Biomedical subjects

Jun Kobayashi

Publications and source records attributed to Jun Kobayashi.

39 records · Page 3Linked to original sources

PubMed2002

Entomological surveys of malaria in Khammouane Province, Lao PDR, in 1999 and 2000.

Anopheline mosquitos and their relation to malaria transmission were studied 3 times: in July and August, 1999; in December, 1999; and in August and September, 2000. The studies took place in the malaria endemic villages of Khammouane Province, southeast of Lao PDR. A total of 28 species were collected using human and animal bait. Human bait attracted predominantly Anopheles dirus and An. minimus, which were identified as vectors by the detection of sporozoites by dissection, PCR, and enzyme-linked immunosorbent assays for Plasmodium falciparum and P. vivax. The vectorial capacity of An. dirus was 0.009-0.428, while that of An. minimus was 0.048-0.186. The inoculation rate of An. dirus was 0.052-0.137 (Boualapha; August, 2000). An. nivipes and its sister species, An. philippinensis, were principally zoophilic, although a considerable number of the females were also attracted to human bait in the villages of the paddy field areas. An. philippinensis infected with oocysts of P. vivax was detected in a specimen collected by animal bait. These two species were considered as vectors in Khammouane Province. Four species, An. notanandai, An. sawadwongporni, An. willmori, and An. hodgkini, had not been recored before in Lao PDR. Information is provided on host preference and the nocturnal biting activities of common species and the incidence of malaria in the study areas.

Animals↗

PubMed2000

Inactivation Analysis of HcNPV Cysteine Protease Gene and Chitinase Gene.

The fragment of Hyphantria cunea nuclear polyhedrosis virus (HcNPV), which contains cysteine protease gene(CP) and chitinase gene (ChiA),was inserted into plasmid PCRII to construct transfer vector pHcCVdel. Recombinant transfer vector pHcCvpolh was constructed by inserting the fragment of HcNPV polyhedrin gene (polh) into the EcoRI site of the pHcCVdel. By contransfection of the pHcCvpolh and HcNPV-PTTH(+) DNA, which contained Bombyx mori prothoracicotropic hormone gene (PTTH) into SPIM cells, the region from +76 downstream of ChiA gene initiation codon to +20 downstream of CP gene initiation codon was substituted by the polh gene, and the recombinant virus HcNPVpolh(+)CP(-)ChiA(-)PTTH(+) was produced. The recombinant virus, in which CP gene and ChiA gene were inactive, could express PTTH gene and form polyhedra. SPIM cells infected with the recombinant virus revealed that CP and ChiA gene were not essential for viral replication and had no significant effect on polyhedron formation, but the infected cells survived 2 days more than those infected with HcNPV and HcNPVPTTH(+). Therefore, the expression time of foreign gene may be prolonged when CP gene and ChiA gene were inactivated.

Journal Article↗

PubMed1998

Nucleotide Sequence Analysis of the HcNPV Cysteine Protease Gene.

The cysteine protease (CP) gene of Hyphantria cunea nuclear polyhedrosis virus (HcNPV) has been located at the Hind III--3.5 kb fragment. The nucleotide sequence has been determined. The results indicated that its open reading frame of 975 nt encoded the protein of 324 amino acids. The baculovirus late gene promoter TAAG motif was identified at -24 nt upstream from the start codon ATG; The typical poly (A) signal sequence AATAAA was detected at 33 nt downstream from the stop codon TAA. The HcNPV CP exhibited 81%, 76% and 76% homology at the nucleotide level, and 85%, 78%, 76% homology at the amino acid level to that of CfNPV (Choristoneura fumiferana nuclear polyhedrosis virus), AcNPV (Autographa californica nuclear polyhedrosis virus) and BmNPV (Bombyx mori nuclear polyhedrosis virus), respectively. HcNPV CP was a memeber of the papain superfamily and showed high homology to other cysteine protease, particularly, to those from Trypanosoma brucei and Dictyostelium discoideumwith 31.8%, 34.5% identity at the amino acid level, respectively. Of 36 residues conserved among cathepsins B, H, L and S and papain, 32 were identical in HcNPV CP. The ERFNIN interspersed amino acid motif was found within the propeptide region of the HcNPV CP. The Gly-Cys-Asn-Gly-Gly motif conserved among all cysteine protease was also detected in HcNPV CP.

Journal Article↗