A NEW CLASS OF THIN FILM HYDROGELS PRODUCED BY PLASMA POLYMERIZATION.

A simple, direct route to preparation of surface immobilized hydrogel films is described. Specifically, low pressure RF pulsed plasma polymerization of 1-amino-2-propanol and 2-(ethylamino)ethanol monomers produced thin hydrogel films deposited on substrates located in the plasma reactor. The successful syntheses were carried out under plasma conditions which not only yield the hydrogel but are also sufficiently energetic to produce films strongly grafted to the substrates. The polymer films obtained exhibit the thermoresponsive property of hydrogels, as shown by film color change with temperature. Additional evidence for the phase transition properties of these films was obtained using water contact angle and capillary rise measurements. The plasma polymerization approach provides an unusually simple route to synthesis of hydrogels in which the films are pin-hole free and are of easily controlled thickness. An important added advantage, particularly for applications involving biomaterials, is the conformal property of the plasma generated polymer films. The results obtained suggest that this approach should be applicable to a variety of other monomers and, based on differences observed with the present two monomers, suggest synthesis of films which exhibit a range of phase transition temperatures.

Does splenectomy in cystic fibrosis related liver disease improve lung function and nutritional status? A case series.

AIMS: To review the effect of total splenectomy on lung function and nutrition in children with cystic fibrosis related liver disease (CFLD) and associated portal hypertension. The stated indications for surgery and the short and long term risks of the procedure were also documented. METHOD: Over a 25 year period from January 1980 to June 2005, approximately 650 patients with cystic fibrosis (CF) were treated at the Royal Children's Hospital, Melbourne, Australia. Nine patients with CFLD who underwent a splenectomy during that time were identified and their medical records were reviewed. RESULTS: FEV1% predicted dropped by -16+/-11% in the two years pre-splenectomy. This contrasts with the increase in FEV1% predicted of 2+/-16% in the two years post-splenectomy (p = 0.05). The cumulative gain in WAZ score (DeltaWAZ pre) over the two years prior to splenectomy of 0.045+/-0.69 was not significantly different from the cumulative gain in WAZ score (DeltaWAZ post) for the two years after splenectomy of 0.15+/-0.36 (p = 0.65). The average age at splenectomy was 14.8 years (SD = 3 years). The average weight of an excised spleen was 983 g (SD = 414 g). There were no deaths associated with splenectomy. The median length of follow up post-splenectomy was 6.0 years (range 0.7-15.8). There were no episodes of bacterial peritonitis or overwhelming sepsis. CONCLUSIONS: Splenectomy may have a beneficial effect on lung function although this may not manifest itself until the second year post-splenectomy. Splenectomy in patients with CFLD appears to be a safe procedure.

Association of body composition and lung function in children with cystic fibrosis.

Survival in cystic fibrosis has improved significantly in the last 30 years, with major therapeutic goals of delaying the progressive loss of pulmonary function and maintaining normal growth. Dual-energy X-ray absorptiometry (DEXA) was performed in children with cystic fibrosis (CF) to assess both bone mineral density and body composition. We hypothesised that there would be an association between body composition and pulmonary function in children with CF. Fifty subjects with CF (28 males), mean age 12.7 years, participated in the study. Body composition was determined by DEXA. Body mass index (BMI) was calculated from the ratio of weight/height2 (kg/m2). Lung function was assessed by spirometry. Most patients (78%) had mild lung disease. The mean forced expired volume in 1 sec percent predicted (FEV1% predicted) for the 50 patients was 79.2% (range, 24-117%). There was a strong association between FEV1% predicted and BMI (R=0.59, P=0.0001). Fat-free mass had positive association with pulmonary function tests (R=0.30, P=0.03). Although fat mass showed a positive correlation with pulmonary function, this association did not reach statistical significance. In our group of children with CF and mild lung disease, pulmonary function was more strongly associated with BMI than with fat and fat-free mass.

Effect of gluten-free diet and adherence on growth and diabetic control in diabetics with coeliac disease.

AIMS: To study the effect of gluten-free diet on growth and diabetic control of children with type 1 diabetes mellitus and coeliac disease. METHODS: Twenty one children (mean age 7.5 years, range 1.6-12.9) with type 1 diabetes, primarily initially identified on the basis of symptoms and consecutively diagnosed with coeliac disease by biopsy over a 10 year period, were matched by sex, age at onset, and duration of diabetes with two diabetic controls without coeliac disease. Weight, height, haemoglobin A1c, and insulin requirements were measured before and for 12 months after the diagnosis and treatment of coeliac disease. Dietary awareness and adherence were assessed by structured questionnaire. RESULTS: A gluten-free diet resulted in a significant increase in weight-for-age z scores at 12 months after diagnosis (mean increase in z score 0.33) and in BMI (mean increase in z score 0.32). Increases in height did not achieve statistical significance. Controls showed no significant changes in weight, height, or BMI over the same period. Insulin dosage at diagnosis was less in coeliacs than in controls (mean difference 0.16 units/kg/day), but was similar to controls once a gluten-free diet had been established. Questionnaires were obtained in 20 patients. There appeared to be a relation between dietary awareness/adherence and growth parameters, but the small number of patients with "poor/fair" dietary adherence prevented meaningful analysis of this group. CONCLUSION: Identification and dietary treatment of coeliac disease in children with diabetes improved growth and influenced diabetic control. Evaluation of the outcome of treatment of coeliac disease in diabetics should include assessments of gluten intake.

Ranitidine-enhanced 99mtechnetium pertechnetate imaging in children improves the sensitivity of identifying heterotopic gastric mucosa in Meckel's diverticulum.

Meckel's diverticulum is the most common congenital gastrointestinal anomaly. (99m )Technetium pertechnetate imaging (Meckel's scan) is the best noninvasive method used to diagnose this condition when heterotopic gastric mucosa (HGM) is present. Although cimetidine enhancement has been shown to improve sensitivity of the Meckel's scan, ranitidine enhancement has also been advocated; however, this recommendation is based on unpublished data. Thirty-seven children with confirmed Meckel's diverticulum were reviewed retrospectively. Of eight children with HGM in the Meckel's diverticulum who presented with profuse rectal bleeding and underwent the conventional Meckel's scan, three of them (37.5%) had a false negative study. Ranitidine, when administered either intravenously or orally for 24 h prior to the Meckel's scan, enhanced the sensitivity of this test to 87.5% in our patient cohort.

Delayed presentation of an ingested foreign body causing gastric perforation.

Ingested foreign bodies may lead to perforation of the gastrointestinal tract. We present a case of a 14-month-old boy who presented with an unusual abdominal mass secondary to ingesting a foreign body 4 months previously. Abdominal computerized tomography scan was valuable in making this diagnosis.

Gastrointestinal transit and anorectal manometry in children with colonic substance P deficiency.

BACKGROUND AND AIMS: Severe intractable constipation in children may be associated with a reduction of substance P (SP)- containing fibers in colonic circular muscle. The aim of this study was to characterize gastrointestinal transit (GIT), anorectal manometry (ARM) and electromyographic (EMG) changes in these children. METHODS: Seromuscular laparoscopic biopsies of the colon were obtained from 35 children with severe constipation. Immunofluorescent staining for SP and vasoactive intestinal peptide (VIP) were then performed on these specimens. The cohort of patients studied included a SP-deficient group (SPD, n = 25) who had reduced numbers of SP-immunoreactive nerve fibers. The other group consisted of patients with normal staining for both SP and VIP (SPN, n = 10). Gastrointestinal transit studies (gastric emptying, orocecal and colonic transit) suitable for analysis were available for 17 patients (SPD, n = 9 and SPN, n = 8). The colon was divided into segments and radioactivity counts in each segment were expressed as a percentage of the total colonic count at each time point (6, 24, 32 and 48 h). The geometric center (GC), ARM, EMG, clinical and demographic data characteristics of both groups of patients were compared. RESULTS: There were no differences in demographic data, gastric emptying, orocecal transit or geometric center of transit in the colon between the two patient groups. The ARM and EMG studies suggested that the SPN group have a higher mean threshold volume of balloon distension required to initiate a rectoanal inhibitory reflex, and a higher incidence of anismus; however, this did not reach statistical significance. CONCLUSIONS: These data suggest a trend that the SPN patients have a greater problem with obstructive defecation and abnormal rectal sensation than those with SPD. We were unable to confirm any defect in colonic transit in the SPD patients compared with the SPN group.

Carbohydrate-deficient glycoprotein syndrome 1b: a new answer to an old diagnostic dilemma.

A patient with carbohydrate-deficient glycoprotein syndrome type 1b (CDGS1b) is reported. The patient presented at 5 months of age with failure to thrive, prolonged diarrhoea, hepatomegaly and elevated serum liver transaminases. Liver biopsy showed steatosis. A low serum albumin and elevated serum liver transaminases persisted throughout childhood during which he had repeated infectious illnesses. From the age of 10 years he had oesophageal and duodenal ulceration together with recurrent bacterial cholangitis. Liver biopsy demonstrated hepatic fibrosis. CDGS1b was suspected, supported by the finding of a protein-losing enteropathy and finally confirmed by showing a reduced phosphomannoseisomerase activity. This case illustrates a rare condition with a wide range of presentations.

Ataxia with isolated vitamin E deficiency: a clinical, biochemical and genetic diagnosis.

A case of ataxia with isolated vitamin E deficiency, in conjunction with supportive genetic studies, is reported. This is a neurodegenerative condition that involves a mutation in the tocopherol (alpha) transfer protein gene (TTPA). Measurement of serum vitamin E concentration should be included as part of the investigations in children with progressive ataxia, even in the absence of fat malabsorption. Early treatment with vitamin E may protect such patients against further neurological damage.

Elevated aminotransferase as a presenting finding in a patient with occult muscle disease.

We report a patient with occult muscle disease who presented with raised serum aminotransaminases. This case report emphasises the importance of considering muscle disease in the differential diagnosis of raised serum aminotransaminases, as it may negate the need for invasive investigations such as liver biopsy.

Case report: Colonic duplication: a rare cause of obstruction.

Complete duplication of the entire large bowel with partial ileal involvement is very rare and diagnosis can often be difficult as illustrated by this case report. We also review the other clinical associations of this rare condition and briefly discuss the embryology of duplications of the gastrointestinal tract.

An unusual cause of rectal bleeding in a patient with cystic fibrosis.

Here we identify a previously unreported cause of rectal bleeding (juvenile polyposis) in a patient with cystic fibrosis (CF). We believe this patient most likely has two coexisting genetic diseases. It also raises many issues about organ transplantation in a patient with medical conditions that individually increase the risk of gastrointestinal malignancy and stresses the diagnostic value of endoscopy in CF patients with rectal bleeding.

Colonic and jejunal motor disturbances after colonic antigen challenge of sensitized rat.

BACKGROUND & AIMS: Inflammation in the colon may alter motility in the proximal gut and potentiate clinical symptoms. The aim of this study was to characterize the effect of colonic anaphylaxis on local (colonic) and remote (small intestinal) motility and identify the mechanism and mediators involved. METHODS: Rats were sensitized by intraperitoneal injection of 10 microg egg albumin and surgically prepared with electrodes in jejunum and colon and a colostomy tube. Colonic and jejunal myoelectric activity were recorded in fasted animals before and after colonic antigen challenge without and then after pretreatment with specific antagonists. RESULTS: Colonic antigen challenge of sensitized rats was associated with significant (1) increase in colonic myoelectric spike activity, (2) disruption of fasting jejunal motility and initiation of aborally propagating spike complexes, and (3) increase in plasma rat mast cell protease II levels with a decrease in granulated mast cells in colon but not jejunum. The myoelectric disturbance in both colon and jejunum was inhibited significantly by pretreatment with atropine and hexamethonium, doxantrazole, cyclooxygenase, and lipoxygenase inhibitors. Methysergide inhibited only the jejunal disturbance. CONCLUSIONS: Colonic antigen challenge of sensitized animals results in local mast cell activation and the release of mediators that modulate neural pathways to initiate both a local colonic and a remote jejunal myoelectric disturbance.

Intestinal anaphylaxis induces Fos immunoreactivity in myenteric plexus of rat small intestine.

Fos immunohistochemistry was used to identify myenteric neurons activated as a consequence of intestinal anaphylaxis in Hooded-Lister rats sensitized to egg albumin (EA 10 micrograms ip). After incubation in test solutions, or after in vivo challenge, jejunal tissues were processed for immunohistochemistry with an anti-Fos antibody (1:500, TF161). The neuronal identity of the Fos-labeled nuclei was confirmed by double labeling with neuron-specific enclose (1:1,000). In in vitro studies, exposure of control tissue to 50 mM K(+)-Krebs-EA (2 x 10(-5) M) solutions significantly increased Fos immunoreactivity in the myenteric plexus, whereas a basal level of Fos was seen in control tissue incubated in Krebs solution, sham-sensitized tissue exposed to bovine serum albumin (BSA, 2 x 10(-5) M), or EA and sensitized tissue exposed to BSA. Pretreatment of sensitized tissue with doxantrazole (10(-4) M) markedly reduced Fos immunoreactivity observed after EA exposure. In in vivo studies, there was negligible Fos immunoreactivity in the myenteric plexus of control, sham-sensitized, or sensitized rats challenged with saline. A low level of Fos was seen in neurons of sham-sensitized rats challenged with BSA or EA and in sensitized rats challenged with BSA. Significantly greater levels of Fos were observed in the myenteric plexus of sensitized animals challenged with EA, even after pretreatment with capsaicin (125 mg/kg). These results suggest a role for myenteric neurons in intestinal anaphylaxis. In sensitized rats, activation of myenteric neurons is dependent on antigen-induced mast cell activation and occurs independently of capsaicin-sensitive afferent nerves.

Colonic motor response to IgE-mediated mast cell degranulation in the Hooded-Lister rat.

After challenge of sensitized individuals, food protein-induced colonic anaphylaxis may contribute to the symptom of diarrhoea. The aim of this study was to characterize the effect of food protein-induced anaphylaxis on colonic circular muscle in vitro, identify the mediators involved, and then evaluate the effect of antigen challenge on colonic transit in vivo. Hooded-Lister rats were sensitized by intraperitoneal injection of egg albumin and controls were sham-sensitized with saline. Rings of distal colonic tissue were suspended in standard tissue baths (mucosa intact) and circular muscle contractility was measured in response to antigen or other agents on day 14. In conscious animals, Na2(51)CrO4 was instilled alone, or with antigen, via proximal colostomy and the geometric centre of distribution of51Cr calculated. Following antigen challenge, a contractile response occurred only in animals that were sensitized (specific IgE antibody levels > or = 1:64), and was specific for the sensitizing antigen. Mast cell involvement was suggested when (1) concanavalin A (a degranulator of both mucosal and connective tissue mast cells) mimicked the antigen-induced response, and (2) Ag-induced contraction was significantly inhibited by mast cell stabilizers. The Ag-induced response was significantly and independently inhibited by a lipo-oxygenase enzyme inhibitor and by LTD4 and platelet activating factor receptor antagonists. The antigen-induced response was resistant to histamine and 5-hydroxytryptamine receptor antagonists, indomethacin, atropine and tetrodotoxin. The geometric centre of distribution of 51Cr was significantly more distal in sensitized animals challenged with antigen rather than placebo, and only sensitized animals challenged with antigen developed diarrhoea. These results suggest that colonic antigen challenge of sensitized rats is associated with IgE-mediated mast cell activation, the release of membrane derived mediators which, in vitro, act directly on smooth muscle to induce contraction, and in vivo result in an increased rate of aboral transit and diarrhoea.

Hepatic mucormycosis in a bone marrow transplant recipient who ingested naturopathic medicine.

This case report describes a bone marrow transplant recipient in whom hepatic zygomycosis developed after ingestion of multiple naturopathic medicines. Mucor was isolated from the patient's liver aspirate and from one of the naturopathic medicines. Arbitrary-primed polymerase chain reaction (PCR) analyses were performed on the Mucor isolates from the patient's liver aspirate and from his naturopathic medicine to see if they were genotypically related. Mucor indicus was the species identified in both the patient's liver aspirate and the naturopathic medicine. Arbitrary-primed PCR analysis revealed that these isolates were genotypically identical. We conclude that this bone marrow transplant recipient acquired hepatic mucormycosis from ingestion of a naturopathic medicine containing Mucor.

Intestinal anaphylaxis: mediation of the response of colonic longitudinal muscle in rat.

Colonic smooth muscle function may be altered in food protein hypersensitivity reactions and could contribute to the clinical manifestation of diarrhea. To characterize such functional changes and elucidate the mediators and mechanisms involved. Hooded-Lister rats were sensitized by intraperitoneal injection of egg albumin (10 micrograms), and controls were sham sensitized with saline. Fourteen days later the contractility of longitudinally oriented distal colonic segments (mucosa intact) were studied in standard tissue baths in response to antigen (Ag) or other agents. After Ag exposure, a contractile response was documented in animals that were sensitized [specific immunoglobulin E (IgE) antibody levels > or = 1:64] and was specific for the sensitizing Ag. Mast cell involvement was suggested by a significant reduction in the number of granulated mucosal mast cells in sensitized tissues after Ag challenge and in the magnitude of the Ag-induced contractile response in the presence of mast cell stabilizers. The antigen-induced response was significantly and independently inhibited by both cyclooxygenase and lipoxygenase enzyme inhibitors and by leukotriene D4 and platelet activating factor receptor antagonists. The Ag-induced response was resistant to histamine and the 5-hydroxytryptamine antagonists, atropine and tetrodotoxin. These results suggest that the food protein-induced contraction of colonic longitudinal smooth muscle in the sensitized rat is due to IgE-mediated mast cell activation with the subsequent production and release of membrane-derived mediators that, in vitro, act directly on the smooth muscle.