Development and characterization of a live varicella vaccine (Oka strain)

A live varicella vaccine (Oka strain) was developed by serial passage of the Oka strain isolated in our laboratory, in human embryonic lung cells (11 times at 34 C) and guinea pig embryo cells (12 times at 37 C). It is slightly temperature sensitive at 39 C and shows a higher ratio of infectivity in guinea pig embryo cells to infectivity in human embryo cells than wild-type strains. The DNA digest with Hpa I enzyme of the Oka strain contained one unique fragment (K), although its mobility differed only slightly from that of the corresponding fragment of wild-type strains. Studies with clinical varicella zoster virus (VZV) isolates from vaccinees indicated that tests on the ratio of infectivity in guinea pig embryo fibroblasts (GPEF) to that in human embryo fibroblasts (HuEF) and the profile of the DNA digest with Hpa I are useful for differentiation of the vaccine strain from wild-type strains. The vaccine virus showed stable immunogenicity during at least 15 further repeated passages in human diploid cells, a character which seems helpful for production of a large quantity of vaccine virus for practical use.     

Acute admissions of patients with sickle cell disease who live in Britain.

All acute admissions of patients with sickle cell disease who lived in the London borough of Brent and attended this hospital were analysed for a period of one year. Sixty three of the 211 patients who were followed up by the haematology department required 161 acute admissions during the year. Most admissions (126) were for the 42 patients with homozygous sickle cell disease; 147 (91%) were for vaso-occlusive episodes, 142 of which were for painful crises, three for cerebrovascular accidents, and two for renal papillary necrosis. Preschool children with sickle cell disease were admitted predominantly with limb pain, whereas in schoolchildren and adults the incidence of trunk pain was higher. Twenty four of the 93 episodes of trunk pain culminated in an episode of severe visceral sequestration usually affecting the lungs, the liver, or the mesenteric circulation. Two patients died: an 18 month old baby with an acute splenic sequestration crisis and a 19 year old man with a severe girdle syndrome (sickling in the mesenteric circulation, liver, and lungs). Infective episodes were rare (11 episodes) but severe: one haemophilus meningitis, two salmonella infections, and three aplastic crises due to parvovirus infections. The average duration of the hospital stay was 7.4 days per admission. It is concluded that because sickle cell disease causes appreciable morbidity in older children, adolescents, and adults a systematic approach to management is needed to deal with acute episodes such as sequestration syndromes.     

Rearing tench (Tinca tinca L.) larvae on live feed (Artemia) and on two transition schedules from live to dry diets

Two 60‐day experiments were carried out on tench (Tinca tinca L.) from day 5 post‐hatch. Density was 20 larvae L^?1 and temperature 24 ± 0.5°C. In experiment 1, Artemia nauplii were the sole food, testing nauplii amounts and feeding frequency. High survival rates (between 79.5% and 95.5%) were obtained. Growth was faster as nauplii amounts were greater; the highest growth rate (11.00), weight (265.5 mg) and Fulton’s coefficient (1.40) were obtained when fish were fed in excess once a day, without significant differences from the growth obtained by feeding in excess of eight times a day. In experiment 2, a dry diet for marine fish was tested as a replacement for Artemia nauplii, following two transition protocols, one faster than the other; high survival rates (between 77.7% and 87.1%) were again obtained. The slower transition allowed a growth rate of 10.14, length of 23.1 mm, weight of 158.3 mg and a Fulton’s coefficient of 1.28, without significant differences from the faster transition. At all stages, growth values were significantly higher from feeding nauplii in excess as the sole food, but the required nauplii quantity was six times higher than the amount supplied to the animals fed the dry diet.     

Automated identification of live moths (Macrolepidoptera) using digital automated identification System (DAISY)

Two hundred and thirty‐seven species of Macrolepidoptera were light trapped at Treborth Botanical Garden, Gwynedd, UK. Live adults were digitally imaged using a simple, inexpensive method suitable for field use, then released. Inconsistent lighting, variation in resting posture and inclusion of worn individuals produced image sets high in intraspecific variation. Thirty‐five common species were selected to provide training images for the Digital Automated Identification SYstem (DAISY). Twenty individuals per species were pre‐processed to standardize size and posture and to enhance features. The right forewing of each was highlighted manually and the pattern rendered polar and greyscale for DAISY analysis. Despite poor quality of some images, 83% of unknown species were identified correctly. The best species had 100% correct identification and the worst 35%. The most poorly identified images were those of moths that had lost scales or been unevenly illuminated. The precision with which the forewing was highlighted affected performance. When highlighted carefully, Laothoe populi was identified correctly twice as successfully as when the same image was highlighted poorly. Size of the training set was also important. Sets of 5, 10, 15 and 20 training images, plotted against performance produced a curve of diminishing returns. Colourimages and inclusion of size should improve accuracy.     

麻疹减毒活疫苗国家参考品的制备及标定

为了制备麻疹减毒活疫苗国家参考品,选用国内麻疹疫苗生产株沪191制备麻疹疫苗参考品。生产过程中严格控制精密性、水分含量,对候选参考品进行鉴别试验、水分含量、病毒滴度及无菌检查等检验。检验合格后组织进行候选参考品病毒滴度协作标定,共有5个实验室参加了协作标定。协作标定完成后,对实验室内变异、实验室间变异及国际参考品在不同实验室间的变异进行了分析。此外还对疫苗进行了热稳定性和实时稳定性分析。结果显示经5个实验室协作标定后,麻疹减毒活疫苗国家参考品的滴度为4.96±0.26 lgCC ID50/m l,实验室内部变异在1.09%～4.64%之间,实验室间变异为2.62%。国际参考品在不同实验室间的变异为4.19%。稳定性考核数据表明制备的参考品具有较好的稳定性,符合作为麻疹减毒活疫苗国家参考品的要求,滴度为4.96±0.26 lgCC ID50/m l。     

A novel zinc bis(thiosemicarbazone) complex for live cell imaging

Fluorescent zinc complexes have recently attracted a lot of interest owing to their vast applications in cellular imaging. We report the synthesis as well as physical, chemical and biological studies of a novel zinc glyoxalbis(4-methyl-4-phenyl-3-thiosemicarbazone), [Zn(GTSC)]₃, complex. As compared with the well-studied zinc biacetylbis(4-methyl-3-thiosemicarbazone), Zn(ATSM), complex, which was used as a reference, [Zn(GTSC)]₃ had 2.5-fold higher fluorescence. When cellular fluorescence was measured using flow cytometry, we observed that [Zn(GTSC)]₃ had 3.4-fold to 12-fold higher fluorescence than Zn(ATSM) in various cell lines (n = 9) of different tissue origin. Confocal fluorescence microscopy results showed that [Zn(GTSC)]₃ appeared to have a nuclear localization within 30 min of addition to MCF7 cells. Moreover, [Zn(GTSC)]₃ showed minimal cytotoxicity compared with Zn(ATSM), suggesting that [Zn(GTSC)]₃ may be less deleterious to cells when used as an imaging agent. Our data suggest that the novel [Zn(GTSC)]₃ complex can potentially serve as a biocompatible fluorescent imaging agent for live cells.