Retention of allergic potential of parthenium following composting
Parthenium hysterophorus is known to cause allergic contact dermatitis (1). Changing clinical patterns of the dermatitis are reported (2, 3). Recently, the role of type I (immediate) and type III (Arthus phenomenon) has been postulated (4, 5). This weed, a native of tropical America, is wide spread in grasslands, fruit tree orchards, and arable land in neutral and acid soils. This weed interferes with the growth of other plants (allelopathic potential) resulting from the release of phytotoxic substances such as ferulic, caffeic, vanillic, chlorogenic, p-hydroxybenzoic acids, parthenin, ambrosin, and coronopilin, which inhibit the germination and growth of several crop plants (6). Because it has no economic value, efforts have been made to use parthenium as a green leaf manure, as a biopesticide, as a compost for agricultural purposes, and as an additive with cattle manure in biogas production (7). Compost obtained from parthenium can be used for agricultural purposes and as manure. This is likely to get widely dispersed, get airborne, and aggravate parthenium dermatitis if the allergenicity is retained. Parthenium compost was obtained from the Department of Agronomy, Tamil Nadu Agricultural University, Coimbatore. Compost made by 2 methods, anaerobic and aerobic, was collected. The composting procedure was carried out for 90 days for each of themethods. Samples were obtained on D45 and D90. The 2 methods of composting are described below.
Allelopathic effects of Parthenium hysterophorus on germination and seedling growth of a few multi-purpose trees and arable crops.
SUMMARY The allelopathic influence of Parthenium hysterphorus, a gregarious and ubiquitous weed, on four multi-purpose tree species – Acacia leucophloea, Casuarina equisetifolia, Eucalyptus tereticornis and Leucaena leucocephala and three agricultural crops – cowpea, sorghum and sunflower – were tested by germinating seeds of these species in composite leachate obtained from the leaves, stem and flowers of the weed species. Germination of seeds of all test species, arboreal and arable, was severely inhibited by the leachate. In the tree crops, the magnitude of injury was the same under extracts prepared from 2 or 4 ml of distilled water per g of plant tissue. Among the arable crops, sunflower was affected to a greater extent. While radicle and plumule elongation were unaffected in the tree crops and in sunflower, plumule was curbed to a greater extent than radicle in cowpea. In sorghum, only radicle growth was impaired. The inhibition of germination and seedling growth is attributed to parthenin, an unsat...
Atopic dermatitis: pathogenetic mechanisms
Atopic dermatitis (AD) is a chronic inflammatory skin disease with increasing incidence and socio‐economical relevance. The diagnosis is made on clinical grounds and different diagnostic criteria sets have been established. The majority of all AD cases is associated with a sensitization to environmental allergens and increased serum IgE (so‐called extrinsic AD), but about 10‐30% of all cases suffer from the so‐called intrinsic AD, which obviously lacks any link to the classical atopic diathesis. The genetic background of AD has been investigated by target gene approach by different groups with mostly contradictory results for each of the genes under study. An imbalance in the spectrum of Th1/Th2 responses, a disturbed prostaglandin metabolism, intrinsic defects in keratinocyte function, delayed eosinophil apoptosis, IgE‐mediated facilitated antigen presentation by epidermal dendritic cells, a two phase model of the inflammatory response and staphylococcal superantigen effects are among the currently studied pathogenetical aspects of extrinsic AD, which are reviewed in this paper.