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Biomedical subjects

P Malaguti

Publications and source records attributed to P Malaguti.

At least 19 recordsLinked to original sources

Lactulose hydrogen breath test in orocecal transit assessment. Critical evaluation by means of scintigraphic method.

Orocecal transit time can be studied easily using the hydrogen breath test with lactulose, but the method has some important limitations. The orocecal transit time of 10 patients suffering from irritable bowel syndrome was measured twice, at a one-week interval, by breath test and scintigraphy simultaneously using an aqueous solution of 20 g lactulose containing 74 MBq of [99mTc]DTPA. Abdominal radioactivity and alveolar hydrogen values obtained every 5 min were noted and used to obtain the following: orocecal transit time by the two methods; ileocecal lactulose flow; total and per gram of lactulose hydrogen production; mean hydrogen concentration during the right colon filling; and measurement error of the breath test with respect to the scintigraphy. In the case of the breath test, the orocecal transit time intrapatient reproducibility was better (coefficient of variation = 13.5%) when a hydrogen threshold increment of 5 ppm was used; the best correlation with the scintigraphic measurement was observed at this threshold (r = 0.90, P < 0.001). The breath test overestimated orocecal transit time with the error correlating negatively and significantly with the total hydrogen production and, particularly, the mean hydrogen concentration (r = 0.79, P < 0.01): for a mean hydrogen concentration of more than 15 ppm, the error was negligible, while within this value there was a noticeable overestimation. To conclude, the lactulose hydrogen breath test is capable of giving an accurate measurement of orocecal transit time if a hydrogen threshold increment of 5 ppm is chosen and if the mean hydrogen concentration in the first 30 min of the right colon filling is taken into account.

Adult

Absence of histopathological changes of ileum and colon in functional chronic diarrhea associated with bile acid malabsorption, assessed by SeHCAT test: a prospective study.

OBJECTIVES: Chronic diarrhea of unknown origin is often associated with bile acid malabsorption, the pathogenetic role of which is uncertain. The aim of this study was to identify morphological abnormalities in the ileal and colonic mucosa in patients with this disorder. METHODS: We performed a prospective and blinded histopathological study (between June 1991 and November 1992) of endoscopic biopsies of the distal ileum and colon of 23 patients suffering from chronic diarrhea of unknown origin. In 14, the SeHCAT (75-selena-homo-cholic acid taurine) test was abnormal owing to bile acid malabsorption; in the other nine, the diarrhea control group, the test results were normal. A detailed evaluation of surface epithelium, immune response and inflammatory changes was made. RESULTS: in two patients and two controls, mild villous atrophy was observed; there was also slight inflammation of the ileal and colonic mucosa occurring with the same frequency in both groups. A slight replacement of goblet cells was more evident in the diarrhea control group. CONCLUSIONS: Chronic diarrhea of unknown origin associated with bile acid malabsorption does not involve specific morphological changes of ileal or colonic mucosa, and its pathogenesis must be looked for in dysfunction of the ileum and/or colon.

Adult

Bile acid malabsorption in AIDS-associated chronic diarrhea: a prospective 1-year study.

OBJECTIVES: In patients with chronic diarrhea associated with acquired immunodeficiency syndrome, bile acid malabsorption, very rarely investigated, may have an important pathogenetic role. METHODS: In this 1-yr prospective study, 15 patients with AIDS-associated chronic diarrhea and 10 AIDS-controls were studied for bile acid malabsorption by means of the SeHCAT abdominal retention test. The patients with diarrhea underwent the glucose hydrogen breath test to identify any bacterial proliferation in the small bowel. RESULTS: In the chronic diarrhea group, only one case of small bowel bacterial overgrowth, and seven cases (47%) with generally severe bile acid malabsorption, were observed. Among the controls, only one had an abnormal low SeHCAT retention. In both cases with Cryptosporidium infection, the SeHCAT test was pathological. CONCLUSIONS: These data are of clinical importance for the pathogenetic study of AIDS-associated chronic diarrhea and for specific treatment with cholestyramine.

AIDS-Related Opportunistic Infections

Technetium-99m hexamethyl propylene amine oxime granulocyte scintigraphy in Crohn's disease: diagnostic and clinical relevance.

Scintigraphy with autologous granulocytes labelled by technetium-99m hexamethyl, propylene amine oxime (99mTc-HMPAO) was performed in 103 Crohn's disease patients and 52 healthy controls. In 31 patients endoscopic and histologic activity was compared with scan activity index. In the 98 patients with a positive scan, the extent of Crohn's disease, assessed by scintigraphy, was compared with that evaluated by small bowel x ray or colonoscopy with biopsies. In 48 patients, Crohn's disease activity index, activity index, simple index, erythrocyte sedimentation rate, C-reactive protein were correlated with the scan results. In 16 patients the five parameters and scan were repeated after treatment with methyl-prednisolone (10 cases), enteral nutrition (3), and 5-acetylsalicylic acid (3). The results showed that 99mTc-HMPAO granulocyte scan had a 95% sensitivity and 100% specificity to detect active inflammation; it correctly showed an abscess or a fistula in all the 24 cases found. The correlation between histological inflammatory activity and scan activity index was highly significant (r = 0.85; p < 0.01), less significant (r = 0.65; p < 0.01) between endoscopy and scan activity index. The evaluation for the extent of Crohn's disease by scan was completely correct in the small bowel (100%) and 93% correct in the large bowel. No correlation was seen between the three clinical activity parameters and scanning; in more than 80% of the cases in remission on the basis of a clinical or laboratory index, scintigraphy remained positive. Medical treatment was effective on the clinical indices but not on the active inflammation in the ileum, whereas it led to a negative scan in 5/11 cases in the large intestine. Scintigraphy with 99mTc-HMPAO granulocyte plays an important part in Crohn's disease for the diagnosis of complications, for activity and assessment of the extent, and for the treatment results evaluation.

Abscess

Scintigraphic study of gastrointestinal transit and disintegration sites of mesalazine tablets labeled with technetium-99m.

Tablets of mesalazine covered with a pH-dependent coating (Pentacol), labeled by an original technique with technetium-99m, were administered to 12 patients, 9 with Crohn's disease, 3 of which recurrent, 1 with ulcerative colitis, and 2 with irritable bowel syndrome, with the aim of verifying in vivo the intestinal site of disintegration and how the contents spread throughout the intestine. In all cases the tablet was broken down in the distal ileum at extremely variable intervals, from 5 to 27 h, and the contents spread into the nearby loops and into the colon. The notable differences in the residence time of the whole tablet in the ileum can be explained by differences in adhesion to the inflamed mucosa and by a lower pH in the part of the ileum affected by the disease.

Adult

Dynorphin B-like immunoreactivity in gastroduodenal biopsy specimens from gallstone patients.

Dynorphin B-like immunoreactivity (ir-dyn B) was measured by a validated radio-immunoassay in gastroduodenal biopsy specimens from control and gallstone patients. Levels were significantly lower in acetic acid extracts of specimens of the transverse portion of the duodenum from gallstone patients. Gel permeation chromatography showed that almost all ir-dyn B in duodenal samples corresponded to a molecular form co-eluting with authentic dyn B. Duodenal extracts from gallstone patients had less of this form. Reverse-phase high performance liquid chromatography of the pooled gel chromatography fractions showed up a molecular form with the same retention time as synthetic dyn B which was significantly less in fractions from duodenal extracts of gallstone patients. These results indicate the occurrence of dyn B in the human gastrointestinal tract; however, at this stage of our understanding, no causal relationship can be demonstrated with functional alterations of the biliary tree.

Adult

Post-cholecystectomy diarrhea: evidence of bile acid malabsorption assessed by SeHCAT test.

Although bile acid malabsorption (BAM) in post-cholecystectomy diarrhea (PCD) is a well-known clinical condition, its true etiopathogenetic role is not entirely clear. The SeHCAT (23-selena-25-homotaurocholic acid) test, a simple and reliable BAM test, was performed in 33 cholecystectomized patients, 26 with chronic diarrhea. The test revealed a marked degree of BAM in 25/26 cases. Cholestyramine in doses of 2-12 g/day was effective in 23/25, ineffective in two, and was not tolerated in one patient. When treatment was suspended, diarrhea recurred in nine, whereas bowel habit remained regular in 60%, with brief sporadic episodes of diarrhea in the other cases. The SeHCAT test was repeated in 11 cases after cholestyramine treatment interruption, and revealed the normalization of parameters in two patients and an improvement in three. We conclude that BAM is an important etiopathogenetic factor in PCD that responds favorably to cholestyramine. In 60% of the cases, it resolved diarrhea definitively, although without eliminating BAM in all cases: this suggests that existence of other factors associated with BAM. The SeHCAT test is essential for a differential diagnosis between PCD and the irritable bowel syndrome.

Adult

A new faecal chymotrypsin method for evaluating the exocrine pancreatic function in patients with different pancreatic diseases.

Using a new colorimetric method we measured the faecal chymotrypsin in 407 subjects, divided as follows: 252 adult subjects with a normal exocrine pancreatic function as shown by duodenal intubation, 24 adult patients with a mild to moderate pancreatic insufficiency, and 26 adult patients with severe pancreatic insufficiency. In addition, 40 healthy children, 50 children with chronic diarrhoea, and 15 with cystic fibrosis were studied before and after substituting enzyme therapy. Faecal chymotrypsin was found to be useful in evaluating the degree of exocrine functional insufficiency in subjects with diseases of the pancreas that had already been clinically ascertained. The same cannot be said for its ability to provide an early diagnosis of subjects with a slight-moderate insufficiency in exocrine pancreatic function.

Adult

Serum elastase 1 in clinical practice.

Using radioimmunoassay, we tested serum elastase 1 (E1), an enzyme secreted only from the pancreas, in 200 subjects as follows: 39 healthy subjects as controls, 56 patients with diseases of the digestive tract, 66 patients with hepatobiliary diseases, and 39 patients with pancreatic diseases. The serum E1 showed high specificity and proved very useful in the diagnosis of acute pancreatitis. However it was not useful in diagnosis of clinically silent chronic pancreatitis, nor in its functional evaluation. On the other hand, it was found to be a valuable guide in revealing a concomitant pancreatic pathology during hepatobiliary diseases. Further investigation is needed of the behavior of E1 in patients who have undergone a total pancreatectomy, where the enzyme remains measurable, and in those with an ileocolic disease in an acute phase where E1 is increased in many patients.

Adult

Scintigraphic evaluation of enterogastric reflux using 75Se-HCAT: methodology and first clinical observations.

The aim of this study was to assess the possibility of detecting enterogastric reflux (EGR) by 75Se-HCAT cholescintigraphy. The lowest detectable activity in the gastric area at different concentrations of the radiotracer in the gallbladder was preliminary measured both in a plastic phantom and in an in vivo model. Ten patients were studied after a single oral administration of 1480 KBq 75Se-HCAT. Gamma camera imaging was carried out for five consecutive days during both fasting and after meal ingestion. In our in vivo model an EGR corresponding to 1% of gallbladder content on day one and 8% on day five was detected. In three out of five patients in whom bile was present in the stomach at endoscopy, 75Se-HCAT cholescintigraphy demonstrated an EGR, while in three out of five patients in whom endoscopy was negative, 75Se-HCAT cholescintigraphy detected EGR either during fasting or after meal ingestion. As EGR is not constant, 75Se-HCAT may be a useful tracer of bile to detect EGR over a prolonged period of time and in different physiological conditions.

Bile Reflux

Different responses of serum cationic trypsinogen to secretin and bombesin in normal subjects and patients with chronic alcoholic pancreatitis.

We evaluated the behavior of serum cationic trypsinogen (SCT), an enzyme of solely pancreatic origin, in 30 patients with chronic pancreatitis and 25 healthy subjects as a control, after secretin and bombesin stimulation. After both the stimulations, serum cationic trypsinogen is unable to distinguish between the healthy control subjects and the patients with chronic pancreatitis. On the other hand, after secretin, the enzyme is able to separate chronic pancreatitis patients with different levels of exocrine function insufficiency. It does so with a greater statistical significance than that obtained by the rapid injection of bombesin and equal to that of trypsin into the duodenal juice during duodenal intubation. For these reasons, as well as the absence of any side-effects, secretin is preferred to bombesin stimulation in the evaluation of the exocrine pancreatic function in patients with chronic pancreatitis.

Adult

75Se HCAT test in the detection of bile acid malabsorption in functional diarrhoea and its correlation with small bowel transit.

The purpose of this study was to evaluate whether bile acid malabsorption assessed by the 75SeHCAT test, had a pathogenetic role in functional chronic diarrhoea and to ascertain whether the small bowel transit time (SBTT) could be correlated with the 75SeHCAT test results. The test was based on the counting of the abdominal retention of a 75-selenium labelled homotaurocholic acid. The 75SeHCAT test was carried out in a control group of 23 healthy adults and in 46 patients, 38 of whom were suffering from irritable bowel syndrome (IBS) of diarrhoeic form and eight patients who had undergone cholecystectomy and were suffering from chronic diarrhoea. Faecal bile acid loss was determined in nine patients, and in 14, serum bile acid increase after a standard meal was measured. In 17, SBTT was studied by hydrogen breath test after lactulose administration (21 g in 300 ml water). In 15 patients, choledochocaecal transit time was estimated by Tc99m-HIDA (111 MBq) cholescintigraphy. In 20 of 46 subjects, 75SeHCAT retention was below normal level, and in 19 cholestyramine administration relieved diarrhoea. 75SeHCAT results were related to faecal bile acid loss, while no correlation was found with serum bile acids and SBTT. The data suggest a possible wider use of the 75SeHCAT test in chronic diarrhoea to estimate bile acid malabsorption in irritable bowel syndrome, diarrhoeic form, and provide an effective treatment. In our patients small bowel transit velocity does not seem to be a pathogenetic factor of bile acid malabsorption.

Adolescent

Use of 23-selena-25-homocholyltaurine to detect bile acid malabsorption in patients with illeal dysfunction or diarrhea.

Abdominal gamma-counting after oral administration of 23-selena-25-homocholyltaurine (75SeHCAT) was carried out on 23 healthy volunteers and 66 patients: 33 with distal ileum resections, 3 with Crohn's disease of the ileum, 17 suffering from various intestinal diseases but with normal ileum, and 13 with chronic diarrhea syndrome but without evident intestinal or extraintestinal pathology. The percentage value of 75SeHCAT abdominal retention was assessed by analysis of the activity versus time curve, obtained by single exponential least-squares fit in five consecutive measurements (time zero and 1, 3, 5, and 7 days after 75SeHCAT administration) and directly by the gamma-camera countings on days 3, 5, and 7. The percentage values obtained from the curve on the third day were found to be the most suitable for differentiating between the groups, giving the 75SeHCAT test a 94% sensitivity and a 100% specificity. Our data show that this test is a valid indicator of bile acid loss: actually, it gave evidence of idiopathic malabsorption of bile salts in 6 patients with diarrhea of unknown origin who responded to cholestyramine and showed a correlation (correlation index = 0.585) with the residual ileum of the last meter in resected patients. Moreover, the 75SeHCAT test is easy to perform in any hospital with gamma-counting facilities and has negligible radiation risk.

Adolescent

Changes in serum pancreatic enzymes after hormonal stimulation in chronic pancreatitis.

Eighteen patients with chronic pancreatitis and 12 healthy controls were subjected to hormonal stimulation by continuous secretin plus cerulein intravenous infusion or a rapid injection of secretin. In both tests total serum amylase, lipase, and TLI (trypsin-like immunoreactive substances) levels were measured. Continuous intravenous infusion does not bring about changes in the serum levels of the enzymes studied; rapid injection of secretin, however, induces changes in the serum levels of TLI and lipase (but not amylase) which makes it possible to distinguish patients with chronic pancreatitis in its early stages from advanced chronic pancreatitis but is of doubtful value in distinguishing healthy subjects from those suffering with chronic pancreatitis.

Adult

Effect of secretin upon the levels of pancreatic enzymes in blood serum.

We have evaluated the serum changes of trypsin, pancreatic isoamylase and lipase, after rapid infusion of secretin, in 45 patients with chronic pancreatitis compared with 35 healthy control subjects. On the basis of duodenal intubation results, chronic pancreatitis patients were divided into two subgroups at different levels of functional impairment. Using the peak activities of the enzymes we have been able to separate the two chronic pancreatitis subgroups by statistical difference; only trypsin distinguishes healthy control subjects from mild to moderate chronic pancreatitis. Therefore, we propose to put into clinical practice this serum provocative test to evaluate the functional damage of an established chronic pancreatitis.

Adult

A new endoscopic balloon for sclerotherapy in active bleeding from esophageal varices.

A new balloon for flexible endoscopes has been developed and used in 25 patients with esophageal varices: sclerotherapy was carried out as prophylaxis against rebleeding in 17 cases, and during active hemorrhage in 8 cases. The balloon was shown to be effective in controlling hemorrhage and enabling sclerosing injections to be carried out, both in emergency and in cases of bleeding response to injections.

Endoscopes

Hydrogen breath test quantification and clinical correlation of lactose malabsorption in adult irritable bowel syndrome and ulcerative colitis.

Lactose malabsorption was studied, by hydrogen breath test, in 72 adults suffering from irritable bowel syndrome, in 20 ulcerative colitis patients, and in 69 healthy subjects. The minimum dose of lactose required to cause a positive breath test was determined, and the symptoms caused and the resulting hydrogen eliminated quantified. A high incidence of lactose malabsorption was shown at standard doses (up to 50 g) in both the healthy subjects (70%) and the patients (86% and 85%, respectively). In the irritable bowel syndrome and the ulcerative colitis groups, symptoms occurred with a smaller quantity of breath hydrogen, presumably in association with a greater individual sensitivity of the colon to distension. The threshold lactose dose was notably lower in the diseased subjects who registered as evidence a prevalence of malabsorption at a 20-g lactose load. The pathogenetic role of lactose malabsorption in the irritable bowel syndrome is emphasized, as is the importance of the personal lactose tolerance.

Adolescent