• 한국동물학회지
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• 제1권1호
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• pp.1-6
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• 1958

A rat-fleas survey was carried out in Ducksonm and Kwangnaru areas of Seoul city from Janurary to December 1955 . In this survey, 1,204 redents were trapped alive and 740 of which being Rattus norvegicus, 457 Apodemus agrarius, 5 Eutamiias asiaticus and 2 shrewes ((crocidura rusila). On these rodents 270 fleas were collected and identified thus : Ceratopylidae : Monopsyllus anisus (Rothschild 1908) ···200 Leptosylla segnis(Schonherr, 1832)···1 Hystrichopsyllidae : Ctenophthalmus congener, Rothschild ···43 Neopsylla bidentiformis (Wagner, 1893)···11 Stenoponia sidimi Marikovsky, 1936···9 Pulcidae : Xenopsylla cheopis (Rothschild, 1903)···6 On the average 8.5% of the rodents were infestated with fleas. The infestation rate showed a marked varying degree in a year and three high incidence peaks in Spring (10.3%), Summer (11.4%-11.8%) and Winter (13.7%). The average number of fleas per rat (flea-index) was 0.22 for the whole year with a maximum of 0.41 in December and a minimum of 0.03 in February. Of all, the most prevalent species are Monopsyllus anisus (74.1%) and secondly Ctenophthalmus congener (15.9%). both species occupied 90% of all. Xenopsylla cheopis, a known vector of plague, was found very rare in our survey and only appeared in Winter. The striking lower incidence of flea-index compared with previous data (6.6 by Nagahana, 1931-1936) appears to be due to the nationwide application of DDT and BHC insecticides since 1945.

• Anatomy and Cell Biology
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• 제51권4호
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• pp.284-291
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• 2018

The role of androgens in the development of cardiovascular diseases remains controversial. The current study therefore sought to determine the changes in the histomorphology of the common carotid artery of the male rat in orchidectomy-induced hypogonadism. Twenty-two Rattus norvegicus male rats aged 2 months were used. The rats were randomly assigned into baseline (n=4), experimental (n=9), and control (n=9) groups. Hypogonadism was surgically induced in the experimental group by bilateral orchiectomy under local anesthesia. At experiment weeks 3, 6, and 9, three rats from each group (experimental and control) were euthanized, their common carotid artery harvested, and routine processing was done for paraffin embedding, sectioning, and staining. The photomicrographs were taken using a digital photomicroscope for morphometric analysis. Orchidectomy resulted in the development of vascular fibrosis, with a significant increase in collagen fiber density and decrease in smooth muscle and elastic fiber density. Moreover, there was development of intimal hyperplasia, with fragmentation of medial elastic lamellae in the common carotid artery of the castrated rats. Orchidectomy induces adverse changes in structure of the common carotid artery of the male rat. These changes may impair vascular function, therefore constituting a possible structural basis for the higher incidences of cardiovascular diseases observed in hypogonadism.

• 한국축산식품학회지
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• 제43권1호
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• pp.170-183
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• 2023

This study evaluated the effects of milk fermented with Pediococcus acidilactici strain BE and Pediococcus pentosaceus strain M103 on diabetes in rats (Rattus norvegicus). The bacteria were separately used as starter cultures for milk fermentation, and the products were then fed to diabetic rats for 15 days. Blood glucose levels, immunohistochemical and histological indicators, lipid profiles, and total lactic acid bacterium counts were evaluated before and after treatment. The administration of milk fermented with P. acidilactici strain BE reduced blood glucose levels from 410.27±51.60 to 304.07±9.88 mg/dL (p<0.05), similar to the effects of metformin (from 382.30±13.39 mg/dL to 253.33±40.66 mg/dL, p<0.05). Increased insulin production was observed in diabetic rats fed milk fermented with P. acidilactici strain BE concomitant with an increased number and percentage area of immunoreactive beta-cells. The structure of insulin-producing beta-cells was improved in diabetic rats fed milk fermented with P. acidilactici strain BE or metformin (insulin receptor substrate scores of 5.33±0.94 and 3.5±0.5, respectively). This suggests that the administration of milk fermented with P. acidilactici BE potentially reduces blood glucose levels and improves pancreatic beta-cell function in diabetic rats.

• Parasites, Hosts and Diseases
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• 제48권3호
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• pp.237-243
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• 2010

Comprehensive quarterly serosurveillance on scrub typhus in small mammals collected from military training sites located near the Demilitarized Zone (DMZ), northern Gyeonggi-do (Province), ROK was conducted to determine the potential rodent-borne and associated ectoparasite disease risks to military personnel. A total of 1,196 rodents and insectivores representing 8 species, Apodemus agrarius (87.3%, n = 1,044), Mus musculus (5.4%, n = 65), Crocidura lasiura (3.3%, n = 40), Microtus fortis (2.6%, n = 31), Micromys minutus (0.3%, n = 4), Tscherskia triton (0.3%, n = 4), Rattus norvegicus (0.3%, n = 4), and Myodes regulus (0.3%, n = 4) were assayed for the presence of antibodies to Orientia tsutsugamushi. O. tsutsugamushi antibodies were detected in 6 of 8 species and seroprevalence determined; A. agrarius (45.6%), M. musculus (23.1%), M. fortis (48.4%), M. minutus (50.0%), T. triton (50.0%), and R. norvegicus (25.0%). A total of 31,184 chigger mites collected from 508 rodents and insectivores were slide-mounted and 10 species belonging to 4 genera were identified. Leptotrombidium pallidum (53.4%) was the most frequently collected, followed by L. pal pale (15.7%), Neotrombicula tam/yai (14.3%), L. orientate (10.7%), L. zetum (3.1%), Walchia fragilis (2.1%), and L. gemiticutum (0.8%), while the remaining 3 species, L subintennedium, N. gardellai, and Euschoengastia koreaensis were rarely observed (prevalence < 10%). In contrast to previous surveys, higher chigger indices of the primary scrub typhus vectors, L. pallidum (165.4), L. orientale (45.0), and L. palpate (21.4), were observed during the spring season.

• 한국동물위생학회지
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• 제26권3호
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• pp.203-214
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• 2003

Scrub typhus and murine typhus are common endemic febrile illness in the fall in Korea. Scrub typhus is caused by Orientia tsutsugomushi, murine typhus is caused by Rickettsia typhi. Trombiculid mites are known as both the vector and the reservoir host of O tsutsugamushi, the mites which transmit O tsutsugomushi have been reported to be Leptotrombidium pallidum and L scutellare. The author carried out an epidemiological study of scrub typhus and murine typhus in Kyodong-Myeon, Kanghwa-Gun, Incheon in relation to the residents and the host rodents, such as their distribution, seroepidemiology, and population density of chigger mites. 1. Out of 900 residents, 33(3.7%) showed positive reaction to O tsutsugamushi, 24(2.7%) to R typhi. 2. In the seropositives to O tsutsugamushi or R typhi, between the sixties and the seventies of the age were dominant. 3. In the seropositives to O tsutsugamushi serotypically Gilliam was dominant. 4. Among the total 42 field rodents trapped by the sherman traps, 18 rodents were Apodemus agrarius(42.9%), 13 rodents were Crocidura lasiura(31.0%), 5 rodents were Musmusculus(11.9%), 2 rodents(4.8%) were Crocidura suaveolens, Rattus norvegicus, Tscherskia triton, respectively. 5. Out of 42 field rodents, 25 were parasitized by 4,419 chigger mites, showing 59.5% of the infestation rate and 98.8 of the chigger index. L pallidum parasitized in A agrarius, C lasiura, M musculus, R norvegicus and T triton, and L scutellare parasitized only C lasiura. 6. Antibodies in the sera of field rodents against O tsutsugamushi and R typhi were investigated by indirect immunofluorescent antibody technique. Positive rate of antibody against O tsutsugamushi were 11.9(5 of 42) and all of the positive is A agrarius. Antibody against R typhi was not detected. These results might provide the basic information for the management of scrub typhus and murine typhus in Kyodong-myeon, where the epidemiological studies on scrub typhus and murine typhus was not carried out enough.

• Fisheries and Aquatic Sciences
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• 제14권3호
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• pp.174-178
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• 2011

This study aimed to determine the degree of hydrolysis and angiotensin-I-converting enzyme (ACE)-inhibitory activity of Giant Jellyfish Nemopilema nomurai (jellyfish) hydrolysates. The degree of hydrolysis using six proteolytic enzymes (Alcalase, Flavozyme, Neutrase, papain, Protamex, and trypsin) ranged from 13.1-36.8% and the inhibitory activities from 20.46-79.58%. Using papain hydrolysate, we newly isolated and characterized ACE-inhibitory peptides with a molecular weight of 3,000-5,000 Da that originated from jellyfish collagen. The purified peptide (FII-b) was predicted to be produced from an alpha-2 fragment of the type IV collagen of jellyfish. The N-terminal sequence of FII-b was Asp-Pro-Gly-Leu-Glu-Gly-Ala-His-Gly- and showed 87% identity to the collagen type IV alpha-2 fragment of Rattus norvegicus and a predicted protein from Nematostella vectensis, indicating that the ACE-inhibitory peptide originated from the collagen hydrolysate and had an $IC_{50}$ value of 3.8 ${\mu}g$/mL. The primary structure of the fragment is now being studied; this peptide represents an interesting new type of ACE inhibitor and will provide knowledge of the potential applications of jellyfish components as therapies for hypertension.

• Parasites, Hosts and Diseases
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• 제55권5호
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• pp.555-559
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• 2017

Chigger mites are parasites of rodents and other vertebrates, invertebrates, and other arthropods, and are the only vectors of scrub typhus, in addition to other zoonoses. Therefore, investigating their distribution, diversity, and seasonal abundance is important for public health. Rodent surveillance was conducted at 6 districts in Shandong Province, northern China ($114-112^{\circ}E$, $34-38^{\circ}N$), from January to December 2011. Overall, 225/286 (78.7%) rodents captured were infested with chigger mites. A total of 451 chigger mites were identified as belonging to 5 most commonly collected species and 3 genera in 1 family. Leptotrombidium scutellare and Leptotrombidium intermedia were the most commonly collected chigger mites. L. scutellare (66.2%, 36.7%, and 49.0%) was the most frequently collected chigger mite from Apodemus agrarius, Rattus norvegicus, and Microtus fortis, respectively, whereas L. intermedia (61.5% and 63.2%) was the most frequently collected chigger mite from Cricetulus triton and Mus musculus, respectively. This study demonstrated a relatively high prevalence of chigger mites that varied seasonally in Shandong Province, China.

• 대한바이러스학회지
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• 제29권1호
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• pp.1-9
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• 1999

Hantaan virus is widely distributed among rodent populations in Korea. Two antigenically distinct hantaviruses were isolated from Apodemus agrarius in 1976 and Rattus norvegicus in 1980 in Korea. This study was designed to investigate the serological evidence of hantavirus infection among indegenous wild rodents, which were captured in 11 mountains located in Kyunggi, Kangwon, Chungnam, Chunbug and Kyungnam province of South Korea. A total 252 wild rodents of 3 species were trapped from Myungsung Mt., Chumbong Mt., Kali Mt., Hansuk Mt., Chachil peak, Kyebang Mt., Odae Mt., Kyerong Mt., Kaya Mt., Togju Mtand Chiri Mtin 1997. Serologic test for hantavirus infection was performed using hantavirus antigens by indirect immunofluorescent antibody techniqueAmong 122 Apodemus agrarius, 88 Apodemus peninsulae and 42 Eothenomys regulus; 18 A. agrarius (14.8%), 12 A. peninsulae (13.6%) and 4 E. regulus (9.5%) were immunofluorescent antibody (IFA) positive against hantaan virus. IFA titers 3 Eothenomys regulus sera were higher against puumalavirus than hantaan virus. These data imply that above three species of rodent might be natural reservoirs of hantaviruses in Korea.

• 대한바이러스학회지
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• 제28권3호
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• pp.287-293
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• 1998

Hantaan virus are widely distributed in rodents populations in Korea. Two antigenically distinct hantaviruses have been isolated from Apodemus agrarius in 1976 and Rattus norvegicus in 1980 in Korea. This study was designed to find the serological evidence of hantavirus infection among indigenous wild rodents captured in 7 Mountains located in Kangwon province of south Korea. A total 191 wild rodents of 3 species were trapped in Chumbong mountain, Kali mountain, Hansuk mounatin, Chachil peak, Bukam ridge, Kyebang mountain and Odae mountain in 1997. Serologic evidence for hantavirus infection were tested using hantavirus antigens by indirect immunofluorescent antibody technique (IFA). Among 85 Apodemus agrarius, 77 Apodemus peninsulae and 29 Eothenomys regulus; 8 A. agrarius (9.4%), 11 A. peninsulae (14.3%) and 4 E. regulus (13.8%) were immunofluorescent antibody positive against hantaan virus. IF antibody titers against Puumala virus of 3 E. regulus sera were higher than against hantaan virus. This data suggest that several antigenically distinct hantaviruses have been circulated in rodent populations in Korea.

• 대한바이러스학회지
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• 제30권1호
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• pp.19-28
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• 2000

Two distinct hantaviruses have been isolated from Apodemus agrarius in 1976 and Rattus norvegicus in 1980 in Korea. Since our serosurveys conducted in 1994, a genetically distinct hantavirus from Apodemus peninsulae has been investigated. To isolate hantavirus from Apen insulae captured in Korea, the lung homogenate of seropositive Apeninsulae inoculated Vero E6 cells. Viral antigen was detected in a progressively higher percentage of cells with subsequent passage after 80 days postinoculation. The new isolate from seropositive Apodemus peninsulae was designated Suchong virus after Suchong valley located in northeastern region of South Korea. Comparing with hantaan virus 76-118 strain, Suchong virus-1, 2, 3 and 4 showed the similarity of $71.0{\sim}91.8%$ at nucleotide and $90.9{\sim}94.8%$ at amino acid sequences in 231 nucleotides region of M segment, and the similarity of $75.1{\sim}81.0%$ at nucleotide and $97.5{\sim}100%$ at amino acid sequences in 237 nucleotides of S segment.