ABSTRACT
The free radical nitric oxide (NO*) is involved in a variety of diverse biological processes from acting as a vasodilator in the cardiovascular system to being the rate-limiting component in the production of peroxynitrite (ONOO-), a contributor to neurodegenerative disorders such as multiple sclerosis (MS). Uric acid (UA), the end product of purine metabolism in humans and a selective inhibitor of toxic reactions attributed to radicals formed by the interaction of ONOO- and CO2, is generally low in MS patients. We investigated the relationship between serum ONOO-, CO2, and UA in MS patients and normal controls by comparing the circadian characteristics of the NO* metabolites nitrite/ nitrate (NO), CO2, and UA. In this preliminary study, we found the functional relationship ascribed to the circadian timing of the peak and trough levels of NO, CO2, and UA in healthy subjects to be clearly altered in MS patients. These findings suggest that alterations in the temporal relationship between the 24h pattern in serum ONOO- formation and UA may either contribute to or reflect the disease processes in MS.
Subject(s)
Carbon Dioxide/blood , Circadian Rhythm/physiology , Multiple Sclerosis/blood , Nitric Oxide/blood , Uric Acid/blood , Adult , Aged , Case-Control Studies , Female , Humans , Male , Middle Aged , Multiple Sclerosis/etiology , Peroxynitrous Acid/blood , Reference ValuesABSTRACT
UNLABELLED: We evaluated intragastric food distribution and antral motor activity in patients with functional dyspepsia. METHODS: A standard gastric emptying test and dynamic imaging of the antrum were used to characterize gastric antral motility disturbances and to correlate them with total and compartmental gastric emptying in 25 dyspeptic patients. RESULTS: We found a 40% prevalence of gastroparesis in functional dyspepsia. Solid gastric emptying delay is indicated by a prolonged lag phase and an increase in frequency and amplitude of gastric contractions, resulting in nonexpulsive antral contractions and/or antropyloric dyscoordination. Food retention in the distal stomach and antral distention appears to account for patients' dyspeptic symptoms. CONCLUSION: This study demonstrates that scintigraphy not only detects abnormalities of food distribution in the stomach but also provides information on antral motor activity noninvasively. Dynamic antral scintigraphy and compartmental gastric emptying are useful tools to define the pathophysiology of dyspeptic patients with or without gastroparesis.
Subject(s)
Dyspepsia/diagnostic imaging , Gastric Emptying , Pyloric Antrum/diagnostic imaging , Adult , Dyspepsia/etiology , Dyspepsia/physiopathology , Female , Gastrointestinal Motility , Gastroparesis/complications , Gastroparesis/diagnostic imaging , Humans , Male , Middle Aged , Pyloric Antrum/physiopathology , Radionuclide ImagingABSTRACT
In this study, food distribution in the stomach and gastric antral motor activity in patients with longstanding diabetes have been evaluated. With use of a standard gastric emptying test with an acquisition protocol and a refined Fourier algorithm to analyze the data, antral contractions have been characterized and gastric motility parameters were correlated to gastric retention in 20 diabetic patients with or without gastroparesis and in 10 healthy subjects. The results of this study show that, in longstanding diabetes, gastric emptying retardation is accounted for by a retention of food in the proximal stomach, which is reflected by a prolonged lag phase as well as by a reduction in antral motor activity that is determined by a decrease in the amplitude of the antral contractions. This study demonstrates that scintigraphy can noninvasively characterize abnormalities of food distribution in the stomach and provides information similar to that obtained from manometry.
