Ulcerative colitis treatment : an insight into daily clinical practice

BACKGROUND

The natural history of ulcerative colitis (UC) is unpredictable. Factors associated with the need for different types of step-up therapy in UC patients failing on 5-aminosalicylic acid (5-ASA) or corticosteroids are understudied.

AIMS

Describe step-up therapy in patients with UC the first year after failing on 5-ASA or corticosteroids.

METHODS

A Belgian, multi-center, prospective, non-interventional observational study comprising adult UC patients failing on 5-ASA or corticosteroids and naïve to immunomodulators/ biologicals. During a 12 months follow-up, patient characteristics, demography, medical therapy, biomarkers, therapy adherence and quality of life (QoL) were assessed.

RESULTS

After 1 year, 35% of the patients were on biological therapy. Use of anti-TNF differed depending on baseline treatment: corticosteroid-refractory patients (55.8%), 5-ASA refractory (20.0%), and corticosteroid-dependent (16.0%) patients (p<0.001). The decision to start a line of therapy was based on the Mayo combined severity but not on biomarkers like faecal calprotectin, haemoglobin, CRP, albumin, platelets, and number of extraintestinal manifestations. At year 1, 84.2% of the patients had only mild UC or remission and a significant improvement of fatigue (p=0.004) and IBDQ scores (p<0.001) were observed implying an improved QoL.

CONCLUSION

Treatment step-up, based on clinical scores in immunomodulatory and anti-TNF naïve patients with UC, provides good clinical outcomes and QoL.

Grapevine trunk diseases under thermal and water stresses

Heat and water stresses, individually or combined, affect both the plant (development, physiology, and production) and the pathogens (growth, morphology, dissemination, distribution, and virulence). The grapevine response to combined abiotic and biotic stresses is complex and cannot be inferred from the response to each single stress. Several factors might impact the response and the recovery of the grapevine, such as the intensity, duration, and timing of the stresses. In the heat/water stress-GTDs-grapevine interaction, the nature of the pathogens, and the host, i.e., the nature of the rootstock, the cultivar and the clone, has a great importance. This review highlights the lack of studies investigating the response to combined stresses, in particular molecular studies, and the misreading of the relationship between rootstock and scion in the relationship GTDs/abiotic stresses. Grapevine trunk diseases (GTDs) are one of the biggest threats to vineyard sustainability in the next 30 years. Although many treatments and practices are used to manage GTDs, there has been an increase in the prevalence of these diseases due to several factors such as vineyard intensification, aging vineyards, or nursery practices. The ban of efficient treatments, i.e., sodium arsenite, carbendazim, and benomyl, in the early 2000s may be partly responsible for the fast spread of these diseases. However, GTD-associated fungi can act as endophytes for several years on, or inside the vine until the appearance of the first symptoms. This prompted several researchers to hypothesise that abiotic conditions, especially thermal and water stresses, were involved in the initiation of GTD symptoms. Unfortunately, the frequency of these abiotic conditions occurring is likely to increase according to the recent consensus scenario of climate change, especially in wine-growing areas. In this article, following a review on the impact of combined thermal and water stresses on grapevine physiology, we will examine (1) how this combination of stresses might influence the lifestyle of GTD pathogens, (2) learnings from grapevine field experiments and modelling aiming at studying biotic and abiotic stresses, and (3) what mechanistic concepts can be used to explain how these stresses might affect the grapevine plant status.

Vitis Methods to Understand and Develop Strategies for Diagnosis and Sustainable Control of Grapevine Trunk Diseases

Vitis vinifera is affected by many diseases every year, depending on causal agents, susceptibility of cultivars, and climate region. Some are caused by a single agent, such as gray mold caused by Botrytis cinerea or powdery mildew caused by Erysiphe necator. Others result from the actions of a complex of pathogens such as grapevine trunk diseases (GTDs). GTDs are presently among the most devastating diseases in viticulture worldwide because both the economic losses and the long-term sustainability of vineyards are strongly affected. The complexity of GTDs results from the diversity of associated fungi, the undetermined period of latency within the vine (asymptomatic status), the erratic foliar symptom expression from one year to the next, and, probably correlated with all of these points, the lack of efficient strategies to control them. Distinct methods can be beneficial to improve our knowledge of GTDs. In vitro bioassays with cell suspensions, calli, foliar discs, full leaves, or plantlets, and in vivo natural bioassays with cuttings, grafted plants in the greenhouse, or artificially infected ones in the vineyard, can be applied by using progressive integrative levels of in vitro and in vivo, depending on the information searched. In this review, the methods available to understand GTDs are described in terms of experimental procedures, main obtained results, and deliverable prospects. The advantages and disadvantages of each model are also discussed.

Thermal convection in three-dimensional fractured porous media

Thermal convection is numerically computed in three-dimensional (3D) fluid saturated isotropically fractured porous media. Fractures are randomly inserted as two-dimensional (2D) convex polygons. Flow is governed by Darcy's 2D and 3D laws in the fractures and in the porous medium, respectively; exchanges take place between these two structures. Results for unfractured porous media are in agreement with known theoretical predictions. The influence of parameters such as the fracture aperture (or fracture transmissivity) and the fracture density on the heat released by the whole system is studied for Rayleigh numbers up to 150 in cubic boxes with closed-top conditions. Then, fractured media are compared to homogeneous porous media with the same macroscopic properties. Three major results could be derived from this study. The behavior of the system, in terms of heat release, is determined as a function of fracture density and fracture transmissivity. First, the increase in the output flux with fracture density is linear over the range of fracture density tested. Second, the increase in output flux as a function of fracture transmissivity shows the importance of percolation. Third, results show that the effective approach is not always valid, and that the mismatch between the full calculations and the effective medium approach depends on the fracture density in a crucial way.

Toxicity of extracellular proteins from Diplodia seriata and Neofusicoccum parvum involved in grapevine Botryosphaeria dieback

Botryosphaeria dieback, esca and Eutypa dieback are three economic major grapevine trunk diseases that cause severe yield reduction in vineyards worldwide. The frequency of disease symptoms has increased considerably over the past decade, and no efficient treatment is currently available to control these diseases. The different fungi associated with grapevine trunk diseases mainly induce necrotic wood and characteristic foliar symptoms. In this context, fungi virulence factors and host invasion are not well understood. We hypothesise that extracellular proteins produced by Diplodia seriata and Neofusicoccum parvum, two causal agents associated with Botryosphaeria dieback, are virulence factors responsible for the pathogenicity. In our previous work, we demonstrated that the total extracellular compounds produced by N. parvum induced more necrosis on Chardonnay calli and triggered a different defence gene expression pattern than those produced by D. seriata. Furthermore, this aggressiveness was not clearly correlated with the production of mellein, a characteristic phytotoxin of Botryosphaeriaceae, in our in vitro calli model. To characterise other potential virulence factors and to understand the mechanisms of host invasion by the fungus, we evaluated the profile, quantity and the impact of extracellular proteins produced by these fungi on Vitis vinifera calli necrosis and defence gene expression. Our results reveal that, under the same conditions, N. parvum produces more extracellular proteins and in higher concentrations than D. seriata. With Vitis vinifera cv. Chardonnay cells, we showed that equivalent concentrations of proteins secreted by N. parvum were more aggressive than those of D. seriata in producing necrosis and that they clearly induced more grapevine defence genes.

Extracellular compounds produced by fungi associated with Botryosphaeria dieback induce differential defence gene expression patterns and necrosis in Vitis vinifera cv. Chardonnay cells

Three major grapevine trunk diseases, esca, botryosphaeria dieback and eutypa dieback, pose important economic problems for vineyards worldwide, and currently, no efficient treatment is available to control these diseases. The different fungi associated with grapevine trunk diseases can be isolated in the necrotic wood, but not in the symptomatic leaves. Other factors seem to be responsible for the foliar symptoms and may represent the link between wood and foliar symptoms. One hypothesis is that the extracellular compounds produced by the fungi associated with grapevine trunk diseases are responsible for pathogenicity.In the present work, we used Vitis vinifera cv. Chardonnay cells to test the aggressiveness of total extracellular compounds produced by Diplodia seriata and Neofusicoccum parvum, two causal agents associated with botryosphaeria dieback. Additionally, the toxicity of purified mellein, a characteristic toxin present in the extracellular compounds of Botryosphaeriaceae, was assessed.Our results show that the total extracellular compounds produced by N. parvum induce more necrosis on Chardonnay calli and induce a different defence gene expression pattern than those of D. seriata. Mellein was produced by both fungi in amounts proportional to its aggressiveness. However, when purified mellein was added to the culture medium of calli, only a delayed necrosis and a lower-level expression of defence genes were observed. Extracellular compounds seem to be involved in the pathogenicity of the fungi associated with botryosphaeria dieback. However, the doses of mellein used in this study are 100 times higher than those found in the liquid fungal cultures: therefore, the possible function of this toxin is discussed.

Profile of pediatric Crohn's disease in Belgium

AIM

A Belgian registry for pediatric Crohn's disease, BELCRO, was created. This first report aims at describing disease presentation and phenotype and determining associations between variables at diagnosis and registration in the database.

METHODS

Through a collaborative network, children with previously established Crohn's disease and newly diagnosed children and adolescents (under 18 y of age) were recruited over a 2 year period. Data were collected by 23 centers and entered in a database. Statistical association tests analyzed relationships between variables of interest at diagnosis.

RESULTS

Two hundred fifty-five patients were included. Median age at diagnosis was 12.5 y (range: 1.6-18 y); median duration of symptoms prior to diagnosis was 3 m (range: 1-12 m). Neonatal history and previous medical history did not influence disease onset nor disease behavior. Fifty three % of these patients presented with a BMI z-score < -1. CRP was an independent predictor of disease severity. Steroids were widely used as initial treatment in moderate to severe and extensive disease. Over time, immunomodulators and biological were prescribed more frequently, reflecting a lower prescription rate for steroids and 5-ASA. A positive family history was the sole significant determinant for earlier use of immunosuppression.

CONCLUSION

In Belgium, the median age of children presenting with Crohn's disease is 12.5 y. Faltering growth, extensive disease and upper GI involvement are frequent. CRP is an independent predictive factor of disease activity. A positive family history appears to be the main determinant for initial treatment choice.

Fast and sharp decrease in calprotectin predicts remission by infliximab in anti-TNF naïve patients with ulcerative colitis

AIM

To evaluate the effect of infliximab induction therapy on calprotectin levels in patients with ulcerative colitis (UC).

PATIENTS AND METHODS

In this prospective study 53 patients with active UC from 17 centers were treated with infliximab therapy (5 mg/kg) at baseline, week 2, and week 6. Faecal calprotectin was measured every week. Sigmoidoscopies were performed at baseline, week 6 and week 10.

RESULTS

Median calprotectin levels decreased from 1260 (IQR 278.5- 3418) at baseline to 72.5 (IQR 18.5 - 463) at week 10 (p<0.001). After 10 weeks, infliximab therapy induced endoscopic remission and a decrease in calprotectin to<50 mg/kg or at least a 80% decrease from baseline level in 58% of patients. A significant and steep decrease of calprotectin levels was seen at week 2 for patients with an endoscopic remission at week 10 as compared to patients who did not show a remission. (p<0.001). At week 10 an excellent correlation was found between endoscopic remission and clinical Mayo score reflected by an AUC of ROC analyses of 0.94 (0.87-1) and with calprotectin measurements (AUC 0.91 (0.81-1)) : all patients with calprotectin levels <50 mg/kg, and a normal clinical Mayo score (=0) were in endoscopic remission.

CONCLUSIONS

Infliximab induces a fast and significant decrease of faecal calprotectin levels in anti-TNF naïve patients with ulcerative colitis predictive for remission of disease.

Use of immunoglobulins in the prevention of GvHD in a xenogeneic NOD/SCID/γc- mouse model

The efficacy of IVIG in preventing GvHD has not been definitely demonstrated clinically. Using a xenogeneic model of GvHD in NOD/SCID/γc- (NSG) mice, we showed that weekly administration of IVIG significantly reduced the incidence and associated mortality of GvHD to a degree similar to CsA. Unlike CsA and OKT3, IVIG were not associated with inhibition of human T-cell proliferation in mice. Instead, IVIG significantly inhibited the secretion of human IL-17, IL-2, IFN-γ and IL-15 suggesting that IVIG prevented GvHD by immunomodulation. Furthermore, the pattern of modification of the human cytokine storm differed from that observed with CsA and OKT3. Finally, in a humanized mouse model of immune reconstitution, in which NSG mice were engrafted with human CD34(+) stem cells, IVIG transiently inhibited B-cell reconstitution, whereas peripheral T-cell reconstitution and thymopoiesis were unaffected. Together these in vivo data raise debate related to the appropriateness of IVIG in GvHD prophylaxis. In addition, this model provides an opportunity to further elucidate the precise mechanism(s) by which IVIG inhibit GvHD.

Early events prior to visual symptoms in the apoplectic form of grapevine esca disease

Plant infection by pathogens generates various forms of symptoms. Most of them have been described as soon as they become visible, whereas preceding, discrete signs during incubation are poorly or not understood. In Vitis vinifera, esca-related pathogenic fungi inhabit living trunk wood and induce the so-called apoplexy, a sudden wilting of leaves within a few days. To further understand the apoplexy expression, the period preceding symptom appearance was investigated by following physiological and molecular markers associated with photosynthetic mechanisms and stress responses. Within the week preceding symptoms, drastic physiological alterations of photosynthesis were registered in pre-apoplectic vines, as revealed by a decrease in gas exchange, changes in chlorophyll fluorescence, and repression of photosynthesis-related genes. In the meantime, expression of defense-related genes was induced and amplified during symptom expression. Water-stress-related genes were specifically investigated because water transport may be impeded by clogging xylem vessels due to esca-causing fungi. Neither of the tested water-stress-related genes was affected in pre-apoplectic grapevine leaves whereas these genes were downregulated in drying leaves. Our results suggest that, during incubation of esca apoplexy, grapevine perceives some signals (likely fungi-originated toxins) and reacts by reducing photosynthesis and triggering defense mechanisms.

Season of birth and not vitamin D receptor promoter polymorphisms is a risk factor for multiple sclerosis

Both genetic and environmental factors contribute to multiple sclerosis, the most common neurodegenerative disorder with onset in young adults. The objective of the current study is, based on the hypothesis that environmentally predisposed individuals are at risk for multiple sclerosis, to investigate whether they also carry genetic variants within the vitamin D machinery. Using medical files and DNA samples from 583 trios (a patient and both parents) of the French Multiple Sclerosis Genetics Group as well as data from the French Statistics Bureau, we aimed to assess whether: (1) a seasonality of birth was observed in French multiple sclerosis patients; (2) three single nucleotide polymorphisms within the promoter region of the vitamin D receptor were associated with multiple sclerosis susceptibility; and (3) the combination of a high risk month of birth and vitamin D receptor polymorphisms were correlated to multiple sclerosis incidence. We observed a significantly reduced number of individuals born in November who were later diagnosed as multiple sclerosis patients. However, we found no association between the three studied vitamin D receptor polymorphisms and multiple sclerosis. In conclusion, our data suggest that high levels of vitamin D during the third trimester of pregnancy could be a protective factor for multiple sclerosis.

Sugars and flowering in the grapevine (Vitis vinifera L.)

Sugars play an important role in grapevine flowering. This complex process from inflorescence initiation to fruit maturity takes two growing seasons. Currently, most of the available data concern the involvement of sugars as energy sources during the formation of reproductive structures from initiation of inflorescences during the summer of the first year, until flower opening during the following spring. Sugars devoted to the development of reproductive structures are supplied either by wood reserves or by photosynthesis in leaves or inflorescences, depending on the stage of development. Female meiosis appears to be a key point in the success of flower formation because (i) flowers are vulnerable at this stage and (ii) it corresponds in the whole plant to the transition between reserve mobilization from perennial organs (roots, trunk, and canes) towards efficient leaf photosynthesis. The perturbation of reserve replenishment during the previous year provokes perturbation in the development of inflorescences, whereas altering the photosynthetic sources affects the formation of flowers during the same year. In particular, a lack of sugar availability in flowers at female meiosis caused by various environmental or physiological fluctuations may lead to drastic flower abortion. Apart from energy, sugars also play roles as regulators of gene expression and as signal molecules that may be involved in stress responses. In the future, these two topics should be further investigated in the grapevine considering the sensitivity of flowers to environmental stresses at meiosis.

[Reactivation of ocular toxoplasmosis after laser in situ keratomileusis]

Laser in situ keratomileusis (LASIK) is a safe and efficient refractive surgical procedure that provides excellent results in most cases. Several complications have been reported, most of them related to the posterior segment of the eye. Although they are quite rare, a growing number of vitreoretinal pathologic conditions after LASIK have been reported. To date no article has reported an inflammatory or infectious disease of the posterior segment after a LASIK procedure. We report a case of reactivation of toxoplasmic chorioretinitis that occurred 5 days after a LASIK procedure. Clinical outcome was spontaneously favorable after 1 month, with no loss of vision. Although a causal effect between LASIK and toxoplasmic chorioretinitis reactivation cannot be proven with a single case report, we stress the importance of dilated fundus examination in LASIK preoperative assessment: our case suggests that in the presence of preoperative toxoplasmic chorioretinitis scars, increased retinal monitoring is required.

[Clinical case of the month. Hepatitis B reactivation in an Ag HBs negative patient]

A 66-year-old man, Ag HBs negative, suffering from glomerulonephritis was treated with prednisone. Hepatitis B reactivation was observed after increasing and regression of corticotherapy. Pathogenesis, efficient therapy and prevention of reactivation of hepatitis B will be reviewed.

Alteration of photosynthesis in grapevines affected by esca

ABSTRACT To further understand the development of esca disease in grapevine, its physiological impact on plants grown in the vineyard was characterized, focusing mainly on photosynthesis. For this purpose, the state of the photosynthetic apparatus was evaluated in symptomatic and asymptomatic leaves in esca-infected grape plants, and wood carbohydrates stored in annual canes were assayed. In symptomatic leaves, esca greatly affected grapevine physiology. Foliar symptoms were associated with both stomatal closure and alteration of the photosynthetic apparatus as revealed by (i) a decrease in CO(2) assimilation, transpiration, and a significant increase in intercellular CO(2) concentration; (ii) a strong drop in both the maximum fluorescence yield and the effective Photosystem II quantum yield; and (iii) a reduction of total chlorophyll but a stable carotenoid content. On symptomatic canes, all these variables were affected more on leaves with symptoms than without symptoms, suggesting a gradation in photosynthesis disruptions in the plant according to the degree of symptom severity. In addition, canes of symptomatic plants had reduced carbohydrate reserves during the winter rest, whether they exhibit symptoms or not. The following year, the lower pool of reserves may contribute to a significant decrease in plant development, as well as a global loss in plant vigor.

Early development of stricturing or penetrating pattern in Crohn's disease is influenced by disease location, number of flares, and smoking but not by NOD2/CARD15 genotype

BACKGROUND

Crohn's disease is a heterogeneous entity. Disease behaviour, characterised as stricturing, penetrating, or non-stricturing non-penetrating, is a clinically important phenotype as it is associated with complications and need for surgery. It has recently been showed that the behaviour of Crohn's disease changes over the course of the disease.

AIM

To assess the association between rapid development of a penetrating or stricturing pattern of Crohn's disease and demographic and clinical characteristics as well as NOD2/CARD15 genotype.

PATIENTS AND METHODS

A total of 163 patients with a firm diagnosis of Crohn's disease and who had non-penetrating non-stricturing disease at diagnosis were studied. Various demographic and clinical characteristics as well as antisaccharomyces cerevisiae antibody status and NOD2/CARD15 genotype were documented in these patients. These characteristics were compared in subgroups of patients according to evolution of disease behaviour five years after diagnosis.

RESULTS

Five years after diagnosis there were 110 (67.5%) patients with non- structuring non-penetrating disease, 18 (11%) with stricturing disease, and 35 (21.5%) with penetrating disease. In multivariate analysis, only disease location and number of flares per year were significantly discriminant between the three subgroups (p=0.0009 and 0.0001, respectively). Ileal location of the disease was associated with a stricturing pattern while a high number of flares was associated with a penetrating pattern. Active smoking was also associated with a penetrating pattern compared with a non-stricturing non-penetrating pattern only.

CONCLUSIONS

Early development of stricturing or penetrating behaviour in Crohn's disease is influenced by disease location, clinical activity of the disease, and smoking habit, but not by NOD2/CARD15 genotype.

Adhesion of Escherichia coli, Citrobacter freundii and Klebsiella pneumoniae isolated from milk: consequence on the efficiency of sanitation procedures

The effects of adhesion and of biofilm development on the efficiency of cleaning and disinfection procedures were investigated on three strains belonging to the E. coli, C. freundii and K. pneumoniae species, which were able to raise more or less complex biofilms. Resistance to a rinsing procedure was strain dependent but not related to the biofilm structure: E. coli was poorly adherent although embedded in an organic matrix. Conversely, a similar increase in the heat- and disinfectant-resistance was observed, regardless of the complexity of the biofilm (more or less significant organic matrix). These result suggested the essential role of the bacterial physiological state in resistance to sanitation procedures.

[Barrett's esophagus: overview]

Barrett's oesophagus (BE) is a segment of columnar lined epithelium in the distal oesophagus, above the gastrooesophageal junction. So it is important to localize this junction endoscopically; the proximal margin of the gastric folds is the anatomic landmark. Another important feature of BE is the specialized intestinal metaplasia. In the aetiology of this condition, acid reflux is a primary event but there is evidence that other factors are causal. As BE is a well known premalignant condition, detection of dysplastic epithelium and its severity is the crucial element. Practical guidelines are presented for endoscopic surveillance program. The purpose is the early detection of high grade dysplasia and carcinoma to advise oesophagectomy or endoscopic ablation therapy for patients unfit to undergo surgery.

Isolation of a member of ets gene family in the polychaete annelid Perinereis cultrifera

Numerous genes belonging to the ets gene family have been described for a few years. The founder of this family is the v-ets proto-oncogene, which is the viral counterpart of the chicken c-ets-1 proto-oncogene. Main research was carried out both on Vertebrates, Drosophila and the nematod Caenorhabditis elegans. Previously, two genes of this family named Nd ets and Nd erg, were isolated in the polychaete annelid Hediste (Nereis) diversicolor. Here we have described the isolation of one gene from the ets family in another polychaete annelid named Perinereis cultrifera. By polymerase chain reaction using degenerated primers, we have amplified an approximatively 515 pb genomic region encoding the ETS domain and another domain designed as "R" domain by Qi et al. (1992) and which can mediate transactivation. By using this method for isolating members of the ets gene family, we are going to realize a phylogenetic study of the phylum of polychaete annelids.

Extensive protein carbonylation precedes acrolein-mediated cell death in mouse hepatocytes

Allyl alcohol hepatotoxicity is mediated by an alcohol dehydrogenase-derived biotranformation product, acrolein. This highly reactive alpha,beta-unsaturated aldehyde readily alkylates model proteins in vitro, forming, among other products, Michael addition adducts that possess a free carbonyl group. Whether such damage accompanies acrolein-mediated toxicity in cells is unknown. In this work we established that allyl alcohol toxicity in mouse hepatocytes involves extensive carbonylation of a wide range of proteins, and that the severity of such damage to a subset of 18-50 kDa proteins closely correlated with the degree of cell death. In addition to abolishing cytotoxicity and glutathione depletion, the alcohol dehydrogenase inhibitor 4-methyl pyrazole strongly attenuated protein carbonylation. Conversely, cyanamide, an aldehyde dehydrogenase inhibitor, enhanced cytotoxicity and protein carbonylation. Since protein carbonylation clearly preceded the loss of membrane integrity, it may be associated with the toxic process leading to cell death.

Binding interactions between barley thaumatin-like proteins and (1,3)-beta-D-glucans. Kinetics, specificity, structural analysis and biological implications

The specificity and kinetics of the interaction between the pathogenesis-related group of thaumatin-like proteins (PR5) in higher plants and (1,3)-beta-D-glucans have been investigated. Two thaumatin-like proteins with 60% amino-acid sequence identity were purified from extracts of germinated barley grain, and were designated HvPR5b and HvPR5c. Purified HvPR5c interacted with insoluble (1,3)-beta-D-glucans, but not with cellulose, pustulan, xylan, chitin or a yeast mannoprotein. Tight binding was observed with unbranched and unsubstituted (1,3)-beta-D-glucans, and weaker binding was seen if (1,6)-beta-linked branch points or beta-glucosyl substituents were present in the substrate. The HvPR5b protein interacted weakly with insoluble (1,3)-beta-D-glucans and did not bind to any of the other polysaccharides tested. This indicated that only specific barley PR5 isoforms interact tightly with (1,3)-beta-D-glucans. The complete primary structures of HvPR5b and HvPR5c were determined and used to construct molecular models of HvPR5b and HvPR5c, based on known three-dimensional structures of related thaumatin-like proteins. The models were examined for features that may be associated with (1,3)-beta-D-glucan binding, and a potential (1,3)-beta-D-glucan-binding region was located on the surface of HvPR5c. No obvious structural features that would prevent binding of (1,3)-beta-D-glucan to HvPR5b were identified, but several of the amino acids in HvPR5c that are likely to interact with (1,3)-beta-D-glucans are not present in HvPR5b.

Potential occurrence of adhering living Bacillus spores in milk product processing lines

AIMS

The hygienic risk associated with microbial soil on surfaces of milk processing lines was evaluated, based on experimental results.

METHODS AND RESULTS

From a panel of Bacillus spores isolated from milk products, B. cereus CUETM 98/4, was found to be highly resistant to heat (D100=3.32 min in whole milk) and oxidant disinfectant (70% lethality of adherent spores with Ikalin 2%). From adhesion trials, up to 1.1 x 10(7) spores cm(-2) were found to be adherent to solid surfaces when suspended in saline or in custard (10(5) and 10(7) cfu ml(-1)), and over 10% of these adherent spores would resist the cleaning procedure.

CONCLUSION

A highly contaminated milk (10(5) cfu ml(-1)) subjected to a current sterilization process (8 log reduction) led to a residual contamination of less than 1 cfu in the representative processing line after a complete production run.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study highlighted the fact that under appropriate processing conditions (efficient sterilization and cleaning procedures), even disinfection would be sufficient to eliminate any contamination risk. Conversely, the disinfection procedure becomes an essential step under inappropriate processing conditions.

The antihypertensive hydralazine is an efficient scavenger of acrolein

Recent work indicates the highly toxic alpha,beta-unsaturated aldehyde acrolein is formed during the peroxidation of polyunsaturated lipids, raising the possibility that it functions as a 'toxicological second messenger' during oxidative cell injury. Acrolein reacts rapidly with proteins, forming adducts that retain carbonyl groups. Damage by this route may thus contribute to the burden of carbonylated proteins in tissues. This work evaluated several amine compounds with known aldehyde-scavenging properties for their ability to attenuate protein carbonylation by acrolein. The compounds tested were: (i) the glycoxidation inhibitors, aminoguanidine and carnosine; (ii) the antihypertensive, hydralazine; and (iii) the classic carbonyl reagent, methoxyamine. Each compound attenuated carbonylation of a model protein, bovine serum albumin, during reactions with acrolein at neutral pH and 37 degrees C. However, the most efficient agent was hydralazine, which strongly suppressed carbonylation under these conditions. Study of the rate of reaction between acrolein and the various amines in a protein-free buffered system buttressed these findings, since hydralazine reacted with acrolein at rates 2-3 times faster than its reaction with the other scavengers. Hydralazine also protected isolated mouse hepatocytes against cell killing by allyl alcohol, which undergoes in situ alcohol dehydrogenase-catalysed conversion to acrolein.

[Prevalence and treatment of Helicobacter pylori in gastro-duodenal ulcers. An experience in Liege]

Between April 1998 and July 1999, we prospectively investigated 152 patients with gastric or duodenal ulcer and we observed concomitant H. pylori infection in 72.8% and 78.5% respectively. We proposed to the GPs of these patients the recommended triple therapy (omeprazole 20 mg, amoxicillin 1 g and clarithromycin 500 mg (OAC) twice daily for 7 or 10 days). H. pylori eradication was tested using the C13-urea breath test. Our results showed a modest overall eradication rate of about 70%. We have to persuade the patients and the GPs of the benefit of antibiotics and of the importance of the correct dosages. We have to continue to follow the resistance against antibiotics.

Effects of macrolide antibiotics on CYP3A expression in human and rat hepatocytes: interspecies differences in response to troleandomycin

The effects of various macrolide antibiotics [triacetyloleandomycin (TAO), clarithromycin, azithromycin, roxithromycin, erythromycin base] and the new ketolide HMR3004 on CYP3A expression were evaluated in human and rat hepatocytes. Cells were treated for 3 days with nontoxic concentrations of the drugs, and CYP3A induction was assessed through midazolam hydroxylase activity and Western and Northern blot analyses. In rat hepatocytes, no induction of CYP3A1 expression was observed following exposure to macrolides, even to erythromycin base and TAO (well known in vivo CYP3A1 inducers), whereas dexamethasone and phenobarbital were confirmed to induce this enzyme. In contrast, treatment of fresh and thawed human hepatocytes with TAO, produced an increase of midazolam hydroxylation (4-fold over control). This result was in agreement with the high amount of CYP3A4 protein and mRNA revealed by Western and Northern blot analyses. Other tested macrolides had no induction effect on CYP3A expression. These results confirmed the interspecies variability of CYP3A regulation in hepatocytes and raised the question of its mechanism of induction by macrolides in human liver.

Role of cytochrome P450 3A in the metabolism of mefloquine in human and animal hepatocytes

We studied mefloquine metabolism in cells and microsomes isolated from human and animal (monkey, dog, rat) livers. In both hepatocytes and microsomes, mefloquine underwent conversion to two major metabolites, carboxymefloquine and hydroxymefloquine. In human cells and microsomes these metabolites only were formed, as already demonstrated in vivo, while in other species several unidentified metabolites were also detected. After a 48 hr incubation with human and rat hepatocytes, metabolites accounted for 55-65% of the initial drug concentration, whereas in monkey and dog hepatocytes, mefloquine was entirely metabolized after 15 and 39 hrs, respectively. The consumption of mefloquine was less extensive in microsomes, and unchanged drug represented 60% (monkey) to 85-100% (human, dog, rat) of the total radioactivity after 5 hr incubations. The involvement of the cytochrome P450 3A subfamily in mefloquine biotransformation was suggested by several lines of evidence. Firstly, mefloquine metabolism was strongly increased in hepatic microsomes from dexamethasone-pretreated rats, and also in human and rat hepatocytes after prior treatment with a cytochrome P450 3A inducer. Secondly, mefloquine biotransformation in rifampycin-induced human hepatocytes was inhibited in a concentration-dependent manner by the cytochrome P450 3A inhibitor ketoconazole and thirdly, a strong correlation was found between erythromycin-N-demethylase activity (mediated by cytochrome P450 3A) and mefloquine metabolism in human microsomes (r=0.81, P < 0.05, N=13). Collectively, these findings concerning the role of cytochrome P450 3A in mefloquine metabolism may have important in vivo consequences especially with regard to the choice of agents used in multidrug antimalarial regimens.

[Endoscopic ultrasonography in the diagnosis and staging of pancreatic and ampullary cancer: influence on patient management]

Accurate preoperative staging is now more prerequisite in the management of cancer of the pancreas and ampulla in order to orientate the patient toward the best selected treatment: either a curative or a palliative surgery associated or not with a pre- or postoperative multimodal therapy, or an endoscopic palliative technique which does not require surgery. Endoscopic ultrasonography (EUS) appears to be a highly accurate diagnostic procedure in the assessment of local resectability because it enables detailed visualization of the pancreatic gland, the depth of infiltration into the surrounding tissue and organs and visualisation of regional lymph nodes involvement. EUS-guided fine needle aspiration for cytology will provide a tissue diagnosis. The likelihood of successful resection for palliative or cure can be predicted before surgery. The following overview will point out the clinical impact of EUS on diagnosis, staging and management of these tumors.

[Epidemiological aspects, risk factors, and detection of pancreatic cancer]

The incidence of pancreatic cancer (PC) is increasing in developing countries. Smoking, reduced consumption of fruits and vegetables, chronic pancreatitis appear to be the best established risk factors. PC is often diagnosed at a late stage. We have to look for it when dyspepsia with weight loss, pancreatic pain or impaired glucose tolerance occurs. Tumor markers are briefly exposed and we discuss the place of endoscopic retrograde cholangiopancreatography (ERCP) after non invasive imaging techniques.

Tumour necrosis factor (TNF) gene polymorphism in Crohn's disease (CD): influence on disease behaviour?

Crohn's disease (CD) is a multifactorial disease with genetic heterogeneity. TNF-alpha plays a key role in the development of the mucosal lesions. The aim of our work was to study a single base pair polymorphism located in the promoter region of TNF gene, in a large population of CD patients with well defined phenotypes. One hundred and ninety-three patients with CD and 98 ethnically matched controls were studied. The -308 single base pair polymorphism of TNF gene was studied using an allele-specific polymerase chain reaction. Genotype and allelic frequencies were compared between patients and controls and between subgroups of patients defined by sex, age at diagnosis, familial history, location of disease, type of disease, extra-intestinal manifestations, and response to steroid treatment. In 29 patients a measure of TNF-alpha production by colonic biopsies was performed. The frequency of the allele TNF2 as well as the proportion of carriers of the allele TNF2 were slightly but not significantly lower in CD than in controls (11.9% versus 14.8% and 21.5% versus 27.6%, respectively). A more prominent difference in frequencies of allele TNF2 and in proportions of TNF2 carriers was found when comparing subgroups of patients. The frequency of allele TNF2 was significantly higher in steroid-dependent than in non-steroid-dependent disease (28.1% versus 10.3%; Delta = 17.8%, 95% confidence interval (CI) = 6.3-29.5%, P = 0.0027) and tended to be higher in colonic than in small bowel disease and in fistulizing than in stricturing disease. Furthermore, TNF2 carriers tended to be more frequent in patients with steroid-dependent than non-steroid-dependent disease (43.8% versus 19.3%; Delta = 24.5%, 95% CI = 3.6-45.4%, P = 0.022), in patients with fistulizing than stricturing disease (26.5% versus 9.6%; Delta = 16.9%, 95% CI = 1. 1-32.6%, P = 0.036), and in patients with colonic than small bowel disease (26.5% versus 11.1%; Delta = 15.4%, 95% CI = -0.8-31.6%, P = 0.063). Finally, patients carrying at least one copy of allele 2 were found to produce slightly more TNF-alpha at the colonic level. The -308 TNF gene polymorphism may have a slight influence on the behaviour of CD. The carriage of allele 2 may favour steroid-dependent disease and to a lesser extent fistulizing and colonic disease, possibly secondary to a more intense TNF-alpha-driven inflammatory reaction at the mucosal level.

Acute lower gastrointestinal bleeding in Crohn's disease: characteristics of a unique series of 34 patients. Belgian IBD Research Group

OBJECTIVE

Acute lower gastrointestinal bleeding is a rare complication of Crohn's disease, which represents a diagnostic and therapeutic challenge. The aim of this study was to define epidemiological characteristics and therapeutic options of hemorrhagic forms of Crohn's disease.

METHODS

Thirty-four cases of hemorrhagic forms of Crohn's disease were studied retrospectively. Acute lower gastrointestinal hemorrhage was defined as acute rectal bleeding originating in diseased bowel and requiring a transfusion of at least 2 units of red blood cells within 24 h. Upper gastrointestinal tract hemorrhage or anal lesions and postoperative bleeding were excluded.

RESULTS

Mean age at time of hemorrhage was 34.2 +/- 14 yr. Mean duration of disease before the hemorrhage was 5.6 +/- 6 yr. The hemorrhage occurred during a flare up of the disease in 35% of cases. The hemorrhage revealed Crohn's disease in 23.5% of cases. The hemorrhage was more frequent in colonic disease (85%) than in isolated small bowel disease (15%) (p < 0.0001). The origin of bleeding was identified in 65% of cases, by colonoscopy (60%), by angiography (3 patients), or at surgery (1 patient). The bleeding lesion was an ulcer in 95% of cases, most often in the left colon. The treatment was surgical in 20.5% (colectomy in 36%), endoscopical (7 patients, including 5 successes), or medical. Hemorrhage recurred in 12 patients (35%) within a mean time of 3 yr (4 days-8 yr), requiring surgery in 3 cases. No death was observed.

CONCLUSIONS

This study performed in a series characterized by a nonsurgical recruitment, the largest to date, shows that hemorrhagic forms of Crohn's disease may reveal disease in 23.5%, occurs in quiescent Crohn's disease in two-thirds of cases. Given the potential efficacy of endoscopical or medical treatment, as well as the absence of mortality, a conservative approach may be suggested as first-line therapy in the majority of patients.

Postoperative radiotherapy in the management of adult soft tissue sarcoma of the extremities: results with two different total dose, fractionation, and overall treatment time schedules

PURPOSE

This retrospective study was performed to evaluate two postoperative radiotherapy schedules in terms of dose, fractionation, and overall treatment time in soft tissue sarcoma (STS) of the extremities.

METHODS AND MATERIALS

Between January 1984 and December 1993, 62 patients with newly diagnosed localized STS of the extremities were treated with maximal conservative surgery and postoperative radiotherapy (RT). Forty-five patients received 50 Gy with conventional fractionation plus a boost dose (5 to 20 Gy). Seventeen patients had hyperfractionated accelerated radiotherapy (HFART) up to a dose of 45 Gy in 3 weeks.

RESULTS

With a median follow-up of 72 months, the 5-year local failure rate was 25%, the 5-year disease-free and overall survival rates were respectively 42% and 62%. The 3-year local relapse, disease-free, and overall survival rates were respectively 16%, 44%, and 70% in the conventional radiotherapy group, and 36%, 47%, and 82% in the HFART group (NS). No factor significantly influenced local control with a trend, however, in favor of conventional RT (p = 0.10).

CONCLUSION

HFART at the dose of 45 Gy does not seem to be superior to the standard RT schedule, neither in terms of local control, survival, nor in terms of long-term side effects. However this dose could be considered too low as well as the power of comparison between the two groups to draw definitive conclusions.

Cytochrome 1A1 induction by primaquine in human hepatocytes and HepG2 cells: absence of binding to the aryl hydrocarbon receptor

Malaria remains the most prevalent infectious disease of tropical and subtropical areas of the world. It represents a crucial problem in public health care, affecting 750 million people annually, of whom at least two million die. Various antimalarials currently used were studied for their capability to induce expression of the cytochrome P450 1A1 (CYP1A1) gene, an enzyme that plays an important role in the activation of xenobiotics to genotoxic derivatives. Studies on human hepatocytes and HepG2 cell lines showed that primaquine was capable of dose dependently increasing both the ethoxyresorufin-O-deethylase activity and CYP1A1 mRNAs, suggesting a transcriptional activation of this gene. Moreover, alpha-naphthoflavone, a partial aryl hydrocarbon receptor (AhR) antagonist, and 8-methoxypsoralen, which interferes with the binding of activated AhR to the xenobiotic responsive element, were shown to suppress CYP1A1 induction when added to the cultures. However, neither primaquine nor its metabolites were able to displace [3H]2,3,7,8-tetrachlorodibenzo-p-dioxin from AhR in competitive binding studies using 9S-enriched fractions of human cytosol. These data, together with the induction of CYP1A1 promoter-directed chloramphenicol acetyl transferase gene expression, suggest that CYP1A1 induction involves the participation of the AhR but not a direct primaquine-receptor interaction. This supports the notion that an alternative ligand-independent mechanism has to be considered. Given the pharmaco-toxicological significance of CYP1A1 induction, these findings may have important implications in the treatment of malaria with primaquine and new analogs.

Gastric endoluminal treatment of Dieulafoy's ulcer

Dieulafoy's ulcer, accounting for approximately 5% of upper GI bleeding, is best managed by therapeutic endoscopy. Some patients, however, require surgical treatment. Presented here is a case in which the lesion was treated by combined endoscopy and endogastric surgery. To the authors' best knowledge, this is the first published report of such management. This relatively new technique may be offered in suitable cases but should be attempted only by well-trained laparoscopic surgeons.

Nutritional depletion in staged spinal reconstructive surgery. The effect of total parenteral nutrition

STUDY DESIGN

A prospective randomized study evaluating nutritional depletion in spine surgery patients.

OBJECTIVE

To determine whether use of total parenteral nutrition (TPN) in patients undergoing staged spinal reconstructive procedures could affect their nutritional parameters or decrease their complication rates.

SUMMARY OF BACKGROUND DATA

Several studies have shown that nutritional depletion occurs after major spinal surgery and that patients undergoing staged spinal surgery may be at particular risk of nutritional loss and its complications.

METHODS

Forty adult patients undergoing staged spinal reconstructive surgery were randomized as to whether they received TPN postoperatively. Nutritional parameters, including skin fold measurement and albumin, pre-albumin, transferrin, and total lymphocyte counts, were obtained pre-operatively and at regular intervals.

RESULTS

Five patients did not complete the study, leaving 35 patients for analysis. There was a significant decrease in incidence of albumin and pre-albumin depletion for the patients who did not receive TPN compared with those who did receive TPN (P < 0.025, P < 0.006, respectively). Patients with depleted albumin or pre-albumin counts were more likely to develop other postoperative infectious complications such as pneumonia or urinary tract infections (P < 0.035). There were no statistically significant differences in wound complications in this small patient study. There were no complications secondary to use of the TPN.

CONCLUSIONS

For complex patients requiring staged anterior/posterior surgery, TPN appears to significantly lessen the decrease in nutritional parameters. Because depletion of nutritional parameters appears to correlate with an increased likelihood of perioperative infectious complications, use of TPN may result in a decrease of such complications in these patients.

Familial Crohn's disease: a study of 18 families

The high frequency of familial Crohn's disease (CD) suggests a genetic predisposition. The most recent data from epidemiology and molecular biology are consistent with a multifactorial, polygenic inheritance with a possible genetic heterogeneity. The aim of our study was, first to compare familial and sporadic CD on the basis of the type and location of the disease, and age at diagnosis, and second, to evaluate among families, the concordance rate for the type and location of the disease.

PATIENTS AND METHODS

18 families with 2 (n = 16) and 3 (n = 2) affected first degree relatives were studied. They were compared to a population of 154 sporadic CD coming from the same gastroenterology unit.

RESULTS

Age at diagnosis was the same in sporadic and familial CD. There was an increased frequency of ileal (p = 0.02), and fibro stenotic (p = 0.005) CD and a decreased frequency of colonic (p = 0.006) and inflammatory (p = 0.02) disease, in familial CD. There was a significant increase in concordance rate for fibrostenotic disease (p < 0.001) and a decrease for inflammatory disease (p < 0.01), among the families. The observed concordance rate for the location of the disease was not significantly different from the expected one. In conclusion, these data suggest that CD may be heterogenous and that different clinical patterns may be determined either by genetic or environmental factors.