Installing tungsten Fischer carbene complexes into a calixarene framework

The first examples of calix[4]arene-based Fischer carbene complexes are here reported. The organometallic calixarene complexes showed a promising cytotoxicity towards human tumor cell lines.

Selective immunoglobulin A deficiency and celiac disease: let's give serology a chance

Patients with selective immunoglobulin (Ig) A deficiency have a 10- to 20-fold increased risk of celiac disease. In these patients, serological diagnosis of celiac disease can be difficult, since specific IgA-based assays are usually negative and IgG-specific antibody tests are insufficiently reliable. We describe a girl with selective IgA deficiency who had a troublesome diagnosis of celiac disease that was established only after an unexpected positive test result for antitransglutaminase IgA and antiendomysium IgA. Our observation indicates that IgA-based serology should not be forgotten in patients with selective IgA deficiency, since positive results for antitransglutaminase IgA, antiendomysium IgA, or both can be observed at any time during diagnostic investigations.

Celiac disease and obesity: need for nutritional follow-up after diagnosis

More than 20 years of serological approach to diagnosis of celiac disease (CD) has deeply changed the classical clinical presentation of the disease, and some reports indicate that CD and obesity can coexist in both childhood and adolescence. We reviewed clinical records of 149 children with CD followed in our institution between 1991 and 2007, considering weight, height and body mass index (BMI), both at diagnosis and after at least 12 months of gluten-free diet (GFD). In all, 11% of patients had BMI z-score >+1 and 3% were obese (z-score >+2) at presentation. In our population, there was a significant (P=0.008) increase in BMI z-score after GFD and the percentage of overweight (z-score >+1) subjects almost doubled (11 vs 21%, P=0.03). Our data suggest the need for a careful follow-up of nutritional status after diagnosis of CD, especially addressing those who are already overweight at presentation.

Early diagnosis and treatment of celiac disease in type 1 diabetes. A longitudinal, case-control study

OBJECTIVES

Subjects with type 1 diabetes mellitus (DM) are at increased risk to develop celiac disease (CD). However, most of the published investigations on the association between type 1 DM and CD are cross-sectional ones. In this paper, longitudinal data are presented on the effects of gluten-free diet (GFD) on growth and metabolic control in children and adolescents with type 1 DM screened for CD.

METHODS

Clinical records of 27 patients with type 1 DM+CD (7% of a population of 385 subjects with type 1 DM) were reviewed. The following variables were considered at the diagnosis of CD (T0) and after 24 (T24) and 48 (T48) months of GFD according to the length of available follow-up: weight, height, body mass index (BMI), Hb and HbA1c levels and per kg/day dose of insulin. Forty-three patients with type 1 DM alone, matched for sex, age and duration of diabetes were chosen as controls.

RESULTS

In patients with type 1 DM+CD, mean (SD) age at type 1 DM diagnosis was 8 (3.3) years. Median time interval between diagnosis of type 1 DM and of CD was 1.8 years (range 0.1-23.9 years). At T0 (n = 23), height and BMI z-score, HbA1c levels and daily insulin dose were comparable in type 1 DM+CD and in control subjects. Mean Hb concentration was significantly lower in subjects with type 1 DM+CD (12.6 (1.3) vs. 13.3 (0.7) g/dl, p < 0.05). At T24 (n = 22) and T48 (n = 16), no difference was detectable in height, BMI, HbAlc and insulin dose and also Hb concentration was comparable in both groups.

CONCLUSIONS

This study shows that, at diagnosis of CD, screened subjects with type 1 DM had only minor signs of malnutrition and metabolic disturbances were uncommon. Dietary treatment of CD can allow a growth and diabetes control comparable with subjects with diabetes alone.

Screening of coeliac disease in north Italian children with type 1 diabetes: limited usefulness of HLA-DQ typing

AIM

To determine the contribution of HLA-DQA1* and HLA-DQB1* genes to the risk of coeliac disease (CD) in a cohort of children with type 1 diabetes mellitus (T1DM) from northern Italy.

METHODS

Three hundred and fifty-seven children with T1DM, attending the Childhood Diabetes Unit of the University of Verona, have been regularly tested for serum IgA endomysial antibodies (EMA). All patients with positive EMA underwent small bowel biopsy to confirm the diagnosis of CD. HLA typing was performed in subjects with T1DM and CD, and in a control group of 79 EMA-negative patients with T1DM.

RESULTS

Of the 357 patients tested, 25 (7%) had CD. The frequency of HLA-DQA1*0501-DQB1*0201 (T1DM + CD 68% vs T1DM 62%) and of DQA1*0301-DQB1*0302 (T1DM + CD 40% vs T1DM 35%) haplotypes, between T1DM patients with and without CD, was statistically comparable. A trend towards a reduction of the risk of CD (p = 0.055, OR: 0.22, CI 0.05: 1.04) was observed in patients with T1DM (28% vs T1DM + CD 2%) who did not carry either the HLA-DQA1*0501-DQB1*0201 or the DQA1*0301-DQB1*0302 haplotype.

CONCLUSION

A high prevalence of HLA-DQA1* and -DQB1* susceptibility haplotypes for CD was observed both in EMA-negative diabetics and in those with associated CD. The implementation of screening programmes of CD in a T1DM population, based on the identification of HLA susceptibility haplotypes, seems to be of limited usefulness. Serial serologic screening of diabetic patients remains the advisable strategy.

[Feeding neurologically disabled children with dysphagia: the role for gastrostomy]

INTRODUCTION

Undernutrition and growth retardation are often observed in children with severe neurological disabilities. Our experience of feeding gastrostomy in children and adolescents with central nervous system (CNS) disease and dysphagia is reported.

PATIENTS AND METHODS

A gastrostomy feeding tube was placed in 11 children who had severe impairment of swallowing and clinically evident food aspiration. Percutaneous endoscopic technique was preferred, unless operative placement was suggested by unfavourable anatomical conditions or concomitant abdominal surgery. Commercial formulas or natural food were used at home and the children were regularly followed-up at the outpatient clinic.

RESULTS

Median age at the gastrostomy placement and median follow-up lenght were 5.9 years (range 1.8-16.7 years) and 15 months (3-66 months) respectively. Four of 11 patients had moderate (weight/height (W/H) ratio = 80%) and 3 severe (W/H ratio < 70%) malnutrition. Ten of 11 subject were exclusively gastrostomy fed. After 3 months of enteral nutrition a weight gain was observed in all patients as well as a significant increase of mean W/H ratio (81.2% vs. 87.2%, p = .002). Nutritional improvement was confirmed at follow-up, despite caloric intakes lower (< 50%) than recommended for age and weight. Micronutrients and vitamins were supplemented on the basis of calculated intakes.

CONCLUSIONS

In children with severe CNS disease and dysphagia, long-term gastrostomy feeding is a safe and useful method that allows adequate nutritional and micronutrient intakes and prevents the risk of dystrophy.

[Primary ad secondary gastro-esophageal reflux in pediatric age]

AIM

This study takes into consideration children traited for: a) "primary" gastro-esophageal reflux (GER); b) GER "secondary" to delayed gastric emptying; c) some congenital anomalies which can cause or favour GER in pediatric age.

METHODS

During 2002, 21 infants or children operated on for "primary" or "secondary" GER and 62 patients operated on for esophageal atresia, diaphragmatic hernia or abdominal wall defect were followed-up to evaluate the frequency and the course of post-operative GER.

RESULTS

Patients with "primary" GER had 14% relapses after partial or total fundoplication; all patients with "secondary" GER submitted to fundoplication, usually associated to pyloroplasty, had 0% relapses. One child, after Bianchi's operation, developed an erosive gastritis. Variable degrees of GER developed in 43% of patients operated on for esophageal atresia, in 25% for congenital diaphragmatic hernia and in 0% for abdominal wall defect. In 90% of GER occurred after treatment of esophageal atresia and in 100% of diaphragmatic hernia (predominantely "acquired") an exclusively medical therapy was successfully performed.

CONCLUSION

The conclusion is drawn that: a) the relatively high percentage of relapses after fundoplication in "primary" GER may be related to an incorrect classification of a few number of cases ("secondary" GER considered--and treated--like "primary" GER in the '70s and '80s years?); b) fundoplication associated to a best gastric-emptying operation (pyloroplasty) may lead to excellent results in secondary GER; c) esophageal atresia and congenital diaphragmatic hernia (not including the abdominal wall defects) can cause GER in most cases responsive to simple medical therapy.

Gluten sensitivity and 'normal' histology: is the intestinal mucosa really normal?

BACKGROUND

Early pathogenetic events of gluten intolerance may be overlooked in patients with serologic markers of celiac disease and normal intestinal mucosa by both conventional histology and immunohistochemistry.

AIMS

To investigate if a submicroscopical damage of the absorptive cell surface was associated with developing gluten sensitivity.

PATIENTS AND METHODS

Duodenal biopsies of seven subjects with positive anti-endomysial antibodies and normal histology underwent ultrastructural evaluation of the epithelial surface by means of both scanning and transmission electron microscopy. Specimens of intestinal mucosa of 14 children with non-celiac conditions were used as controls.

RESULTS

In four patients, electron microscopy revealed alterations of the enterocyte brush border with a significant reduction of the height of microvilli. After several months, three of them had a second biopsy that eventually showed histological modifications suggestive of celiac disease. In the other three patients, no significant alteration of enterocyte ultrastructure was observed. One of them, rebiopsied after 12 months, still showed a normal duodenal histology.

CONCLUSIONS

Gluten sensitivity can be associated with 'minimal' mucosal changes not detectable with conventional light microscopy. Such lesions, which primarily involve microvillous structure, may imply a reduction of intestinal absorptive surface already in the latent stage of the disease.

[Percutaneous endoscopic gastrostomy in children with ventriculoperitoneal shunt]

The complications of percutaneous endoscopic gastrostomy (PEG) placement or replacement or of home management of gastrostomy, must be taken in account in patients with hydrocephalus and ventriculoperitoneal shunt. In this report we describe four children with spastic quadriplegia and ventriculoperitoneal shunt who had a median follow-up of 15 months (range 4-32 months) after PEG placement. Intravenous antibiotic prophylaxis was always used during routine procedures and no shunt infection was observed. In a patient, during accidental PEG dislodgement, peritoneal infection developed that required temporary diversion of the catheter. A second dislodgement, in the same individual, determined a large amount of serous peritoneal fluid that needed to be evacuated but no shunt infection or malfunction. In nobody of our patients, the shunt, located in the upper left abdomen, interfered with gastrostomy placement. Our experience confirms that PEG is not contraindicated in patients with ventriculoperitoneal shunt, provided that the risks of catheter infection are known and prevented.

[Latent celiac disease in subjects with serum anti-endomysial antibodies and normal intestinal biopsy]

OBJECTIVES

Data on the follow-up of a group of subjects with serum antiendomysial antibodies (EMA) and normal mucosal architecture at the intestinal biopsy are reported. Clinical problems concerning possible evolution of potential celiac disease (CD) towards gluten-induced histological damage are discussed.

METHODS

Eleven patients belonging to high-risk groups for CD (5 with type-1 diabetes, 2 with familiarity for CD and 4 with symptoms suggesting CD) who had a normal intestinal biopsy, despite positive antiendomysial test, were followed-up. Antigliadin and antitransglutaminase antibodies (anti-tTG) and HLA genotyping were also assessed. According to clinical and serological data a second biopsy was performed in six of them.

RESULTS

At the time of the first normal biopsy, all patients were positive for EMA and 5/8 for anti-tTG. Five of 6 subjects genotyped were HLA-DQ2+ or DQ8+. Six patients were rebiopsed after 1 to 4 years. Three had mucosal atrophy, 1 had mild increase of intraepithelial lymphocytes and 2 were morphologically normal.

CONCLUSIONS

Subjects with antiendomysial antibodies and normal intestinal biopsy deserve clinical and serological follow-up to reduce the time of possible latency of CD. Although good predictors of progression of the disease are not still available, antiendomysial antibodies assessment and HLA genotyping may help to suggest individuals at higher risk to develop gluten-induced enteropathy. This study confirms that subjects with persistent signs of gluten sensitivity and normal biopsy should be re-examined.

Measurement of NADPH oxidase activity in detergent lysates of human and mouse macrophage monolayers

An assay to measure NADPH oxidase activity in detergent lysates of macrophage monolayers is described. The addition of a reaction mixture containing appropriate concentrations of disrupting detergents, NADPH as oxidase substrate and cytochrome c as electron acceptor, to macrophages monolayers permits the reliable detection of a superoxide dismutase-sensitive NADPH-dependent cytochrome c reductive activity. This activity is strictly substrate dependent and NADH could not substitute for NADPH. The NADPH-dependent superoxide anion-forming activity (NADPH oxidase) was investigated in different populations of human and mouse macrophages. NADPH oxidase was activated by stimulation of macrophages with phorbol-myristate acetate and activity levels correlated with ability of intact cells to produce superoxide anion. The optimal conditions for assay of NADPH oxidase were investigated and the assay was used to measure the kinetic properties of the NADPH oxidase. The assay permits investigations of the enzymatic basis of oxidative metabolism in macrophages cultivated as adherent cells without any requirements for recovery of the cells in suspension and subcellular fractionation.