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ABSTRACT: Vibrio parahaemolyticus is a marine bacterium known to be a common cause of seafood gastroenteritis worldwide. The thermostable direct hemolysin (TDH) has been proposed to be a major virulence factor of V. parahaemolyticus. TDH causes intestinal fluid secretion as well as cytotoxicity in a variety of cell types. In this study, we investigated the interplay between the hemolysin's enterotoxic and cytotoxic effects by using both human and rat cell monolayers. As revealed by microspectrofluorimetry, the toxin causes a dose-dependent increase in intracellular free calcium in both Caco-2 and IEC-6 cells. This effect was reversible only when low toxin concentrations were tested. The TDH-activated ion influx pathway is not selective for calcium but admits ions such sodium and manganese as well. Furthermore, in the same range of concentration, the hemolysin triggers a calcium-dependent chloride secretion. At high concentrations, TDH induces a dose-dependent but calcium-independent cell death as assessed by functional, biochemical, and morphological assays.
Infection and Immunity 07/2000; 68(6):3180-5. · 4.16 Impact Factor
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ABSTRACT: To analyze possible early abnormalities in bone resorption in type 1 diabetes mellitus the urinary excretion of the collagen crosslinks pyridinoline and deoxypyridinoline was evaluated by immunoassay in 26 prepubertal diabetic patients (mean age 7.8 +/- 1.6 years, mean duration 3.0 +/- 1.1 years) and 46 healthy children (age 8.3 +/- 1.3 years). Relationships with growth parameters (height-standard deviation score, body mass index and height velocity during the year preceding the study) and metabolic control were sought. Longitudinal and ponderal growth was normal in diabetic children. Urinary collagen crosslink excretion was 88.4 +/- 25 nmol/mmol creatinine (median 86, range 44-146) in diabetic patients and 65.6 +/- 19 nmol/mmol creatinine (median 61, range 32-108) in controls (p = 0. 0002). It was positively influenced by diabetic status (beta = 20.5) and negatively by age (beta = -6.41), controlling by sex and BMI (p = 0.0001). A positive correlation was found between collagen crosslinks and blood glucose (r = 0.48, p = 0.01) or HbA1c levels (r = 0.44, p = 0.02) evaluated at the time of the study, while no significant correlation was found with the mean HbA1c values assessed in the last year or throughout the whole duration of diabetes. Collagen crosslink excretion was significantly increased in patients who presented worsening of their metabolic control in the last 3 months. No relationship was found with the duration of disease or growth parameters. In conclusion, the elevated urinary excretion of collagen crosslinks in diabetic children indicates that bone resorption may be disturbed. Poor metabolic control influences the increased rate of bone resorption and may expose growing diabetic patients to a risk of bone loss.
Hormone Research 02/1999; 51(4):173-7. · 2.48 Impact Factor
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ABSTRACT: Previous evidence suggested a role of enterotoxin in the pathophysiology of cryptosporidiosis. If so, antisecretory drugs should be effective in reducing diarrhea. We evaluated the in vivo and in vitro efficacy of octreotide, which possesses antisecretory effects, for cryptosporidial diarrhea. Two children with severe cryptosporidial diarrhea were treated with octreotide. The volume modifications and chemical composition of stools were determined. Fecal supernatant was added to Caco-2 cell monolayers mounted in Ussing chambers with or without serosal octreotide and electrical parameters were monitored. Octreotide was effective in reducing the stool volume and fecal Na+ concentration. Fecal supernatant induced an enterotoxin-like increase in transepithelial potential difference. Octreotide induced a dose-dependent decrease in basal potential difference, consistent with an absorptive effect. In cells pretreated with octreotide, fecal supernatant induced an increase in the potential difference, whose magnitude and duration were significantly reduced compared to untreated cells. These results provide in vivo and in vitro evidence for the secretory nature of cryptosporidial diarrhea and for the efficacy of octreotide through a direct interaction with the enterocyte.
Digestive Diseases and Sciences 02/1998; 43(2):436-41. · 2.12 Impact Factor
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ABSTRACT: Enteric cryptosporidiosis is a frequent problem in adults with human immunodeficiency virus (HIV) infection, but little is known of its features in children. The aim of this study was to investigate the incidence and the clinical features of cryptosporidiosis in HIV-infected children.
Thirty-five children with symptomatic HIV infection were screened every 2 months, and in case of diarrhea, for the presence of Cryptosporidium. Intestinal function tests were performed, and the fecal osmotic gap was measured in children with cryptosporidiosis.
Seventy episodes of diarrhea occurred in 16 children in a median period of 17 months. Cryptosporidium was detected in five cases, all with full-blown acquired immunodeficiency syndrome. Cryptosporidiosis was significantly more protracted than any other form of diarrhea and was associated with dehydration and severe weight loss. Intestinal function was not modified during cryptosporidiosis. Osmotic gap values were consistent with secretory rather than osmotic diarrhea. In four cases, recovery was observed without specific treatment.
Enteric cryptosporidiosis is a severe problem in advanced stages of HIV infection. It does not induce intestinal malabsorption. It induces diarrhea of secretory type. Recovery may be observed independently of therapy.
Journal of Pediatric Gastroenterology and Nutrition 09/1997; 25(2):182-7. · 2.30 Impact Factor
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ABSTRACT: Our aim was to evaluate incidence and risk factors of liver involvement in obese Italian children as assessed by both ultrasonographic and biochemical parameters. In seventy-five consecutive obese children (age 9.5 +/- 2.9 years, males/females 41/34), serum levels of enzymes and ultrasonography of the liver were evaluated. Tests were repeated one, three, and six months after starting a moderate hypocaloric diet and an exercise program. Three obese children who were found to have chronic viral hepatitis were excluded from the study. Thirty-eight of 72 (53%) obese children had an ultrasonographic image of bright liver consistent with liver steatosis. The latter was severe in nine children, moderate in 16, and mild in 13. Eighteen obese children (25%) had elevated transaminase levels. Bright liver and hypertransaminasemia were not due to any of the most common causes of liver disease. Both were rapidly responsive to loss of weight, confirming that liver involvement was secondary to obesity and that steatosis or steatohepatitis rather than fibrosis were involved. Obesity duration not more than three years (odds ratio = 4.77), a higher degree of obesity (odds ratio = 2.09), and hypertransaminasemia (odds ratio = 2.15) appeared as important predictive factors of liver involvement at ultrasonography. Incidence of liver involvement assessed by means of ultrasonography is significantly higher than that revealed by measurement of serum liver enzymes. A short duration of obesity emerged as a potentially new risk factor of liver involvement in the pediatric obese population and needs to be confirmed in future studies.
Digestive Diseases and Sciences 08/1997; 42(7):1428-32. · 2.12 Impact Factor
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Recenti progressi in medicina 02/1997; 88(1):35-9.
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ABSTRACT: Oral administration of human serum immunoglobulin reduces the duration of diarrhea and of rotaviral excretion in children. To investigate the in vitro effects of immunoglobulin on virus-enterocyte interaction, Caco-2 cells were infected with Rotavirus strain SA11. Immunoglobulin was added prior to and at various times postinfection. Indirect immunofluorescence was performed with an antibody against VP-6 rotaviral antigen. Cell viability and monolayer transepithelial electrical resistance (TEER) were monitored. Immunofluorescence showed a perinuclear distribution in 90% of cells. Rotavirus infection induced a progressive decrease in TEER and a parallel reduction in cell viability, depending on viral load. Preincubation of the virus with immunoglobulin prevented cell infection as judged by immunofluorescence. Immunoglobulin addition to infected cells partially prevented the decrease in TEER and induced a later shift of TEER toward increasing values, suggesting restoration of monolayer's integrity. The efficacy of immunoglobulin depended on its concentration and on the time of its addition. These results indicate that immunoglobulin is effective in preventing infection and in reducing cell damage, through a direct anti-Rotavirus action and may indicate that immunoglobulin should be administered in the early phase of diarrhea, to reduce the severity of Rotavirus infection.
Pediatric Research 01/1997; 40(6):881-7. · 2.70 Impact Factor
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AIDS 10/1996; 10(10):1176-8. · 6.24 Impact Factor
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ABSTRACT: The present study estimates the prevalence of obesity among ten-year old children living in Southern Italy and compares it with the prevalence of obesity among children living in other western countries.
110 children attending the 4th grade of a randomly selected primary school in Naples were studies in the 1992. Eighty-eight per cent of the total school population was examined: 52 girls, 58 boys: mean age = 9.6 years (SEM = +/- 0.10). Each child underwent medical examination and anthropometric assessment. The percentile values for Body Mass Index (BMI = weight/height 2) and triceps skinfolds thickness (mm) were calculated and compared to that of children of the same age and sex living in other countries, chosen from comparable studies available in the literature.
Percentile values for triceps skinfolds thickness in Neapolitan children are similar to those reported in the other populations considered for comparison, however BMI values were different. Children in Naples have the highest BMI values at the 50th, 75th, 90th and 95th percentile. The prevalence of obesity among Neapolitan children was estimated using as a cut-off, the BMI value at the 90th percentile of each population considered for the comparison and calculating the rate ratio with 95% confidence interval (95% CI). The prevalence of obesity in Naples among girls, was 5.2 times (3.8-6.6 95% CI) as high as in France, 3.3 times (2.2-4.4) as high as in Holland, 1.7 times (0.9-2.5) as high as in USA, 2.5 times (1.7-3.4) as high as in Milan (Northern Italy); among boys it was 4.3 times (3.0-5.6) as high as in France, 4.0 times (2.7-5.2) as high as in Holland, 2.1 times (1.2-3.0) as high as in the USA, 2.5 times (1.7-3.4) as high as in Milan.
International Journal of Obesity 04/1996; 20(3):283-6. · 4.69 Impact Factor
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ABSTRACT: It has been reported that: 1) ovine growth hormone stimulates intestinal water, sodium, and chloride absorption and 2) specific growth hormone receptors are present in the rat intestine. Aims of this work were to investigate the effects of acute administration of hGH on water and ion transport in the rat ileum in vivo and in vitro. In vivo, the absorption rates of water, sodium, chloride, and potassium were determined in the rat perfused ileum, during a basal period and after i.v. administration of 6 micrograms/kg recombinant DNA-derived hGH. In vitro, electrical parameters were measured before and after the hormone addition to the mucosal or the serosal side of rat ileal mucosa mounted in Ussing chambers. In vivo, growth hormone induced a rapid increase in the absorption rates of water, sodium, chloride, and potassium. In vitro, the serosal, but not the mucosal, addition of growth hormone induced a rapid decrease of transepithelial potential difference and of short-circuit current. The effect was time- and dose-dependent, saturable, but not reversible in the short time. The electrical effect was abolished in the absence of chloride, indicating that it was related, at least in part, to inhibition of basal active chloride secretion. Growth hormone also reduced the short-circuit current increase induced by the secretagogues Escherichia coli heat-stable enterotoxin, theophylline, and calcium ionophore A23187. These results indicate that hGH has a rapid absorptive effect that is related, at least in part, to a direct intestinal antisecretory mechanism. It also reduces active intestinal secretion induced by various secretagogues.
Pediatric Research 06/1995; 37(5):576-80. · 2.70 Impact Factor
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ABSTRACT: A cell line model to detect enterotoxic effect was used to test fecal specimens of patients with enteric cryptosporidiosis. Fecal samples were obtained from 11 patients with Cryptosporidium diarrhea, and osmotic gap was determined. Caco-2 cell monolayers grown on filters were mounted in Ussing chambers, and electrical parameters were measured before and after the addition of fecal supernatant. A significant increase in short-circuit current was seen in 9 of 11 specimens. The enterotoxic effect was time- and dose-dependent, saturable, and Cl(-)- and Ca(2+)-dependent. Fecal osmotic gap was consistent with secretory diarrhea in the 9 enterotoxin-positive but not in the 2 enterotoxin-negative samples. In conclusion, a cell line model for studying the pathophysiology of enteric cryptosporidiosis was established. Enterotoxic activity was observed in most patients with enteric cryptosporidiosis and was strictly associated with secretory diarrhea.
The Journal of Infectious Diseases 05/1995; 171(4):976-83. · 6.41 Impact Factor
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ABSTRACT: Recent advances in the nutrition of low birth weight infants are discussed, with special emphasis on concepts and methods to establish parameters for the control of growth and nutrition. Furthermore, the recent developments of methods in the research on newborn nutrition, the problems related to the use of breast milk, the timing of feeding and the problems of the intravenous alimentation are discussed in some detail. Secondly, the effects of breast feeding on infant health are summarised, with particular emphasis on the long term consequences (occurrence of diseases later in life) and on the effects on some surgical diseases of infancy. Recent acquisitions in the field of enteral and parenteral nutrition are also mentioned, and the problems related to composition of the nutritive solutions and indications in pediatric age are covered in some detail. Finally, the dietary management of infant with cow's milk protein allergy or intolerance is discussed, with special regard to composition and indications of hydrolysed protein formulas (casein based, whey based, soy and collagen based), soy based formulas and aminoacid based formulas.
Annali dell'Istituto superiore di sanita 02/1995; 31(4):403-9. · 0.94 Impact Factor
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ABSTRACT: Preliminary evidence has been reported on the antirotavirus effect of human serum immunoglobulin administered orally. The aim was to see whether such treatment might be effective in rotavirus acute gastroenteritis.
A prospective, double-blind, placebo-controlled study was performed. Ninety-eight children admitted with acute gastroenteritis were enrolled and randomly assigned to groups A (treated) and B (control). Children in group A received a single oral dose of 300 mg/kg body weight of human serum immunoglobulin. Parameters of efficacy were clinical condition, frequency and consistency of stools, duration of diarrhea, duration of viral excretion, and length of hospital stay. Antirotaviral activity was determined in the immunoglobulin preparation by a specific neutralization assay.
Seventy-one of the 98 children enrolled had rotaviral gastroenteritis; 36 belonged to group A. Children who received immunoglobulin had significantly faster clinical improvement of clinical condition and stool pattern than control children. Mean total duration of rotaviral diarrhea was 76 hours in group A and 131 in group B (P < .01). Viral excretion lasted 114 and 180 hours, respectively (P < .01). Hospital stay was significantly reduced in children in group A. Neutralizing antibodies against rotavirus were detected in the immunoglobulin preparation.
Oral administration of immunoglobulin is associated with a faster recovery from acute gastroenteritis and should be given to children hospitalized with this illness.
Pediatrics 01/1994; 93(1):12-6. · 5.44 Impact Factor
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ABSTRACT: In order to evaluate the factors affecting body fat excess and distribution, we have studied children attending the 4th grade of a primary school randomly selected in Naples. 52 girls, 58 boys; mean age = 9.6 years (SE +/- 0.1) were examined. Among the familial factors assessed, a correlation between parental BMI and child's anthropometry was found. Among congenital factors, sex correlates with the children's waist/hip ratio ("t" = -2.07; p = 0.05). Moreover the girl's percent body fat was higher. These two findings suggest the expression of sexual characters in prepubertal age. Systolic blood pressure showed a positive correlation with children's percent body fat ("t" = 2.43; p = 0.016) and subscapular skinfold thickness ("t" = 1.19; p = 0.05), suggesting an influence of these factors on blood pressure level since this age. No correlation was found between children's BMI and weight at birth, family history of diabetes, hypertension or hyperlipidemia. Among environmental factors, only the mothers weight gain during pregnancy ("t" = -2.21; p = 0.03) and breast feeding ("t" = -2.07; p = 0.05) correlated with the children's BMI. The correlation between children's BMI and waist/hip ratio ("t" = 4.64; p = 0.0001), was not confirmed in children who exercise, suggesting a beneficial action of physical activity on body fat distribution. The identification in different populations of factors associated with childhood obesity is important for prevention planning.
Minerva pediatrica 11/1993; 45(10):383-8.
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ABSTRACT: Conflicting data have been published in favor of or against a secretory effect of atrial natriuretic peptide (ANP) in the intestine. The reported effects resemble that of Escherichia coli heat-stable enterotoxin (ST). In this work the effects of ANP were studied in well established experimental systems and compared with that of ST. Both peptides induced a prompt secretion of water, Na, and Cl with no effects on K net transport in the in vivo rat perfused jejunum. The addition of ST, but not of ANP, evoked an increase of short circuit current in rat intestinal mucosa mounted in Ussing chambers. ST induced a significant increase in guanylate cyclase activity in intestinal homogenates, whereas ANP showed no effect. No binding sites for ANP were detected in basolateral or brush border membranes, nor in isolated enterocytes by a suction filtration technique. In conclusion, ANP acts as a short-lived intestinal secretagogue in the rat. Its mechanism of action is different from that of E. coli ST and appears to be indirect, since is not mediated by specific intestinal receptors and is not evident in vitro.
Journal of Pediatric Gastroenterology and Nutrition 09/1992; 15(2):105-11. · 2.30 Impact Factor
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ABSTRACT: Conflicting results have been reported on the use of the steatocrit to measure fecal fat excretion. Aiming to assess the reliability of this method and its usefulness in the diagnosis of intestinal enteropathies, we measured the steatocrit in 747 healthy children and 442 children with diarrhea grouped according to diagnosis. The steatocrit was found to correlate strictly (r = 0.93) with the chemical measurement of fecal fat. Reference values and ranges were established. The maximal steatocrit was observed in neonates; afterwards, it progressively decreased to an undetectable level in children older than 2 years of age. A steatocrit abnormally high for age was found in 20% of patients with acute diarrhea and in 53% of those with chronic diarrhea. All celiac patients with a gluten-containing diet showed a marked increase of steatocrit. We conclude that the steatocrit is a reliable and easy-to-perform test, which quickly provides valuable information in the diagnostic workup of the child with diarrhea.
Journal of Pediatric Gastroenterology and Nutrition 05/1992; 14(3):268-74. · 2.30 Impact Factor
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The Pediatric Infectious Disease Journal 09/1991; 10(8):612-4. · 3.58 Impact Factor
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ABSTRACT: A longitudinal (10-22 month) evaluation of intestinal symptoms and function was performed in five children with symptomatic human immunodeficiency virus (HIV) infection. All received cotrimoxazole, ketoconazole, and immunoglobulins. A search for enteric pathogens and intestinal function tests were repeatedly performed in all patients. Mild episodes of diarrhea were observed in two children. One had cow's milk protein intolerance. Giardia lamblia was found in an asymptomatic carrier. Evidence for impaired intestinal function was found in all patients. These consisted of positive D-xylose and iron oral loads, increased steatorrhea, increased fecal excretion of alpha 1-antitrypsin, abnormal intestinal permeability, and increased food antibody levels. Our results suggest that severe diarrhea may be uncommon in children with HIV infection receiving antimicrobial prophylaxis, but that the intestinal function is frequently, and often markedly, impaired.
Journal of Pediatric Gastroenterology and Nutrition 06/1991; 12(4):453-8. · 2.30 Impact Factor
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ABSTRACT: To define the action of deconjugated bile acids on the small intestinal permeability in an in vitro system, we investigated the effects of chenodeoxycholic acid and ursodeoxycholic acid on the rate of transmural flux of lactulose in jejunal and ileal mucosa of rabbits, stripped of their muscle layers and mounted in Ussing chambers. In a series of experiments, tissue samples from small intestinal segments either exposed to bile acids or not also were examined by scanning and transmission electron microscopy to study the integrity of the tight junctions. Results show that chenodeoxycholate, starting at the concentration of 0.1 mM, enhanced in a dose-related manner the transepithelial flux of lactulose in the ileum. Both chenodeoxycholate (0.5 mM) and ursodeoxycholate (0.5 mM) significantly increased mucosal permeability to lactulose in jejunum and ileum; the effect of chenodeoxycholate was also shown to be reversible, as it completely disappeared within 40 min after its withdrawal and it did not result in permanent changes of epithelial transport function. Finally, the tight junctions appeared loosened by the addition of 1 mM chenodeoxycholate, suggesting that this is the major site of the transient bile acid increase of small intestinal permeability to compounds such as lactulose, having a molecular radius wider than 0.5 nm.
Digestive Diseases and Sciences 08/1990; 35(7):801-8. · 2.12 Impact Factor
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The Lancet 02/1990; 335(8680):46. · 38.28 Impact Factor
