Virological and Epidemiological Studies on Encephalitis in Chiang Mai Area, Thailand, in the Year of 1982 : III. Virus isolation from clinical materials

1982年7月19日から8月17日までの調査期間中,3例の死亡した脳炎患者中1検体から1株の日本脳炎ウイルスが分離された.一方患者末梢血177検体からデングウイルスは11株分離され,単一クローン抗体による型同定で8株は1型,2株は2型,1株は3型である事が判明した.脳炎あるいは髄膜炎と診断された患者からデングウイルスが分離されたことはデング脳症の存在を示すものと考えられる.Japanese encephalitis (JE) virus was isolated from one out of 3 postmortem brain materials taken as necropsy specimens, while 11 strains of dengue viruses were isolated from peripheral blood of 9 dengue hemorrhagic fever (DHF), 1 encephalitis and 1 aseptic meningitis patients, during study period from July 19 to August 17, 1982. Typing by monoclones revealed that 8 strains were type 1, 2 were type 2, and 1 was type 3 virus, respectively. Isolation of dengue viruses from encephalitis and meningitis cases appears to indicate the presence of dengue encephalopathy

Antimutagenicity and DT-diaphorase inducing activity of Gynostemma pentaphyllum Makino extract

The hotwater extract of the herbal tea, Gynostemma pentaphyllum Makino, was not found tobemutagenicinSalmonellamutationassaywithorwithoutmetabolicactivation.However, the extract had both DT-diaphorase inducing activity in the murine hepatoma (Hepa1c1c7) cell line and antimutagenic properties towards chemical-induced mutation in Salmonella typhimurium strains TA98 and TA100. Mutagenicity of aflatoxinB1(AFB1),2-amino-6-methyldipyrido [1, 2-a : 3’, 2’, 3-d] imidazole (Glu-P-1), 2-aminodipyrido [1, 2-a:3’,2’,3-d]imidazole(Glu-P-2),2-amino- 1, 4-dimethyl-5H-pyrido [4, 3-b] indole (Trp-P-1), 3-amino-1-methyl-5H-pyrido [4, 3-b] indole (Trp-P-2), 2-amino-3-methylimidazo [4, 5-f] quinoline (IQ) and Benzo [a] pyrene (B[a]P)was inhibited by the extract of Gynostemma pentaphyllum Makino in a dose-dependent manner, but no effect was found on the mutagenic activity of 2-(2-Furyl)-3-(5-nitro-2-furyl) acrylamide (AF-2). However, the extract enhanced themutagenicity induced by 2-aminoanthracene (2AA), and N-methyl-N’-nitro-N-nitrosoguanidine (MNNG)

Virological and Epidemiological Studies on Encephalitis in Chiang Mai Area, Thailand, in the Year of 1982 : VII. Mosquito collection and virus isolation

1982年7月13日より8月12日までの間,タイ国チェンマイ市の近郊4カ所の豚舎にライトトラップを設置し,飛来する蚊を採集した.採集された蚊のうち日本脳炎媒介蚊として知られているコガタアカイエカ4935匹,Cx. gelidus 7052匹.Cx. fuscocephala 3526匹からヒトスジシマカ培養細胞クローンC6/36を用いてウイルスの分離を試みた.その結果2株の未同定のフラビウイルスと59株の未知濾過性因子が分離されたが,日本脳炎ウイルスは分離されなかった.この3種のイエカ属の蚊はブタからよく吸血しており日本脳炎の伝搬に大きな役割を果しているものと思われる.Totalling 15513 mosquitoes composed of Culex tritaeniorhynchus, Cx. gelidus and Cx. fuscocephala were collected in Chiang Mai Area from July 13 to August 12, 1982, and processed for virus isolation, using Aedes albopictus, clone C6/36, cells. JE virus was not isolated, although two unidentified flavivirus and 59 strains of unknown filtrable agents producing cytopathic changes in C6/36 cells were detected. Host preference of the above three species of Culex mosquitoes showed that they fed mostly on swine, followed by smaller percentages of bovines. Daily survival rate observed for Cx. tritaeniorhynchus females in Chiang Mai did not differ significantly from those observed in Japan

Mother-to-child transmission of the human immunodeficiency virus type 1 (role of neutralizing antibodies and molecular characteristics of the transmitted variants.)

Ce travail a confirmé le rôle protecteur de certains anticorps neutralisants dans la TME du VIH-1, a permis de suggérer que certaines souches seraient de bons indicateurs d anticorps neutralisants associés à la protection, et a confirmé le rôle de la région V2 de l enveloppe virale en tant que cible des anticorps neutralisants. Les caractéristiques moléculaires des virus transmis dans le contexte de la TME confortent les données en faveur de la transmission à l enfant d une population virale restreinte génétiquement. Une gp 120 plus compacte et une moindre glycosylation ne sont pas des caractéristiques des virus transmis de la mère à l enfant. Cependant, deux sites de N-glycosylation semblent être sélectionnés chez les virus transmis. L identification de deux cas de TME liés à des variants issus de recombinaisons entre variants maternels a confirmé la présence d un hot spot dans la région C2 du gène env, et a révélé pour la première fois un second hot spot dans la région C3.A lower risk of MTCT was associated with higher NAb titers against the CRF01_AE strain, MBA, in Thailand. The results suggest that some primary isolates may be useful indicators for identifying protective antibodies, and confirm the role of the V2 region in neutralization. We found that only viruses of a restricted subset were transmitted to the infant. We did not find that shorter gp120 or fewer PNGS were characteristics of viruses transmitted from mother to infant. However, a limited number of PNGS, particularly at positions N301 and N384, may confer an advantage on the virus to be transmitted. Moreover, we identified two cases that suggest that recombination probably contributed to adaptation of HIV-1 to its environment to be successfully transmitted from mothers to their infants. In addition, our data allow both to confirm, in natural in vivo conditions, a hot spot for recombination in the C2 region of HIV-1 envelope gene, and to suggest another hot spot in the C3 region.TOURS-Bibl.électronique (372610011) / SudocSudocFranceF