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.

Stimulation by 1,25-dihydroxyvitamin D3 of adenylate cyclase along the villus of chick duodenum.

Administration of 650 pmol 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] to vitamin D-deficient chicks increased adenylate cyclase activity in the basolateral membrane of duodenal epithelial cells within 24 h. This increase in enzymatic activity was accompanied by an increase in calmodulin content of the basolateral membrane. Although neither exogenously added calmodulin (up to 10 micrograms/ml) nor calcium (from 10(-7)-10(-5) M) stimulated enzyme activity, calmodulin antagonists trifluoperazine, W7, and W13 inhibited it. When calmodulin content, adenylate cyclase activity, and alkaline phosphatase activity were measured in cells sequentially eluted from the tip to the base of the villus, cells from the midregion and base had the highest calmodulin content and adenylate cyclase activity, whereas alkaline phosphatase activity (a brush border membrane enzyme) was highest in cells eluted from the tip. Adenylate cyclase activity was increased by 1,25-(OH)2D3, particularly in cells from the midvillus. Our results indicate that the response of adenylate cyclase activity to 1,25-(OH)2D3 varies along the villus and suggest that calmodulin may be involved.

The effect of somatostatin analogs on secretion of growth, pancreatic, and gastrointestinal hormones in man.

The potency and specificity of somatostatin (SS) and four of its analogs were compared in seven patients with pancreatic endocrine tumors. The analogs tested were [D-Trp8]-SS, [D-Trp8, D-Cys14]-SS, Des-Asn5-[D-Trp8, D-Ser13]-SS, and Des (AA)1,2,4,5,12,13, [D-Trp8]-SS, and they did not show selective effects on the suppression of basal concentrations of GH, insulin, glucagon, pancreatic polypeptide, gastrin, gastric inhibitory peptide, motilin, enteroglucagon, or neurotensin. The observation that the potency of these analogs is similar to that of the parent molecule throws considerable light on the structure/activity relationship of the somatostatin molecule. Des-AA1,2,4,5,12,13, [D-Trp8]-Ss has been reported to have a prolonged action when administered sc. When administered iv, however, this octapeptide analog ws not long acting, suggesting that the prolonged action seen in the previous study was a result of delayed uptake from the injection site. An increment in plasma SS concentrations of 19 +/- 3 pmol/liter suppressed basal concentrations of GH, insulin, glucagon, and several gastrointestinal hormones by more than 50%, suggesting that even small changes in plasma SS levels may be physiologically important.

The inhibition of human duodenal adenylate cyclase activity by Ca2+ and the effects of EGTA.

This study demonstrates that the inhibition of adenylate cyclase activity by Ca2+ is enhanced in the presence of increasing [EGTA] (0, 0.3, 1, 2.5 mM) by 2 orders of magnitude. It has been established that this effect is not because of poor Ca2+ buffering by low [EGTA] or high Ca2+ binding by the membrane preparation. It is present irrespective of stimulus. We suggest the enhanced sensitivity of adenylate cyclase to Ca2+ induced by EGTA is caused by the Ca-EGTA complex being a more inhibitory species than Ca2+. Thus consideration of the effects of the Ca-EGTA complex should be made when interpreting the results from experiments involving Ca2+ and EGTA.

Adult Niemann-Pick disease: its relationship to the syndrome of the sea-blue histiocyte.

Three unrelated female patients with adult Niemann-Pick disease are described. All the patients had reduced coagulation factors and involvement of the marrow, liver, spleen and lungs. Two patients were shown to have abnormal platelet function; two patients also had pingueculas and a late onset of a menarche. Foam cells and sea-blue histiocytes were seen in the marrow and livers in all three patients, in the spleen in two patients in the lymph nodes in one patient. The clinical presentation, the histologic appearance, the histochemical staining reactions, the lipid analysis and the ultrastructure were all consistent with a diagnosis of adult Niemann-Pick disease. On the basis of these observations, it is clear that adult Niemann-Pick disease is a cause of the syndrome of the sea-blue histiocyte. The existence of the syndrome of the sea-blue histiocyte as a separate entity is also questioned.

Review: long-acting somatostatin analogues.

This article reviews the chemistry, actions and chemical applications of somatostatin and its analogues. At present, their gastroenterological use should be considered in patients with the carcinoid syndrome and functioning pancreatic endocrine tumours; in endocrinology there is interest in their use for the management of patients with resistant acromegaly. With these possible exceptions, somatostatin analogues should at present be used only in the context of clinical trials.

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.

Lansoprazole versus ranitidine for the treatment of reflux oesophagitis. UK Lansoprazole Clinical Research Group.

BACKGROUND: Lansoprazole is a H+.K(+)-ATPase (proton pump) inhibitor with an anti-secretory action and is therefore potentially useful in the treatment of gastro-oesophageal reflux. METHODS: This study was conducted to determine the efficacy and short-term safety of lansoprazole at doses of 30 mg or 60 mg once daily, compared with ranitidine 150 mg twice daily, in the treatment of patients with reflux oesophagitis. This was a double-blind, stratified, randomized, comparative, parallel group study conducted in five centres in the UK. A total of 229 patients (155 men) aged 18-79 years with endoscopically-confirmed oesophagitis were randomized to receive lansoprazole 30 mg p.o. daily, lansoprazole 60 mg p.o. daily, or ranitidine 150 mg p.o. b.d. Efficacy was assessed by endoscopic examination at 4 weeks and 8 weeks, together with symptom relief and antacid usage. RESULTS: Lansoprazole 30 mg and 60 mg were superior at 4 and 8 weeks (P < 0.01) to ranitidine in healing reflux oesophagitis: respective healing rates being 84%, 72% and 39% after 4 weeks and 92%, 91% and 53% after 8 weeks. Relief of heartburn with lansoprazole 30 mg and 60 mg was superior to that achieved with ranitidine at both week 4 (P < 0.01) and week 8 (P < 0.02). Sixty-four patients experienced a total of 85 adverse events, one-third of which were considered drug-related. The incidence and severity were similar in the three groups. CONCLUSION: Lansoprazole 30 mg and 60 mg once daily are more effective than ranitidine 150 mg twice daily in the short-term treatment of reflux oesophagitis.

Twenty-four-hour intragastric acidity and clinical trial of bedtime enprostil 70 micrograms compared with ranitidine 300 mg in duodenal ulcer.

The effects of bedtime 70 micrograms and twice daily 35 micrograms doses of enprostil on 24-hour intragastric acidity were investigated in nine duodenal ulcer patients in remission. Median nocturnal acidity decreased significantly by 30% with 35 micrograms twice daily, and by 48% with 70 micrograms at bedtime. In a clinical trial using bedtime dosing, 102 duodenal ulcer patients randomly received either ranitidine 300 mg or enprostil 70 micrograms. More ulcers healed after 4 and 8 weeks treatment with ranitidine than with enprostil (76% ranitidine vs 52% enprostil, at 4 weeks p = 0.0065 and 94% vs 68%, respectively at 8 weeks, P = 0.0007). However, 6 months after cessation of treatment there was no material difference in overall outcome. Despite combining mucosal protection with acid inhibition enprostil treatment conferred no advantage over simple acid inhibition.

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 comparison of roxatidine and ranitidine for the acute treatment of duodenal ulcer.

Roxatidine acetate is a new histamine H2-antagonist of about twice the potency of ranitidine on a weight-for-weight basis. Two hundred and thirty-two patients participated in a double-blind randomized trial of duodenal ulcer healing comparing 300 mg ranitidine nocte with 150 mg roxatidine nocte. Endoscopy was repeated fortnightly to 4 weeks in each of four participating centres. Usual exclusion criteria applied but NSAID users were allowed. There were no important demographic differences between treatment recipients. Three analyses were used: protocol (dropouts and violators not included), intention-to-treat I (dropouts considered failures), and intention-to-treat II (dropouts considered failures, but violators outcome included). Healing rates differed markedly (but not significantly) with each analysis. After 2 weeks of treatment ulcers had healed in 51% versus 45% using the intention to treat I analysis with roxatidine and ranitidine, respectively; by the protocol analysis the healing proportions were 60% and 55%. These differences between treatments were not significant. After 4 weeks of treatment healing rates ranged from 71% to 83% on roxatidine and between 69% and 84% on ranitidine depending on the analysis. Differential healing proportions of smokers and non-smokers were non-significant (83% vs. 79%). Both drugs were well tolerated and adverse events were similar with each agent. Roxatidine should prove as effective as ranitidine for acute duodenal ulcer treatment.

Rapid healing of gastric ulcers with lansoprazole.

BACKGROUND: Lansoprazole is a new proton pump inhibitor which powerfully decreases acid secretion. METHODS: We compared the efficacy and short-term safety of lansoprazole against ranitidine in the healing of gastric ulcer. This was a parallel group, comparative multicentre, prospectively randomized, double-blind study which included 250 patients with gastric ulcer, 219 of whom had follow-up endoscopic data. RESULTS: Both lansoprazole 30 mg and 60 mg daily produced significantly more rapid healing of gastric ulcer than ranitidine 300 mg nightly with healing rates after 4 weeks of 78% (P < 0.05), 84% (P < 0.01) and 61%, respectively. After 8 weeks, the corresponding healing rates were 99%, 97% and 91% (P = 0.08). Symptom relief was similar for all treatment groups, but fewer antacids were used by patients receiving lansoprazole. Sixty-nine patients experienced 91 adverse events; the incidence, pattern and severity was similar across all three treatment groups. CONCLUSIONS: Lansoprazole 30 mg and 60 mg once daily had similar efficacy. Both were superior to ranitidine 300 mg nocte in healing gastric ulcer. The short-term safety profile of lansoprazole was similar to ranitidine. These data indicate that lansoprazole should be used at a dose of 30 mg once daily for the treatment of gastric ulcers.

Pre-eclampsia presenting with deep jaundice.

Pre-eclampsia complicated by deep jaundice occurred in a previously healthy primigravida. The main aetiological factor was disseminated intravascular coagulation; this caused both haemolysis and liver cell necrosis. Liver biopsy showed fibrin thrombi in the capillaries with microhaemorrhages and loss of periportal liver cells. The jaundice was attributed to both haemolytic and hepatocellular processes. Organs other than the liver were relatively unaffected.

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.

Blood-group sialyl-Tn antigen is more specific than Tn as a tumor marker in the pancreas.

The aim of this study was to evaluate the expression of blood group Tn and sialyl-Tn antigens in the pancreas to determine whether they could help to interpret histochemically needle biopsies obtained from the pancreas. Lectin and immunohistochemistry was carried out using the biotin-labeled Vicia villosa agglutinin isolectin B4 and the mouse monoclonal antibody MLS102 to detect the Tn and sialyl-Tn blood-group antigens in the pancreas. All the pancreatic ductal adenocarcinomas (11/11) were positively stained by V. villosa agglutinin and MLS102 monoclonal antibody. None of the normals or chronic pancreatitics bound MLS102 monoclonal antibody. The acini of all the normals and chronic pancreatitics were V. villosa agglutinin positive, which was absent in the normal ductal cells and present only sparingly in the chronic pancreatitis ductal tissues (10/16). Thus, both the Tn and the sialyl-Tn blood-group antigens are present in pancreatic ductal tissues that have undergone malignant transformation. MLS102 is superior to V. villosa agglutinin in distinguishing malignant from normal and nonmalignant pancreatic tissues in needle biopsies.

Plasma calcium and magnesium fractions in liver disease.

Plasma calcium and magnesium fractions were measured in 51 patients with either hepatocellular or biliary disease. The fractions were found to be only minimally deranged. Plasma albumin correlated with total calcium and with the protein bound and ionized fractions. Abnormalities of plasma calcium or magnesium fractions are unlikely to play a role in the pathogenesis of the osteomalacia seen in chronic biliary disease.