Zinc toxicity: denture adhesives, bone marrow failure and polyneuropathy.

A 36-year-old female developed bone marrow failure diagnosed as myelodysplastic syndrome (MDS) (Sidebar), followed shortly by a peripheral neuropathy and a gait disturbance. While waiting for a bone marrow transplant, she reported to us that she had seen attorney-generated, televised advertisements concerning the role of denture adhesives relating to her malady. Labs were then obtained demonstrating she had dramatic and unsuspected hypocupremia and hyperzincemia. Administration of copper and cessation of denture adhesives resulted in recovery of her hematopoietic system and partial resolution of the neurological sequela.

Diagnosis and treatment of sick sinus syndrome.

Sick sinus syndrome comprises a variety of conditions involving sinus node dysfunction and commonly affects elderly persons. While the syndrome can have many causes, it usually is idiopathic. Patients may experience syncope, pre-syncope, palpitations, or dizziness; however, they often are asymptomatic or have subtle or nonspecific symptoms. Sick sinus syndrome has multiple manifestations on electrocardiogram, including sinus bradycardia, sinus arrest, sinoatrial block, and alternating patterns of bradycardia and tachycardia (bradycardia-tachycardia syndrome). Diagnosis of sick sinus syndrome can be difficult because of its nonspecific symptoms and elusive findings on electrocardiogram or Holter monitor. The mainstay of treatment is atrial or dual-chamber pacemaker placement, which generally provides effective relief of symptoms and lowers the incidence of atrial fibrillation, thromboembolic events, heart failure, and mortality, compared with ventricular pacemakers.