Levels and congener profiles of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and dioxin-like polychlorinated biphenyls in cow's milk collected in Campania, Italy

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and certain dioxin-like polychlorinated biphenyls (dl-PCBs) are a family of chemically-related lipophilic compounds characterized by similar toxicity. Due to their properties they are universally distributed in the environment and classified as persistent organic pollutants (POPs). From most of studies carried out to evaluate human dietary intake, milk and dairy products result as a major contributors of PCDD/Fs uptake. Of course the main source of milk contamination is animal feeds. Lactating ruminants, cows included, transfer these compounds to the food chain by ingestion of contaminated vegetables or soil. Their resistance to degradation and a high lipophilicity means that PCDD/Fs and dl-PCBs may be accumulated into fat tissues from which they are transferred to milk during lactation period. Seventy-nine cows milk samples, collected in the monitoring plan 2008, were analyzed for PCDD/Fs and dl-PCBs. Eleven milk samples were non-compliant corresponding to five breeding livestock located in Caserta province. The distribution of PCDD/Fs and dl-PCBs congeners in these samples was examined in order to determine the likely sources of dioxins. The results show that the congener profile is characterized by a prevalence of PCDFs in respect of PCDDs, that represents the typical pattern of thermal origin contamination.

Is resistin a link between highly active antiretroviral therapy and fat redistribution in HIV-infected children?

OBJECTIVES

To assess the features of fat redistribution, detected by clinical and ultrasound (US) methods, and the presence of metabolic disorders in HIV-infected children undergoing antiretroviral therapy. To evaluate if serum levels of resistin, a hormone produced only by visceral adipose tissue, are a marker of fat redistribution in these patients.

DESIGN AND METHODS

Forty-five consecutive symptomatic HIV-infected children were considered for inclusion in the study. Patients were enrolled if treated for at least 6 months with antiretroviral therapy with or without protease inhibitor (PI) and if compliant to the study protocol. Patients were evaluated for: anthropometric measures, fat redistribution by clinical and US methods, serum lipids, parameters of insulin resistance by homeostasis model assessment for insulin resistance, serum resistin levels by an enzyme-linked immunosorbent assay.

RESULTS

Eighteen children fulfilled the inclusion criteria and were enrolled in the study. Twelve (66%) children had clinical and/or US evidence of fat redistribution; 9 (75%) of them were on PI therapy; only 3 of 6 children without fat redistribution were on PI therapy (p<0.05). Serum lipids and insulin resistance parameters did not differ between children with or without fat redistribution. There was a highly significant linear correlation between visceral fat detected by US and circulating resistin levels (r=0.87; p<0.0001).

CONCLUSIONS

Fat redistribution occurred in most HIV-infected children undergoing PI therapy. Because serum resistin levels reflect the amount of visceral fat, they could be considered a sensitive marker of fat redistribution in HIV-infected children.

Clinical variability of cardio-facio-cutaneous syndrome: report of two additional cases

We describe two new cases of cardio-facio-cutaneous (CFC) syndrome, and underline the clinical variability of the CFC phenotype in our two patients presenting with border-line psychomotor development. The first patient showed some additional clinical manifestations, such as cryptorchidism and scoliosis, and the second one had atypical skin lesions.

Preparing for an influenza pandemic in Italy: resources and procedures in paediatric hospital units

The World Health Organization (WHO) has stated that preparedness for effectively facing a major influenza epidemic should involve the training of physicians in the management of contagious diseases and upgrading hospital resources and procedures [1]. Children would be particularly vulnerable during an influenza pandemic and specific measures are needed to face the threat to them effectively. We performed a national survey to obtain information about the preparedness in facing a major influenza outbreak in Italian paediatric units. In Italy, paediatrics clinics are found in both paediatric wards and paediatric departments. Departments are more complex structures, containing several units with different specialisations and facilities. For this study, we interviewed heads of both departments and units. A structured questionnaire, including 30 items, was submitted to the heads of 150 paediatric hospital departments across the country. Responses were obtained from 123 units; 10% of these had rooms dedicated to infectious diseases, and 4% had experts in infectious diseases available and routinely applied procedures for preventing the spreading of acute infectious diseases. Only 8% of departments have paediatric intensive care facilities. Few paediatric units, usually located in large children's hospitals or in academic paediatric departments, have a sufficient degree of preparedness to face severe influenza pandemics. A structural improvement of the paediatric units and the use specific procedures are essential for effectively care for children hospitalised because of contagious diseases.

Atomic force microscopy images suggest aggregation mechanism in cerato-platanin

Cerato-platanin (CP), the first member of the "cerato-platanin family", is a moderately hydrophobic protein produced by Ceratocystis fimbriata, the causal agent of a severe plant disease called "canker stain". The protein is localized in the cell wall of the fungus and it seems to be involved in the host-plane interaction and induces both cell necrosis and phytoalexin synthesis (one of the first plant defence-related events). Recently, it has been determined that CP, like other fungal surface protein, is able to self assemble in vitro. In this paper we characterize the aggregates of CP by Atomic Force Microscopy (AFM) images. We observe that CP tends to form early annular-shaped oligomers that seem to constitute the fundamental bricks of a hierarchical aggregation process, eventually resulting in large macrofibrillar assemblies. A simple model, based on the hypothesis that the aggregation is energetically favourable when the exposed surface is reduced, is compatible with the measured aggregates' shape and size. The proposed model can help to understand the mechanism by which CP and many other fungal surface proteins exert their effects.

Impact of prebiotics on human health

It is becoming clear that intestinal microflora plays an important role in the development of local and systemic immune response. Nutritional ingredients have been added to infant formula in an attempt to make its composition similar to that of human milk. The effects of these modifications have been observed in the composition of intestinal microflora. Prebiotics are non-digestible foods able to selectively stimulate the growth/activity of a limited number of colonic bacteria. A mixture of galacto-oligosaccharides and fructo-oligosaccharides (GOS/FOS) induces an increase in Bifidobacteria, similar to that of breast-fed infants. What is less clear is whether the modifications of intestinal microflora obtained by functional foods are associated with clinically measurable effects. Preliminary indirect data suggest that increasing the load of Bifidobacteria and Lactobacilli may protect from infections and allergies and this effect may persists beyond infancy. The emerging concept is that early nutritional intervention may be effective in modifying the intestinal microflora composition in a phase in which microbiological imprinting may drive immunological imprinting thereby producing clinical effects. Further investigations and well designed randomised clinical trials are needed to demonstrate the potential beneficial effects and to exclude the potential side effects.

Early treatment with ursodeoxycholic acid for cholestasis in children on parenteral nutrition because of primary intestinal failure

BACKGROUND

There is conflicting evidence as to whether ursodeoxycholic acid (UDCA) reduces the incidence of parenteral nutrition-associated cholestasis.

AIM

To investigate the efficacy of UDCA on parenteral nutrition-associated cholestasis in children with intestinal failure due to short bowel syndrome or to other causes.

METHODS

Children with cholestasis received 30 mg/kg/day UDCA. Improvement or normalization of parenteral nutrition-associated cholestasis was evaluated at 6 months of therapy and at the last follow-up. In a subgroup of children, serum UDCA levels were measured while receiving UDCA and after 4 weeks withdrawal.

RESULTS

Twelve children were treated with UDCA. Full remission or partial improvement of parenteral nutrition-associated cholestasis occurred in 11 of 12 children. In three of four children, withdrawal of UDCA was associated with a rebound rise of cholestasis. Only one of 12 treated children showed no improvement and in this patient, in contrast to four other patients, plasma levels of UDCA did not increase during treatment.

CONCLUSIONS

Ursodeoxycholic acid was effective in controlling parenteral nutrition-associated cholestasis. The efficacy of UDCA also in children with short bowel is related to intestinal absorption.

Refractive indices of Sn2P2S6 at visible and infrared wavelengths

We report on the refractive indices of Sn2P2S6 crystals in the wavelength range 550 - 2300 nm. The measurements are performed at room temperature using the minimum deviation method. The dispersion is described by a two oscillator model yielding the oscillator energies and strengths (Sellmeier parameters) for all polarization directions. The rotation of the indicatrix in the mirror plane and the direction of the optical axes have also been determined in the wavelength range lambda= 550-2200 nm.

Neospora caninum in pastured cattle: determination of climatic, environmental, farm management and individual animal risk factors using remote sensing and geographical information systems

A cross-sectional serological survey was conducted on cattle pasturing in an area of the southern Italian Apennines to evaluate the seroprevalence to Neospora caninum, and to investigate the climatic, environmental, farm management, and individual animal factors that influence the distribution of this protozoan. Blood samples were collected from 864 pastured cattle raised on 81 farms. Serum samples were tested for antibodies to N. caninum using an ELISA assay (HerdCheck), IDEXX). A geographical information system (GIS) for the study area was constructed using the following remote sensing (RS) and landscape feature data: autumn-winter, spring and summer normalized difference vegetation index (NDVI), land cover, elevation, slope, aspect, mean rainfall and minimum, mean, and maximum temperature in spring, summer, autumn and winter. Data on each of these features were then extracted for "buffer zones" consisting of the area included in a circle of 3 km diameter centered on the 81 geo-referenced centroids of the main cattle pastures. Climatic and environmental data obtained from RS and GIS and individual animal characteristics and farm management data obtained from a questionnaire were analyzed in relation to N. caninum seropositivity and antibody titres both by linear and logistic regression models. Out of the 81 farms sampled, 63 (77.8%) had at least one tested animal positive for N. caninum. Out of the 864 bovine sera samples, 266 (30.8%) were found to have antibodies to N. caninum. The results of the logistic regression model show that significantly high seroprevalence to N. caninum was found in heifers/steers and adults, in cattle raised on farms having a large number of dogs, and in cattle raised in buffer zones having high minimum temperatures in the spring, and a narrow extension of summer NDVI. In addition, positive linear correlations were found between N. caninum antibody titres and the number of dogs on farm, and the minimum temperature in spring. All the above determined risk factors for N. caninum seroprevalence indicate that horizontal infection resulting from the ingestion of oocysts shed by dogs is the most probable route of N. caninum infection in pastured cattle of the southern Italian Apennines.

Intestinal inflammation is a frequent feature of cystic fibrosis and is reduced by probiotic administration

AIMS

To assess the incidence of intestinal inflammation in children with cystic fibrosis and to investigate whether probiotics decrease it.

STUDY DESIGN

In this two-phase, controlled, prospective study, faecal calprotectin was measured by enzyme-linked immunosorbent assay in 30 children with cystic fibrosis, 30 healthy controls and 15 children with active inflammatory bowel disease. Ten children with cystic fibrosis received Lactobacillus GG, and faecal calprotectin was re-measured 4 weeks later. Rectal nitric oxide production was measured with the rectal dialysis bag technique in 20 children with cystic fibrosis, 20 healthy controls and 15 children with inflammatory bowel disease. Five children with cystic fibrosis received Lactobacillus GG and nitric oxide was re-measured 4 weeks later.

RESULTS

Mean faecal calprotectin was significantly higher in the two groups of patients than in controls. Abnormal values were detected in 27 of 30 cystic fibrosis and in 15 of 15 inflammatory bowel disease children. Also mean nitric oxide production was increased in both group of patients, and abnormal values were detected in 19 of 20 cystic fibrosis and in 15 of 15 inflammatory bowel disease children. Calprotectin and nitric oxide concentrations were reduced after probiotics administration.

CONCLUSIONS

Intestinal inflammation is a major feature of cystic fibrosis and is reduced by probiotics. The latter finding suggests that intestinal microflora play a major role in intestinal inflammation in cystic fibrosis children.

Oral rehydration solution containing a mixture of non-digestible carbohydrates in the treatment of acute diarrhea: a multicenter randomized placebo controlled study on behalf of the ESPGHAN working group on intestinal infections

OBJECTIVE

A randomized, double-blind, placebo-controlled multicenter study to evaluate efficacy and safety of a mixture of non-digestible carbohydrates (NDC) as an adjunct to oral rehydration therapy in treatment of acute infectious diarrhea in children with mild to moderate dehydration.

METHODS

144 boys aged 1 to 36 months with diarrhea defined as three or more watery stools per day for >1 day but <5 days with mild or moderate dehydration (World Health Organization criteria) were randomly assigned to receive hypotonic oral rehydration solution (ORS) (Na 60 mmol/L, glucose 111 mmol/L) with or without a mixture of NDC (soy polysaccharide 25%, alpha-cellulose 9%, gum arabic 19%, fructooligosaccharides 18.5%, inulin 21.5%, resistant starch 7%).

RESULTS

Intention-to-treat analysis did not show significant differences in mean 48 hour stool volume (ESPGHAN-ORS with NDC versus ESPGHAN-ORS, 140 +/- 124 g/kg versus 143 +/- 114 g/kg; P = 0.41). Duration of diarrhea after randomization was similar in both groups (82 +/- 39 hours versus 97 +/- 76 hours, P = 0.24). There were no significant differences in the duration of hospital stay (111 +/- 44 hours versus 126 +/- 78 hours; P = 0.3). Unscheduled intravenous rehydration was similar in both groups (21.4% versus 16.2%, P = 0.42).

CONCLUSION

In boys with acute non-cholera diarrhea with mild to moderate dehydration a mixture of non-digestible carbohydrates was ineffective as an adjunct to oral rehydration therapy.

[Canine leishmaniasis in Campania: new and old foci]

Canine Leishmaniasis (CanL) is endemic in Campania Region (Italy) and is strictly related to Human Visceral Leishmaniasis. Past and present reports of the prevalence in the Region show that exist places were CanL has been known for a century (Vesuvius and Ischia Foci) and other localities where the disease appears to be recent (Caserta and Salerno provinces); moreover, the zoonosis is seen not only in endemic foci (autochthonous), but also in non-endemic areas (imported cases), for example in the Benevento and Avellino provinces. Two zymodemes have been identified in human and canine population and also in sandflies: MON 1 and MON 72. Endemic or stable CanL foci correspond with Vesuvius Area, Ischia island, Maddaloni and neighbouring Commons, other foci in the Salerno province. These foci are associated with optimal ecological condition, abundance of reservoirs and hosts, abundance of phlebotomine vectors, prevalence in canine population around 10-40%, incidence in canine population 5%, risk for human population 0.002%. Instable foci occur at the border of the stable foci: they may be the result of changes in climate with the occasional introduction of infected dogs in the areas; in the foci are registered low presence of phlebotomine vectors, prevalence around 0.5-3%, sporadic human cases. Today, in Campania region CanL undoubtedly has an increased incidence and a wider geographic distribution than before: new cases are now reported in areas that were previously non-endemic. Ecological, demographic and environmental changes, large population movements, urbanization have led to an increased incidence and to importation into suburbs with high densities of people and sand-flies. These changes include "global warming", increased number of stray dogs, dogs and population movements, changes in human population (increased number of immune-depressed and old people). Nowadays, the most important focus of CanL and Human Visceral Leishmaniasis of the Mediterranean area is located in Campania Region: during the year 2000, 143 cases of Human Visceral Leishmaniasis have been recorded in Italy, an half of them (83 cases) in Campania region.

Adherence to antiretroviral therapy and its determinants in children with human immunodeficiency virus infection: a multicentre, national study

AIM

To investigate rates and determinants of adherence to antiretroviral therapy in Italian children infected with the human immunodeficiency virus (HIV).

METHODS

An observational, cross-sectional multicentre study was performed through a structured interview with the caregivers of HIV-infected children. The interview included quantitative information on adherence in the 4 d before interview. Sociodemographic, clinical and psychosocial characteristics of children were recorded.

RESULTS

129 children (median age 96 mo) were enrolled, of whom 94 were on highly active antiretroviral therapy (HAART). Twenty-one (16%) omitted more than 5% of total doses in 4 d and were considered non-adherent. However, only 11% of caregivers reported that therapy had been administered at the correct times. No significant difference was found between age and the stage of HIV infection. Children aware of their HIV status were less adherent. Individual drugs showed a broad adherence pattern and children who received HAART were more adherent. Children receiving therapy from foster parents were more adherent than those receiving drugs from biological parents or relatives.

CONCLUSIONS

Adherence is a major problem in children. Psychological rather than clinical or sociodemographic features and types of drug are major determinants of adherence.

Short duration of breastfeeding and early introduction of cow's milk as a result of mothers' low level of education

Inappropriate infant feeding including a lack of breastfeeding and the early introduction of cow's milk are the most common forms of infant feeding malpractice. To evaluate the hypothesis that infant feeding malpractices are associated with mothers' low level of education, questionnaires were administered to 400 mothers of infants below 12 mo of age divided into 3 groups according to their various educational levels. Items included the type of milk given at birth and at 1, 3 and 6 mo of age. To investigate the efficacy of paediatricians in orienting infant feeding, the same questionnaire was given to 30 paediatricians in primary paediatric healthcare, in hospitals or in private practices. Initiation of breastfeeding was similar in the three groups. An analysis of the data showed that an increasing number of infants born to mothers of low and intermediate educational level did not receive exclusive breastfeeding compared with those with a higher level of education, a difference that was significant as early as 1 mo of age. In infants aged 3 mo, the prevalence of exclusive breastfeeding was 37%, 40% and 65% in the three groups, respectively, in relation to progressively increasing levels of education. In infants of 6 mo, the respective prevalence rates were 13%, 15% and 48%. Early introduction of cow's milk showed a similar correlation with educational level. A greater number of infants born to mothers with a low level of education received cow's milk at 3 mo of age compared with those born to mothers with an intermediate education (12% vs 5%). A similar difference was observed between the latter group and infants born to mothers with a high educational level (0%). This pattern was supported by data for infants at 6 mo of age with prevalence rates for cow's milk feeding of 39%, 20% and 0% in the three groups in association with progressively increasing level of educational (p < 0.05). The analysis of the paediatricians' response to the questionnaire showed that while physicians know and correctly prescribe age-related infant nutrition regimens, they are unaware that a substantial number of mothers do not comply with what they prescribe. Overall, these data support the relationship between a low educational level and infant feeding malpractice and suggest that a more effective role should be played by paediatricians in supporting an adequate duration of breastfeeding and the use of formula rather than cow's milk protein.

Vascular prosthetic graft infection: epidemiology, bacteriology, pathogenesis and treatment

Vascular prosthetic graft infection remains a major surgical challenge. Prevention of risk factors and antibiotic therapy can reduced but not eradicate it. Management of infected vascular grafts depends on several factors, including the location of the infected prosthesis, the extent of infection, and the underlying micro-organism. Classic treatment consists of extra-anatomic bypass grafting. The disappointing results due to the high mortality and amputation rate have kindled interest in alternative approaches, such as in situ reconstruction with antibiotic-bonded prostheses, autogenous veins or arterial allografts.

PURPOSE

We focused on the treatment of aortic graft infection by means of both fresh and cryopreserved arterial allograft. Here, the experience of the Italian Collaborative Vascular Homograft Group is reported.

METHODS

Between March 1994 and December 2000 seventy-nine patients with aortic graft infection were treated. The results of 68 patients are analysed. Eleven patients were treated with fresh, and 57 with cryopreserved homograft. Emergency surgical procedures were performed in 12 patients (17%). Aortoenteric fistula was diagnosed in 22 patients. The mean interval between the first procedure and the insertion of a homograft for patients with infected aortic graft was 3 years (range 1-15). The mean duration of follow-up was 30 months (range 1-68). Clinical and duplex scanning evaluation were routinely performed. Computer tomography (CT), magnetic resonance (MR), or arteriography were performed on the basis of duplex scanning results.

RESULTS

The analysis was performed on 68 cases for which there were sufficient reliable data. Eleven deaths occurred during the early postoperative period (30 days), a mortality rate of 16%. There were also seventeen late deaths, a mortality rate of 25%. Eleven patients had graft occlusion; six cases were successfully treated with thrombectomy. In three cases leg amputation was necessary. The results of fresh and cryopreserved homografts were compared. No significant differences of early postoperative mortality, late mortality, homograft-related mortality, graft failure were observed. The presence of aortoenteric fistula is a negative predicting factor of perioperative early mortality, which causes a rapid decline in the survival curve. Thirty-six months after the surgery the actuarial survival of the patients was 57% and the actuarial patency of the allograft was 41%.

CONCLUSION

No significant difference in terms of clinical outcome was observed when using fresh, rather than cryopreserved homografts. The only factor that significantly influenced the survival rate appeared to be the aorto-enteric fistula.

Efficacy of oral pancreatic enzyme therapy for the treatment of fat malabsorption in HIV-infected patients

BACKGROUND

Nutrient malabsorption is a negative prognostic factor in acquired immunodeficiency syndrome and recent studies have shown that pancreatic insufficiency is a codetermining factor of malabsorption.

AIMS

To evaluate the effectiveness of open-label oral pancreatic enzyme supplementation therapy in acquired immunodeficiency syndrome patients with fat malabsorption.

PATIENTS AND METHODS

Twenty-four consecutive patients with human immunodeficiency virus infection and fat malabsorption were recruited (11 males, 13 females; median age, 9.1 years). Faecal fat loss was evaluated by steatocrit assay at entry to the study (T-0), after 2 weeks (T-1) without pancreatic enzyme treatment and after a further 2 weeks (T-2) of treatment with pancreatic extracts (Creon 10 000 at a dose of 1000 units of lipase per gram of ingested dietary fat). Faecal elastase-1 and chymotrypsin were assayed at entry.

RESULTS

Six patients (25%) had abnormally low elastase-1 and/or chymotrypsin faecal concentration. In all patients, steatocrit values were elevated at both T-0 and T-1. Five patients proved intolerant to pancreatic enzyme treatment because of the onset of abdominal pain, and therapy was discontinued. In the 19 patients who concluded the study, steatocrit values during pancreatic enzyme treatment (T-2) were significantly lower than at entry (P < 0.0001). At T-2, in eight of 19 patients, steatocrit values were within the normal limit and the frequency of cases cured or improved on pancreatic enzyme therapy (at T-2) was significantly higher than that observed during the previous study period without enzyme treatment (T-1) (P < 0.01). A positive significant correlation was found between steatocrit values at entry and the Centers for Disease Control class (P < 0.0005); also, the decrease in steatocrit values during pancreatic enzyme therapy (difference between steatocrit value at T-2 and steatocrit value at T-0) positively correlated with the Centers for Disease Control class (P < 0.05).

CONCLUSIONS

This pilot, open-label study showed that pancreatic enzyme supplementation therapy is highly effective in reducing faecal fat loss in human immunodeficiency virus-infected patients with nutrient malabsorption. Further double-blind studies must be undertaken to verify these results and, if they are confirmed, pancreatic enzymes can be added to our weapons in the fight against human immunodeficiency virus-associated nutrient malabsorption.

Glenoid hypoplasia. Description of a clinical case and analysis of the literature

Glenoid hypoplasia, or dysplasia of the scapular neck, is a relatively rare alteration that in most cases involves the pectoral girdle in a bilateral and symmetrical manner. In general, glenoid hypoplasia is associated with skeletal changes such as hypoplasia of the humeral head, or changes in the morphology of the acromion and of the coracoid. The authors describe a case of unilateral glenoid hypoplasia, which was symptomatic for a few years, reporting the clinical-radiographic findings and based on the data published in the literature reporting how this disease, which often goes unrecognized, is much more frequent than is imagined.

Colonocyte basolateral membranes contain Escherichia coli heat-stable enterotoxin receptors

Heat-stable enterotoxin (ST(a)) elaborated by E. coli is a major cause of diarrhea. The transmembrane protein guanylyl cyclase C (GC-C) is the acknowledged receptor for ST(a) and for the mammalian peptides guanylin and uroguanylin. Binding to GC-C results in generation of cGMP, activation of type II cGMP-dependent protein kinase, phosphorylation of CFTR and increased chloride and bicarbonate secretion. We had previously shown that ST(a) receptors (GC-C) are found on the brush border membranes of small intestinal enterocytes and of colonocytes. However, since it has subsequently been shown that the endogenous ligands for these receptors, guanylin and uroguanylin, circulate in blood, we proposed the existence of ST(a) binding sites on the basolateral membranes (BLM) of colonocytes. Specific binding of 125I-ST(a) to rat colonocyte BLM was seen. The kinetics of binding to the BLM were similar to binding to BBM. The nature of the BLM receptor is unknown. This suggests that circulating guanylin and uroguanylin, analogues of ST(a), may also function via the basolateral surface.

Which place for bismuth subsalicylate in the treatment of enteric infections?

ORS has led to improved outcome of acute gastroenteritis in both industrialised and developing countries. In both settings there is an increasing demand for active therapy to reduce the duration of diarrhoea and its complications. Persistent diarrhoea is a major consequence of intestinal infections and is responsible for a high number of deaths in poor countries. Bismuth subsalicylate has been used for treatment of acute diarrhoea, with preliminary promising results. In this issue of Acta Paediatrica, a trial with BSS is essential. However the results were marginal and did not justify a mass scale use of BSS, also because of poor cost efficacy rate.

[Banks of vascular homografts]

We define as Banking of the tissues all the procedures that include the finding, preparation, conservation and distribution of the homograft. The vascular homografts are taken and put into a solution of transportation at +4 degrees C and kept at this temperature till their arrival at the Bank. The following step is the dissection of the homograft which will have to be performed as quickly as possible at most 24 hours after the taking in conditions of maximum sterility. At the Italian Homograft Bank at Centro Cardiologico, the vascular homografts are kept at +4 degrees C for 96 hours on average with antibiotics. After a phase of sterilization at +4 degrees C the tissue is frozen according to a homogeneous and controlled thermic decrease and stored at -150 degrees C/-180 degrees C in fumes of liquid nitrogen till the moment of their employment allowing a long term conservation. The aim of all these procedures of cryopreservation is to keep the structural and functional integrity of cells and tissues. The thermic decrease of the tissues must occur so that to avoid all the damages of the cellular vitality and functionality and especially of the tissue structure in toto. In order to limitate these events some cryoprotector agents are employed because they reduce the concentration of the solutes, the cellular dehydration, the formation of micro-macro crystals. Another step to establish if the homograft is proper is the study of bacteriological and viral aspects. The viral screenings are performed on the donor's blood and the bacteriological tests are performed on the tissue and on the liquids. For each phase of the banking a series of information about the donor and about the tissues are recorded and filed both on paper and database so that to grant always a right conduct of the material.

Smectite in the treatment of acute diarrhea: a nationwide randomized controlled study of the Italian Society of Pediatric Gastroenterology and Hepatology (SIGEP) in collaboration with primary care pediatricians. SIGEP Study Group for Smectite in Acute Diarrhea

BACKGROUND

Childhood gastroenteritis is associated with considerable health costs. The natural clay dioctahedral smectite increases intestinal barrier function and is effective against infectious diarrhea in children in developing countries. The purpose of this work was to investigate the efficacy of smectite in Italian children with acute diarrhea of mild to moderate severity.

METHODS

A national, prospective, randomized, case-controlled study was performed in collaboration with primary care pediatricians. Children seen by pediatricians for acute gastroenteritis were treated with oral rehydration solution (ORS) alone or ORS with smectite. Parents returned a form in which total duration of diarrhea, incidence of vomiting and fever, persistence of diarrhea for more than 7 days and hospital admissions were recorded.

RESULTS

Eight hundred four children with acute diarrhea were randomly assigned to treated or control groups. Administration of smectite was associated with significant reduction of the duration of diarrhea, as judged by stool frequency and consistency. The incidence and duration of vomiting and fever were not different. Diarrhea lasted more than 7 days in 10% of treated and in 18% of control children (P < 0.01). Hospital admission was necessary in seven treated and six control children. No side effects were observed.

CONCLUSIONS

Smectite reduces the duration of diarrhea and prevents a prolonged course. It may therefore consistently reduce the costs of gastroenteritis.

["Difficult" venous ulcers of the legs]

The aim of the study was to analyze the diagnostic and surgical criteria in cases of "critical" venous leg ulcers. This report describes the management of 200 patients with trophic lesions of the lower limbs. Patients with venous leg ulcers were identified with the aid of ultrasonography and echocolor Doppler. Among these patients, according to the chronic evolution of the lesions, we identified all those with critical venous leg ulcers. The management of the lesions involved both medical and fairly aggressive surgical treatment with the use of general anaesthesia and deep surgical toilette of the ulcer. In the cases with poor epithelialisation we adopted oxygen therapy and skin grafts using the "mesh graft" technique. Critical venous leg ulcers were identified in 23 patients (19%). After surgical treatment, we observed complete epithelialisation of the lesion only in 5 cases (21.7%). In 13 patients (56.6%) the use of oxygen therapy was necessary and epithelialisation occurred on postoperative day 12. Skin grafts were used in 5 cases (21.7%). Only one recurrence was observed one year after operation in an area adjacent to the site of the graft. The "golden goal" of critical venous leg ulcer management is to establish a correct aetiological diagnosis, distinguishing between venous leg ulcers and other trophic lesions of the lower limbs. The medical and surgical treatment described in this report reduce healing time and the social costs of the disease, without any significant complications for the patient.

Structural and functional features of modified heat-stable toxins produced by enteropathogenic Klebsiella cells

Heat-stable enterotoxins (STs) are 18- or 19-amino acid peptides (STa or ST1) produced by enteropathogenic bacteria with small differences in their amino acid sequence and a highly conserved carboxy terminus. All STs contain a core of three disulfide bridges whose integrity is believed to be necessary for full biologic activity. We previously reported that strains of Klebsiella pneumoniae transformed by the plasmid pSLM004 produce a modified toxin not recognized by MAb raised against genuine Escherichia coli ST. Investigation of the chemical structure of the modified toxins revealed that three new toxins were present. These were purified to homogeneity by a series of sequential chromatography on reverse-phase columns using guanylate cyclase to monitor the enterotoxic activity during purification procedures. The sequence of the modified toxins was obtained by a combination of Edman degradation and mass spectrometry, showing that they are proteolytically processed forms of E. coli ST1b. In particular, toxin A-2 lacks the cysteine at position 18 and then is not able to form the disulfide bridge cysteine-10-cysteine-18. All three toxins showed the ability to stimulate guanylate cyclase and to elicit chloride secretion in Caco-2 cell monolayers mounted in Ussing chambers. Toxin A-1 and toxin B demonstrated greatly reduced immunoreactivity whereas toxin A-2 was not recognized at all in the ELISA. It is likely that the three modified toxins were generated by Klebsiella specific proteolytic processing of the original pretoxin. These results have important implications for the diagnosis and prevention of heat-stable toxin-induced diarrhea.

Experimental tracheal transplantation using a cryopreserved aortic allograft

BACKGROUND

The tracheal reconstruction after wide resections remains a critical surgical problem. Our aim was to replace trachea with a tissue easy to vascularize, which allows a simple reconstruction and does not require an immunosuppressive regimen.

MATERIALS AND METHODS

A segment of cryopreserved aorta was used in order to verify its adequacy as tracheal substitute. In phase 1, the thoracic aorta of 10 rabbits was excised, obtaining 20 segments that were cryopreserved. Ten segments were implanted in the omentum of 10 rabbits that were sacrificed on postoperative days 7, 14 and 21, and the grafts were examined histologically. In phase 2, a segment of cryopreserved aorta arranged with a silicone prosthesis was transplanted in 10 rabbits and wrapped with omentum. The animals were sacrificed on postoperative days 7, 14 and 21.

RESULTS

In phase 1, the neovascularization of the grafts was present after 7 days, and after 14 days the fibroblasts invaded the lumen of the aorta. In phase 2, 8 rabbits survived and the histologic examination after 7, 14 and 21 days showed neovascularization, the absence of rejection and the proliferation of fibroblasts inside the lumen of the aorta; this growth has been restrained by an endoluminal prosthesis.

CONCLUSIONS

Our study demonstrated that replacing the trachea with cryopreserved aorta is technically feasible and does not evoke immunologic reactions. It requires, however, a silicone tube inside the allograft to limit the colonization of fibroblasts.