Recognizing the Toxicodendrons (poison ivy, poison oak, and poison sumac).
Poison ivy, poison oak, and poison sumac are now classified in the genus Toxicodendron which is readily distinguished from Rhus. In the United States, there are two species of poison oak, Toxicodendron diversilobum (western poison oak) and Toxicodendron toxicarium (eastern poison oak). There are also two species of poison ivy, Toxicodendron rydbergii, a nonclimbing subshrub, and Toxicodendron radicans, which may be either a shrub or a climbing vine. There are nine subspecies of T. radicans, six of which are found in the United States. One species of poison sumac, Toxicodendron vernix, occurs in the United States. Distinguishing features of these plants and characteristics that separate Toxicodendron from Rhus are outlined in the text and illustrated in color plates.
Systemic contact dermatitis from herbal and homeopathic preparations used for herpes virus treatment.
Systemic contact dermatitis may occur in contact-sensitized individuals when they are exposed to haptens orally, transcutaneously, intravenously or by inhalation. We report the case of a woman developing a diffuse skin eruption after the topical use of Rhus toxicodendron alcoholic extract and the oral introduction of a homeopathic preparation of the same substance for herpes treatment. An open test, performed with the Rhus toxicodendron tincture, showed an erythemato-oedematous response at 48 h and vesicular reaction at 96 h that was still present after 7 days. Patch test with 65% ethyl alcohol gave negative results. The open test performed, as control, in eight healthy informed subjects revealed negative responses to Rhus tincture application. The result is interesting because in Italy, allergic contact dermatitis to Rhus is uncommon and this case increases the understanding of the pathogenetic mechanism leading to systemic contact dermatitis development.
Morpho-biometric Relationship, Relative Condition Factor and Meat Yield of Distant Scallop Bractechlamys vexillum (Reeve, 1853) in Asid Gulf, Philippines
Understanding the relationships of morphometric and biometric characters of a species allows the prediction of one trait from the other and generate a measure of relative condition. These relationships were studied for the Distant scallop Bratechlamys vexillum (Reeve, 1853) in Asid Gulf. Representative samples collected during the dry season (May 2018, n = 99) and wet season (September 2018, n = 100) were used to analyse these relationships through models of simple linear and power regression analyses, revealing allometric growth patterns. For both periods, it was revealed that shell width (SW) is a slightly better predictor than the height (SH) for total weight (TW) (R2 = 0.90 and 0.92) and the adductor muscle weight (AW) (R2 = 0.78 and 0.80). The strong functional relationship was also observed between TW and AW (R2 = 0.80 and 0.81). The relative condition factors (Kn) were high in both seasons. High meat yields were also observed in May (12.77 %) and September (14.26 %). The significant difference in meat yields (P < 0.05) can be a result of the seasonal difference manifested by the dynamics of energy partitioning during gametogenesis and spawning. These biological metrics are vital inputs in analysing mariculture prospects for the resource and a contribution to the scarce information on the biology of the species.