Colonic motor activity in women during sleep.

The relationship between colonic motility, sleep, and arousals from sleep has never been studied in women and only once in men. The purpose of this study was to determine how sleep and arousals from sleep affected colonic motility in women during the follicular phase of their menstrual cycle. We monitored sleep and segmental colonic motility in six healthy women during the follicular phase of the menstrual cycle. We observed no colonic motility during sleep; during awake periods or during arousals, we observed isolated low-amplitude bursts of colonic motility. This colonic motility occurred during 25% of the arousal and awakening time. In contrast, morning awakening was associated with high-amplitude independent and related colonic motility in all colonic segments. We conclude that in women in the follicular phase of their menstrual cycle, colonic motility is inhibited during sleep; colonic motility at night only occurs during arousals or awakenings from sleep.

The international autoimmune hepatitis score in chronic hepatitis C.

Clinical and laboratory findings of autoimmunity are common in chronic hepatitis C. Autoimmune hepatitis (AIH), a disease of unknown cause, has been defined by use of the International Autoimmune Hepatitis Group Score (AIH score), which quantifies clinical and laboratory parameters. To further validate the specificity of the International AIH score and investigate the similarities between hepatitis C and AIH, we measured the International Autoimmune Hepatitis Group Score in patients with well-defined chronic hepatitis C. Thirty consecutive non-cirrhotic patients with chronic hepatitis C were evaluated. Scoring was performed using both components of the AIH score: a set of minimum required parameters including laboratory and historical data and a second set of additional parameters dominated by histological criteria. Autoantibodies were positive in 21 of 30 hepatitis C patients and associated (patient or first-degree relative) autoimmune diseases were present in eight of 30 patients. Histologically, chronic active hepatitis with periportal piecemeal necrosis was seen in 24 of 30 patients and lymphoid follicles in 16 of 30 patients. No patient scored as probable or definite AIH using the minimum required parameters of the AIH score. When histological parameters were included, four of 30 patients scored as probable AIH but none as definite AIH. Therefore, AIH was excluded by the minimal and additional criteria of the AIH score in 86% of patients with hepatitis C despite a high prevalence of autoantibodies in these patients. We conclude that the criteria set forth by the International AIH scoring system defines a distinct disease although it shares some features with chronic hepatitis C. Modification of the AIH scoring system to include other commonly accepted risk factors for hepatitis C and additional histological parameters would further improve its specificity.

Misoprostol in the treatment of chronic refractory constipation: results of a long-term open label trial.

BACKGROUND: Misoprostol is known to be effective in stimulating intestinal transit both in healthy individuals and in patients with chronic constipation when evaluated in short-term trials. The aim of this study was to determine the utility of misoprostol in the long-term management of patients with chronic refractory constipation. METHODS: Eighteen patients were offered misoprostol (600-2400 microg/day) as adjunctive therapy in an open-ended, non-blinded trial. All patients were encouraged to continue the drug for a minimum of 4 weeks, after which time the effect on bowel movement patterns was evaluated and continued use of misoprostol was offered to those patients who demonstrated a clinical benefit. RESULTS: Six patients withdrew prior to 4 weeks because of side-effects. In the 12 patients who continued the treatment and were evaluated at 4 weeks, the mean interval between bowel movement frequency had decreased from a baseline of 11.25 to 4.8 days (P = 0.0004). Eight patients continued the long-term treatment, with sustained response seen in six. In a subset of patients (n = 4) the effect of single-dose misoprostol (400 microg) was evaluated compared to healthy controls (n = 5) on post-prandial segmental colonic motility. Misoprostol augmented the colonic motility response to a meal throughout the colon, and this was significantly greater in the left versus right colonic segments (P < 0.05). CONCLUSIONS: Misoprostol can be effective as part of the long-term medical treatment of patients with chronic refractory constipation, but side-effects are observed at higher doses and can be a limiting factor. Part of misoprostol's action may be mediated through the augmentation of colonic motility, particularly of the left colon.

Renin response to graded haemorrhage in conscious rats.

1. A haemorrhage volume/plasma renin activity (PRA) response relationship was established for five levels of acute haemorrhage ranging from 1.5 to 15 ml/kg in conscious rats. In addition, the effects of chronic indomethacin and/or acute propranolol administration on the PRA response to 5 and 10 ml/kg haemorrhage was assessed. 2. Mean arterial pressure decreased in a haemorrhage volume dependent manner which was not significantly altered by indomethacin and/or propranolol. 3. Haemorrhage volumes of 1.5 and 3.0 ml/kg did not significantly alter PRA. At haemorrhage volumes of 5.0 ml/kg and higher, PRA increased in a volume-dependent manner. Propranolol decreased basal PRA levels but had little effect on the response to haemorrhage. Indomethacin had no effect on basal PRA, but attenuated the response to haemorrhage somewhat. When propranolol and indomethacin were combined, the PRA response to haemorrhage was significantly attenuated. 4. The conscious cannulated rat model exhibits predictable and reproducible renin responses to haemorrhage and is an excellent model for studying the control of renin secretion.

Renin, ACTH, and aldosterone during acute hypercapnia and hypoxia in conscious rats.

The control of aldosterone secretion may be altered during acute changes in arterial blood gases. We studied the blood gas, plasma electrolyte, renin (PRA), adrenocorticotropic hormone (ACTH), and aldosterone (ALDO) responses to acute hypercapnia (4 and 8% CO2), acute hypocapnic hypoxia (10% O2), acute severe normocapnic hypoxia (7% O2-4% CO2), and acute hypercapnic hypoxia (7% O2-8% CO2) in conscious, cannulated Long-Evans rats. Normoxia resulted in normal levels of PRA (6.9 +/- 2.0 ng.ml-1.h-1), ACTH (96 +/- 32 pg/ml), and ALDO (10 +/- 3 ng/dl). Hypercapnia had no effect on PRA but did lead to an increase in ACTH (to 298 +/- 69 pg/ml) and ALDO (to 33 +/- 7 ng/dl) during 8% CO2 exposure. Normocapnic hypoxia resulted in a significant increase in ACTH (to 196 +/- 14 pg/ml) and ALDO (to 30 +/- 3 ng/dl). Hypercapnic hypoxia resulted in the greatest increases in PRA (to 30 +/- 2 ng.ml-1.h-1), ACTH (to 397 +/- 114 pg/ml), and ALDO (to 41 +/- 5 ng/dl). We conclude that in conscious rats 1) hypercapnia (less than 80 Torr) had no significant effect on PRA, 2) isocapnic, severe hypoxia (Po2 approximately 34 Torr) increased ACTH, and 3) the combination of hypercapnia and hypoxia was a very potent stimulus to PRA, ACTH, and ALDO. The ALDO responses to increases in endogenous ACTH and angiotensin II appear to be normal in conscious rats during acute hypoxia and/or hypercapnia.