Computer-assisted diagnosis for precancerous lesions in the esophagus.

OBJECTIVES: The interpretation of endoscopic findings by gastroenterologists is still a difficult and highly subjective task. Despite important developments such as chromo-endoscopy, pit pattern analysis, fluorescence imaging as well as narrow band imaging it still requires lots of experience and training with a certain tentativeness until the final biopsy. By the development of computer-assisted diagnosis (CAD) systems this process can be supported. METHODS: This paper presents a new approach to CAD for precancerous lesions in the esophagus based on color-texture analysis in a content-based image retrieval (CBIR) framework. The novelty of our approach lies in the combination of newly developed color-texture features with the interactive feedback loop provided by a relevance feedback algorithm. This allows the expert to steer the query and is still robust against accidental false decisions. RESULTS: We reached an inter-rater reliability of kappa = 0.71 on a database of 390 endoscopic images. The retrieval accuracy didn't change significantly until a wrong decision rate of 20%. CONCLUSIONS: Thus, the system could be able to support practitioners with less experience or in private practice. In combination with a connected case database it can also support case-based reasoning for the diagnostic decision process.

UGT1A7 polymorphisms in chronic pancreatitis: an example of genotyping pitfalls.

UDP-glucuronosyltransferases (UGT) catalyze the glucuronidation of various compounds and thus inactivate toxic substrates. Genetic variations reducing the activity of UGT1A7 have been associated with various gastrointestinal cancers. Most recently, the UGT1A7*3 allele has been reported as a significant risk factor for pancreatic disorders, but we could not confirm these data. This study focused on the possible causes for the noted discrepancy. UGT1A7 genotypes were assessed in 37 samples, which were previously analyzed for UGT1A7 polymorphisms by others. We determined genotypes by melting curve analysis and by DNA sequencing. Additionally, we produced UGT1A7*1 and *3 constructs with or without a mutation at position - 57 of UGT1A7 and analyzed various combinations of these constructs. In 14/37 samples UGT1A7 genotyping results differed. The discrepancy could be explained by polymerase chain reaction bias owing to an unbalanced allelic amplification which was caused by a -57T>G variant located within the sequence of the chosen primer template in previous studies. Our findings indicate that most of the previously reported genetic associations between UGT1A7 and gastrointestinal cancers are based on primer-dependent genotyping errors.

Polymorphisms of UDP-glucuronosyltransferase 1A7 are not involved in pancreatic diseases.

BACKGROUND: Xenobiotic mediated cellular injury is thought to play a major role in the pathogenesis of pancreatic diseases. Genetic variations that reduce the expression or activity of detoxifying phase II biotransformation enzymes such as the UDP-glucuronosyltransferases might be important in this respect. Recently, a UGT1A7 low detoxification activity allele, UGT1A7*3, has been linked to pancreatic cancer and alcoholic chronic pancreatitis. OBJECTIVE: To investigate whether UGT1A7 polymorphisms contribute to the risk of pancreatitis and pancreatic cancer. METHODS: Genetic polymorphisms in the UGT1A7 gene were assessed in a large cohort of patients with different types of pancreatitis and pancreatic cancer originating from the Czech Republic (n = 93), Germany (n = 638), Netherlands (n = 136), and Switzerland (n = 106), and in healthy (n = 1409) and alcoholic (n = 123) controls from the same populations. Polymorphisms were determined by melting curve analysis using fluorescence resonance energy transfer probes. In addition, 229 Dutch subjects were analysed by restriction fragment length polymorphism. RESULTS: The frequencies of UGT1A7 genotypes did not differ between patients with acute or chronic pancreatitis or pancreatic adenocarcinoma and alcoholic and healthy controls. CONCLUSIONS: The data suggest that, in contrast to earlier studies, UGT1A7 polymorphisms do not predispose patients to the development of pancreatic cancer and pancreatitis.

Autologous epidermal cells can induce wound closure of neurotrophic ulceration caused by trigeminal trophic syndrome.

Trigeminal trophic syndrome is an extremely rare complication following surgical ablation of the trigeminal nerve or after alcohol injection or thermocoagulation of the Gasserian ganglion. These lesions show a poor healing tendency and sometimes persist for years. The therapeutic results of local wound care with ointments and wound dressings are often unsatisfactory, and those of plastic surgery are variable. In the case presented, the skin area affected by neurotrophic ulceration is successfully treated with autologous cultivated epidermal cells. This form of tissue engineering is already a clinically established procedure for treating burns and chronic wounds. The results show for the first time that transplantation of in vitro cultivated epidermal cells can induce tissue regeneration and may be an effective tool in the treatment of neurotrophic ulcerations in the facial region.

Oral isobutyramide reduces transfusion requirements in some patients with homozygous beta-thalassemia.

The butyrate derivative isobutyramide (IBT) increases fetal hemoglobin (HbF) in patients with beta-hemoglobinopathies, but little is known about its usefulness for prolonged therapeutic use. We treated 8 patients with transfusion-dependent beta-thalassemia with 350 mg/kg of body weight per day of oral IBT for 126 to 384 days. During the trial period, the hemoglobin level was maintained between 85 g/L (range 82-87 g/L) (pretransfusion) and 115 g/L (range 110-119 g/L) (post-transfusion) (median, interquartile range), corresponding to 4-week transfusion intervals in all patients during the pretreatment phase. Adverse effects (bitter taste, epigastric discomfort) did not cause discontinuation of IBT. HbF increased in all patients from 3.1% (range 1.9%-4.8%) to 6.0% (range 3.3%-8.7) (P =.0017), while free Hb dropped from 0.48 g/L (range 0.39-0.81 g/L) to 0.19 g/L (range 0.16-0.24 g/L) (P <.0001). Transfusion intervals were consistently extended to 8 or 9 weeks in 1 patient, resulting in a decrease of daily iron load from 455 microgram/kg per day (range 451-459 microgram/kg per day) before therapy to 211 microgram/kg per day (range 203-286 microgram/kg per day) during the 12-month treatment period. Prolongation of transfusion intervals achieved by IBT was less consistent in another patient, whose parenteral iron load nevertheless decreased from 683 microgram/kg per day (range 618-748 microgram/kg per day) to 542 microgram/kg per day (340-596 microgram/kg per day). In the other 6 patients, no prolongation of transfusion intervals was achieved. Response to treatment was associated with high pretreatment HbF (> 4.5%), high parental HbF, and increased erythropoietin levels (> 150 IU/L). We conclude that IBT prolongs transfusion intervals and reduces parenteral iron burden in some patients with transfusion-dependent beta-thalassemia.

Mutations in the gene encoding the serine protease inhibitor, Kazal type 1 are associated with chronic pancreatitis.

Chronic pancreatitis (CP) is a continuing or relapsing inflammatory disease of the pancreas. In approximately one-third of all cases, no aetiological factor can be found, and these patients are classified as having idiopathic disease. Pathophysiologically, autodigestion and inflammation may be caused by either increased proteolytic activity or decreased protease inhibition. Several studies have demonstrated mutations in the cationic trypsinogen gene (PRSS1) in patients with hereditary or idiopathic CP. It is thought that these mutations result in increased trypsin activity within the pancreatic parenchyma. Most patients with idiopathic or hereditary CP, however, do not have mutations in PRSS1 (ref. 4). Here we analysed 96 unrelated children and adolescents with CP for mutations in the gene encoding the serine protease inhibitor, Kazal type 1 (SPINK1), a pancreatic trypsin inhibitor. We found mutations in 23% of the patients. In 18 patients, 6 of whom were homozygous, we detected a missense mutation of codon 34 (N34S). We also found four other sequence variants. Our results indicate that mutations in SPINK1 are associated with chronic pancreatitis.

Suppression of interleukin-10 release from human periodontal ligament cells by interleukin-1beta in vitro.

Periodontitis is characterized by an inflammatory process induced by periodontopathogenic bacteria in the subgingival plaque. Periodontal inflammation can be enhanced by both an increase of inflammatory stimulators, e.g. interleukin (IL)-6, and a decrease of inflammatory inhibitors, e.g. IL-10. The amount of IL-1beta is known to be increased in gingival tissues and in the gingival crevicular fluid from inflamed sites compared to healthy sites. This in vitro study sought to clarity whether IL-1beta (1 ng/ml) has a regulatory effect on the release of these two cytokines from human periodontal ligament (PDL) cells. PDL cells derived from healthy premolars were grown in the presence and absence (control) of IL-1beta. The concentration of IL-6 and IL-10 in the supernatants was assessed by enzyme-linked immunosorbent assay after 48 h of culture. PDL cells incubated with IL-1beta released significantly (p < 0.05) higher amounts of IL-6 and significantly (p < 0.01) smaller amounts of IL-10 compared to control. These results give further support to the observation that IL-1beta can increase the IL-6 secretion from PDL cells. Moreover, they provide original evidence that PDL cells secrete IL-10, which can be suppressed by IL-1beta. It is concluded that PDL cells can function as accessory immunoinflammatory cells amplifying the inflammatory process in periodontitis and, thereby, contributing to periodontal breakdown.

Epithelial uptake and transport of cell-free human immunodeficiency virus type 1 and gp120-coated microparticles.

Cell-free human immunodeficiency virus type 1 (HIV-1) can be taken up and released by a monolayer of primary human gingival cells and remain infectious for CD4+ cells. Virus-sized latex particles covalently coated with purified native HIV-1 envelope glycoprotein gp120 are also transported through the primary epithelial cells. This process is significantly stimulated by increasing the intracellular cyclic AMP (cAMP) concentration. Inhibition experiments with mannan and alpha-methyl-mannopyranoside indicated that mannosyl groups are involved in the interaction between gp120 and gingival cells. An increase of cellular oligomannosyl receptors by incubation with the mannosidase inhibitor deoxymannojirimycin augmented transcellular transport of the gp120-coated particles. The results suggest that infectious HIV can penetrate gingival epithelia by a cAMP-dependent transport mechanism involving interaction of the lectin-like domain of gp120 and mannosyl residues on glycoproteins on the mucosal surface. Penetration of HIV could be inhibited by soluble glycoconjugates present in oral mucins.

Lectin specificity and binding characteristics of human C-reactive protein.

C-reactive protein (CRP) is thought to play an important role in immunomodulation. The exact biologic function of this pentraxin protein is, however, still unclear. Here we report experiments designed to further characterize the binding properties of CRP. Using purified human CRP it could be shown that CRP immobilized onto polystyrene surfaces or onto latex beads binds distinct plasma glycoproteins including IgG, asialofetuin, asialo-beta 2-glycoprotein I and, likewise, synthetic glycoproteins as a lectin, exhibiting binding specificity for terminal galactosyl residues of the glycoprotein glycans. Binding of CRP to IgA, IgM, IgG, asialofetuin, asialo-beta 2-glycoprotein I and to synthetic glycoproteins requires immobilization onto surfaces of both CRP and the ligand. Fibronectin and fibrinogen are bound by surface-immobilized CRP also in soluble phase. Comparing various mono-, di-, and trisaccharides as competitive inhibitors of the lectin binding activity of CRP, only beta-D-Gal-(1-3)-D-GalNAc, beta-D-Gal-(1-4)-D-GalNAc, and beta-D-Gal-(1-4)-beta-D-Gal-(1-4)-D-GlcNAc had significant inhibitory power at a concentration of 8 mmol/liter. Binding activity of CRP was pH-dependent with an optimum at pH 5 to 6 and was reduced by 90% when pH was shifted from 6 to the physiologic pH value of 7.4. CRP exhibited lectin-like properties with binding specificity for galactosyl residues also when bound to K-562 erythroleukemia cells. It is therefore suggested that CRP immobilized onto surfaces exhibits lectin activity toward galactosyl groups preferentially in a mildly acidic environment as present at sites of inflammation.