Effects of gestational exposure to ethane dimethanesulfonate in CD-1 mice: microtia and preliminary hearing tests

BACKGROUND: Microtia is a reduction in pinna size, usually seen in humans in conjunction with other medical conditions. We report microtia in CD‐1 mice after gestational exposure to ethane dimethanesulfonate (EDS), an alkylating agent and adult rat Leydig cell toxicant. METHODS: Time‐pregnant CD‐1 mice were administered 0, 80, or 160 mg EDS/kg on gestation days (GD) 11–17, or 0 or 160 mg EDS/kg on GD 11–13, GD 13–15 or GD 15–17. Pinnae were measured on postnatal days (PND) 4, 8, 18, and 28; and were observed for detachment from birth through PND 8. Branchial‐arch derived skeletal structures and histology of the pinna was examined on PND 4 and 24. Brainstem auditory evoked response (BAER) tests were carried out at approximately PND 160 to determine possible effects on hearing. RESULTS: All offspring of EDS‐treated dams exhibited bilateral, dose‐related decreases in pinna size. Gestational exposure during GD 11–13 produced smaller ears than during GD 13–15 or 15–17, but not as small as the GD 11–17 regimen. Ossification of other pharyngeal arch derivatives was delayed whereas histology was unremarkable. BAER analysis showed a decrease in the proportion of adult offspring producing a quantifiable response to varied auditory stimuli among EDS‐treated litters. CONCLUSIONS: Gestational exposure to EDS affects pinna development in the mouse, with a broad period of sensitivity during the second half of gestation. Microtia induced by EDS may be associated with hearing deficits, suggesting functional importance of pinna size or additional effects of EDS on ear development not detected by morphological examination. Birth Defects Res B68:383–390, 2003. © 2003 Wiley‐Liss, Inc.     

Role of Liv-52 in protection against beryllium intoxication

An ayurvedic medicine, Liv-52, was studied as a prophylactic agent against beryllium-induced toxicity in rats. Administration of berylliumper se caused severe degenerative and necrotic changes in kidneys, liver, and uterus. Beryllium exposure also reduced glycogen content, activities of alkaline phosphatase, succinate-dehydrogenase, and adenosine-triphosphatase in these organs. On the contrary, activities of acid phosphatase and glucose-6-phosphatase showed marginal increase. Liv-52-primed rats exhibited comparatively less marked toxic effects.     

CONTRIBUTION OF CIRCADIAN PHYSIOLOGY AND SLEEP HOMEOSTASIS TO AGE-RELATED CHANGES IN HUMAN SLEEP

The circadian pacemaker and sleep homeostasis play pivotal roles in vigilance state control. It has been hypothesized that age-related changes in the human circadian pacemaker, as well as sleep homeostatic mechanisms, contribute to the hallmarks of age-related changes in sleep, that is, earlier wake time and reduced sleep consolidation. Assessments of circadian parameters in healthy young (～20–30 years old) and older people (～65–75 years old)—in the absence of the confounding effects of sleep, changes in posture, and light exposure—have demonstrated that an earlier wake time in older people is accompanied by about a 1h advance of the rhythms of core body temperature and melatonin. In addition, older people wake up at an earlier circadian phase of the body temperature and plasma melatonin rhythm. The amplitude of the endogenous circadian component of the core body temperature rhythm assessed during constant routine and forced desynchrony protocols is reduced by 20–30% in older people. Recent assessments of the intrinsic period of the human circadian pacemaker in the absence of the confounding effects of light revealed no age-related reduction of this parameter in both sighted and blind individuals. Wake maintenance and sleep initiation are not markedly affected by age except that sleep latencies are longer in older people when sleep initiation is attempted in the early morning. In contrast, major age-related reductions in the consolidation and duration of sleep occur at all circadian phases. Sleep of older people is particularly disrupted when scheduled on the rising limb of the temperature rhythm, indicating that the sleep of older people is more susceptible to arousal signals genernpated by the circadian pacemaker. Sleep-homeostatic mechanisms, as assayed by the sleep-deprivation–induced increase of EEG slow-wave activity (SWA), are operative in older people, although during both baseline sleep and recovery sleep SWA in older people remains at lower levels. The internal circadian phase advance of awakening, as well as the age-related reduction in sleep consolidation, appears related to an age-related reduction in the promotion of sleep by the circadian pacemaker during the biological night in combination with a reduced homeostatic pressure for sleep. Early morning light exposure associated with this advance of awakening in older people could reinforce the advanced circadian phase. Quantification of the interaction between sleep homeostasis and circadian rhythmicity contributes to understanding age-related changes in sleep timing and quality. (Chronobiology International, 17(3), 285–311, 2000)     

Diversity and antimicrobial activity of endophytic fungi isolated from Nyctanthes arbor-tristis, a well-known medicinal plant of India

Endophytic fungi from Nyctanthes arbor-tristis were isolated and evaluated for their antimicrobial activity. A total of 19 endophytic fungi were isolated from 400 segments of healthy leaf and stem tissues of N. arbor-tristis. Eighteen endophytic fungi were obtained from leaf, while only ten from stem. Alternaria alternata had the highest colonization frequency (15.0%) in leaf, whereas Cladosporium cladosporioides ranked first in stem with a colonization frequency of 12%. The diversity and species richness were found higher in leaf tissues than in stem. The similarity indices between leaf and stem were 0.473 for Jaccard’s and 0.642 for the Sorenson index, respectively. Of 16, 12 (75%) endophytic fungal extracts showed antibacterial activity against either one or more pathogenic bacteria. The endophytic Nigrospora oryzae showed maximum inhibition against Shigella sp. and Pseudomonas aeruginosa. The leaf endophytes Colletotrichum dematium and Chaetomium globosum exhibited a broad range of anibacterial activity and were active against Shigella flexnii, Shigella boydii, Salmonella enteritidis, Salmonella paratyphi, and P. aeruginosa. Nine out of 16 (56.25%) endophytic fungi exhibited antifungal activity to one or more fungal pathogens. Colletotrichum dematium inhibited 55.87% of the radial growth of the phytopathogen Curvularia lunata. The antimicrobial activity of these endophytic microorganisms could be exploited in the biotechnological, medicinal, and agricultural industries.     

Interactions of Paecilomyces lilacinus strain 251 with the mycorrhizal fungus Glomus intraradices: Implications for Meloidogyne incognita control on tomato

The interactions of Paecilomyces lilacinus strain 251 with the arbuscular mycorrhizal fungus Glomus intraradices and their significance for the control of Meloidogyne incognita on tomato were investigated in greenhouse experiments. Application of P. lilacinus had no effect on the frequency and intensity of tomato root colonization by G. intraradices. Likewise, the decline of the nematophagous fungus densities after single application in soil was not affected by the presence of the mycorrhizal fungus. Single application of P. lilacinus, as pre-planting soil treatment, resulted in significant reduction of nematode damage. In contrast, mycorrhizal inoculation did not provide sufficient biocontrol. Combined application of the two agents did not enhance root protection compared to single treatments. Double treatment of mycorrhized seedlings with P. lilacinus, as seedling drench and pre-planting soil treatment, 4 and 1 week before transplanting, respectively, resulted in the highest reduction of the nematode damage. These results indicate the potential of the commercial P. lilacinus strain 251 and mycorrhiza for integration in nematode control strategies.     

葡激酶的研究进展

本文综述了葡激酶的生化特性、溶栓特性、免疫原性和临床应用方面的研究进展。     

Demographic and Biomass Production Consequences of Inundative Treatment of Cirsium arvense with Sclerotinia sclerotiorum

The adventitious shoots in three populations of Cirsium arvense in sheep-grazed pastures were treated in October (spring) 1991 with a mycelium/wheat formulation of Sclerotinia sclerotiorum and the fates of mapped shoots were followed over the growing season. In untreated plots, deaths through natural causes were compensated for by births (emergence of new shoots above the soil) throughout the growing season, but, on plots treated with S. sclerotiorum, deaths from the induced disease exceeded births for 35 days following treatment, causing the shoot population to decline markedly. Disease-induced deaths occurred only among shoots present at the time of treatment; there was no evidence of transfer of the pathogen to shoots emerging after the treatment was applied. A life-table analysis showed that only 8% of the adventitious shoots emerging during the growing season survived to seeding on treated plots, compared with 28% on the untreated plots; most mortalities occurred in shoots at the vegetative stage of development. The dry mass of propagative roots in autumn was reduced to 35% of that on the untreated plots by the pathogen and the density of shoots emerging the following spring was reduced to a similar extent. The results of this study indicate that S. sclerotiorum has potential as a mycoherbicide for C. arvense in sheep-grazed pasture in New Zealand.     

Synthesis and biological evaluation of longanlactone analogues as neurotrophic agents

Longanlactone analogues were synthesized using a route featuring Friedel-Crafts acylation, Sonogashira coupling and 1,3-dipolar cycloaddition reactions. Structure–activity relationships were investigated for neurotrophic activity. Compound 6 was found to have the most potent neurotrophic activity among all the synthesized analogues in Neuro2a cells as evidenced by a battery of in vitro/cell based assays for assessment of neurogenic and potential neurotrophic activity including neurite outgrowth assay and real time PCR for popular markers of augmented neurotrophic activity. Compound 6 might serve as a template for further development of highly effective neurotrophic molecules.     

Bottom‐up effect of host plants on life‐history characteristics of Aphidoletes aphidimyza feeding on Aphis gossypii

The predatory midge Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae) is widely used for the control of Aphis spp. in many agricultural systems. We aimed to determine the most suitable host plant for rearing the predatory midges on the prey Aphis gossypii Glover (Hemiptera: Aphididae). Six host plants were selected: cucumber (Cucumis sativus L. cv. Beith Alpha), tomato (Solanum lycopersicum L. cv. Falat111), eggplant (Solanum melongena L. cv. Yummy), pepper (Capsicum annuum L. cv. Bertene) (all Solanaceae), okra [Abelmoschus esculentus (L.) Moensch cv. Clemson Spineless] (Malvaceae), and squash (Cucurbita pepo L. cv. Hybrid rajai) (Cucurbitaceae). Some physical traits (length and density of trichomes) and chemical attributes (nitrogen content) of prey host plants were investigated. The results showed that prey host plants differed significantly in their effect on fitness of the predator. The shortest immature development time (18.07 ± 0.257 days), the longest female adult longevity (7.5 ± 0.18 days), and the highest fecundity (89 eggs/female) of A. aphidimyza were found with squash as prey food. The highest intrinsic rate of increase (0.171 ± 0.009 day^?1) and also the shortest mean generation time (22.4 ± 0.32 days) were also obtained when A. aphidimyza fed on A. gossypii reared on squash. Canonical correlation analysis (CCA) approved the correlation between life‐history traits of A. aphidimyza and characteristics of prey host plants. The suitability of squash for rearing A. aphidimyza can be attributed to the higher nitrogen content, longer trichomes, and relatively high density of trichomes, which provided a better environment for A. gossypii and indirectly favored A. aphidimyza. This study showed that squash is the most suitable host plant for rearing A. aphidimyza feeding on A. gossypii.     

食线虫真菌侵染性胞外酶和生防应用

食线虫真菌作为重要的植物寄生线虫的生物防治资源,深入了解它们的侵染方式、毒力因子是了解食线虫真菌侵染的分子机理和开发高效、稳定的生物杀线虫制剂的关键。目前的研究表明,食线虫真菌能分泌具有降解线虫体壁或线虫卵壳的胞外酶,它们在食线虫真菌侵染线虫的过程中起着非常重要的作用。对这些侵染性胞外水解酶的深入研究将促进人们对食线虫真菌的侵染过程和侵染机制的了解以及高效生防制剂的开发。综述了近年来食线虫真菌侵染性胞外酶的研究概况,对食线虫真菌胞外丝氨酸蛋白酶进行同源性分析,对以后食线虫真菌侵染性胞外酶的研究和高效生防制剂开发进行了评述。