Detection of synchrony in the discharge of a population of neurons. II. Implementation and sensitivity of a synchronization index

This report describes the use of a synchronization index (Is; Hamm et al., 1985a) and its sensitivity to various forms and degrees of synchrony between spike trains. The dependence of the Is on signal-to-noise ratio, the number of synchronized spike trains and their degree of synchrony is shown in analog and digital simulations. These simulations and a comparison with peristimulus time histograms under conditions of induced synchrony reveal that the Is is a sensitive measure of synchronization in a population of spike trains.     

Massive intractable hematuria secondary to cyclophosphamide

A case of massive intractable hematuria following cyclophosphamide therapy is presented. This patient had bilateral vesicoureteral reflux. The treatment consisted of occluding both ureters with Fogarty catheters while formalin was instilled into the bladder. The urine has cleared with no further gross hematuria. This has been accomplished in another patient with unilateral vesicoureteral reflux with equal success.     

Excess intravascular coagulation complicating low cardiac output.

In 42 children with congenital heart disease coagulation factor levels were studied serially during the first 20 hours following cardiopulmonary bypass surgery. The acyanotic patients, and also cyanotic patients who survived the operation, showed a progressive improvement in their coagulation profile from initial low postoperative levels. In 12 cyanotic patients who died within 72 hours, however, the coagulation factor levels either remained low, or fell further, until death. Fresh frozen plasma was administered to eight of these patients without apparent benefit. The abnormal coagulation profile correlated significantly with low skin temperature and increased blood loss and was considered to represent excess intravascular coagulation secondary to low cardiac output and poor tissue perfusion.     

Bursts of miniature end-plate potentials can be released from localized regions of the frog motor nerve terminal

We examined spontaneous transmitter release by simultaneously recording from end-plates with both an intracellular electrode and a focal extracellular electrode. In normal Ringer's solution the focal releases appear to be a near random portion of the pooled output. But in elevated [Sr²⁺]_out bursts of miniature end-plate potentials (m.e.p.p.s.) occur, and these can be localized at a portion of the presynaptic terminal. The bursts are not artifacts caused by the focal recording technique. In some conditions, sections of the nerve terminal can exhibit an enhanced probability of quantal release that persists for seconds.We occasionally observe extracellular events that must be generated by m.e.p.p.s. in adjacent fibers.     

Understanding cardiac arrhythmias

This review highlights the applied science intrinsic to the interpretation of the electrocardiogram and cardiac arrhythmias in children.     

Hypersensitivity pneumonitis associated with mushroom worker's lung: an update on the clinical significance of the importation of exotic mushroom varieties

Hypersensitivity pneumonitis remains an important industrial disease in mushroom workers. It has a significant morbidity, and early diagnosis and removal from exposure to the antigen are critically important in its management. Recently, several new allergens have been described, particularly those from mushroom species originating in the Far East, which are of clinical significance to workers occupationally exposed to such allergens in cultivation, picking, and packing of commercial mushroom crops. Importing of exotic mushrooms including Shiitake is common in EU countries, and some of the exotic species of mushrooms are cultivated for local markets. This practice may contribute to an increase in clinical cases of mushroom hypersensitivity pneumonitis. This update reviews the recent literature and examines changing trends of mushroom worker's lung, with increased movement of commercial product and labour markets worldwide.