the heart was detected from four dogs by echocardiography. Among the four echocardiography-positive dogs, two dogs also displayed evidence of heartworms in the right ventricle by echocardiography. Upon necropsy, a total of 547 adult worms was collected from the 12 infected dogs (av = 45.6, range = 9-166). Dogs with positive echocardiograpic images of heartworms contained 48, 74, 104 and 166 adult worms in the heart, pulmonary arteries and/or in the caudal vena cava (av. 98.0), whereas 9 to 39 worms (av. 19.4) were collected from those organs of dogs with negative echocardiography. Most heartworms were found in the right ventricle (438, 80%) at necropsy, whereas relatively fewer worms were found in the pulmonary arteries (96, 17.6%), and in the caudal vena cava (13, 2.4%). The necropsy findings on the location of adult worms significantly differed from the results of echocardiographic analysis in which the right ventricle of most dogs did not show the presence of heartworms. These results indicated that the adult heartworms had been located in the terminal branches of the pulmonary arteries when the host was alive, but the worms moved toward the right ventricle shortly after the heart of the infected dogs stopped beating. Microfilaremia in the peripheral blood was the highest in the blood samples collected at 10 pm. However, the correlation between the number of microfilaria and of adult worms was not observed. Clinical and vital signs of infected dogs did not show any significant difference before and after a 30 minute-exercise at 5 km/hr compared to those of uninfected control dogs.