Radiofrequency Irradiation Mitigated UV-B-Induced Skin Pigmentation by Increasing Lymphangiogenesis

Dermal macrophages containing melanin increase skin pigmentation since dermal melanin removal is slower than epidermal melanin removal. Lymphatic vessels are also involved in melanin clearance. We evaluated whether radiofrequency (RF) irradiation induced an increase in HSP90, which promotes lymphangiogenesis by activating the BRAF/MEK/ERK pathway and decreasing tyrosinase activity, in the UV-B exposed animal model. The HSP90/BRAF/MEK/ERK pathway was upregulated by RF. Tyrosinase activity and the VEGF-C/VEGFR 3/PI3K/pAKT1/2/pERK1/2 pathway, which increase lymphangiogenesis, as well as the expression of the lymphatic endothelial marker LYVE-1, were increased by RF. Additionally, the number of melanin-containing dermal macrophages, the melanin content in the lymph nodes, and melanin deposition in the skin were decreased by RF. In conclusion, RF increased HSP90/BRAF/MEK/ERK expression, which decreased tyrosinase activity and increased lymphangiogenesis to eventually promote the clearance of dermal melanin-containing macrophages, thereby decreasing skin pigmentation.

Knowledge, attitude and perception of related toxicity of pesticide exposure in humans and animals in Ibadan, Nigeria

This study reported knowledge, attitude and perception of pesticide use among farmers to determine the level of farmers’ education on use and handling of pesticides. Data on pesticide types purchased were collected from pet-shops and agro-allied stores in three states in Nigeria. Questionnaires were administered to 100 farmers within Ibadan (Oyo State) to determine specific pesticides used, handling procedures adopted by farmers, protective measures employed and perception of toxic potentials of pesticides to human handlers and exposed animal. Survey reports showed majority used DDVP, 34% of farmers were uneducated, while 42%, 18% and 6% had primary, secondary and tertiary education, respectively. About 63.5% had been farming for 11-20years, 75% kept poultry while others kept sheep/goat and cattle. About 75% sought information from extension agents on pesticide use. The farmers were aware pesticides pose health hazards to animals but only 75% knew it could affect humans, 40% knew of pesticide withdrawal period with diverse opinions on route of pesticide poisoning. The study concluded that farmers and pet-owners in Southwest Nigeria use pesticides unethically and majority are unaware of toxicity and hazards of misuse and handling of pesticides, consequently exposing themselves and animals to hazardous and toxic pesticide levels. Legislations on pesticides enacted to prevent pesticide abuse should be enforced and awareness campaigns intensified to enlighten farmers and pet-owners on potential hazard pesticides pose to themselves, animals and environment. This would eventually prevent unnecessary exposure through misuse/mishandling of pesticides and create a safer ecosystem at large. Keywords: Attitude, Knowledge, Perception, Pesticide, Toxicity

Effect of a High-Fat Diet and Occupational Exposure in Different Rat Strains on Lung and Systemic Responses: Examination of the Exposome in an Animal Model

The exposome is the measure of all exposures of an individual in a lifetime and how those exposures relate to health. The goal was to examine an experimental model integrating multiple aspects of the exposome by collecting biological samples during critical life stages of an exposed animal that are applicable to worker populations. Genetic contributions were assessed using strains of male rats with different genetic backgrounds (Fischer-344, Sprague Dawley, and Brown-Norway) maintained on a regular or high-fat diet for 24 weeks. At week 7 during diet maintenance, groups of rats from each strain were exposed to stainless steel welding fume (WF; 20 mg/m3 × 3 h/d × 4 days/week × 5 weeks) or air until week 12, at which time some animals were euthanized. A separate set of rats from each strain were allowed to recover from WF exposure until the end of the 24-week period. Bronchoalveolar lavage fluid and serum were collected at 7, 12, and 24 weeks to assess general health indices. Depending on animal strain, WF exposure and high-fat diet together worsened kidney toxicity as well as altered different serum enzymes and proteins. Diet had minimal interaction with WF exposure for pulmonary toxicity endpoints. Experimental factors of diet, exposure, and strain were all important, depending on the health outcome measured. Exposure had the most significant influence related to pulmonary responses. Strain was the most significant contributor regarding the other health indices examined, indicating that genetic differences possibly drive the exposome effect in each strain.

Why do chitons curl into a ball?

Many animals with external armour, such as hedgehogs, isopods and trilobites, curl into a protective ball when disturbed. However, in situations where predators would engulf an exposed animal whole, regardless of position, conglobation may provide limited added defence and the benefits were previously unclear. We show that polyplacophoran molluscs (chitons) are three times less likely to spend time curled into a ball in the presence of a predator. When the cue of a potential predator is present, animals instead spend significantly more time in active, high risk, high reward behaviours such as arching, balancing on the head and tail ends of their girdle and pushing the soft foot up into an exposed position. Arching increases vulnerability, but also can increase the likelihood of rapidly encountering new substratum that would allow the animal to right itself. In some other animals, the ability to roll into a ball is associated with rolling away from danger. Curling into a ball would improve mobility, to be rolled on to a safer position, but reattachment is the higher priority for chitons in the face of danger.

Infaunal survival: alternative functions of shell ornamentation in the Bivalvia (Mollusca)

Two kinds of adaptation aid infaunal bivalve mollusks in sustaining their life positions against potentially disruptive water movements: (1) ability to retard scour of surrounding sediment and (2) ability to reburrow rapidly if exhumed.The shell of the venerid Anomalocardia brasiliana is ornamented with concentric ridges that are asymmetrical in cross-section; experiments show that these ridges aid the animal in burrowing by gripping the sediment during backward rotation of the shell. The shell of the less deeply burrowing venerid Chione cancellata also bears concentric ridges, but these are symmetrical and experiments show that they hinder burrowing; other experiments demonstrate that these ridges reduce scour of sand from around a partly exposed animal. The single cardiid species Trachycardium egmontianum possesses adaptations comparable to those of the two venerid species, in the form of spines of two varieties; experiments show that the flared anterior spines facilitate burrowing and the cupped posterior spines reduce scour.Conspicuous ornamentation of the kinds considered here was rare throughout the Paleozoic. Its evolutionary deployment occurred primarily during the post-Paleozoic adaptive diversification of infaunal bivalves, which was triggered by the evolution of efficient burrowing mechanisms. The general premium on maintaining infaunal life positions was accentuated for bivalves after the Paleozoic by the origins of important modern predatory taxa.