bluuebunny/crossref_metadata_2025 huggingface dataset:
Glycosylation of the Collagen Adhesin EmaA ofAggregatibacter actinomycetemcomitansIs Dependent upon the Lipopolysaccharide Biosynthetic Pathway
Authors: Tang Gaoyan , Mintz Keith P.
Published: January 2010

The human oropharyngeal pathogenAggregatibacter actinomycetemcomitanssynthesizes multiple adhesins, including the nonfimbrial extracellular matrix protein adhesin A (EmaA). EmaA monomers trimerize to form antennae-like structures on the surface of the bacterium, which are required for collagen binding. Two forms of the protein have been identified, which are suggested to be linked with the type of O-polysaccharide (O-PS) of the lipopolysaccharide (LPS) synthesized (G. Tang et al., Microbiology 153:2447-2457, 2007). This association was investigated by generating individual mutants for a rhamnose sugar biosynthetic enzyme (rmlC; TDP-4-keto-6-deoxy-d-glucose 3,5-epimerase), the ATP binding cassette (ABC) sugar transport protein (wzt), and the O-antigen ligase (waaL). All three mutants produced reduced amounts of O-PS, and the EmaA monomers in these mutants displayed a change in their electrophoretic mobility and aggregation state, as observed in sodium dodecyl sulfate (SDS)-polyacrylamide gels. The modification of EmaA with O-PS sugars was suggested by lectin blots, using the fucose-specificLens culinarisagglutinin (LCA). Fucose is one of the glycan components of serotype b O-PS. ThermlCmutant strain expressing the modified EmaA protein demonstrated reduced collagen adhesion using anin vitrorabbit heart valve model, suggesting a role for the glycoconjugant in collagen binding. These data provide experimental evidence for the glycosylation of an oligomeric, coiled-coil adhesin and for the dependence of the posttranslational modification of EmaA on the LPS biosynthetic machinery inA. actinomycetemcomitans.
Two Regions of
Bacillus subtilis
Transcription Factor SpoIIID Allow a Monomer To Bind DNA
Authors: Himes Paul , McBryant Steven J. , Kroos Lee
Published: January 2010

Nutrient limitation causes
Bacillus subtilis
to develop into two different cell types, a mother cell and a spore. SpoIIID is a key regulator of transcription in the mother cell and positively or negatively regulates more than 100 genes, in many cases by binding to the promoter region. SpoIIID was predicted to have a helix-turn-helix motif for sequence-specific DNA binding, and a 10-bp consensus sequence was recognized in binding sites, but some strong binding sites were observed to contain more than one match to the consensus sequence, suggesting that SpoIIID might bind as a dimer or cooperatively as monomers. Here we show that SpoIIID binds with high affinity as a monomer to a single copy of its recognition sequence. Using charge reversal substitutions of residues likely to be exposed on the surface of SpoIIID and assays for transcriptional activation
in vivo
and for DNA binding
in vitro
, we identify two regions essential for DNA binding, the putative recognition helix of the predicted helix-turn-helix motif and a basic region near the C terminus. SpoIIID is unusual among prokaryotic DNA-binding proteins with a single helix-turn-helix motif in its ability to bind DNA monomerically with high affinity. We propose that the C-terminal basic region of SpoIIID makes additional contacts with DNA, analogous to the N-terminal arm of eukaryotic homeodomain proteins and the “wings” of winged-helix proteins, but structurally distinct. SpoIIID is highly conserved only among bacteria that form endospores, including several important human pathogens. The need to conserve biosynthetic capacity during endospore formation might have favored the evolution of a small transcription factor capable of high-affinity binding to DNA as a monomer, and this unusual mode of DNA binding could provide a target for drug design.
Genome Sequence of the Deep-Rooted
Yersinia pestis
Strain Angola Reveals New Insights into the Evolution and Pangenome of the Plague Bacterium
Authors: Eppinger Mark , Worsham Patricia L. , Nikolich Mikeljon P. , Riley David R. , Sebastian Yinong , Mou Sherry , Achtman Mark , Lindler Luther E. , Ravel Jacques
Published: January 2010

To gain insights into the origin and genome evolution of the plague bacterium
Yersinia pestis
, we have sequenced the deep-rooted strain Angola, a virulent Pestoides isolate. Its ancient nature makes this atypical isolate of particular importance in understanding the evolution of plague pathogenicity. Its chromosome features a unique genetic make-up intermediate between modern
Y. pestis
isolates and its evolutionary ancestor,
Y. pseudotuberculosis
. Our genotypic and phenotypic analyses led us to conclude that Angola belongs to one of the most ancient
Y. pestis
lineages thus far sequenced. The mobilome carries the first reported chimeric plasmid combining the two species-specific virulence plasmids. Genomic findings were validated in virulence assays demonstrating that its pathogenic potential is distinct from modern
Y. pestis
isolates. Human infection with this particular isolate would not be diagnosed by the standard clinical tests, as Angola lacks the plasmid-borne capsule, and a possible emergence of this genotype raises major public health concerns. To assess the genomic plasticity in
Y. pestis
, we investigated the global gene reservoir and estimated the pangenome at 4,844 unique protein-coding genes. As shown by the genomic analysis of this evolutionary key isolate, we found that the genomic plasticity within
Y. pestis
clearly was not as limited as previously thought, which is strengthened by the detection of the largest number of isolate-specific single-nucleotide polymorphisms (SNPs) currently reported in the species. This study identified numerous novel genetic signatures, some of which seem to be intimately associated with plague virulence. These markers are valuable in the development of a robust typing system critical for forensic, diagnostic, and epidemiological studies.
Role of apoptosis induced by Helicobacter pylori infection in the development of duodenal ulcer
Authors: Kohda K , Tanaka K , Aiba Y , Yasuda M , Miwa T , Koga Y
Published: January 2010

BACKGROUND

Helicobacter pylori affects gastric epithelium integrity by acceleration of apoptosis. However, it remains unclear what product of the bacteria causes apoptosis, or whether or not the apoptosis is involved in the development of ulcers.

AIMS

To elucidate the factor from H pylori that causes acceleration of apoptosis and the role of apoptosis in the development of duodenal ulcer in H pylori infection.

PATIENTS

FiveH pylori negative healthy volunteers, 47H pylori positive patients with duodenal ulcer, and 35 H pylori positive patients with gastric ulcer.

METHODS

An endoscopic examination was carried out to diagnose ulcers and determine their clinical stage. To analyse apoptosis, a cell cycle analysis was performed using biopsy specimens.

RESULTS

There was a significant correlation between the urease activity of theH pylori strain and the level of apoptosis induced by this bacterial strain. Moreover, in duodenal ulcer patients infected with H pylori, the patients with an active ulcer exhibited a significantly higher level of apoptosis than those with ulcers at both the healing and scarring stages.

CONCLUSION

These findings suggest that acceleration of apoptosis in the antral mucosa caused by the urease of H pylori plays a crucial role in the development of ulcers in the duodenum.
Direct detection of Helicobacter pylori resistance to macrolides by a polymerase chain reaction/DNA enzyme immunoassay in gastric biopsy specimens
Authors: Marais A , Monteiro L , Occhialini A , Pina M , Lamouliatte H , Mégraud F
Published: January 2010

BACKGROUND

The increasing use of macrolides especially in the treatment ofHelicobacter pylori infection has led to an increase in resistant strains. The resistance of H pylori to macrolides, especially clarithromycin, is one of the major causes of eradication failure. In H pylori, clarithromycin resistance is due to point mutations localised in domain V of 23S rRNA.

AIM

To develop a molecular technique based on amplification of a relevant fragment of the 23S rRNA and colorimetric hybridisation in liquid phase to detect directly in biopsy specimens the type of mutation associated with resistance of H pylori to clarithromycin.

METHODS

Gastric biopsy samples from 61 patients were submitted to this test. The results were compared with standard methods (determination of minimal inhibition concentration, polymerase chain reaction/restriction fragment length polymorphism, and/or DNA sequencing) in order to evaluate the test and to define the cut off values, specificity, and sensitivity.

RESULTS

The 14 biopsy samples in which H pylori was not detected did not give a positive result in any assay, and the 14 samples harbouring strains susceptible to clarithromycin gave a positive result with the wild type probe as expected. The 33 biopsy specimens containing resistant strains always gave a positive signal with one of the probes detecting resistant organisms, but in eight cases they also reacted with the wild type probe, indicating that a mixture of resistant and susceptible organisms was present.

CONCLUSION

The importance of this new assay is that it allows the detection of multiple genotypes corresponding to either heterogeneous genotypes or mixed infections. Moreover, it allows in a single step not only the detection of H pylori but also the determination of its susceptibility to clarithromycin directly in biopsy specimens without the need for culture.
Helicobacter pylori infection potentiates the inhibition of gastric acid secretion by omeprazole
Authors: Gillen D , Wirz A A , Neithercut W D , Ardill J E S , McColl K E L
Published: January 2010

BACKGROUND

Omeprazole has a greater intragastric pH elevating effect in Helicobacter pylori positive than negative subjects. Ammonia production byH pylori has been suggested as a probable mechanism.

AIMS

To assess the effect ofH pylori status on gastric acid secretion during omeprazole treatment, and to examine the possible role of ammonia neutralisation of intragastric acid in increased omeprazole efficacy in infected subjects.

METHODS

TwentyH pylori positive and 12H pylori negative healthy volunteers were examined before and six to eight weeks after commencing omeprazole 40 mg/day. On both occasions plasma gastrin and acid output were measured basally and in response to increasing doses of gastrin 17 (G-17). Gastric juice ammonium concentrations were also measured.

RESULTS

Prior to omeprazole, measurements were similar in the H pyloripositive and negative subjects. During omeprazole, median basal intragastric pH was higher in the H pyloripositive (7.95) versus negative (3.75) subjects (p<0.002). During omeprazole basal, submaximal (180 pmol/kg/h G-17), and maximal acid outputs (800 pmol/kg/h G-17) were lower in H pylori positive subjects (0.0, 3.6, 6.0 mmol/h respectively) versus negative subjects (0.3, 14.2, 18.6 mmol/h) (p<0.03 for each). This effect was not explained by neutralisation by ammonia.

CONCLUSION

The presence ofH pylori infection leads to a more profound suppression of acid secretion during omeprazole treatment. The effect cannot be explained by neutralisation of intragastric acid by bacterial ammonia production and its precise mechanism has to be explained.
The effect of hiatus hernia on gastro-oesophageal junction pressure
Authors: Kahrilas P J , Lin S , Chen J , Manka M
Published: January 2010

BACKGROUND

Hiatus hernia and lower oesophageal sphincter hypotension are often viewed as opposing hypotheses for gastro-oesophageal junction incompetence.

AIMS

To examine the interaction between hiatus hernia and lower oesophageal sphincter hypotension.

METHODS

In seven normal subjects and seven patients with hiatus hernia, the squamocolumnar junction and intragastric margin of the gastro-oesophageal junction were marked with endoscopically placed clips. Axial and radial characteristics of the gastro-oesophageal junction high pressure zone were mapped relative to the hiatus and clips during concurrent fluoroscopy and manometry. Responses to inspiration and abdominal compression were also analysed.

RESULTS

In normal individuals the squamocolumnar junction was 0.5 cm below the hiatus and the gastro-oesophageal junction high pressure zone extended 1.1 cm distal to that. In those with hiatus hernia, the gastro-oesophageal junction high pressure zone had two discrete segments, one proximal to the squamocolumnar junction and one distal, attributable to the extrinsic compression within the hiatal canal. Inspiration and abdominal compression mainly augmented the distal one. Simulation of hernia reduction by algebraically summing the proximal segment pressures with the hiatal canal pressures restored normal maximal pressure, radial asymmetry, and dynamic responses of the gastro-oesophageal junction.

CONCLUSIONS

Hiatus hernia reduces lower oesophageal sphincter pressure and alters its dynamic responsiveness by spatially separating pressure components derived from the intrinsic lower oesophageal sphincter and the extrinsic compression of the oesophagus within the hiatal canal.
Geography of intestinal permeability and absorption
Authors: Menzies I S , Zuckerman M J , Nukajam W S , Somasundaram S G , Murphy B , Jenkins A P , Crane R S , Gregory G G
Published: January 2010

BACKGROUND

Intestinal morphology and function vary geographically.

AIMS

These functions were assessed in asymptomatic volunteers in European, North American, Middle Eastern, Asian, African, and Caribbean countries.

METHODS

Five hour urine collections were obtained from each subject following ingestion of a 100 ml iso-osmolar test solution containing 3–0-methyl-d-glucose,d-xylose, l-rhamnose, and lactulose after an overnight fast, to assess active (3–0-methyl-d-glucose) and passive (d-xylose) carrier mediated, and non-mediated (l-rhamnose) absorption capacity, as well as intestinal permeability (lactulose:rhamnose ratio).

RESULTS

A comparison of results for subjects from tropical countries (n=218) with those resident in the combined temperate and subtropical region (Europe, United States, Qatar) (n=224) showed significant differences. Residents in tropical areas had a higher mean lactulose:rhamnose ratio and lower mean five hour recoveries of 3–0-methyl-d-glucose,d-xylose, and l-rhamnose, indicating higher intestinal permeability and lower absorptive capacity. Investigation of visiting residents suggested that differences in intestinal permeability and absorptive capacity were related to the area of residence. Subjects from Texas and Qatar, although comprised of several ethnic groups and resident in a subtropical area, showed no significant difference from European subjects.

CONCLUSIONS

There are clearly demarcated variations in intestinal permeability and absorptive capacity affecting asymptomatic residents of different geographical areas which correspond with the condition described as tropical enteropathy. Results suggest the importance of environmental factors. The parameters investigated may be relevant to the predisposition of the indigenous population and travellers to diarrhoeal illness and malnutrition. Intestinal function in patients from the tropics may be difficult to interpret, but should take into account the range of values found in the asymptomatic normal population.
Acute increase, stimulated by prostaglandin E2, in glucose absorption via the sodium dependent glucose transporter-1 in rat intestine
Authors: Scholtka B , Stümpel F , Jungermann K
Published: January 2010

BACKGROUND/AIMS

Acute stimulation by cAMP of the sodium dependent glucose cotransporter SGLT1 has previously been shown. As prostaglandin E2(PGE2) increases intracellular cAMP concentrations via its receptor subtypes EP2R and EP4R, it was investigated whether PGE2 could enhance intestinal glucose absorption.

METHODS

The action of PGE2 on carbohydrate absorption in the ex situ perfused rat small intestine and on 3-O-[14C]methylglucose uptake in isolated villus tip enterocytes was determined. Expression of mRNA for the PGE2 receptor subtypes 1–4 was assayed in enterocytes by reverse transcriptase polymerase chain reaction (RT-PCR).

RESULTS

In the perfused small intestine, PGE2 acutely increased absorption of glucose and galactose, but not fructose (which is not a substrate for SGLT1); in isolated enterocytes it stimulated 3-O-[14C]methylglucose uptake. The 3-O-[14C]methylglucose uptake could be inhibited by the cAMP antagonist RpcAMPS and the specific inhibitor of SGLT1, phlorizin. High levels of EP2R mRNA and EP4R mRNA were detected in villus tip enterocytes.

CONCLUSION

PGE2acutely increased glucose and galactose absorption by the small intestine via the SGLT1, with cAMP serving as the second messenger. PGE2 acted directly on the enterocytes, as the stimulation was still observed in isolated enterocytes and RT-PCR detected mRNA for the cAMP-increasing PGE2 receptors EP2R and EP4R.
Involvement of tachykinin receptors in sensitisation to cow’s milk proteins in guinea pigs
Authors: Gay J , Fioramonti J , Garcia-Villar R , Emonds-Alt X , Bueno L
Published: January 2010

BACKGROUND

There is growing evidence for a pivotal role for tachykinins in gut neuroimmune interactions.

AIMS

To determine whether NK1, NK2, and NK3 tachykinin receptors are involved in milk protein induced allergic sensitisation.

METHODS

Eight groups of 12 Dunkin-Hartley guinea pigs (250–300 g) were used. Four groups were sensitised to milk proteins for three weeks. During this period, these animals were injected intraperitoneally each day with NK1 (SR 140333; 0.3 mg/kg), NK2 (SR 48968; 5 mg/kg), or NK3 (SR 142801; 5 mg/kg) receptor antagonist or vehicle. The fifth group had water available instead of milk and was used as a non-sensitised control. The three other groups received the NK receptor antagonists for three weeks but were not sensitised to milk proteins.

RESULTS

Sensitised animals treated with NK1 and NK3 receptor antagonists had both lower IgE and IgG serum titres, evaluated by passive cutaneous anaphylaxis, and lower specific IgG serum titres, determined by enzyme linked immunosorbent assay (ELISA), than vehicle treated animals. Sensitisation induced an increase in intestinal mast cell number which was abolished by treatment with the NK1 receptor antagonist. Antigenic challenge-induced jejunal hypersecretion was also blocked by treatment with the NK1 receptor antagonist.

CONCLUSION

In guinea pigs, NK1 and NK3 but not NK2 receptors are involved in sensitisation to cow’s milk. However, NK1 but not NK3 receptor antagonists abolish both the hypermastocytosis induced by food allergy and the hypersecretion induced by antigenic challenge, suggesting different roles for NK1 and NK3 receptors in the mechanisms of sensitisation to β-lactoglobulin.
Bacteroides fragilis toxin 2 damages human colonic mucosa in vitro
Authors: Riegler M , Lotz M , Sears C , Pothoulakis C , Castagliuolo I , Wang C C , Sedivy R , Sogukoglu T , Cosentini E , Bischof G , Feil W , Teleky B , Hamilton G , LaMont J T , Wenzl E
Published: January 2010

BACKGROUND

Strains ofBacteroides fragilis producing a 20 kDa protein toxin (B fragilis toxin (BFT) or fragilysin) are associated with diarrhoea in animals and humans. Although in vitro results indicate that BFT damages intestinal epithelial cells in culture, the effects of BFT on native human colon are not known.

AIMS

To examine the electrophysiological and morphological effects of purified BFT-2 on human colonic mucosa in vitro.

METHODS

For resistance (R) measurements, colonic mucosa mounted in Ussing chambers was exposed to luminal or serosal BFT-2 (1.25–10 nM) and after four hours morphological damage was measured on haematoxylin and eosin stained sections using morphometry. F actin distribution was assessed using confocal microscopy.

RESULTS

Serosal BFT-2 for four hours was four-, two-, seven-, and threefold more potent than luminal BFT-2 in decreasing resistance, increasing epithelial3H-mannitol permeability, and damaging crypt and surface colonocytes, respectively (p<0.05). Confocal microscopy showed reduced colonocyte F actin staining intensity after exposure to BFT-2.

CONCLUSIONS

BFT-2 increases human colonic permeability and damages human colonic epithelial cells in vitro. These effects may be important in the development of diarrhoea and intestinal inflammation caused by B fragilis in vivo.
Clinical spectral characterisation of colonic mucosal lesions using autofluorescence and δ aminolevulinic acid sensitisation
Authors: Eker C , Montán S , Jaramillo E , Koizumi K , Rubio C , Andersson-Engels S , Svanberg K , Svanberg S , Slezak P
Published: January 2010

BACKGROUND AND AIMS

Laser induced fluorescence (LIF) from colonic mucosa was measured in vivo with and without δ aminolevulinic acid (ALA) in an attempt to differentiate between neoplasia and non-neoplasia in real time during colonoscopy.

METHODS

Spectra from 32 adenomas, 68 normal sites, and 14 hyperplastic polyps in 41 patients were obtained with a point monitoring system. Twenty one of the patients had been given a low dose of ALA as a photosensitiser before the examination. Light of 337, 405, or 436 nm wavelength was used as excitation. Stepwise multivariate linear regression analysis was performed.

RESULTS

With 337 nm excitation, 100% sensitivity and 96% specificity was obtained between normal mucosa and adenomas. Seventy seven per cent of the hyperplastic polyps were classified as non-neoplastic. When exciting with 405 and 436 nm, the possibility of distinguishing different types of tissue was considerably better in the ALA patients than in the non-ALA patients.

CONCLUSIONS

The in vivo point measurements imply that a good discrimination between normal tissue and adenomatous polyps can be obtained using the LIF technique. Excitation at 337 nm and at 405 nm or 436 nm using ALA gives good results. LIF also shows potential for distinguishing adenomatous from hyperplastic polyps. The number of detection wavelengths could be reduced if chosen properly.
Linkage of Crohn’s disease to the major histocompatibility complex region is detected by multiple non-parametric analyses
Authors: Yang H , Plevy S E , Taylor K , Tyan D , Fischel-Ghodsian N , McElree C , Targan S R , Rotter J I
Published: January 2010

BACKGROUND

There is evidence for genetic susceptibility to Crohn’s disease, and a tentative association with tumour necrosis factor (TNF) and HLA class II alleles.

AIMS

To examine the potential of genetic linkage between Crohn’s disease and the MHC region on chromosome 6p.

METHODS

TNF microsatellite markers and, for some families, additional HLA antigens were typed for 323 individuals from 49 Crohn’s disease multiplex families to generate informative haplotypes. Non-parametric linkage analysis methods, including sib pair and affected relative pair methods, were used.

RESULTS

Increased sharing of haplotypes was observed in affected sib pairs: 92% (48/52) shared one or two haplotypes versus an expected 75% if linkage did not exist (p=0.004). After other affected relative pairs were included, the significance level reached 0.001. The mean proportion of haplotype sharing was increased for both concordant affected (π=0.60, p=0.002) and unaffected sib pairs (π=0.58, p=0.031) compared with the expected value (π=0.5). In contrast, sharing in discordant sib pairs was significantly decreased (π=0.42, p=0.007). Linear regression analysis using all three types of sib pairs yielded a slope of −0.38 at p=0.00003. It seemed that the HLA effect was stronger in non-Jewish families than in Jewish families.

CONCLUSIONS

All available analytical methods support linkage of Crohn’s disease to the MHC region in these Crohn’s disease families. This region is estimated to contribute approximately 10–33% of the total genetic risk to Crohn’s disease.
Validation of a specific quality of life questionnaire for functional digestive disorders
Authors: Chassany O , Marquis P , Scherrer B , Read N W , Finger T , Bergmann J F , Fraitag B , Geneve J , Caulin C
Published: January 2010

BACKGROUND

Dyspepsia and irritable bowel syndrome are suitable conditions for assessment of quality of life. Their similarities justify the elaboration of a single specific questionnaire for the two conditions.

AIMS

To examine the process leading to the validation of the psychometric properties of the functional digestive disorders quality of life questionnaire (FDDQL).

METHODS

Initially, the questionnaire was given to 154 patients, to assess its acceptability and reproducibility, analyse its content, and reduce the number of items. Its responsiveness was tested during two therapeutic trials which included 428 patients. The questionnaire has been translated into French, English, and German. The psychometric validation study was conducted in France, United Kingdom, and Germany by 187 practitioners. A total of 401 patients with dyspepsia or irritable bowel syndrome, defined by the Rome criteria, filled in the FDDQL and generic SF-36 questionnaires.

RESULTS

The structure of the FDDQL scales was checked by factorial analysis. Its reliability was expressed by a Cronbach’s α coefficient of 0.94. Assessment of its discriminant validity showed that the more severe the functional digestive disorders, the more impaired the quality of life (p<0.05). Concurrent validity was supported by the correlation found between the FDDQL and SF-36 questionnaire scales. The final version of the questionnaire contains 43 items belonging to eight domains.

CONCLUSIONS

The properties of the FDDQL questionnaire, available in French, English, and German, make it appropriate for use in clinical trials designed to evaluate its responsiveness to treatment among patients with dyspepsia and irritable bowel syndrome.
Pancreatic stellate cells are activated by proinflammatory cytokines: implications for pancreatic fibrogenesis
Authors: Apte M V , Haber P S , Darby S J , Rodgers S C , McCaughan G W , Korsten M A , Pirola R C , Wilson J S
Published: January 2010

BACKGROUND

The pathogenesis of pancreatic fibrosis is unknown. In the liver, stellate cells play a major role in fibrogenesis by synthesising increased amounts of collagen and other extracellular matrix (ECM) proteins when activated by profibrogenic mediators such as cytokines and oxidant stress.

AIMS

To determine whether cultured rat pancreatic stellate cells produce collagen and other ECM proteins, and exhibit signs of activation when exposed to the cytokines platelet derived growth factor (PDGF) or transforming growth factor β (TGF-β).

METHODS

Cultured pancreatic stellate cells were immunostained for the ECM proteins procollagen III, collagen I, laminin, and fibronectin using specific polyclonal antibodies. For cytokine studies, triplicate wells of cells were incubated with increasing concentrations of PDGF or TGF-β.

RESULTS

Cultured pancreatic stellate cells stained strongly positive for all ECM proteins tested. Incubation of cells with 1, 5, and 10 ng/ml PDGF led to a significant dose related increase in cell counts as well as in the incorporation of3H-thymidine into DNA. Stellate cells exposed to 0.25, 0.5, and 1 ng/ml TGF-β showed a dose dependent increase in α smooth muscle actin expression and increased collagen synthesis. In addition, TGF-β increased the expression of PDGF receptors on stellate cells.

CONCLUSIONS

Pancreatic stellate cells produce collagen and other extracellular matrix proteins, and respond to the cytokines PDGF and TGF-β by increased proliferation and increased collagen synthesis. These results suggest an important role for stellate cells in pancreatic fibrogenesis.
Underestimation of acute pancreatitis: patients with only a small increase in amylase/lipase levels can also have or develop severe acute pancreatitis
Authors: Lankisch P G , Burchard-Reckert S , Lehnick D
Published: January 2010

BACKGROUND

In most treatment studies on acute pancreatitis, pancreatologists base their diagnosis on amylase/lipase levels more than three times above the upper limit of normal (>3n) and thus exclude patients with smaller enzyme level increases. The recommendations derived from the results of treatment studies do not take into account such patients. Non-pancreatologists frequently believe that only patients with high enzyme levels have a serious prognosis.

AIMS

To question the assumption that high enzyme levels indicate severe, and conversely low enzyme levels indicate mild, acute pancreatitis.

PATIENTS/METHODS

This retrospective study includes 284 consecutive patients with a first attack of acute pancreatitis. The cause was biliary in 114 (40%) patients, alcoholism in 83 (29%), other in 21 (7%), and unknown in 66 (23%). Patients were divided into two groups according to their serum enzyme levels (amylase: ⩽3n, n = 88; >3n, n = 196; lipase: ⩽3n, n = 51; >3n, n = 233). Renal impairment, indication for dialysis and artificial ventilation, development of pseudocysts, necessity for surgery, and mortality were taken as parameters of severity.

RESULTS

The incidence of severity was the same for both the ⩽3n and >3n groups.

CONCLUSIONS

The severity of acute pancreatitis is independent of the elevation in serum amylase/lipase level (⩽3n or >3n) on admission. Patients with only a slight increase can also have or develop severe acute pancreatitis. Patients with ⩽3n elevated enzyme levels on admission represent a substantial group that treatment studies have frequently overlooked. This is especially true for patients with alcohol induced acute pancreatitis whose amylase levels are lower than in other aetiological groups.
Immunoreactive pancreatic Reg protein in sera from cystic fibrosis patients with and without pancreatic insufficiency
Authors: Carrère J , Guy-Crotte O , Gaia E , Figarella C
Published: January 2010

BACKGROUND

The biological function of the Reg protein, a non-enzymic protein produced in fairly large amounts by pancreatic acinar cells, remains elusive. Its susceptibility to proteolysis leading to precipitation of the proteolysis product at neutral pH suggests that it could contribute to the protein plugging observed in cystic fibrosis (CF).

AIMS

To study its behaviour in the serum of CF patients with or without pancreatic insufficiency and to compare it with that of other pancreatic secretory proteins.

PATIENTS

170 patients (93 with CF, 55 controls, and 22 with chronic pancreatitis) were studied.

METHODS

Reg protein was measured using a specific enzyme immunoassay and its molecular form in CF sera was characterised by gel filtration. Molecular gene expression was investigated by dot-blot hybridisation.

RESULTS

Reg protein was present in all CF sera studied from patients with or without pancreatic insufficiency, and in all cases the level was significantly higher than in controls. Its chromatographic behaviour in CF sera was identical with that of the protein present in normal serum. No correlation was found between the levels of Reg protein and trypsin(ogen) (or lipase) in CF, nor in control sera or normal pancreatic juice. Molecular gene expression of the corresponding proteins investigated in pancreatic tissues showed an absence of correlation between the mRNA levels.

CONCLUSIONS

Reg protein may not be a secretory exocrine protein like the digestive enzymes but rather a hormone-like secretory substance with an endocrine or paracrine function.
Effect of long term simvastatin administration as an adjunct to ursodeoxycholic acid: evidence for a synergistic effect on biliary bile acid composition but not on serum lipids in humans
Authors: Lanzarotto F , Panarotto B , Sorbara R , Panteghini M , Pagani F , Sosta S , Lanzini A
Published: January 2010

BACKGROUND

Stimulated bile acid synthesis preferentially utilises newly synthesised cholesterol, raising the posssiblity that combination of simvastatin (an inhibitor of cholesterol synthesis) with ursodeoxycholic acid (UDCA; a stimulator of bile acid synthesis) may result in reduced bile acid synthesis and greater enrichment of the pool with UDCA than that achieved with UDCA treatment alone.

AIMS

To investigate the effect of simvastatin and UDCA given alone and in combination on serum and biliary lipid and biliary bile acid composition.

METHODS

Eighteen patients with primary non-familial hypercholesterolaemia were studied during treatment with simvastatin 20 mg/day, UDCA 10 mg/kg/day, and a combination of the two drugs. Each regimen was given in random order for three months following a three month lead in period.

RESULTS

Simvastatin significantly reduced serum low density lipoprotein (LDL) cholesterol but biliary cholesterol concentration remained unchanged. Combination of the two drugs had no synergistic effect on serum cholesterol concentration, but significantly increased the proportion of UDCA in the bile acid pool from 35% during UDCA to 48% during combination treatment (p<0.04).

CONCLUSIONS

Results showed that: (1) simvastatin reduces serum LDL cholesterol but has no effect on biliary cholesterol concentration, supporting the concept that newly synthesised cholesterol is not the preferential source for biliary cholesterol; and (2) combination of simvastatin with UDCA has the predicted effect of enhancing the proportion of UDCA in the pool. This effect may be of benefit in the treatment of cholestatic liver diseases.
The role of apolipoprotein E and glucose intolerance in gallstone disease in middle aged subjects
Authors: Niemi M , Kervinen K , Rantala A , Kauma H , Päivänsalo M , Savolainen M J , Lilja M , Kesäniemi Y A
Published: January 2010

BACKGROUND

The polymorphism of apolipoprotein E has been suggested to be associated with the cholesterol content of gallstones, the crystallisation rate of gall bladder bile, and the prevalence of gallstone disease (GSD).

AIMS

To investigate whether apolipoprotein E polymorphism modulates the susceptibility to GSD at the population level and to study the possible associations between impaired glucose tolerance, diabetes, and GSD.

METHODS

Apolipoprotein E phenotypes were determined in a middle aged cohort of 261 randomly selected hypertensive men, 259 control men, 257 hypertensive women, and 267 control women. All subjects without a documented history of diabetes were submitted to a two hour oral glucose tolerance test (OGTT). GSD was verified by ultrasonography.

RESULTS

In women with apolipoprotein E2 (phenotypes E2/2, 2/3, and 2/4) compared with women without E2 (E3/3, 4/3, and 4/4), the odds ratio for GSD was 0.28 (95% confidence interval 0.08–0.92). There was no protective effect in men. The relative risk for GSD was 1.2 (0.8–1.7) for hypertensive women and 1.8 (1.0–2.7) for hypertensive men. In a stepwise multiple logistic regression model, E2 protected against GSD in women, whereas two hour blood glucose in the OGTT, serum insulin, and plasma triglycerides were risk factors. Elevated blood glucose during the OGTT was also a significant risk factor for GSD in men.

CONCLUSIONS

The data suggest that apolipoprotein E2 is a genetic factor providing protection against GSD in women. In contrast, impaired glucose tolerance and frank diabetes are associated with the risk of GSD.
The natural course of hepatitis C virus infection 18 years after an epidemic outbreak of non-A, non-B hepatitis in a plasmapheresis centre
Authors: Datz C , Cramp M , Haas T , Dietze O , Nitschko H , Froesner G , Muss N , Sandhofer F , Vogel W
Published: January 2010

BACKGROUND

The natural history of hepatitis C virus (HCV) infection is variable and factors determining the course of the illness are unclear.

AIMS

To determine the natural course of HCV infection in a well characterised group of patients 18 years after an epidemic outbreak of non-A, non-B hepatitis at a plasmapheresis centre.

METHODS

Between 1994 and 1996, 20 of 30 affected individuals were studied. HCV infection was confirmed using second and third generation ELISA test kits. HCV RNA was detected by a polymerase chain reaction (PCR) method and HCV genotyping was performed by analysing amplicons from the conserved 5′-non-translated region generated by nested PCR. Thirty two liver biopsies were carried out in 14 patients.

RESULTS

HCV antibodies were detected in all subjects. Eighteen patients had abnormal liver enzymes and 17 were HCV RNA positive, all of whom were infected with genotype 1a. Ninety per cent of this cohort showed evidence of chronic HCV infection with 50% having progressive liver disease and 20% cirrhosis 18 years after acute onset of non-A, non-B hepatitis. Considerable variation in disease outcome occurred between individuals and no correlation with clinical features of the acute illness was found.

CONCLUSIONS

Variability in the consequences of HCV infection in cases infected with the same virus suggests that host factors are important in determining disease outcome. The factors which determine differences in the natural history of the disease still remain to be elucidated.
Managing Budd-Chiari syndrome: a retrospective review of percutaneous hepatic vein angioplasty and surgical shunting
Authors: Fisher N C , McCafferty I , Dolapci M , Wali M , Buckels J A C , Olliff S P , Elias E
Published: January 2010

BACKGROUND

The role of percutaneous hepatic vein angioplasty in the management of Budd-Chiari syndrome has not been well defined. Over a 10 year period at our unit, we have often used this technique in cases of short length hepatic vein stenosis or occlusion, reserving surgical mesocaval shunting for cases of diffuse hepatic vein occlusion or failed angioplasty.

AIMS

To review the outcome of angioplasty and surgical shunting to define their respective roles.

PATIENTS

All patients treated by angioplasty or surgical shunting for non-malignant hepatic vein obstruction over a ten year period from 1987 to 1996.

METHODS

A case note review of pretreatment features and clinical outcome.

RESULTS

Angioplasty was attempted in 21 patients with patent hepatic vein branches and was succesful in 18; in three patients treatment was unsuccessful and these patients had surgical shunts. Fifteen patients were treated by surgical shunting only. Mortality according to definitive treatment was 3/18 following angioplasty and 8/18 following surgery; in most cases this reflected high risk status prior to treatment. Venous or shunt reocclusion rates were similar for both groups and were associated with subtherapeutic warfarin in half of these cases. Most surviving patients in both groups are asymptomatic although one surgical patient has chronic hepatic encephalopathy.

CONCLUSION

With appropriate case selection, many patients with Budd-Chiari syndrome caused by short length hepatic vein stenosis or occlusion may be managed successfully by angioplasty alone. Medium term outcome is good following this procedure provided that anticoagulation is maintained. Further follow up is required to assess for definitive benefits but we suggest that this should be included as a valid initial approach in the algorithm for management of Budd-Chiari syndrome.
Hepatitis C virus recurrence after liver transplantation
Authors: BIZOLLON T , DUCERF C , TREPO C , MUTIMER D
Published: January 2010

Cirrhosis due to hepatitis C virus (HCV) is now the most common indication of liver transplantation in Western Europe and the United States. In the absence of effective prophylaxis, recurrent HCV infection is almost inevitable. Though the natural history and intermediate term outcome of recurrent HCV are now better documented, those factors which may influence the recurrence of hepatitis and consequent progression of graft disease remain unclear. Interferon (IFN) as a sole agent for the treatment of recurrent infection has proved unsatisfactory. Early intervention with a combination of IFN and ribavirin seems promising, and this approach may prevent or delay progression of HCV related graft disease after liver transplantation.
Endoscopic assessment of oesophagitis: clinical and functional correlates and further validation of the Los Angeles classification
Authors: Lundell L R , Dent J , Bennett J R , Blum A L , Armstrong D , Galmiche J P , Johnson F , Hongo M , Richter J E , Spechler S J , Tytgat G N J , Wallin L
Published: January 2010

BACKGROUND

Endoscopic oesophageal changes are diagnostically helpful and identify patients exposed to the risk of disease chronicity. However, there is a serious lack of agreement about how to describe and classify the appearance of reflux oesophagitis

AIMS

To examine the reliability of criteria that describe the circumferential extent of mucosal breaks and to evaluate the functional and clinical correlates of patients with reflux disease whose oesophagitis was graded according to the Los Angeles system.

METHODS

Forty six endoscopists from different countries used a detailed worksheet to evaluate endoscopic video recordings from 22 patients with the full range of severity of reflux oesophagitis. In separate studies, Los Angeles system gradings were correlated with 24 hour oesophageal pH monitoring (178 patients), and with clinical trials of omeprazole treatment (277 patients).

RESULTS

Evaluation of circumferential extent of oesophagitis by the criterion of whether mucosal breaks extended between the tops of mucosal folds, gave acceptable agreement (mean κ value 0.4) among observers. This approach is used in the Los Angeles system. An alternative approach of grouping the circumferential extent of mucosal breaks as occupying 0–25%, 26–50%, 51–75%, 76–99%, or 100% of the oesophageal circumference, gave unacceptably high interobserver variation (mean κ values 0–0.15) for all but the lowest category of extent (mean κ value 0.4). Severity of oesophageal acid exposure was significantly (p<0.001) related to the severity grade of oesophagitis. Preteatment oesophagitis grades A–C were related to heartburn severity (p<0.01), outcomes of omeprazole (10 mg daily) treatment (p<0.01), and the risk for symptom relapse off therapy over six months (p<0.05).

CONCLUSIONS

Results add further support to previous studies for the clinical utility of the Los Angeles system for endoscopic grading of oesophagitis.
Corpus gastritis is protective against reflux oesophagitis
Authors: El-Serag H B , Sonnenberg A , Jamal M M , Inadomi J M , Crooks L A , Feddersen R M
Published: January 2010

BACKGROUND

Gastric acid is important in the pathogenesis of reflux oesophagitis. Acid production by the gastric corpus is reduced in corpus gastritis.

AIMS

To determine whether corpus gastritis protects against reflux oesophagitis.

METHODS

Patients presenting for elective oesophagogastroduodenoscopy were studied. Two biopsy specimens were taken from the antrum, corpus, and cardia and stained with haematoxylin/eosin and Diff-Quick II stains. The presence and severity of gastritis were graded according to a modified updated Sydney classification.

RESULTS

Of 302 patients, 154 had endoscopic signs of reflux oesophagitis. There was no difference between patients with and controls without oesophagitis in the overall infection rates with Helicobacter pylori. Acute or chronic corpus gastritis occurred less often in patients with than those without reflux oesophagitis. Compared with controls, corpus gastritis was less severe in patients with reflux oesophagitis. The presence of acute or chronic gastritis in the corpus was significantly correlated with either type of gastritis in other areas of the stomach. In a multivariate logistic regression, age, sex, smoking status, and the presence of chronic corpus gastritis all exerted a significant influence on the presence of reflux oesophagitis. Chronic corpus gastritis was associated with a 54% reduced risk for reflux oesophagitis.

CONCLUSIONS

While infection withH pylori alone may not affect the occurrence of reflux oesophagitis, the development of chronic corpus gastritis seems to be protective.
A prospective randomised trial of a “test and treat” policy versus endoscopy based management in youngHelicobacter pylori positive patients with ulcer-like dyspepsia, referred to a hospital clinic
Authors: Heaney A , Collins J S A , Watson R G P , McFarland R J , Bamford K B , Tham T C K
Published: January 2010

BACKGROUND

Management of dyspepsia remains a controversial area. Although the EuropeanHelicobacter pylori study group has advised empirical eradication therapy without oesophagogastroduodenoscopy (OGD) in young H pylori positive dyspeptic patients who do not exhibit alarm symptoms, this strategy has not been subjected to clinical trial.

AIMS

To compare a “test and treat” eradication policy against management by OGD.

PATIENTS

Consecutive subjects were prospectively recruited from open access OGD and outpatient referrals.

METHODS

H pylori status was assessed using the carbon-13 urea breath test.H pylori positive patients were randomised to either empirical eradication or OGD. Symptoms and quality of life scores were assessed at baseline and subsequent reviews over a 12 month period.

RESULTS

A total of 104H pylori positive patients aged under 45 years were recruited. Fifty two were randomised to receive empirical eradication therapy and 52 to OGD. Results were analysed using an intention to treat policy. Dyspepsia scores significantly improved in both groups over 12 months compared with baseline; however, dyspepsia scores were significantly better in the empirical eradication group. Quality of life showed significant improvements in both groups at 12 months; however, physical role functioning was significantly improved in the empirical eradication group. Fourteen (27%) in the empirical eradication group subsequently proceeded to OGD because of no improvement in dyspepsia.

CONCLUSIONS

This randomised study strongly supports the use of empirical H pylori eradication in patients referred to secondary practice; it is estimated that 73% of OGDs in this group would have been avoided with no detriment to clinical outcome.
Synergistic effects of interferon γ and tumour necrosis factor α on T84 cell function
Authors: Fish S M , Proujansky R , Reenstra W W
Published: January 2010

BACKGROUND

Inflammatory bowel disease (IBD) is characterised by chronic intestinal inflammation and increased epithelial permeability. Both tumour necrosis factor α (TNF-α) and interferon γ (IFN-γ) have been implicated in IBD.

AIMS

To understand better the effects of these cytokines on epithelial cell function.

METHODS

T84 cells were cultured with IFN-γ and TNF-α and changes in transepithelial resistance (TER), fluorescein isothiocyanate (FITC) dextran flux, short circuit current (Isc), cystic fibrosis transmembrane conductance regulator (CFTR) protein levels, cell morphology, TNF receptor gene expression, and apoptosis were assayed.

RESULTS

Relative to controls, significant changes (p<0.05) occurred in cells incubated with IFN-γ for two days: TER was decreased to 20 (6.2)%, FITC–dextran flux was increased by 109 (19)-fold, cAMP and Ca dependentIsc were decreased to 51 (6.4)% and 24 (2.2)%, respectively, and CFTR levels were decreased to 47 (11)%. Cell morphology was altered but cell death was not induced. TNF receptor mRNA levels were increased. When added with IFN-γ, TNF-α accelerated IFN-γ dependent changes. Relative to controls, significant changes occurred after one day of culture with IFN-γ plus TNF-α: TER was decreased to 27 (3.5)%, FITC–dextran flux was increased by 185 (45)-fold, and cAMP and Ca dependentIsc were decreased to 66 (12)% and 35 (6.8)%, respectively. TNF-α also enhanced IFN-γ dependent changes in cell morphology but did not induce cell death.

CONCLUSION

IFN-γ alters T84 cell epithelial properties and TNF-α can enhance these effects, perhaps due to IFN-γ dependent increases in TNF receptor gene expression. Overall, these studies suggest that in IBD, TNF-α may have synergistic effects on IFN-γ mediated alterations of epithelial cell function.