Production of anti-Helicobacter pylori metabolite by the lichen-forming fungus Nephromopsis pallescens.

The present study was conducted to evaluate the antibacterial activity of lichen-forming fungi (LFF) against Helicobacter pylori, and to optimize the culture conditions of LFF for maximum production of natural antibiotics against H. pylori. To accomplish this, a screening assay was first conducted among 19 species of LFF. The extract of Nephromopsis pallescens (KOLRI-040516) exhibited the strongest anti-ff. pylori activity. Bioautograghic TLC and HPLC analysis identified usnic acid as the main antibacterial substance produced by JV. pallescens. The growth of JV. pallescens and production of antibacterial substances produced by the fungus were then investigated under several culture conditions including the culture media, initial medium pHs, incubation temperatures, and the degree of aeration. The results indicated that culture in MY medium with an initial pH of 6.0, a temperature of 15°C and a low degree of aeration supported the largest usnic acid production of the fungus (16.4 ug usnic acid/g dry biomass). Especially, aeration was found to be an important factor that affect both growth and usnic acid production of N. pallescens.

Plant hormones promote growth in lichen-forming fungi.

The effect of plant hormones on the growth of lichen-forming fungi (LFF) was evaluated. The use of 2,3,5-triiodobenzoic acid and indole-3-butyric acid resulted in a 99% and 57% increase in dry weight of the lichen-forming fungus Nephromopsis ornata. The results suggest that some plant hormones can be used as inducers or stimulators of LFF growth for large-scale culture.

Stress and Depression Among the Oldest-Old: A Longitudinal Analysis.

Stress and psychosocial resources play a crucial role in late-life depression. While most studies focus on predominantly those who are young-old, this study used a sample aged 85 and older. The authors' study aims to examine three research questions: (1) What are the trajectories of depression and its associated factors such as types of stress and psychosocial resources among the oldest-old? (2) What are the longitudinal relationships among the changes in stress, psychosocial resources, and depressive symptoms? (3) Are the effects of the changes in stress on depression trajectory mediated by changes in psychosocial resources? The study used a convenience sample of 193 community-dwelling elders aged 85 and older with four interviews every six months from 1986 to 1988. Using multilevel modeling analyses, longitudinal results showed that changes in positive life events, daily hassles (worries), and mastery were significantly associated with changes in late-life depression among the oldest-old.

Worries of the oldest-old.

With the emerging population of the oldest-old (those ages 85 and older), it is crucial to understand and prepare for their psychosocial needs. Worry is linked to psychological well-being and physical health, but little is known about the oldest-old's everyday worries. The authors explored four research questions: (1) What are the worries of the oldest-old? (2) What are their specific dimensions of worry? (3) How alike or different are the worry patterns over time? (4) What factors are related to variations in the pattern of change in worry? A convenience sample of 193 community-dwelling people ages 85 and older was recruited to examine various aspects of health and well-being between 1986 and 1995. This article reports on the survivors (N = 23) across three time points, waves 1, 4, and 5. The findings suggest that the very old mainly worry about health and memory and that, although worry increased over the study period, there were variations in the pattern of worry over time. Results of t tests show that at wave 4 elderly respondents with a higher level of worry reported more frequent social contact than those with a lower level of worry. Implications for social work practice and future research are discussed.