Effects of melatonin administration on oxidative stress and daily locomotor activity patterns in goldfish

Melatonin has a number of physiological functions in addition to light-dark transduction. In recent years, many in vivo and in vitro studies in rodents have revealed an important antioxidant activity of melatonin, both directly and indirectly. Nevertheless, the potential effects of melatonin as an antioxidant in fish remain unknown. The aim of this research was to evaluate the capacity of melatonin injections (3 mg/kg) to attenuate oxidative damage after submitting goldfish to oxidative stress caused directly by hydrogen peroxide (H2O2) baths and indirectly by hypoxia and subsequent reoxygenation, as well as the locomotor activity. The results revealed that melatonin decreased lipid damage in muscle after hypoxia/reoxygenation (1.22 vs. 2.27 nmoles lipid peroxides/g tissue), but not in liver. Mortality caused by oxidative stress was not attenuated by melatonin. Surprisingly, melatonin caused an increase of mortality (50 vs. 95%) when administered before hypoxia. Locomotor activity was also affected by melatonin but not by the administration of the vehicle, suggesting a sedative effect of melatonin in goldfish. In conclusion, melatonin administration provoked slight effects on lipid peroxidation and mortality resulting from oxidative stress, with reduction of locomotor activity in relation to the vehicle.     

人包皮传代细胞作为滋养细胞对人杂交瘤克隆生长的促进作用

用小鼠腹腔细胞等作为滋养细胞培养人杂交瘤,国内外均有报道。我们曾建立了人包皮传代细胞株。本文利用我们所建立的人包皮细胞做滋养细胞,并与小鼠腹腔细胞及不加滋养细胞的空白作对照,观察人包皮细胞对杂交瘤克隆生长的影响。 将人包皮细胞和小鼠腹腔细胞分别接种同一96孔板,次日将两株不同的人杂交瘤细胞1B4及1C8稀释至每毫升含10个或50个细胞,每孔接种0.1ml,使每孔分别含1个及5个细胞,经不同时间观察每孔杂交瘤克隆的生长情况,记录有杂交瘤生长的孔数。表1结果表明,     

Screening of IR50?×?Rathu Heenati F7 RILs and Identification of SSR Markers Linked to Brown Planthopper (Nilaparvata lugens St?l) Resistance in Rice (Oryza sativa L.)

Brown planthopper (Nilaparvata lugens St?l) is one of the major insect pests of rice. A Sri Lankan indica rice cultivar Rathu Heenati was found to be resistant to all biotypes of the brown planthopper. In the present study, a total of 268 F₇ RILs of IR50 and Rathu Heenati were phenotyped for their level of resistance against BPH by the standard seedbox screening test (SSST) in the greenhouse. A total of 53 SSR primers mapped on the chromosome 3 were used to screen the polymorphism between the parents IR50 and Rathu Heenati, out of which eleven were found to be polymorphic between IR50 and Rathu Heenati. The eleven primers that have shown polymorphism between the IR50 and Rathu Heenati parents were genotyped in a set of five resistant RILs and five susceptible RILs along with the parents for co-segregation analysis. Among the eleven primers, two primers namely RM3180 (18.22 Mb) and RM2453 (20.19 Mb) showed complete co-segregation with resistance. The identification of SSR markers linked with BPH resistant could be used for the maker assisted selection (MAS) program in rice breeding and to map the resistant genes on rice chromosomes for further gene cloning.     

Haloarcula spp able to biosynthesize exo- and endopolymers

Three halobacteria strains (T5, T6, T7), growing optimally at a sodium chloride concentration of 3.5 M, were isolated from samples collected in the Tunisian marine saltern located close to Monastir. Although they were different in colony and cell morphology, the isolates were similar in most respects and all produced a homopolyester identified spectroscopically as polyhydroxybutyrate when grown on carbohydrates. Under the same conditions, the isolates formed acidic exopolysaccharides. Acid methanolysis of their complex lipids released archaeol (2,3-di-O-phytanyl-sn-glycerol). All the isolates had polar lipid patterns characteristic of representatives of the genus Haloarcula. Partial sequence analysis of 16S rRNA genes from strain T5 confirmed its assignment to the genus Haloarcula. Although strain T5 differed phenotypically from the species Haloarcula japonica in several respects, DNA–DNA hybridization indicated that the T5 isolate is a new strain of H. japonica. Received 10 June 1998/ Accepted in revised form 29 July 1999     

Connecting human–nature relationships to environmental behaviors that minimize the spread of aquatic invasive species

Management of aquatic invasive species (AIS) is widely recognized as a global conservation concern driven by myriad factors, particularly individual behaviors. A burgeoning literature focused on the human dimensions of AIS has begun to provide insight into the complexities of behavior change; however, most studies are bound to specific geographic locales and have prevented resource management agencies from making regionally valid statements about the anthropogenic factors contributing to biological invasions. We examined stakeholders’ awareness and knowledge of AIS transmission in an evaluation of educational outreach campaign logos and illustrated how human–nature relationships were related to behaviors relevant to AIS reduction at two case study sites. Drawing from a thematic analysis of data from semi-structured interviews with organisms-in-trade hobbyists and recreational water users in the state of Illinois, we observed high awareness of environmental impacts and modes of transmission by the two groups. Both awareness advanced through AIS outreach and a diversity of human–nature relationships were helpful for understanding reported environmental behaviors. Specifically, stakeholders’ views of their relationships with nature affected decisions to engage in activities that contributed to social-ecological change. Results also revealed preferences for national rather than state-level outreach campaign logos, which carry implications for designing communication strategies that will minimize the likelihood of biological invasions in freshwater ecosystems.     

Organoid systems to study the human female reproductive tract and pregnancy

Both the proper functioning of the female reproductive tract (FRT) and normal placental development are essential for women’s health, wellbeing, and pregnancy outcome. The study of the FRT in humans has been challenging due to limitations in the in vitro and in vivo tools available. Recent developments in 3D organoid technology that model the different regions of the FRT include organoids of the ovaries, fallopian tubes, endometrium and cervix, as well as placental trophoblast. These models are opening up new avenues to investigate the normal biology and pathology of the FRT. In this review, we discuss the advances, potential, and limitations of organoid cultures of the human FRT.Subject terms: Cell biology, Physiology, Diseases

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