Functional cell phenotype induction with TGF-ß1 and collagen-polyurethane scaffold for annulus fibrosus rupture repair.

Appropriate cell sources, bioactive factors and biomaterials for generation of functional and integrated annulus fibrosus (AF) tissue analogues are still an unmet need. In the present study, the AF cell markers, collagen type I, cluster of differentiation 146 (CD146), mohawk (MKX) and smooth muscle protein 22α (SM22α) were found to be suitable indicators of functional AF cell induction. In vitro 2D culture of human AF cells showed that transforming growth factor ß1 (TGF-ß1) upregulated the expression of the functional AF markers and increased cell contractility, indicating that TGF-ß1-pre-treated AF cells were an appropriate cell source for AF tissue regeneration. Furthermore, a tissue engineered construct, composed of polyurethane (PU) scaffold with a TGF-ß1-supplemented collagen type I hydrogel and human AF cells, was evaluated with in vitro 3D culture and ex vivo preclinical bioreactor-loaded organ culture models. The collagen type I hydrogel helped maintaining the AF functional phenotype. TGF-ß1 supplement within the collagen I hydrogel further promoted cell proliferation and matrix production of AF cells within in vitro 3D culture. In the ex vivo IVD organ culture model with physiologically relevant mechanical loading, TGF-ß1 supplement in the transplanted constructs induced the functional AF cell phenotype and enhanced collagen matrix synthesis. In conclusion, TGF-ß1-containing collagen-PU constructs can induce the functional cell phenotype of human AF cells in vitro and in situ. This combined cellular, biomaterial and bioactive agent therapy has a great potential for AF tissue regeneration and rupture repair.

Thermoresponsive, redox-polymerized cellulosic hydrogels undergo in situ gelation and restore intervertebral disc biomechanics post discectomy.

Back and neck pain are commonly associated with intervertebral disc (IVD) degeneration. Structural augmentation of diseased nucleus pulposus (NP) tissue with biomaterials could restore degeneration-related IVD height loss and degraded biomechanical behaviors; however, effective NP replacement biomaterials are not commercially available. This study developed a novel, crosslinked, dual-polymer network (DPN) hydrogel comprised of methacrylated carboxymethylcellulose (CMC) and methylcellulose (MC), and used in vitro, in situ and in vivo testing to assess its efficacy as an injectable, in situ gelling, biocompatible material that matches native NP properties and restores IVD biomechanical behaviors. Thermogelling MC was required to enable consistent and timely gelation of CMC in situ within whole IVDs. The CMC-MC hydrogel was tuned to match compressive and swelling NP tissue properties. When injected into whole IVDs after discectomy injury, CMC-MC restored IVD height and compressive biomechanical behaviors, including range of motion and neutral zone stiffness, to intact levels. Subcutaneous implantation of the hydrogels in rats further demonstrated good biocompatibility of CMC-MC with a relatively thin fibrous capsule, similar to comparable biomaterials. In conclusion, CMC-MC is an injectable, tunable and biocompatible hydrogel with strong potential to be used as an NP replacement biomaterial since it can gel in situ, match NP properties, and restore IVD height and biomechanical function. Future investigations will evaluate herniation risk under severe loading conditions and assess long-term in vivo performance.

Fibrin-genipin adhesive hydrogel for annulus fibrosus repair: performance evaluation with large animal organ culture, in situ biomechanics, and in vivo degradation tests.

Annulus fibrosus (AF) defects from annular tears, herniation, and discectomy procedures are associated with painful conditions and accelerated intervertebral disc (IVD) degeneration. Currently, no effective treatments exist to repair AF damage, restore IVD biomechanics and promote tissue regeneration. An injectable fibrin-genipin adhesive hydrogel (Fib-Gen) was evaluated for its performance repairing large AF defects in a bovine caudal IVD model using ex vivo organ culture and biomechanical testing of motion segments, and for its in vivo longevity and biocompatibility in a rat model by subcutaneous implantation. Fib-Gen sealed AF defects, prevented IVD height loss, and remained well-integrated with native AF tissue following approximately 14,000 cycles of compression in 6-day organ culture experiments. Fib-Gen repair also retained high viability of native AF cells near the repair site, reduced nitric oxide released to the media, and showed evidence of AF cell migration into the gel. Biomechanically, Fib-Gen fully restored compressive stiffness to intact levels validating organ culture findings. However, only partial restoration of tensile and torsional stiffness was obtained, suggesting opportunities to enhance this formulation. Subcutaneous implantation results, when compared with the literature, suggested Fib-Gen exhibited similar biocompatibility behaviour to fibrin alone but degraded much more slowly. We conclude that injectable Fib-Gen successfully sealed large AF defects, promoted functional restoration with improved motion segment biomechanics, and served as a biocompatible adhesive biomaterial that had greatly enhanced in vivo longevity compared to fibrin. Fib-Gen offers promise for AF repairs that may prevent painful conditions and accelerated degeneration of the IVD, and warrants further material development and evaluation.

Long-term follow-up of coeliac disease--what do coeliac patients want?

BACKGROUND: Coeliac disease affects up to 1% of the population and the British Society of Gastroenterology recommends long-term follow-up of these patients, although the absolute risk of complications is small. AIM: To determine what proportion of patients with coeliac disease remain under specialist follow-up and to examine patients' perspectives on the long-term management of coeliac disease. METHODS: A questionnaire was sent to 183 patients who had a duodenal biopsy between July 1994 and July 2004 which was consistent with coeliac disease. RESULTS: A total of 126 (69%) patients returned their questionnaire. Patients had on average been diagnosed with coeliac disease 5.4 years earlier. Eighty-eight percentage were trying to follow a strict gluten-free diet. Sixty-two percentage of patients were under regular follow-up although this varied between hospital clinic (doctor/dietitian, 92%) and General Practitioner (8%). Most patients found at least one aspect of the hospital out-patient clinic very useful. The preferred method of coeliac disease follow-up was to see a dietitian with a doctor being available (P < 0.05 vs. all other options). CONCLUSIONS: Respondents to this study showed great variation in follow-up of their coeliac disease -38% were under no active follow-up. Patients would prefer to see a dietitian for long-term follow-up.

Effect of a gluten-free diet on plasma nitric oxide products in coeliac disease.

BACKGROUND: Inducible nitric oxide synthase is expressed in the small intestine of patients with coeliac disease. This produces increased plasma concentration of nitric oxide end products (NOx), most marked in those ingesting gluten. The time-course of change in NOx with a gluten-free diet (GFD) and its correlation with histology and coeliac serology were studied. METHODS: Fasting plasma NOx was determined by the Greiss reaction in 20 coeliac patients at diagnosis and 2, 4 and 6 months after commencing a GFD. Endomysial and gliadin antibodies were checked at the same time. Duodenal biopsies were taken at diagnosis and at 6 months, and then graded according to the Marsh classification. RESULTS: Plasma NOx fell rapidly following the introduction of a GFD (mean before GFD 95.8 microM to 61.5 microM at 2 months), and further still by 6 months (mean = 37.0 microM). Reductions at 2 and 6 months were statistically significant compared with baseline (P < 0.01 and P < 0.005, respectively: Wilcoxon signed ranks test). Plasma NOx was correlated with histological grade initially (P = 0.03: Kruskal-Wallis) but not after 6 months on a GFD (P = 0.24). Coeliac serology correlated poorly with histology. CONCLUSIONS: Plasma NOx falls rapidly following GFD in coeliac disease and is related to histological grade initially. However, values vary widely between individuals, which may limit its use as a clinical tool.

Drug treatments in upper gastrointestinal bleeding: value of endoscopic findings as surrogate end points.

INTRODUCTION: Pharmacotherapy for upper gastrointestinal bleeding has been difficult to evaluate because clinical end points are infrequent and affected by other factors. AIMS: To evaluate whether blood in the stomach at endoscopy reflected severity of bleeding, predicted clinical outcomes, and could be altered by therapeutic agents. METHODS: We studied 414 consecutive admissions with suspected upper gastrointestinal bleeding. Patients were randomised to receive lansoprazole 60 mg followed by 30 mg four times daily, tranexamic acid 2 g followed by 1 g four times daily, both drugs, or placebo for four days, until discharge or a clinical end point occurred. Logistic regression analysis was used to determine predictors of endoscopic changes and clinical outcomes, and to investigate the effects of drug treatments on blood in the stomach. RESULTS: Of 414 patients with suspected upper gastrointestinal bleeding, 379 were endoscoped. Upper gastrointestinal bleeding was confirmed in 316. Sixteen required surgery within 30 days and 16 died on the index admission. Trial treatments were evaluable on a per protocol basis in 228 patients. The amount of blood in the stomach was found to reflect initial risk, with significant associations with high risk categorisation (odds ratio 3.7 (95% confidence interval 1.5-9.4) for more than a trace v none/trace), age (1.5 (1.1-1.9) per decade), and initial pulse (1.02 (1.00-1.04) per beat), and to predict rebleeding (9.2 (4.6-18.7)) and surgery (8.2 (2.9-22.9)). Other stigmata were less significant in these respects. The amount of blood in the stomach at endoscopy was reduced significantly by both lansoprazole (0.22 (0.07-0.63)) and tranexamic acid (0.27 (0.09-0.81)), although there was no evidence of synergy. CONCLUSIONS: Blood in the stomach reflects clinical features in patients with acute upper gastrointestinal bleeding and is reduced by treatment with lansoprazole and tranexamic acid.

Intestinal disaccharidase deficiency without villous atrophy may represent early celiac disease.

BACKGROUND: Intestinal disaccharidase activities are decreased in untreated celiac disease and also in other conditions without villous atrophy. Of 908 patients examined for suspected malabsorption, 37 (4.1%) had generalized disaccharidase deficiency without villous atrophy. The aim was to determine if generalized disaccharidase deficiency without villous atrophy represented latent celiac disease. METHODS: Case notes and histology of the 37 patients were reviewed. History and blood investigations including antigliadin and endomysial antibodies were checked. Where celiac disease was suspected, endoscopic duodenal biopsies for histology and disaccharidase estimation were repeated. RESULTS: Of the initial 37 patients, 6 patients had had repeat endoscopic biopsies; one having celiac disease. A further 18 patients were reviewed. The remainder declined further investigation. Eight had repeat endoscopic duodenal biopsies; one had celiac disease. Two with positive celiac serology also had enteroscopy with jejunal biopsies; both had celiac disease. CONCLUSIONS: At least 11% of patients with generalized disaccharidase deficiency without villous atrophy develop celiac disease. Enteroscopic biopsies from distal duodenum and proximal jejunum should be considered as the next investigation if endomysial or antigliadin antibodies are positive.

Intestinal trehalase activity in a UK population: establishing a normal range and the effect of disease.

Trehalose is a disaccharide, the main dietary source being mushrooms. It has been approved as an additive in the preparation of dried food. Isolated intestinal trehalase deficiency is found in 8% of Greenlanders, but is rare elsewhere. The normal range of trehalase activity and the incidence of isolated trehalase deficiency in the UK have not been reported. Patients (n 400) were investigated for suspected malabsorption. Endoscopic distal duodenal biopsies were taken for histological assessment and maltase, sucrase, lactase and trehalase estimation. Disaccharidase activities were determined by Dahlqvist's technique (Dahlqvist, 1968). Most patients (n 369) had normal duodenal histology. In these, square root transformation of trehalase activity produced a normal distribution. The normal range (mean +/- 2 SD) was 4.79-37.12 U/g protein. One patient had an isolated borderline trehalase deficiency. The thirty-one patients with villous atrophy had significantly reduced disaccharidase activities. With ingestion of a gluten-free diet, maltase, sucrase and trehalase activities recovered to normal in most patients, whereas lactase activity did not. The normal range and very low incidence of isolated enzyme deficiency is comparable with that described in populations from the USA and mainland Europe. Activity is significantly reduced in untreated coeliac disease and recovers with treatment with a gluten-free diet. There is no place for routine determination of trehalase activity in the UK population and there should be no concern over the introduction of trehalose-containing dried foods.

Barium enema or colonoscopy for the investigation of iron deficiency anaemia?

OBJECTIVE: To determine whether double contrast barium enema is adequate for excluding carcinoma of the colon in patients with iron deficiency anaemia. DESIGN: Prospective audit. SUBJECTS: One hundred and twenty-three patients with iron deficiency anaemia. INTERVENTION: All patients had upper intestinal (GI) endoscopy, duodenal biopsy and double contrast barium enema. Malignant disease and other GI pathology were treated. Patients with recurrent or persistent anaemia at follow-up were colonoscoped. OUTCOME MEASURE: Colon cancer missed on barium enema examination but detected on colonoscopic examination. RESULTS: An identified GI lesion contributing to their anaemia and 11 colon cancers were found in 71% of patients, all identified on barium enema. Two pre-cancerous conditions were missed on barium enema examination. Only 45% colonoscopies inspected the caecum. CONCLUSION: Double contrast barium enema with sigmoidoscopy is probably sufficient for excluding carcinoma of the colon in iron deficiency anaemia.

Oral manifestations of systemic diseases.

Many systemic diseases have oral manifestations. The oral cavity might well be thought of as the window to the body because oral manifestations accompany many systemic diseases. These oral manifestations must be properly recognized if the patient is to receive appropriate diagnosis and referral for treatment. We have reviewed a series of recent articles and summarized known and newly described oral manifestations of several systemic diseases. The lesions of the oral mucosa, tongue, gingiva, dentition, periodontium, salivary glands, facial skeleton, extraoral skin and other related structures caused by some of the more common systemic diseases are highlighted.

Short- and long-term outcome of patients treated with cyclosporin for severe acute ulcerative colitis.

BACKGROUND: Recent evidence suggests that the immunosuppressive drug cyclosporin may be of benefit in treating patients with severe colitis who are steroid resistant. Although cyclosporin appears to be effective in reducing colectomy rates in the short term, few data are available on the long-term follow-up of such patients. AIM: To investigate the short- and long-term outcome of patients with severe steroid-resistant ulcerative colitis treated with cyclosporin who were otherwise being considered for colectomy. METHODS: Twenty-two patients with severe steroid-resistant exacerbations of ulcerative colitis who were being considered for colectomy were treated with cyclosporin (4 mg/kg i.v.) daily for 7 days followed by oral treatment (6 mg/kg/day) if colectomy was avoided. RESULTS: Twenty of 22 patients (91%) avoided colectomy during their initial hospital admission. With a mean follow-up period of 39 months (range 31-59), eight of these patients have subsequently relapsed and required colectomy and 12 patients have avoided colectomy (53%). Of the 12 patients avoiding colectomy, seven have successfully been weaned on to azathioprine while five are maintained on an aminosalicylate alone. None of these long-term responders require maintenance corticosteroids. The main side-effects during treatment with cyclosporin were headaches (six patients, 27%), paraesthesia and tremors (four patients, 18%) and hypertension (four patients, 18%). Two patients developed renal impairment on cyclosporin which resolved on lowering the dose. In no case was cyclosporin discontinued because of an adverse reaction. No clinical or laboratory features could be identified that predicted which patients treated with cyclosporin would later require colectomy. CONCLUSION: This study shows that cyclosporin is a viable alternative to emergency colectomy in severe ulcerative colitis in the short term. Although these benefits are not maintained in all patients, more than half were found to avoid colectomy in the longer term.

Clostridium difficile toxin A binding to human intestinal epithelial cells.

Clostridium difficile radiolabelled toxin A ([3H]-toxin A) bound to human duodenal and colonic epithelial cells isolated from endoscopic biopsies. Binding was greater at 4 degrees C than 37 degrees C, consistent with the thermal binding characteristic of toxin A to a carbohydrate moiety. At 37 degrees C colonic cells bound significantly more [3H]-toxin A than duodenal cells. The amount of [3H]-toxin A binding varied considerably between individuals. [3H]-toxin A was displaced by unlabelled toxin A by 50% for duodenal cells and 70% for colonic cells with 94.3 nM unlabelled toxin A. Low non-displacable binding was observed in some samples at 4 degrees C and 37 degrees C, suggesting that these cells came from individuals incapable of specifically binding toxin. Pre-treating cells with alpha- or beta-galactosidases to cleave terminal alpha- and beta-galactose residues reduced [3H]-toxin A binding. There was also a reduction in [3H]-toxin A binding after heat treating cells, which is suggestive of protein binding. The reduction in binding varied between individuals. The reduction of [3H]-toxin A binding, after the removal of beta-linked galactose units, implicates these as components of the receptor and adds credence to the idea that the Lewis X, Y and I antigens may be involved in toxin A binding to human intestinal epithelial cells. However, because the Lewis antigens do not possess terminal alpha-galactose units, the reduction in binding after alpha-galactosidase treatment suggests that other receptors may be involved in toxin A binding to some human intestinal cells. These data are the first demonstration of direct toxin A binding to human intestinal epithelial cells.

Iron uptake by isolated human enterocyte suspensions in vitro is dependent on body iron stores and inhibited by other metal cations.

The uptake of 59Fe ascorbate by suspensions of human enterocytes prepared from endoscopically derived duodenal biopsies was studied, with each subject's serum ferritin concentration determined at the time of endoscopy. Iron uptake was greatest at 37 degrees C. Uptake increased from pH 5.5 to 7.3, before being totally inhibited at pH 9.0. However, ferrous ion concentration, determined by 3-(2-Pyridyl)-5,6-bis(4-phenyl sulfonic acid)-1,2,4-triazine, was greatest at pH 5.5 and fell over this pH range. The rate of uptake was significantly greater by enterocytes isolated from individuals with a low serum ferritin (< 22 ng/L) compared with those with normal serum ferritin (> 22 ng/L). Vmax +/- (SEM) was 78.7 +/- 8.5 pmol Fe/(micrograms DNA.min) in the normal group (n = 12) and 141 +/- 17.2 pmol Fe/(micrograms DNA.min) in the low ferritin group (n = 4, P < 0.008). Corresponding Km values were 52.5 +/- 11.7 and 66.7 +/- 5.1 mumol/L, respectively (P < 0.91). Zinc, lead, cobalt and manganese added to the incubation buffer significantly lowered iron uptake into cells (unselected patients). The concentrations of each metal required to halve the uptake rate from 50 mumol/L iron (IC50) were 85 +/- 5 mumol/L (Zn), 570 +/- 170 mumol/L (Pb), 1.1 +/- 0.1 mmol/L (Co), and 3.8 +/- 0.7 mmol/L (Mn). The results demonstrate that enterocytes isolated by this method show the characteristics of iron uptake seen in animal studies. We suggest that these cells will be useful in the study of iron uptake in humans.

Lansoprazole versus ranitidine in the maintenance treatment of reflux oesophagitis.

AIMS: To assess the relative efficacies of lansoprazole 15 mg once daily, lansoprazole 30 mg once daily and ranitidine 300 mg b.d. in the maintenance treatment of reflux oesophagitis for 12 months. METHODS: Multicentre, out-patient, double-blind, parallel group, prospectively randomized clinical trial. Patients with grade 0, asymptomatic oesophagitis after 8 weeks of treatment with lansoprazole 30 mg once daily were randomized to receive lansoprazole 30 mg once daily (L30) (n = 75), lansoprazole 15 mg once daily (L15) (n = 86) or ranitidine 300 mg b.d. (R600) (n = 74) for 12 months. Endoscopy was repeated at 6 and 12 months, and symptomatic assessment was made every 3 months. Efficacy was primarily assessed by the time to endoscopically confirmed relapse (oesophagitis grade > or = 1) and the proportion of patients who relapsed during the 12-month study period. Severity of symptoms were secondary efficacy measures. RESULTS: For all patients randomized with at least one post-baseline endoscopy (intent-to-treat principle) both lansoprazole 15 mg (P < 0.001) and lansoprazole 30 mg (P < 0.001) were significantly superior to ranitidine 600 mg with respect to time to endoscopic relapse. There was no difference between the lansoprazole groups (P = 0.11). There was evidence of relapse in 27 of 86 (31.4%), 15 of 75 (20.0%) and 50 of 74 (67.6%) of the patients treated with lansoprazole 15 mg and 30 mg and ranitidine 600 mg, respectively. Patients receiving treatment with either lansoprazole dosages experienced significantly less severe heartburn and regurgitation than those patients treated with ranitidine. There were no differences between the treatment groups with respect to the severity or incidence of adverse events. No clinically significant laboratory changes were observed in any of the treatment groups. Serum gastrin levels were elevated in all treatment groups, and most markedly in those patients receiving lansoprazole, but there was no significant difference between the treatments. Morphological and immunohistochemical examination of the gastric biopsies revealed no clinically relevant changes from baseline in any of the treatment groups. CONCLUSION: Both lansoprazole 15 mg and lansoprazole 30 mg once daily are significantly more effective than high-dose ranitidine in maintaining reflux oesophagitis in remission.

A randomised prospective comparison of percutaneous endoscopic gastrostomy and nasogastric tube feeding after acute dysphagic stroke.

OBJECTIVE: To compare percutaneous endoscopic gastrostomy and nasogastric tube feeding after acute dysphagic stroke. DESIGN: Randomised prospective study of inpatients with acute stroke requiring enteral nutrition. SETTING: One university hospital (Nottingham) and one district general hospital (Derby). SUBJECTS: 30 patients with persisting dysphagia at 14 days after acute stroke: 16 patients were randomised to gastrostomy tube feeding and 14 to nasogastric tube feeding. MAIN OUTCOME MEASURES: Six week mortality; amount of feed administered; change in nutritional state; treatment failure; and length of hospital stay. RESULTS: Mortality at 6 weeks was significantly lower in the gastrostomy group with two deaths (12%) compared with eight deaths (57%) in the nasogastric group (P < 0.05). All gastrostomy fed patients (16) received the total prescribed feed whereas 10/14 (71%) of nasogastric patients lost at least one day's feed. Nasogastric patients received a significantly (P < 0.001) smaller proportion of their prescribed feed (78%; 95% confidence interval 63% to 94%) compared with the gastrostomy group (100%). Patients fed via a gastrostomy tube showed greater improvement in nutritional state, according to several different criteria at six weeks compared with the nasogastric group. In the gastrostomy group the mean albumin concentration increased from 27.1 g/l (24.5 g/l to 29.7 g/l) to 30.1 g/l (28.3 g/l to 31.9 g/l). In contrast, among the nasogastric group there was a reduction from 31.4 g/l (28.6 g/l to 34.2 g/l) to 22.3 g/l (20.7 g/l to 23.9 g/l) (P < 0.003). In addition, there were fewer treatment failures in the gastrostomy group (0/16 versus 3/14). Six patients from the gastrostomy group were discharged from hospital within six weeks of the procedure compared with none from the nasogastric group (P < 0.05). CONCLUSION: This study indicates that early gastrostomy tube feeding is greatly superior to nasogastric tube feeding and should be the nutritional treatment of choice for patients with acute dysphagic stroke.