某急性白血病患者化疗期间，WBC由50×10<img border="0" alt="" src="https://img.weimei168.com/uploads/upimg/20221202/11639350_0.gif">／L降至0.8×10<img border="0" alt="" src="https://img.weimei168.com/uploads/upimg/20221202/11639350_0_1.gif">／L，血尿酸浓度明显增高，一旦发生尿酸性结石时，护理人员可直接观察到的征象是