Extreme bradycardia during sleep apnea caused by myxedema

A 52-year-old man with myxedema was evaluated for anterior chest pain that was considered to be compatible with myocardial ischemia. The night after admission he developed extreme bradycardia, hypotension, and apneic episodes lasting up to 25 s. Continuous positive airway pressure and administration of medroxyprogesterone acetate prevented further episodes and relieved much of the somnolence and lethargy that had contributed to the evidence for myxedema. Alveolar hypoventilation caused by decreased sensitivity to carbon dioxide, inadequate central neural drive, peripheral muscle force, and obesity all may have contributed to the apnea. Chest pain has not recurred, and results of electrocardiography have remained normal following full thyroid hormone replacement. The early recognition of myxedema causing sleep apnea will allow specific treatment to avoid the cardiovascular risks related to prolonged apnea and will help avoid confusion with other etiologies of cardiovascular abnormalities.     

E-rosette formation using heteropolymeric monoclonal antibodies.

We have used bispecific, cross-linked monoclonal antibodies (heteropolymers, HP) to facilitate rosette formation between human erythrocytes (EH) and dinitrophenylated sheep erythrocytes (DNP-ES) in the absence of complement. The HP contain monoclonal antibodies (mAbs) specific for both the EH C3b receptor (CR1), and the DNP group, and control experiments with homologous competing non-cross-linked mAbs and naive EH and ES confirm the specificity of the rosetting reaction. These results extend our previous studies, of HP-mediated binding of simple protein antigens to EH CR1, to complex particulate antigens and may eventually allow for the targeting and clearance from the circulation of a variety of pathogens associated with infectious disease.     

Soda pop vending machine injuries: an update.

Soda pop vending machine tipping continues to be a dangerous behavior that can result in lethal or crippling injuries. This study analyzes 64 cases of injuries secondary to crushing by a soda machine. All were male victims except one. The average age was 19.8 years with a range of 5-39 years. Thirteen victims sustained multiple trauma. Fifteen victims were killed. Increased public awareness coupled with support by the government and private industry has contributed to a sharp reduction in incidence of accidents and improved public safety.     

PLASMA PHOSPHOLIPASE A2 ACTIVITY IN CLINICAL ACUTE MYOCARDIAL INFARCTION

1. Phospholipase A2 (PLA2) cleaves phospholipids to produce a lyso-phospholipid and free fatty acid and, in view of the biological activity of the products, PLA2 may play a role in many disease states. Lyso-phospholipids and free arachidonic acid increase in ischaemic myocardium, indicating that ischaemia activates the enzyme. 2. Plasma PLA2 activity was measured in patients with acute myocardial infarction, based on the release of labelled arachidonic acid from Escherichia coli cell membrane. Fourteen males (peak serum creatine phosphokinase (CK) above twice upper normal) were studied on day 1 (within 6 h of chest pain onset), days 2-4, and days 6-9. Normal age matched males (n = 13) were also studied. 3. Plasma PLA2 in patients with uncomplicated myocardial infarction (n = 12) was, initially, 1.14 +/- 0.10 (s.e.m.) nmol/min per mL plasma, similar to that in the normal group (1.52 +/- 0.14). On days 2-4, PLA2 activity increased to 1.94 +/- 0.18 (P less than 0.001) and this activity was correlated with the earlier peak CK level (P less than 0.02). On days 6-9, PLA2 activity was 1.49 +/- 0.13 while in two patients who developed complications and underwent open-heart surgery between the last two measurements, there were further increases to 4.22 and 4.04 nmol/min per mL. 4. The increase in plasma PLA2 in uncomplicated myocardial infarction is likely to be due to release from the damaged myocardium; whether it contributes to pathophysiology is uncertain.     

Fentanyl and the interleukin-6 response to surgery

It has been suggested that large doses of opioids may suppress the interleukin-6 response to surgery. We examined the effects of the supplementation of inhalational anaesthesia with either 3 or 15 μg.kg⁻¹ fentanyl on the circulating interleukin-6, interleukin-8, C-reactive protein, cortisol and glucose concentrations in 16 patients undergoing pelvic surgery. In both groups, surgery evoked the expected glucose, cortisol and interleukin-6 response but no increase in interleukin-8 was detected. There were no significant differences between the two groups. We conclude that the supplementation of inhalational anaesthesia with conventional doses of opioids does not modify the cytokine response to surgery.     

Serum antibody responses in mice to intermittent inhalation of ovalbumin dust

Serum antibody production and induction of antibody tolerance were monitored in mice following intermittent inhalation of ovalbumin dust (mass concentration = 4.2 mg m-3; diameter of 80% of particles less than 2.6 microns). Repeated inhalation of microgram quantities of dust stimulated serum antibody production and development of tolerance. The sequence of these responses is analogous to that following oral presentation of antigen, but is produced by a much lower dose when antigen is presented via the respiratory tract.