RESUMO
A 67-year-old man with high-grade fever and systemic erythema visited our hospital. Based on his symptoms and history of outdoor activities, we considered the possibility of rickettsial diseases, especially Japanese spotted fever (JSF). He was treated with antibiotics. After hospitalization, the patient complained of palpitations, and electrocardiography revealed ventricular tachycardia (VT). He was successfully treated with electrical defibrillation. Moreover, echocardiography showed decreased wall motion at the apex. However, coronary angiography showed no coronary artery-related stenosis. JSF was confirmed via polymerase chain reaction using a biopsy sample of the erythema. Subsequently, the patient was discharged without complications. To our knowledge, this is the first reported case of JSF complicated with VT and acute cardiac damage.
RESUMO
Bis-imidacloprid (bis-IMI) analogues with suitable alkylene spacers have plant-systemic insecticidal properties. The alkylene-tethered bis-IMI binds in a unique mode to the insect nicotinic acetylcholine receptor (nAChR) wherein the chloropyridine moieties are embraced by two distinct and distant domains. The heptamethylene spacer optimally bridges these two subsites, yet the linker itself binds in a relatively nonspecific manner. This investigation examines the hypothesis that a bis-IMI analogue with a heteroaromatic tether, which undergoes specific interaction(s) with the newly recognized receptor cavity, may enhance the potency relative to those of the alkylene-tethered derivatives. Remarkably, a novel bis-IMI with a furan-2,5-dimethylene fulcrum showed highest receptor potency and insecticidal activity among the analogues with various chemotype spacers. The nAChR structural model, simulating the binding site interactions of the furan-2,5-dimethylene-tethered bis-IMI, reveals that the furan ring is nestled in a hydrophobic pocket, consisting of three aromatic amino acids, and is stabilized via hydrogen bonding.
