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Biomedical subjects

G Frieri

Publications and source records attributed to G Frieri.

At least 37 records · Page 2Linked to original sources
PubMed1995

Gastric and duodenal juxtamucosal pH and Helicobacter pylori.

One of the results of gastric cytoprotection is the generation of a juxtamucosal stable pH, maintained close to neutrality by several factors among which bicarbonate secretion and mucus layer. Since Helicobacter pylori (HP) induces structural and functional changes in the gastric mucus, this study was carried out to investigate the relationship between juxtamucosal pH and HP colonization. Thirty-one dyspeptic subjects who denied a past history of gastric or duodenal ulcer and free of endoscopic lesions were studied. Juxtamucosal pH of the gastric body, antrum and duodenum and gastric luminal fluid pH were measured during upper gastrointestinal endoscopy by a flexible glass electrode passed through the biopsy channel of a gastroscope. Multiple biopsies were subsequently taken for histological investigation, HP culture and a urea quick test. Twelve subjects (39%) were infected by HP (HP+). Juxtamucosal pH (mean +/- SE) was significantly lower (p = 0.0014) in the gastric body (5.67 +/- 0.16) in HP+ than in HP-negative (HP- 6.41 +/- 0.13 subjects, but not in the antrum (6.50 +/- 0.20 in HP+ vs. 6.52 +/- 0.09 in HP-) and in the duodenum (6.80 +/- 0.14 in HP+ vs. 6.94 +/- 0.08 in HP- subjects). No difference was found in gastric luminal fluid pH (1.71 +/- 0.23 in HP+ vs. 1.80 +/- 0.22 in HP- subjects). In conclusion, this study shows that dyspeptic HP+ patients have a reduced juxtamucosal pH in the gastric body but a pH in the antrum and duodenum similar to HP-subjects.

Adult↗
PubMed1995

Lactose malabsorption and irritable bowel syndrome. Effect of a long-term lactose-free diet.

Lactose malabsorption may induce abdominal symptoms indistinguishable from those of the irritable bowel syndrome (IBS), however the exact relationship between the two conditions and the optimal differential diagnostic workup are still to be defined. We prospectively studied the prevalence of lactose malabsorption (by means of a hydrogen breath test) and the clinical effect of a long-term lactose-free diet in 230 consecutive patients with a suggested diagnosis of irritable bowel syndrome, no organic disease of the GI tract, and no history of milk intolerance. Lactose malabsorption was diagnosed in 157 patients (68.2%). In 48 (43.6%) of the 110 patients who complied with the diet symptoms subsided, in 43 they were somewhat reduced and in 17 they remained unchanged. Symptoms never fully subsided in lactose malabsorbers non-compliant with the diet or in normal lactose absorbers who adhered to a lactose-free regimen. Partial improvement was observed in 20% of these subjects. No relation was demonstrated between pre-trial symptoms and the outcome of the diet. The occurrence of symptoms during the lactose breath test strongly suggested a favorable response to diet, but did not help in predicting whether symptoms would subside or be reduced. Conversely, their absence during the test was not associated with an acceptable negative predictive value. The high prevalence of lactose malabsorption in the patients under study suggests that in Italy IBS and lactose malabsorption are frequently associated. A test for diagnosing lactose malabsorption should always be included in the diagnostic workup for IBS and a long-term lactose-free regimen recommended if the test is positive.

Adult↗
PubMed1995

[Use of isocolan in bowel preparation of patients with congestive heart failure].

The aim of this study was to verify the safety and effectiveness of a polyethylene-glycol electrolytes lavage solution (PEG-ELS) in patients with delicate fluid and electrolyte balance. Thirteen patients with chronic congestive heart failure (CHF) undergoing diagnostic colonoscopy, were asked to drink three liters of Isocolan (Bracco s.p.a.) at a rate of 500 ml/30 minutes, 8 hours before endoscopic examination. Plasma electrolytes (Na, K, C1), BUN, creatinine, glycemia, hematocrit, urine specific weight, arterial pressure, pulse rate, ECG and body weight were obtained before and after PEG-ELS supply. Colonic cleansing was judged by the same endoscopist as excellent, good or poor. Data, expressed as mean (SE), were analyzed by a two-tailed ranked test. PEG-ELS supply did not alter fluid and electrolyte balance, since no significant differences were found for all laboratory parameters studied. Out of the clinical features, diastolic arterial pressure significantly (p = 0.05) raised from 72.3 (3.0) to 78.8 (2.8) mmHg and body weight significantly (p = 0.007) increased from 70.7 (3.4) to 71.2 (3.4) kg. Colon cleansing resulted excellent in 8 patients and good in 5. This study shows that Isocolan proved to be safe in patients with CHF and that a slow drinking velocity do not impair adequate colon cleansing.

Aged↗
PubMed1995

[Ion transport in the colon].

The large bowel daily absorbs passively 1500 ml of water down an osmotic gradient created by active electrolyte transports. The system is sustained by the enzyme Na(+)-K+ ATPase, the so called sodium-pump, present on the basolateral membrane of colonocytes. Some pathologic conditions may increase the amount of intraluminal water by inhibiting fluid absorbtion or enhancing fluid secretion. Diarrhoea represents the clinical counterpart of these alterations. Three forms of diarrhoea can be recognized on the basis of pathophysiological alterations. Diarrhoea is due to reduced ionic absorbtion, increased secretion or increased endoluminal osmolality. The drugs used to induce bowel actions or gut lavage increase also intraluminal water content by modifying transmural ionic transports. Laxatives or purges act by increasing either water secretion on endoluminal osmolality and therefore may produce systemic idro-electrolyte imbalance. To avoid this inconvenient an isosmotic electrolyte balanced polyethylene glicol solution (PEG-ELS) has been achieved. In addition orally administred PEG-ELS solution cleans the colon during its intestinal transit without producing relevant transmural water-ionic movements. Aim of this article was to describe the normal ionic transport, and its alterations in pathologic and pharmacologic conditions. Details on PEG-ELS were also given. This solution provides for an effective colon preparation for endoscopic or surgical procedures and resulted to be safe for patients with delicate fluid-electrolyte balance.

Bicarbonates↗
PubMed1994

Increase of circulating gamma/delta T lymphocytes in the peripheral blood of patients affected by active inflammatory bowel disease.

In order to study the role of gamma/delta T cells in the pathogenesis of inflammatory bowel disease (IBD) in humans, we measured the percentage of these cells in the peripheral blood, assessed the ratio of the non-disulphide-linked (delta TCS1) type of T cell receptor (TCR) in the total gamma/delta T cells, studied the co-expression of gamma/delta TCR and accessory molecules CD8 and CD16, and compared these data with both the type and the activity of the disease. Percentage levels and absolute numbers of gamma/delta+ T cells were higher in active patients than in controls (P < 0.05), mainly as a result of an increase of V delta 1+ (delta TCS1) T cell subset (P < 0.05). This trend was strongly retained independently of disease activity and clinical picture. An increased percentage of TCR delta 1+/CD16+ cells was observed in our patients compared with controls (P < 0.05). In contrast, no difference was observed as far as the TCR delta 1+/CD8+ cells were concerned. These results suggest that IBD is associated with an expansion of gamma/delta T cells in peripheral blood, which may play a role in the pathogenesis of these disorders.

Adult↗
PubMed1991

Abnormalities of colonic mucin secretion and metabolic changes after internal urinary diversion for bladder exstrophy. A prospective study.

Ten patients with different types of internal urinary diversion for bladder exstrophy were studied prospectively in order to assess metabolic abnormalities and morphological, histochemical and lectin binding changes in the colorectal mucosa. The histochemical and/or lectin binding changes which were found in the majority of patients were identical to those observed in premalignant and malignant conditions of the colon. In some cases they were detectable 3 years after the initial examination but were completely absent from the colorectal mucosa of normal subjects. Metabolic disturbances (metabolic acidosis, increased anion gap, hyperchloraemia) were observed in a substantial number of asymptomatic patients. These findings stress the need for regular endoscopic, histological and metabolic follow-up in these patients and for life-long treatment with bicarbonate or citrate.

Adolescent↗
PubMed1991

Colonoscopic control of uretero-enteric anastomoses in internal urinary diversion.

Twenty-four patients with internal urinary diversion following total bladder ablation underwent colonoscopic control of the uretero-enteric anastomoses. The techniques performed were: rectal bladder with colostomy according to Mauclaire (11 patients); rectal bladder with abdomino-perineal pull-through according to Heitz-Boyer/Hovelacque (6); ureterosigmoidostomy (7). The uretero-enteric anastomoses were divided into 3 categories according to the colonoscopic appearance: "nipple-like", nearly flat and flat anastomosis. Urographic examinations were carried out in all patients and the results demonstrated that the "nipple-like" anastomosis was the most successful for the preservation of upper urinary tract integrity.

Anastomosis, Surgical↗
PubMed1986

Electrolyte and acid base imbalance in patients with rectosigmoid bladder.

The aim of the present investigation was to study systemic metabolic consequences following rectosigmoid bladder (RSB) operation. RSB after cystectomy has recently been employed with increasing frequency in the Urologic Clinic of the University of Rome inasmuch as, compared with ureterosigmoidostomy (USS), it shows a lower incidence of complications. Acid base balance, serum electrolytes and renal function were studied in 22 patients submitted to RSB and in 25 submitted to USS. Urine from patients with RSB and urine-feces mixture from patients with USS was also analyzed. Metabolic acidosis occurred in 86 per cent of patients with RSB and in 80 per cent of patients with USS but was significantly less severe (p less than 0.01) in patients with RSB (pH 7.34 +/- SD 0.04) than in those with USS (pH 7.29 +/- 0.07). This finding corresponded to a significantly lower intestinal loss of HCO3- in the RSB than in the USS group. The frequency of hyperchloremia was very low in both groups of patients whereas the incidence of an increased anion gap was surprisingly high. Data obtained demonstrate that metabolic acidosis develops even after RSB surgery thus indicating that the reduction in the area of the colonic mucosa in contact with the urine is not in itself sufficient to prevent the metabolic changes. Nevertheless patients with RSB were usually asymptomatic, insofar as metabolic alterations were not severe in any of the cases. In conclusion, RSB ensures good functional results and may be considered a satisfactory solution in those patients in whom radical cystectomy is mandatory. Nonetheless, even in these patients, constant clinical surveillance and monitoring of the metabolic situation is necessary.

Acidosis↗
PubMed1986

Abnormal patterns of colorectal mucin secretion after urinary diversion of different types: histochemical and lectin binding studies.

Clinical and experimental evidence indicates that ureterosigmoidostomy is associated with a high risk for the development of colonic cancer, while there is no reported evidence of increased risk in patients who undergo urinary diversion of other types. In the present study the histochemical and lectin binding characteristics of goblet cell mucin were investigated in biopsy specimens from patients who had undergone ureterosigmoidostomy and from patients who had undergone rectal bladder surgery. Specimens from transitional mucosa surrounding colonic cancers and from normal rectal mucosa were also studied. For histochemical studies the high iron diamine-Alcian blue method was used. FITC-conjugated Dolichus biflorus agglutinin (FITC-DBA) and Arachis hypogaea agglutinin (FITC-PNA) were used for the study of lectin binding characteristics. In contrast to the striking increase in numbers of sialomucin-containing goblet cells found in the patients who had undergone ureterosigmoidostomy, the mucin proved to be histochemically normal in the rectal bladder surgery group. Abnormal lectin binding patterns were observed in colorectal mucosa after urinary diversion of both types, with the abnormalities consisting of dramatic decreases in FITC-DBA labeling (compared with controls) and the appearance of substantial numbers of FITC-PNA-labeled goblet cells. These findings indicate that the pattern of mucin secretion is definitely abnormal in patients who have undergone urinary diversion. Whether this abnormality is an indicator of premalignant changes remains to be established. These data, however, confirm that endoscopic and histologic follow-up studies may be of value in assessing the risk for the development of cancer in these patients.

Adult↗
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

Abnormal patterns of colonic mucin secretion after ureterosigmoidostomy.

Colonic epithelial mucin was investigated histochemically in biopsy specimens from a group of patients who had undergone ureterosigmoidostomy. For comparison, colonic biopsy samples from uninvolved mucosa adjacent to carcinomas from another group of patients and from a group of patients undergoing sigmoidoscopy for hemorrhoids were also studied. The high-iron diamine-alcian blue (HID-AB; pH 2.5) method was used, and the proportions of HID-positive and AB-positive cells were assessed semiquantitatively. In both ureterosigmoidostomy and cancer groups, highly significant increases in the proportions of AB-positive cells (sialomucins) were observed, particularly in the middle and lower segments of the crypts. Ureterosigmoidostomy introduces a high risk for the development of colonic carcinoma. Morphologic features that could account for such a high risk were investigated, and an abnormal pattern of colonic mucin secretion after ureterosigmoidostomy was demonstrated. Although this abnormality cannot be related specifically to ureterosigmoidostomy, data from the present investigation suggest that histochemical studies of colonic specimens from patients who have undergone ureterosigmoidostomy may provide a useful tool for follow-up studies.

Aged↗
PubMed1983

Colonic electromyography in chronic constipation.

Myoelectric activity of the sigmoid has been studied in 12 patients with chronic nonorganic constipation and 10 control subjects. All patients showed total gastrointestinal transit time longer than 96 h, with left-colonic or rectocolonic slowed transit. Electrical and mechanical activity was recorded by means of an intraluminal probe with bipolar suction electrodes and open-ended tips. Two groups of frequencies of slow waves, a slower rhythm at approximately 3 cycles/min and a faster rhythm at approximately 6 cycles/min were recorded in patients and control subjects. The mean frequency of the slower rhythm was significantly (p less than 0.005) higher in patients with constipation than in control subjects, whereas the frequency of the faster rhythm and the incidence of both rhythms were similar in the two groups. Mechanical activity showed no difference in terms of motility index and percentage of activity between patients and control subjects. Results of the study indicate that patients with left colonic constipation show an increase in frequency of the slower colonic rhythm in the very segment in which slowing down of transit occurs. It is suggested that the higher slow-wave activity in the sigmoid induces an increase in segmenting contractions and therefore may be responsible for the slowing down of intestinal transit.

Chronic Disease↗
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↗
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↗