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Biomedical subjects

P Vernia

Publications and source records attributed to P Vernia.

35 records · Page 2Linked to original sources
PubMed1991

Rectal irrigation with short-chain fatty acids for distal ulcerative colitis. Preliminary report.

Colon cells from patients with ulcerative colitis utilize short-chain fatty acids inefficiently and may be exposed to decreased concentrations of these compounds. To test whether irrigation of the inflamed mucosa with short-chain fatty acids is useful, we conducted a six-week preliminary trial in 12 patients with distal colitis. Each patient used twice daily rectal irrigations with 100 ml of a solution containing acetate (80 mM), propionate (30 mM), and butyrate (40 mM). Two patients stopped at three weeks, one because of no improvement and the other because of complete resolution of symptoms. Of the 10 who completed the trial, nine were judged to be at least much improved and showed a change in a mean disease activity index score from 7.9 +/- 0.3 (SE) to 1.8 +/- 0.6 (SE) (P less than or equal to 0.002) and in a mucosal histology score from 7.7 +/- 0.7 (SE) to 2.6 +/- 0.7 (SE) (P less than or equal to 0.002). Thus, ulcerative colitis patients appear to benefit from increased contact with or higher than usual levels of these critical energy substrates.

Acetates↗
PubMed1988

Organic anions and the diarrhea of inflammatory bowel disease.

To determine if organic anions contribute to the diarrhea of inflammatory bowel disease, we measured osmolality, electrolytes, short-chain fatty acids, lactic acid, and some Krebs cycle anions in 24-hr fecal collections from 18 patients with chronic ulcerative colitis, 20 with Crohn's disease of the colon, and 16 normals. Mean lactic acid concentration was significantly elevated in ulcerative and Crohn's colitis, but values correlated with fecal weight only in the former syndrome. In ulcerative colitis, concentrations of each short-chain fatty acid, especially butyrate, were decreased compared with those from normals or Crohn's disease. Lactate and short-chain fatty acids accounted for nearly half the variability in fecal weight in ulcerative colitis. Crohn's patients had elevated mean fecal water osmolality and osmotic gap not observed in ulcerative colitis. Increased lactic acid and/or deficient short-chain fatty acids may modulate the diarrhea of ulcerative colitis. This mechanism seems less important in Crohn's colitis where an additional osmotic component may be significant.

Anions↗
PubMed1988

Fecal lactate and ulcerative colitis.

Impaired metabolism of short-chain fatty acids, as well as a modified fecal ionogram, have been reported in ulcerative colitis. Fecal water samples from 62 patients with ulcerative colitis were analyzed in the present investigation to evaluate changes in SCFAs and lactic acid in relation to activity and severity of disease. Short-chain fatty acid levels were high in quiescent and mild disease (162.6 +/- 63.6 and 147.8 +/- 63.2 mM/L, respectively), but significantly decreased in the severe form (64.7 +/- 46.9 mM/L). Lactate showed a progressive increase from mild colitis (3.0 +/- 1.8 mM/L) to severe colitis (21.4 +/- 18.6 mM/L). It thus appears that mild colitis displayed a fecal pattern characterized by normal pH and bicarbonate, slightly impaired electrolyte handling, high short-chain fatty acid values, and only moderately increased lactate. Severe colitis, on the other hand, was characterized by low fecal pH, bicarbonate, and potassium, high sodium and chloride, low short-chain fatty acid levels, and very high lactate levels. A critical lowering of intraluminal pH, which shifts bacterial metabolism from short-chain fatty acid to lactate production, may be responsible for the intraluminal pooling of lactate.

Colitis, Ulcerative↗
PubMed1987

Early recognition of toxic megacolon.

Increased amounts of small bowel gas are a frequent finding on plain abdominal films in toxic megacolon (TMC), but they may also be found in patients with severe colitis. We studied 69 consecutive patients with severe ulcerative colitis to evaluate whether an increased gas content of the small intestine may identify patients prone to TMC. The intestinal gas was measured on plain abdominal films by means of a planimeter. On the basis of gas values, 38 patients showed a normal and 31 an increased amount of small intestinal gas. The outcome of the disease (complications, need for surgery, and mortality rate) and 18 clinical and hematochemical findings were compared in the two groups. Of the 31 patients with increased gas, seven developed TMC, whereas this complication was not observed in the 38 patients with normal gas. The only other different features between the two groups were blood pH and base excess, which were significantly higher in the patients with increased small bowel gas content. We therefore suggest that persistent abnormal gaseous distension of the small bowel, together with severe metabolic alkalosis, characterizes a subgroup of patients with severe colitis at high risk for the development of TMC. The strict surveillance of these patients led to early recognition of seven cases of TMC and prompt institution of aggressive medical treatment. Since all these patients survived, the early detection of TMC may improve prognosis.

Adolescent↗
PubMed1987

Seeking clues for a positive diagnosis of the irritable bowel syndrome.

Despite its high prevalence the irritable bowel syndrome (IBS) lacks acceptable pathophysiological markers and its diagnosis largely depends on the exclusion of underlying organic disease. Systemic acid-base balance, serum electrolytes and the composition of faecal water (electrolytes and organic anions), were studied in thirty-eight diarrhoeal patients out of a series of ninety-three consecutive IBS patients. Only patients with diarrhoea as the predominant symptom were included in the study to evaluate whether this subgroup could provide the clue for a positive diagnosis of the syndrome. Serum electrolytes and systemic acid-base balance were within the normal range. Faecal electrolytes were also normal (Na 26.6 +/- 19.3 SD; K 66.8 +/- 28.3; Cl 19.1 +/- 15.2 mEq 1(-1)), despite the finding of a moderately increased 24-h faecal output. The K:Na ratio was also within the normal range. These data are in agreement with the lack of systemic changes observed in IBS patients even with profuse or longstanding diarrhoea. Both faecal short chain fatty acids and lactic acid were increased in patients vs. controls, but a considerable overlap with normal values was observed (131.4 +/- 62.6 SD vs. 108.5 +/- 58.3 mEq 1(-1). Only lactic acid concentration was significantly higher than in controls (1.3 +/- 1.2 vs. 0.5 +/- 0.2). Despite these findings it is concluded that the subgroup of IBS patients with diarrhoea also appears to lack a pathophysiological marker and does not provide clues for a positive diagnosis of this syndrome.

Acid-Base Equilibrium↗
PubMed1986

Faecal excretion of bicarbonate in ulcerative colitis.

The normal colon absorbs water, sodium and chloride and secretes potassium and bicarbonate. In ulcerative colitis (UC), modifications occur in the absorption of water, sodium and chloride, whereas the secretion of potassium remains unchanged. There appear to be no data in the literature on bicarbonate secretion. Since some 25% of chloride absorption is coupled with bicarbonate secretion by an anion exchange mechanism, the impairment in chloride absorption should be accompanied by modifications in bicarbonate secretion. Faecal bicarbonate was therefore measured in 20 patients with active UC and 15 normal control subjects. Faecal pH, pCO2 and electrolytes (Na+, K+, Cl-, HCO3-), blood acid-base balance, urinary pH and bicarbonate were determined on the same day in all patients. Faecal pH and bicarbonate were significantly reduced in UC versus controls: pH 6.06 +/- 0.39 versus 6.52 +/- 0.43; HCO3- 8.4 +/- 5.2 versus 34.6 +/- 12.3 mEq/l (mean +/- SD), whereas sodium and chloride were increased. Faecal potassium concentration was normal, but potassium output was increased. Metabolic alkalosis was observed in 8 patients and a normal acid-base balance in the remaining 12. Urinary pH was acid and urinary bicarbonate negligible in all patients. No correlation was observed between plasma, faecal and urinary bicarbonate. Data emerging from this study show that the faecal excretion of bicarbonate is reduced in patients with active UC. A possible explanation for this finding may be impairment of the colonic anion exchange mechanism induced by inflammation of the mucosa. The role of organic anions is also hypothesized. The acid-base balance does not seem to be directly affected by the decrease in faecal bicarbonate loss.

Acid-Base Equilibrium↗
PubMed1985

Consequence of colonic involvement on electrolyte and acid-base homeostasis in Crohn's disease.

We evaluated the relationship existing between the site of intestinal lesions and systemic acid-base balance in 78 patients with active Crohn's disease. Patients with enteritis had a normal acid-base balance, while mild and moderate metabolic alkalosis were present in enterocolitis and colitis. These findings appeared to be related to the electrolyte fecal losses. In enteritis fecal sodium and chloride concentrations were within the normal range (Na 29.2 +/- 18.5; Cl 16.6 +/- 11.2 mEq/l) while in colitis they were significantly higher (Na 52.8 +/- 20.8; Cl 29.6 +/- 12.7 mEq/l). Intermediate values were observed in enterocolitis. The fecal potassium concentrations were similar in the three groups of patients, with a slightly lower concentration in enterocolitis and colitis. The fecal K/Na ratio was normal in enteritis and reversed in enterocolitis and colitis. This study suggests that a relationship exists between the site of lesions, fecal electrolyte losses, and systemic acid-base balance in Crohn's disease. Systemic metabolic alkalosis and an abnormal fecal K/Na ratio occurred in patients with colonic involvement, indicating the important role played by the colon in acid-base and electrolyte homeostasis.

Acid-Base Equilibrium↗
PubMed1984

Composition of fecal water. Comparison of "in vitro" dialysis with ultrafiltration.

We describe a simple method for the collection of stool water using dialysis membrane tubing placed directly into the feces. When the membrane was placed in pure aqueous solutions or in homogenized feces stored at 4 degrees C, equilibration for solutes was complete in 24 h. Exchangeable ions, short chain fatty acids, osmolality, and pH were measured in the fecal water of 8 normal subjects and 36 patients affected by different diarrheal diseases. The composition of fecal water collected by this method was almost identical to that obtained by ultrafiltration of feces immediately after collection. Differences, when present, were minimal (about 4%) and practically irrelevant. This in vitro dialysis method is simple, inexpensive, and seems particularly suitable for the measurement of osmolality, electrolytes, and short chain fatty acid concentrations in large numbers of fecal samples.

Dialysis↗
PubMed1980

Risk factors in toxic megacolon.

A retrospective analysis of data from a series of 22 patients with toxic megacolon complicating ulcerative colitis was performed in an attempt to detect factors associated with the fatal outcome of the attack. Of the 25 clinical findings studied, significant differences between survivors (17) and nonsurvivors (5) were observed in only seven. In nonsurvivors, duration of the disease was longer and blood pH and standard bicarbonate levels higher, whereas serum potassium, calcium, phosphorus, and beta-globulins were lower. Discriminant analysis showed that three pairs of features, namely potassium-beta-globulins, potassium-bicarbonate, and potassium-blood pH provided a good discrimination between survivors and nonsurvivors. Results of this study indicate that the severity of the electrolyte and metabolic disorder appears to be an important risk factor in toxic megacolon. Intensive fluid and electrolyte replacement should therefore be considered a crucial point for successful management of toxic megacolon.

Adult↗
PubMed1976

Blood pH: a test for assessment of severity in proctocolitis.

Acid base balance was studied in 58 patients with active idiopathic proctocolitis; the condition of 10 of them was complicated by toxic megacolon. Arterial blood pH increased progressively with increased severity of the colitis and as the lesions became more widespread. Statistically significant differences were observed in pH values between the mild/moderate and severe forms and between the severe and complicated forms ('toxic megacolon'). A linear correlation was found between pH and the amount of intestinal gas, pulse rate, and plasma albumin.

Carbon Dioxide↗
PubMed1975

Effects of bombesin and bombesin-like peptides on gastrointestinal myoelectric activity.

Gastrointestinal myoelectric activity was studied during intravenous infusion of bombesin and bombesin-like peptides in conscious dogs with electrodes chronically implanted at different levels between the stomach and the rectum. The peptides used were bombesin, the COOH-terminal hepta- octa-, and nonapeptide of bombesin, and litorin, a new natural peptide isolated from the skin of Litoria aurea. Bombesin significantly increased the frquency of pacesetter potentials (PP) in tha antrum, duodenum, jejunum, and ileum. In the duodenum and jejunum the increase of PP frequency showed linear correlation with the reduction of PP amplitude. The propagation velocity of PP was clearly reduced. Spikes were not affected in the antrum and ileum, whereas they were abolished in the duodenum and jejunum. In the duodenum the increase of PP frequency and the slowing down of propagation velocity was followed by the loss of PP phase lock and the appearance of a characteristic electric pattern, consisting of an irregular sequence of small and slow potentials ("electric disorganization"). The mechanical counterpart was the disappearance of intraluminal pressure activity. In the colon the effect of bombesin on electric activity was not consistent. Neither the COOH-terminal heptapeptide nor the octapeptide of bombesin showed a significant effect on myoelectric activity, whereas the effect of COOH-terminal-nonapeptide and litorin was similar to that of bombesin. Thus, the characteristic electric changes of PP produced by bombesin appear to be related to the sequence of the nine amino acids in the COOH-terminal residue of the bombesin molecule.

Amino Acid Sequence↗
PubMedDate not supplied

Intestinal gas in ulcerative colitis.

Intestinal gas was measured planimetrically on plain abdominal films from 25 healthy subjects and 47 patients with active ulcerative colitis (mild, moderate, severe and toxic megacolon). Compared with controls, significant colonic distention was found in toxic megacolon. Gas in the small bowel was significantly increased in toxic megacolon and in severe colitis but was within the normal range in the mild and moderate forms. Two groups of patients with severe colitis were identified, showing either normal or increased gas content in the small bowel. Two of seven patients in the latter group developed toxic megacolon in spite of intensive medical treatment. Intestinal gas values showed a linear correlation with arterial blood pH, ESR and body temperature. No correlation was found between intestinal gas and other features of severity. It is suggested that an abnormal collection of gas in the small bowel loops associated with metabolic alkalosis corresponds to an early stage of a toxic complication ("impending megacolon").

Adult↗