• Biomedical Science Letters
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• v.20 no.3
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• pp.139-146
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• 2014

Accurate and rapid diagnosis of dermatophytosis, a disease whose prevalence has been steadily increased, is important for successful treatment. Current laboratory methods for diagnosing dermatophytosis rely on KOH mount and fungal culture method. However, these methods have low sensitivity and are time-consuming (2~4 weeks to diagnosis). In our previous study, a rapid molecular diagnostic assay (PCR-reverse blot hybridization assay, REBA) was developed to identify the following 6 main species of dermatophytes: Trichophyton rubrum, T. mentagrophytes, T. tonsurans, Microsporum canis, M. gypseum, and Epidermophyton floccosum. However, the REBA required more evaluation to validate its use in clinical examinations. The aim of the present study was to evaluate and validate the ability of the PCR-REBA to successfully identify dermatophytes in clinical isolates from dermatophytosis patients. Both conventional identification methods and the PCR-REBA were used to assess the presence of species of dermatophytes in 148 clinical isolates. The results of the two approaches were compared, and discrepancies between the two approaches were resolved by fungal ITS1 sequence analysis. T. rubrum was the most prevalent dermatophyte identified by conventional identification methods (118/148, 79.7%) and the PCR-REBA (131/148, 88.4%). The overall rate of consistency between conventional identification methods and the PCR-REBA was 79.0% (117/148 samples). Fungal ITS1 sequence analysis showed that PCR-REBA results were correct for 93.5% (29/31) of the discrepant samples. The PCR-REBA is rapid, sensitive, and highly specific compared with conventional identification methods. Thus, the PCR-REBA is a potentially useful tool for identifying dermatophytes in clinical settings.

• Toxicological Research
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• v.11 no.2
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• pp.315-327
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• 1995

Diverse neurotoxic insults result in proliferation and hypertrophy of astrocytes, a subtype of glia in central nervous system. The hallmark of this response, often terms "reactive gliosis", is the enhanced expression of the major intermediate filament protein of castrocytes, glial fibrillary acidic protein (GFAP). These changes in the astrocytes suggest that GFAP may be a useful biochemical indicator of neurotoxicity. To investigate this possibility, we administered intra-peritoneally prototype nerotoxicants, metharnphetamine (MAP, 5 mg/kg), cocaine (30 mg/kg), N-buthyl benzenesulfonamide (NBBS, 300 mg/kg) and trimethytin (TMT, 8 mg/kg) to Wistar Rats and then assessed the effects of these agents on content of GFAP, which were determined by Sandwish ELISA and evaluated with neurotoxic symptoms, and quantitative changes of imrnunoreactivity of GFAP by light microscopic image analysis in specific regions. We found that assay of GFAP revealed time- and region-dependant patterns of neurotoxicity. The GFAP immunoreactivity of rat brain was increased in substantia nigra and hippocampus by MAP, NBBS and TMT; in roedial septal nucleus and nucleus accurnbens, it was also increased by RrBBS. Sandwich ELISA showed that GFAP levels of cerebrum in all groups on days 3 and 7 and that of brainstem(including cerebellum) in MAP, NBBS groups on day 1 and 3 were increased. A review of the background, design and results of these experiments are presented in this paper. Our findings indicate that GFAP is a sensitive and specific biomarker of neurotoxicity.otoxicity.

• Toxicological Research
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• v.26 no.4
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• pp.285-291
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• 2010

Recently, reproductive and neurobehavioral effects of bisphenol A (BPA) have been documented, and thus a review was requested for BPA management direction by the government. Therefore, this study was performed to establish a Korean tolerable daily intake (TDI) for BPA. An expert committee, consisting of specialists in fields such as toxicology, medicine, pharmacology, and statistics, was asked to evaluate BPA health based guidance values (HbGVs). Although many toxicological studies were reviewed to select a point of departure (POD) for TDI, rat and mouse reproductive studies by Tyl et al. (2002, 2006), which were performed according to GLP standards and OECD guidelines, were selected. This POD was the lowest value determined from the most sensitive toxicological test. The POD, a NOAEL of 5 mg/kg bw/day, was selected based on its systemic toxicity as critical effects. An uncertainty factor of 100 including interspecies and intraspecies differences was applied to calculate the TDI. According to the evaluation results, a TDI of BPA for Korean was suggested at 0.05 mg/kg bw/day. In addition, the BPA exposure level based on food consumption by the Korean population was estimated as 1.509 ${\mu}g/kg$ bw/day, and the HI was evaluated at 0.03 when the TDI of 0.05 mg/kg bw/day was applied. This HI value of 0.03 indicated that hazardous effects would not be expected from BPA oral exposures. Although highly uncertain, further studies on low dose neurobehavioral effects of BPA should be performed. In addition, it is recommended that the 'as low as reasonably achievable' (ALARA) principle be applied for BPA exposure from food packaging materials in newborn infants and children.

• Parasites, Hosts and Diseases
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• v.28 no.3
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• pp.161-174
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• 1990

The complete life cycle of Spirometra erinacei has been experimentally maintained in the laboratory. The cyclops were reared as the first intermediate host, and the tadpoles of Rana nigromaculata as the second intermediate host. ICR mice were used as another second host. The experimental definitive hosts were dogs and cats. Maturation and hatching of the eggs took 8 to 14 days by incubation at 29℃. The coracidium measured 43.8×36.9㎛. Mesocyclops leuckarti and Eucyclops serrulatus were susceptible to the coracidial infection. The procercoids older than 5 days in the cyclops had minute spines at the anterior end, calcium corpuscles in the body parenchyme and the cercomer at the posterior end. Procercoids 10 to 20 days old were infective to tadpoles, and 15 or 21 day old worms could infect the mice. The plerocercoids from the tadpoles at 15 days after experimental infection were pear-shaped and shorter than 1 mm in the length and were infective to mice. Fifteen to 18 days after experiMental inoculation of plerocercoids to dogs or cats, the adult worms began to produce eggs. One life cycle from egg to egg needed 48 to 67 days in the laboratory. The morphology of larval or adult worms was compatible with the description of Spirometra erinacei.

• Parasites, Hosts and Diseases
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• v.34 no.2
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• pp.113-120
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• 1996

An epidemiological survey was performed to know the status of Cwptespori,mum sp. infection among the people in Seoul and Chollanam-do in 1992. One village of Chollanam-do (Hwasun-gun) which showed the highest oocyst positive rate was re-surveyed in 1995 for human infection and for cattle also. The subjected areas consisted of 8 urban villages (: dongs) of Seoul and 4 urban (: dongs) and 7 rural (: myonsl villages of Chollanam-do. A total of 3,146 fecal samples was collected randomly, and smears were made from formalin-ether sediments. They were examined for Cwptosporinium oocysts by modified acid fast staining. The overall oocyst positive rate was 79% (248/3,146), but the rate was remarkably different between Seoul and Chollanam-do, 0.5% (4/853) and 10.6% (244/2,293), respectively The average size of oocysts was 4.8 ± 0.5 by 4.2 ± 0.5 ㎛, compatible with C. pcnlum. In Chollanam-do, rural villages showed significantly higher rate (14.0%) than urban villages (3.7%). Especially the people in Iyang-myon, Hwasun- gun, a typical rural village, revealed a very high rate of 40.0% (74/185). Adults aged 51-70 years revealed the highest positive rate among all age groups. At the re-survey of the same village of Hwasun-fun in 1995, 44 (35.2%) of 125 villagers and 14 (93.3%) of IS cattle examined were positive for C. pnnpum oocysts. The results suggest that C. pnnpum is highly prevalent in rural areas of Chollanam-do, and an important source or mode of infection seems to be contaminated water or contact with the feces of infected cattle.

• Parasites, Hosts and Diseases
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• v.34 no.2
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• pp.121-126
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• 1996

For the detection of Cwptospori,mum oocysts, fecal samples were collected from 201 calves which showed diarrhea. Among the 201 samples, 29 samples (14.4%) were positive for Cwptosporinium spry. by the DMSO-modified acid-fast stain (MAFS) , 23 samples (11.4%) were positive by commercial kit (Meridian Diagnostics, Cincinnati, Ohiol and 23 by the indirect immunofluorescence antibody (IFA )assay employing the monoclonal antibody (mAb C6). When tested by both IFA and MAFS, 20 fecal samples were positive for Cwptosporinium oocysts whereas 169 fecal samples were negative. If the MAFS is considered a standard method for oocyst detection, the IFA showed 69% of sensitivity and 98% of specificity. When tested by both IFA and commercial kit, 22 fecal samples were positive for Cwptospori,mum oocysts while 177 samples were negative. One sample tested by IFA was found to be false negative, when compared with the results by commercial kit. The sensitivity of IFA was calculated as high as 96%; the specificity as 99% and the predictive value was also 99%. In the present study, IFA employing the nAb C6 revealed that 23 samples (11.4%) were positive among the 201 calves showing diarrhea. Of 23 IFA positive samples, 4 samples (5%) showed cryptosporidial oocysts more than 105 OPG Therefore. it is concluded that the calves showing cryptosporidial oocysts more than 105 OPG in the feces were highly associated with clinical cryptosporidiosis.

• Parasites, Hosts and Diseases
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• v.34 no.2
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• pp.127-134
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• 1996

Twelve isolates of Accnthamoebc app. assigned to either A. castellanii or A. poIMphoSa, and type strains of A. culbefsoni, A. henIWi, A. pqkestinefiE, and A. astronyxi,s were examined by restriction fragment length polymorphism (RFLP) of a conserved region of small subunit ribosomal RMh gene (ssu rDNA) amplified by polymerase chain reaction (PCR). The PCR products of the isolates measured approximately 910-930 bp, except for that of A. astronyxis which was extraordinarily long, approximately 1,170 bp. Average of estimated sequence divergence of the amplified DNA among the isolates assigned to A. castellanii was 9.8% whereas that among the isolates assigned to A. polvphusn 9.6%. The maximum intraspecific sequence divergence among the isolates assigned to A. costellanii was observed between the Chang and Ma strains (17.3%) while that among the isolates assigned to A. poIWphosa was observed between KA/S3 and KA/S7 strains (16.1%). The both maximum sequence divergences were much greater than the minimum interspecific sequence divergence between A. cnstellnnii and A. polwphasa (2.6%) which appeared between the Castellani (or CCAP 1501/12 g) and KA/S3 strains. The PCR-RFLP patterns of A. culbertsoni, A. healyi, A. palestinensis, and A. ostronvxis were quite diverse from one another and from those of isolates assigned to either A. castellanii or A. polyphoga. It is suggested that taxonomic validity of the isolates assigned to either A. castellnnii or A. polyphoga should be reevaluated.

• Parasites, Hosts and Diseases
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• v.34 no.2
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• pp.135-142
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• 1996

Antigenic domain of jai or surface protein (p30) of Toxoplosmc Sondii was analyzed after polymerase chain reaction (PCR) of its gene fragments. Hydrophilic or hydrophobic moiety of amino acid sequences were expressed as glutathione S-transferase (G57) fusion proteins. Fragments of p30 gene were as follows: 737, total p30 open reading frame (ORF) ; S28, total ORF excluding N-terminal signal sequence and C-terminal hydrophobic sequence; Al9, N-terminal 2/3 parts of A28; A19, N-terminal 2/3 of S28; P9, C-terminal 2/3 part of S28; Z9. middle 1/3 of S28; and 29, C-terminal 1/3 of S28. respectively. Primer of each fragment was synthesized to include clamp sequence of EcoR I restriction site. PCR amplified DNA was inserted info GST (26 kDa) expression vector, PGEX-47-1 to transform into Escheri,hia coei (.JM105 strain). G57 fusion proteins were expressed with IPTG induction as 63. 54, 45, 45, 35, 36. and 35 kDa proteins measured by SDS-PAGE. Each fusion protein was confirmed with G57 detection kit. Western blot analysis with the serum of a toxoplasmosis patient revealed antigenicity in proteins expressed by T37. S28, and Al9 but not those by Pl8. X9, Y10, and Z9. Antigenicity of p30 seems to be located either in N-terminal 115 part in the presence of middle 1/3 part or in the oligopeptides between margins of the first and second 1/3 parts.

• Parasites, Hosts and Diseases
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• v.32 no.4
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• pp.259-266
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• 1994

The role of macrophages was observed In intranasally infected CSH/HeJ mice with trophozoites (3 ×105) of Acnnthomoeba culbertsoni which was a kind of free-living amoebae inducing meningoencephalitis in human and experimental animals. The mortality was 60% in the group of intraperitoneally injected mice with silica (0.5 mg/0.5 ml). It was much higher than that of 10% in the group of amoeba infected mice without silica administration. The phagocytic index of peritoneal macrophages co-cultured with Toxoplasma gondii was estimated daily. In contrast to the control and amoeba infected group which didn't show significant fluctuation of the phagocytic indices, the silica administrated group revealed under 3% until day 3, and gradual increase up to 24.7% in day 5 which was same level of amoeba infected group without silica administration. The level of interleukin- lb (IL- lb) measured by ELISA was the highest in the amoeba infected group without silica injection and the lowest in the amoeba infected group with silica administration. In the test of the amoebicidal activity of mice peritoneal macrcphages Dl uitro, silica administration revealed reducing effect on amoebicidal activity of macrophages. In conclusion, macrophages were proven to play a significant role in defense mechanism against the development of experimentally induced Acnnthamoebo menigoencephalitis.

• Parasites, Hosts and Diseases
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• v.32 no.4
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• pp.215-222
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• 1994

The relationship between the intestinal histopathology and number and position of' intraepithelial Iymphocytes(IEL) was observed chronologically in the small intestine of rats experimentally infected wiH Metagonimw vokogawci. Fifteen Sprague-Dawley rats were orally infected each with 3,000 metacercariae, and 3 were kept uninfected for controls. Three rats each were sacrificed on the day 5, 10, 15, 24 and 70 post-infection (PI) and samples of the small intestine, 5 cm, 10 cm, 20 cia and 70 cm posterior to the pylonls were taken. The samples were processed routinely and stained with Giemsa. The intestinal histopathology was severe during the day 5-15 PI and characterized by villous atrophy, crypt hyperplasia, and decrease of villus/ciypt height ratio. After the day 24 PI, the intestinal lesions showed some tendency of recovery The number of IEL increased at the early stage of infection, but decreased thereafter to a lower level than that of controls, with progression of the pathological changes. Then, the IEL number began to increase again after the day 24 PI. In control rats, the great majority of the IEL were located at the basal region of the epithelium. During the early stage of infection, however, a considerable proportion of IEL was found to have moved to the intermediate or apical region of the epithelium. From the above results, it is suggested that the change of IEL number and position during the course of M. yokogowoi infection should be closely related to the progression and recovery of the intestinal histopathology.