Symptoms and esophageal motility based on phenotypic findings of scleroderma.

Scleroderma esophagus is characterized by ineffective peristalsis and reduced esophageal sphincter pressure. Esophageal disease in scleroderma can precede cutaneous manifestations and has been associated with Raynaud's phenomenon (RP) and pulmonary fibrosis (PF). The objective of the study is to evaluate the impact of cutaneous findings, RP, and PF on demographics, symptoms, and esophageal motility in patients with scleroderma. Scleroderma patients with esophageal involvement were included after review of esophageal manometries and charts over a 6-year period. High-resolution esophageal manometry was performed. Patients completed a symptom questionnaire. The study enrolled 28 patients (22 females; mean age 50.3 ± 12.8 years) with scleroderma esophagus. Patients without skin involvement (n= 12) reported more severe heartburn (P= 0.02), while those with cutaneous findings (n= 16) had more frequent dysphagia with solids (P= 0.02). Patients with RP (n= 22) had lower amplitude of distal esophageal contractions (P= 0.01) than those without RP (n= 6). Patients with PF (n= 11) reported more severe coughing and wheezing (both P= 0.03) than those without lung disease (n= 17). This study highlights subgroups of patients with scleroderma esophagus according to phenotypic findings of dermatologic changes, RP, and PF. Heartburn and dysphagia are important symptoms that may be associated with different stages of disease progression based on skin changes in scleroderma. RP was associated with greater esophageal dysmotility. Coughing and wheezing were more severe in patients with PF.

Excitotoxicity in the embryonic chick spinal cord.

Recent evidence implicates excitatory amino acids (EAAs), acting as excitotoxic agents, in the pathogenesis of neurological disorders involving the spinal cord. In this study, we used the chick embryo spinal cord as an in vitro model for studying the sensitivity of spinal neurons to the excitotoxic effects of EAA agonists. Compounds tested include the prototypic receptor-specific agonists, N-methyl-D-aspartate (NMDA), quisqualic acid (Quis), and kainic acid (KA), and the plant-derived excitotoxic food poisons, beta-N-oxalylamino-L-alanine, beta-N-methylamino-L-alanine, and domoic acid. Each agonist induced concentration-dependent acute degeneration of neurons distributed throughout the spinal cord. These cytopathological changes consisted of acute edematous degeneration of dendrosomal structures in the dorsal horn and intermediate zone, and dark cell changes with intracytoplasmic vacuolization of motor neurons; this damage is identical to that induced by excitotoxin agonists in other regions of the central nervous system. The NMDA receptor-specific antagonist MK-801 completely blocked toxicity of NMDA, and the nonNMDA antagonist CNQX preferentially blocked the toxicity of Quis- and KA-type agonists in the spinal cord. Our findings suggest that (1) the majority of spinal neurons have all three subtypes of EAA receptors, making them acutely vulnerable to excitotoxin exposure; and (2) EAA antagonists are effective in preventing excitotoxin-induced damage of the spinal cord.

Expression of tissue factor and factor VIIa/tissue factor inhibitor activity in endotoxin or phorbol ester stimulated U937 monocyte-like cells.

Previously, unstimulated cells of the human monocytic tumor cell line U937 have been shown to possess a negligible cell-surface tissue factor (TF) activity, and to secrete a small amount of factor VIIa/tissue factor (VIIa/TF) inhibitor activity. On stimulation with endotoxin or with phorbol myristate acetate (PMA), TF of these cells is known to be increased approximately fourfold. In this report, we demonstrate that VIIa/TF inhibitor is also increased on stimulation of U937 cells with endotoxin (approximately equal to threefold) or with PMA (approximately equal to 20-fold). Notably, the secretion of the inhibitor persisted after the cell surface TF had started to decline. Further, when serum-free media from PMA stimulated cells was electrophoresed on a sodium dodecyl sulfate (SDS) gel, we eluted two inhibitor activity peaks corresponding to Mr approximately equal to 47,000 and Mr approximately equal to 36,000. The molecular weights of these peaks are similar to those obtained earlier from human plasma for this inhibitor(s).