In Arabidopsis thaliana, RNA-Induced Silencing Complex-Loading of MicroRNAs Plays a Minor Regulatory Role During Photomorphogenesis Except for miR163

The shift of dark-grown seedlings to the light leads to substantial reprogramming of gene expression, which results in dramatic developmental changes (referred to as de-etiolation or photomorphogenesis). MicroRNAs (miRNAs) regulate most steps of plant development, thus miRNAs might play important role in transcriptional reprogramming during de-etiolation. Indeed, miRNA biogenesis mutants show aberrant de-etiolation. Previous works showed that the total miRNA expression pattern (total miRNAome) is only moderately altered during photomorphogenesis. However, a recent study has shown that plant miRNAs are present in two pools, biologically active miRNAs loaded to RISC (RNA-induced silencing complex-loaded) form while inactive miRNAs accumulate in duplex form upon organ formation. To test if RISC-loading efficiency is changed during photomorphogenesis. we compared the total miRNAome and the RISC-loaded miRNAome of dark-grown and de-etiolated Arabidopsis thaliana seedlings. miRNA sequencing has revealed that although regulated RISC-loading is involved in the control of active miRNAome formation during de-etiolation, this effect is moderate. The total miRNAomes and the RISC-loaded miRNAomes of dark-grown and de-etiolated plants are similar indicating that most miRNAs are loaded onto RISC with similar efficiency in dark and light. Few miRNAs were loaded onto RISC with different efficiency and one miRNA, miR163, was RISC-loaded much more effectively in light than in dark. Thus, our results suggest that although RISC-loading contributes significantly to the control of the formation of organ-specific active miRNA pools, it plays a limited role in the regulation of active miRNA pool formation during de-etiolation. Regulated RISC-loading strongly modifies the expression of miRNA163, could play a role in the fine-tuning of a few other miRNAs, and do not modify the expression of most miRNAs.

Changes in resistance pattern of ESKAPE pathogens between 2010 and 2020 in the clinical center of University of Szeged, Hungary

The acronym ESKAPE stands for six antibiotic-resistant bacterial pathogens namely, Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp. Monitoring their resistance is an important task for clinical microbiology laboratories. Our aim was to analyze the resistance patterns of these bacteria over ten years in clinical samples of our department. We examined the sample types from which these pathogens were most frequently isolated. The incidence of tests with resistant results for each pathogen in aggregate and the most important subgroups of each was also analyzed. We have also intended to predict the local priorities amongst these pathogens. The results of 1,268,126 antibiotic susceptibility tests performed on a total of 70,099 isolates over this period were examined. Most strains were derived from urine, blood culture, trachea, vagina, wounds, and abscesses. Prevalence of ESKAPE bacteria increased between 2011 and 2020 however, the steepest intensifications were seen in the cases of K. pneumoniae and P. aeruginosa. The number of antibiotic susceptibility tests with resistant results has also increased over the decade but the most notable increase was detected in E. faecium and A. baumannii. Based on the calculation of antimicrobial resistance index for each pathogen, the most serious challenges for us at present are A. baumannii, P. aeruginosa, and E. faecium and their multi-resistant forms. The theoretical prediction of proportion of resistant tests between 2020 and 2030 in our care area draws attention to a worrying trend in the cases of vancomycin-resistant E. faecium and carbapenem-resistant A. baumannii strains.

Ingol and Ingenol-Type Diterpenes from Euphorbia trigona Miller with Keratinocyte Inhibitory Activity

Ingenol mebutate, isolated from Euphorbia peplus, is an ingenane-type diterpenoid, primarily used for the topical treatment of actinic keratosis, a premalignant skin condition. The aim of our work was to investigate other Euphorbia species to find structurally similar diterpenes that can be used as alternatives to ingenol mebutate. Pharmacological investigation of Euphorbia candelabrum, Euphorbia cotinifolia, Euphorbia ramipressa, and Euphorbia trigona revealed the potent keratinocyte (HPV-Ker cell line) inhibitory activity of these spurge species. From the methanolic extract of the aerial parts of Euphorbia trigona Miller, the most active species, five ingol (1–5) and four ingenane-type diterpenoids (6–9) were isolated by various chromatographic separation techniques, including open column chromatography, vacuum liquid chromatography, thin-layer chromatography, and high-performance liquid chromatography. The structures of the compounds were determined by NMR spectroscopic analysis and by comparison of the assignations with the literature data. The cytotoxic activity of the compounds against keratinocytes was tested in vitro by using ingenol mebutate as a positive control. Among the isolated compounds, two ingenane derivatives (6 and 7) exhibited remarkably stronger cytotoxic activity (IC₅₀ values 0.39 μM and 0.32 μM, respectively) on keratinocytes than ingenol mebutate (IC₅₀ value 0.84 μM). These compounds could serve as starting materials for further investigations to find alternatives to Picato^® (with active substance ingenol mebutate), which was withdrawn from marketing authorization in the European Union.

Argonaute 2 Controls Antiviral Activity against Sweet Potato Mild Mottle Virus in Nicotiana benthamiana

RNA silencing is a sequence specific post-transcriptional mechanism regulating important biological processes including antiviral defense in plants. Argonaute (AGO) proteins, the catalytic subunits of the silencing complexes, are loaded with small RNAs to execute the sequence specific RNA cleavage or translational inhibition. Plants encode several AGO proteins and a few of them, especially AGO1 and AGO2, have been shown to be required for antiviral silencing. Previously, we have shown that the P1 protein of the sweet potato mild mottle virus (SPMMV) suppresses the primary RNA silencing response by inhibiting AGO1. To analyze the role of AGO2 in antiviral defense against the SPMMV, we performed a comparative study using a wild type and ago2^−/− mutant Nicotiana benthamiana. Here we show that the AGO2 of N. benthamiana attenuates the symptoms of SPMMV infection. Upon SPMMV infection the levels of AGO2 mRNA and protein are greatly increased. Moreover, we found that AGO2 proteins are loaded with SPMMV derived viral small RNAs as well as with miRNAs. Our results indicate that AGO2 protein takes over the place of AGO1 to confer antiviral silencing. Finally, we provide a plausible explanation for the AGO2 mediated recovery of an SPMMV-infected sweet potato.

The effect of trimodal prehabilitation on the physical and psychological health of patients undergoing colorectal surgery: a randomised clinical trial

Prehabilitation aims to increase the endurance capacity of patients who are awaiting major surgery. However, there are no studies investigating the implementation of this demanding and expensive intervention in low-income countries. This study aimed to assess the impact of a 4-week trimodal prehabilitation program on the physical and psychological health of patients waiting for colorectal surgery compared with a control group managed according to enhanced recovery after surgery principles supplemented by nutritional care. This study was a single-centre, randomised controlled trial. The primary outcome measures for the physical aspects were 6-minute walking distance (6MWD) and incentive spirometry, whereas the psychological elements were measured using the 36-item short form survey questionnaire and the hospital anxiety and depression score. In total, data from 149 patients were analysed (77 in the prehabilitation group and 72 in the control group). At the time of surgery, patients in the prehabilitation group had improved 6MWD and incentive spirometry compared with the control group (median (IQR [range]) percentage improvement 131% (112-173 [68-376]) vs. 107% (99-120 [63-163]); p < 0.001 and 113% (100-125 [75-200]) vs. 100% (100-112 [86-167]); p < 0.001 respectively). Patients in the prehabilitation group also had reduced anxiety scores compared with the control group (mean (SD) anxiety score (4 (3) vs. 5 (3) respectively; p = 0.032). However, these effects did not translate into improvements in postoperative mortality and morbidity, or a reduction in duration of hospital stay. Trimodal (physical, emotional and nutritional) prehabilitation is able to improve functional status as well as some parameters of emotional and physical well-being of patients waiting for colorectal surgery.

Wild Strawberry, Blackberry, and Blueberry Leaf Extracts Alleviate Starch-Induced Hyperglycemia in Prediabetic and Diabetic Mice

Intestinal α-glucosidase and α-amylase break down nutritional poly- and oligosaccharides to monosaccharides and their activity significantly contributes to postprandial hyperglycemia. Competitive inhibitors of these enzymes, such as acarbose, are effective antidiabetic drugs, but have unpleasant side effects. In our ethnopharmacology inspired investigations, we found that wild strawberry (Fragaria vesca), blackberry (Rubus fruticosus), and European blueberry (Vaccinium myrtillus) leaf extracts inhibit α-glucosidase and α-amylase enzyme activity in vitro and are effective in preventing postprandial hyperglycemia in vivo. Toxicology tests on H9c2 rat embryonic cardiac muscle cells demonstrated that berry leaf extracts have no cytotoxic effects. Oral administration of these leaf extracts alone or as a mixture to normal (control), obese, prediabetic, and streptozotocin-induced diabetic mice attenuated the starch-induced rise of blood glucose levels. The efficiency was similar to that of acarbose on blood glucose. These results highlight berry leaf extracts as candidates for testing in clinical trials in order to assess the clinical significance of their effects on glycemic control.

A viral suppressor of RNA silencing inhibits ARGONAUTE 1 function by precluding target RNA binding to pre-assembled RISC

In most eukaryotes, RNA silencing is an adaptive immune system regulating key biological processes including antiviral defense. To evade this response, viruses of plants, worms and insects have evolved viral suppressors of RNA silencing proteins (VSRs). Various VSRs, such as P1 from Sweet potato mild mottle virus (SPMMV), inhibit the activity of RNA-induced silencing complexes (RISCs) including an ARGONAUTE (AGO) protein loaded with a small RNA. However, the specific mechanisms explaining this class of inhibition are unknown. Here, we show that SPMMV P1 interacts with AGO1 and AGO2 from Arabidopsis thaliana, but solely interferes with AGO1 function. Moreover, a mutational analysis of a newly identified zinc finger domain in P1 revealed that this domain could represent an effector domain as it is required for P1 suppressor activity but not for AGO1 binding. Finally, a comparative analysis of the target RNA binding capacity of AGO1 in the presence of wild-type or suppressor-defective P1 forms revealed that P1 blocks target RNA binding to AGO1. Our results describe the negative regulation of RISC, the small RNA containing molecular machine.

Tobacco rattle virus 16K silencing suppressor binds ARGONAUTE 4 and inhibits formation of RNA silencing complexes

The cysteine-rich 16K protein of tobacco rattle virus (TRV), the type member of the genus Tobravirus, is known to suppress RNA silencing. However, the mechanism of action of the 16K suppressor is not well understood. In this study, we used a GFP-based sensor strategy and an Agrobacterium-mediated transient assay in Nicotiana benthamiana to show that 16K was unable to inhibit the activity of existing small interfering RNA (siRNA)- and microRNA (miRNA)-programmed RNA-induced silencing effector complexes (RISCs). In contrast, 16K efficiently interfered with de novo formation of miRNA- and siRNA-guided RISCs, thus preventing cleavage of target RNA. Interestingly, we found that transiently expressed endogenous miR399 and miR172 directed sequence-specific silencing of complementary sequences of viral origin. 16K failed to bind small RNAs, although it interacted with ARGONAUTE 4, as revealed by bimolecular fluorescence complementation and immunoprecipitation assays. Site-directed mutagenesis demonstrated that highly conserved cysteine residues within the N-terminal and central regions of the 16K protein are required for protein stability and/or RNA silencing suppression.

Treatment Steps, Surgery, and Hospitalization Rates During the First Year of Follow-up in Patients with Inflammatory Bowel Diseases from the 2011 ECCO-Epicom Inception Cohort

BACKGROUND AND AIMS

The ECCO-EpiCom study investigates the differences in the incidence and therapeutic management of inflammatory bowel diseases [IBD] between Eastern and Western Europe. The aim of this study was to analyse the differences in the disease phenotype, medical therapy, surgery, and hospitalization rates in the ECCO-EpiCom 2011 inception cohort during the first year after diagnosis.

METHODS

Nine Western, five Eastern European centres and one Australian centre with 258 Crohn's disease [CD], 380 ulcerative colitis [UC] and 71 IBD unclassified [IBDU] patients [female/male: 326/383; mean age at diagnosis: 40.9 years, SD: 17.3 years] participated. Patients' data were registered and entered in the web-based ECCO-EpiCom database [www.epicom-ecco.eu].

RESULTS

In CD, 36 [19%] Western Europe/Australian and 6 [9%] Eastern European patients received biological therapy [p = 0.04], but the immunosuppressive [IS] use was equal and high in these regions [Eastern Europe vs Western Europe/Australia: 53% vs 45%; p = 0.27]. Surgery was performed in 17 [24%] CD patients in Eastern Europe and 13 [7%] in Western Europe/Australia [p < 0.001, pLogRank = 0.001]. Of CD patients from Eastern Europe, 24 [34%] were hospitalized, and 39 [21%] from Western Europe/Australia, [p = 0.02, pLogRank = 0.01]. In UC, exposure to biologicals and colectomy rates were low and hospitalization rates did not differ between these regions during the 1-year follow-up period [16% vs 16%; p = 0.93].

CONCLUSIONS

During the first year after diagnosis, surgery and hospitalization rates were significantly higher in CD patients in Eastern Europe compared with Western Europe/Australia, whereas significantly more CD patients were treated with biologicals in the Western Europe/Australian centres.

Incidence and initial disease course of inflammatory bowel diseases in 2011 in Europe and Australia: results of the 2011 ECCO-EpiCom inception cohort

BACKGROUND AND AIMS

The aim of the present study was to validate the IBD (inflammatory bowel diseases) incidence reported in the 2010 ECCO-EpiCom (European Crohn's and Colitis Organization-Epidemiological Committee) inception cohort by including a second independent inception cohort from participating centers in 2011 and an Australian center to investigate whether there is a difference in the incidence of IBD between Eastern and Western European countries and Australia.

METHODS

Fourteen centers from 5 Eastern and 9 Western European countries and one center from Australia participated in the ECCO-EpiCom 2011 inception cohort. Patients' data regarding disease type, socio-demographic factors, extraintestinal manifestations and therapy were entered into the Web-based EpiCom database, www.ecco-epicom.eu.

RESULTS

A total of 711 adult patients were diagnosed during the inclusion year 2011, 178 (25%) from Eastern, 461 (65%) from Western Europe and 72 (10%) from Australia; 259 (37%) patients were diagnosed with Crohn's disease, 380 (53%) with ulcerative colitis and 72 (10%) with IBD unclassified. The mean annual incidence rate for IBD was 11.3/100,000 in Eastern Europe, 14.0/100,000 in Western Europe and 30.3/100,000 in Australia. Significantly more patients were diagnosed with complicated disease at diagnosis in Eastern Europe compared to Western Europe (43% vs. 27%, p=0.02).

CONCLUSION

Incidence rates, disease phenotype and initial treatment characteristics in the 2011 ECCO-EpiCom cohort were not significantly different from that reported in the 2010 cohort.

Health-related quality of life improves during one year of medical and surgical treatment in a European population-based inception cohort of patients with inflammatory bowel disease--an ECCO-EpiCom study

BACKGROUND & AIMS

Health-related quality of life (HRQoL) is impaired in patients with Inflammatory Bowel Disease (IBD). The aim was prospectively to assess and validate the pattern of HRQoL in an unselected, population-based inception cohort of IBD patients from Eastern and Western Europe.

METHODS

The EpiCom inception cohort consists of 1560 IBD patients from 31 European centres covering a background population of approximately 10.1 million. Patients answered the disease specific Short Inflammatory Bowel Disease Questionnaire (SIBDQ) and generic Short Form 12 (SF-12) questionnaire at diagnosis and after one year of follow-up.

RESULTS

In total, 1079 patients were included in this study. Crohn's disease (CD) patients mean SIBDQ scores improved from 45.3 to 55.3 in Eastern Europe and from 44.9 to 53.6 in Western Europe. SIBDQ scores for ulcerative colitis (UC) patients improved from 44.9 to 57.4 and from 48.8 to 55.7, respectively. UC patients needing surgery or biologicals had lower SIBDQ scores before and after compared to the rest, while biological therapy improved SIBDQ scores in CD. CD and UC patients in both regions improved all SF-12 scores. Only Eastern European UC patients achieved SF-12 summary scores equal to or above the normal population.

CONCLUSION

Medical and surgical treatment improved HRQoL during the first year of disease. The majority of IBD patients in both Eastern and Western Europe reported a positive perception of disease-specific but not generic HRQoL. Biological therapy improved HRQoL in CD patients, while UC patients in need of surgery or biological therapy experienced lower perceptions of HRQoL than the rest.

Environmental factors in a population-based inception cohort of inflammatory bowel disease patients in Europe--an ECCO-EpiCom study

BACKGROUND AND AIMS

The incidence of inflammatory bowel disease (IBD) is increasing in Eastern Europe possibly due to changes in environmental factors towards a more "westernised" standard of living. The aim of this study was to investigate differences in exposure to environmental factors prior to diagnosis in Eastern and Western European IBD patients.

METHODS

The EpiCom cohort is a population-based, prospective inception cohort of 1560 unselected IBD patients from 31 European countries covering a background population of 10.1 million. At the time of diagnosis patients were asked to complete an 87-item questionnaire concerning environmental factors.

RESULTS

A total of 1182 patients (76%) answered the questionnaire, 444 (38%) had Crohn's disease (CD), 627 (53%) ulcerative colitis (UC), and 111 (9%) IBD unclassified. No geographic differences regarding smoking status, caffeine intake, use of oral contraceptives, or number of first-degree relatives with IBD were found. Sugar intake was higher in CD and UC patients from Eastern Europe than in Western Europe while fibre intake was lower (p<0.01). Daily consumption of fast food as well as appendectomy before the age of 20 was more frequent in Eastern European than in Western European UC patients (p<0.01). Eastern European CD and UC patients had received more vaccinations and experienced fewer childhood infections than Western European patients (p<0.01).

CONCLUSIONS

In this European population-based inception cohort of unselected IBD patients, Eastern and Western European patients differed in environmental factors prior to diagnosis. Eastern European patients exhibited higher occurrences of suspected risk factors for IBD included in the Western lifestyle.

East-West gradient in the incidence of inflammatory bowel disease in Europe: the ECCO-EpiCom inception cohort

OBJECTIVE

The incidence of inflammatory bowel disease (IBD) is increasing in Eastern Europe. The reasons for these changes remain unknown. The aim of this study was to investigate whether an East-West gradient in the incidence of IBD in Europe exists.

DESIGN

A prospective, uniformly diagnosed, population based inception cohort of IBD patients in 31 centres from 14 Western and eight Eastern European countries covering a total background population of approximately 10.1 million people was created. One-third of the centres had previous experience with inception cohorts. Patients were entered into a low cost, web based epidemiological database, making participation possible regardless of socioeconomic status and prior experience.

RESULTS

1515 patients aged 15 years or older were included, of whom 535 (35%) were diagnosed with Crohn's disease (CD), 813 (54%) with ulcerative colitis (UC) and 167 (11%) with IBD unclassified (IBDU). The overall incidence rate ratios in all Western European centres were 1.9 (95% CI 1.5 to 2.4) for CD and 2.1 (95% CI 1.8 to 2.6) for UC compared with Eastern European centres. The median crude annual incidence rates per 100,000 in 2010 for CD were 6.5 (range 0-10.7) in Western European centres and 3.1 (range 0.4-11.5) in Eastern European centres, for UC 10.8 (range 2.9-31.5) and 4.1 (range 2.4-10.3), respectively, and for IBDU 1.9 (range 0-39.4) and 0 (range 0-1.2), respectively. In Western Europe, 92% of CD, 78% of UC and 74% of IBDU patients had a colonoscopy performed as the diagnostic procedure compared with 90%, 100% and 96%, respectively, in Eastern Europe. 8% of CD and 1% of UC patients in both regions underwent surgery within the first 3 months of the onset of disease. 7% of CD patients and 3% of UC patients from Western Europe received biological treatment as rescue therapy. Of all European CD patients, 20% received only 5-aminosalicylates as induction therapy.

CONCLUSIONS

An East-West gradient in IBD incidence exists in Europe. Among this inception cohort--including indolent and aggressive cases--international guidelines for diagnosis and initial treatment are not being followed uniformly by physicians.

East-West gradient in the incidence of inflammatory bowel disease in Europe: the ECCO-EpiCom inception cohort

OBJECTIVE

The incidence of inflammatory bowel disease (IBD) is increasing in Eastern Europe. The reasons for these changes remain unknown. The aim of this study was to investigate whether an East-West gradient in the incidence of IBD in Europe exists.

DESIGN

A prospective, uniformly diagnosed, population based inception cohort of IBD patients in 31 centres from 14 Western and eight Eastern European countries covering a total background population of approximately 10.1 million people was created. One-third of the centres had previous experience with inception cohorts. Patients were entered into a low cost, web based epidemiological database, making participation possible regardless of socioeconomic status and prior experience.

RESULTS

1515 patients aged 15 years or older were included, of whom 535 (35%) were diagnosed with Crohn's disease (CD), 813 (54%) with ulcerative colitis (UC) and 167 (11%) with IBD unclassified (IBDU). The overall incidence rate ratios in all Western European centres were 1.9 (95% CI 1.5 to 2.4) for CD and 2.1 (95% CI 1.8 to 2.6) for UC compared with Eastern European centres. The median crude annual incidence rates per 100,000 in 2010 for CD were 6.5 (range 0-10.7) in Western European centres and 3.1 (range 0.4-11.5) in Eastern European centres, for UC 10.8 (range 2.9-31.5) and 4.1 (range 2.4-10.3), respectively, and for IBDU 1.9 (range 0-39.4) and 0 (range 0-1.2), respectively. In Western Europe, 92% of CD, 78% of UC and 74% of IBDU patients had a colonoscopy performed as the diagnostic procedure compared with 90%, 100% and 96%, respectively, in Eastern Europe. 8% of CD and 1% of UC patients in both regions underwent surgery within the first 3 months of the onset of disease. 7% of CD patients and 3% of UC patients from Western Europe received biological treatment as rescue therapy. Of all European CD patients, 20% received only 5-aminosalicylates as induction therapy.

CONCLUSIONS

An East-West gradient in IBD incidence exists in Europe. Among this inception cohort--including indolent and aggressive cases--international guidelines for diagnosis and initial treatment are not being followed uniformly by physicians.

Early clinical remission and normalisation of CRP are the strongest predictors of efficacy, mucosal healing and dose escalation during the first year of adalimumab therapy in Crohn's disease

BACKGROUND

Adalimumab is a fully human monoclonal antibody targeting tumour necrosis factor with proven efficacy in the treatment of Crohn's disease (CD).

AIM

To investigate the predictors of medium-term clinical efficacy and mucosal healing during adalimumab therapy, in patients with CD, in specialised centres approved for biological therapy in Hungary.

METHODS

Data capture of the 201 CD patients was standardised and prospective (male/female: 112/89, median age: 33.0 years, duration: 8 years). Previous infliximab therapy had been administered in 48% of patients, concomitant steroids in 41%, azathioprine in 69% and combined therapy in 27% of patients.

RESULTS

Overall clinical response and remission rates at 24 weeks were 78% and 52%, respectively; at 52 weeks were 69% and 44%, respectively. Endoscopic improvement and healing were achieved in 43% and 24% of patients. In a logistic regression model, clinical efficacy and CRP at week 12, need for combined immunosuppression at induction, shorter disease duration and smoking were identified as independent predictors for 12-month clinical outcome, whereas CRP at week 12, clinical remission at week 24, inflammatory parameters and nonsmoking were associated to endoscopic improvement/healing. Intensification to weekly dosing was needed in 16% of patients. Parallel azathioprine therapy and clinical remission at week 12 were inversely associated with dose escalation.

CONCLUSIONS

Clinical efficacy and normalised CRP at week 12 (early deep clinical remission) are associated with medium-term clinical efficacy and mucosal healing during adalimumab therapy, whereas need for combined immunosuppression at induction and smoking status are predictors for non-response. Parallel azathioprine therapy may decrease the probability for dose escalation.

Viral protein inhibits RISC activity by argonaute binding through conserved WG/GW motifs

RNA silencing is an evolutionarily conserved sequence-specific gene-inactivation system that also functions as an antiviral mechanism in higher plants and insects. To overcome antiviral RNA silencing, viruses express silencing-suppressor proteins. These viral proteins can target one or more key points in the silencing machinery. Here we show that in Sweet potato mild mottle virus (SPMMV, type member of the Ipomovirus genus, family Potyviridae), the role of silencing suppressor is played by the P1 protein (the largest serine protease among all known potyvirids) despite the presence in its genome of an HC-Pro protein, which, in potyviruses, acts as the suppressor. Using in vivo studies we have demonstrated that SPMMV P1 inhibits si/miRNA-programmed RISC activity. Inhibition of RISC activity occurs by binding P1 to mature high molecular weight RISC, as we have shown by immunoprecipitation. Our results revealed that P1 targets Argonaute1 (AGO1), the catalytic unit of RISC, and that suppressor/binding activities are localized at the N-terminal half of P1. In this region three WG/GW motifs were found resembling the AGO-binding linear peptide motif conserved in metazoans and plants. Site-directed mutagenesis proved that these three motifs are absolutely required for both binding and suppression of AGO1 function. In contrast to other viral silencing suppressors analyzed so far P1 inhibits both existing and de novo formed AGO1 containing RISC complexes. Thus P1 represents a novel RNA silencing suppressor mechanism. The discovery of the molecular bases of P1 mediated silencing suppression may help to get better insight into the function and assembly of the poorly explored multiprotein containing RISC.

RNA silencing is an evolutionarily conserved sequence-specific gene-inactivation system that also functions as a major antiviral mechanism in higher plants and insects. Viral RNAs are processed by Dicer-like proteins into small interfering (si) RNAs, which trigger the RNA-induced silencing complex (RISC) assembly. Then siRNA loaded RISC inactivates cognate viral RNA. However, viral silencing suppressors evolved to counteract with RNA silencing targeting one or more key points in the silencing machinery. Here we show that in Sweet potato mild mottle virus, the role of silencing suppressor is played by P1 protein and it works by inhibiting si/miRNA-loaded RISC through targeting Argonaute 1 (AGO1). We confirmed using immunoprecipitation and in vitro binding assays that the interaction between P1 and small RNA loaded AGO1 is specific and direct. The suppression activity mapped to the N-terminal part of P1 containing three WG/GW motifs that resemble the AGO-binding linear peptide motif conserved in metazoans and plants. Site-directed mutagenesis proved that these three motifs are essential for both binding and suppression of AGO1 function. P1 protein is the only silencing suppressor identified so far that inhibits active RISC and this is the first demonstration of a WG/GW protein having negative effect on RNA silencing.

ATG16L1 and IL23 receptor (IL23R) genes are associated with disease susceptibility in Hungarian CD patients

BACKGROUND

North American and European genome-wide association scans have identified ATG16L1 and IL23R as novel inflammatory bowel disease (IBD) susceptibility genes and subsequent reports confirmed these findings in large independent populations. The aims of this study were to investigate the association and examine genotype-phenotype relationships in a Hungarian IBD cohort.

METHODS

415 unrelated IBD patients (CD: 266, age: 35.2+/-12.1 years, duration: 8.7+/-7.5 years and UC: 149, age: 44.4+/-15.4 years, duration: 10.7+/-8.9 years) and 149 healthy subjects were investigated. IL23R Arg381Gln (R381Q, rs11209026) and ATG16L1 Thr300Ala (T300A, rs2241880) polymorphisms were tested using LightCycler allele discrimination method. Detailed clinical phenotypes were determined by reviewing the medical charts.

RESULTS

The association between IL23R rs11209026, ATG16L1 rs2241880 and CD was confirmed (OR(IL23R381Q): 0.38, 95% CI: 0.16-0.87; OR(ATG16L1300AA): 1.86, 95% CI: 1.04-3.40). No difference was found between patients with UC and either controls or CD. In CD, IL23R 381Gln heterozygosity was associated with inflammatory disease (70% vs. 34%, p=0.037), while disease restricted to the colon was more prevalent in patients with the ATG16L1 300Ala/Ala homozygosity (33.3% vs. 21.1%, p=0.036). In addition, carriage of the variant alleles did not predict response to steroids, infliximab or need for surgery.

CONCLUSIONS

We confirmed that ATG16L1 and IL23R are susceptibility loci for CD in Hungarian CD patients. Further studies are needed to confirm the reported phenotype-genotype associations found in this study.

Inhibition of 3' modification of small RNAs in virus-infected plants require spatial and temporal co-expression of small RNAs and viral silencing-suppressor proteins

Plant viruses are inducers and targets of RNA silencing. Viruses counteract with RNA silencing by expressing silencing-suppressor proteins. Many of the identified proteins bind siRNAs, which prevents assembly of silencing effector complexes, and also interfere with their 3' methylation, which protects them against degradation. Here, we investigated the 3' modification of silencing-related small RNAs in Nicotiana benthamiana plants infected with viruses expressing RNA silencing suppressors, the p19 protein of Carnation Italian ringspot virus (CIRV) and HC-Pro of Tobacco etch virus (TEV). We found that CIRV had only a slight effect on viral siRNA 3' modification, but TEV significantly inhibited the 3' modification of si/miRNAs. We also found that p19 and HC-Pro were able to bind both 3' modified and non-modified small RNAs in vivo. The findings suggest that the 3' modification of viral siRNAs occurs in the cytoplasm, though miRNA 3' modification likely takes place in the nucleus as well. Both silencing suppressors inhibited the 3' modification of si/miRNAs when they and small RNAs were transiently co-expressed, suggesting that the inhibition of si/miRNA 3' modification requires spatial and temporal co-expression. Finally, our data revealed that a HEN1-like methyltransferase might account for the small RNA modification at the their 3'-terminal nucleotide in N. benthamiana.

Analysis of siRNA-suppressor of gene silencing interactions

RNA silencing is an evolutionarily conserved system that functions as an antiviral mechanism in higher plants and animals. To counteract RNA silencing, viruses evolved silencing suppressors that interfere with siRNA guided RNA silencing pathway. We used the heterologous Drosophila in vitro embryo RNA to analyze the molecular mechanism of suppression of silencing suppressors. We found that different silencing suppressors inhibit the RNA silencing via binding to siRNAs. None of the suppressors affected the activity of preassembled RISC complexes. In contrast, suppressors uniformly inhibited the siRNA-initiated RISC assembly pathway by preventing RNA silencing initiator complex formation. Here, we provide the protocol for the detailed analysis of p19 silencing suppressors of tombusviruses in the heterologous Drosophila in vitro system.

NOD1 gene E266K polymorphism is associated with disease susceptibility but not with disease phenotype or NOD2/CARD15 in Hungarian patients with Crohn's disease

BACKGROUND

NOD1/CARD4, a member of the pattern-recognition receptor family, is a perfect candidate as a susceptibility gene for Crohn's disease. Since only limited and conflicting data are available on G796A polymorphisms in inflammatory bowel disease patients, we set out to study the effect of this polymorphism on the susceptibility and course of Crohn's disease in the Hungarian population.

METHODS

Four hundred thirty-four unrelated Crohn's disease patients (age at presentation: 28.6+/-9.6 years, female/male: 210/224, duration of Crohn's disease: 8.2+/-6.9 years) and 200 healthy subjects (blood donors) and 136 non-inflammatory bowel disease gastrointestinal controls with chronic gastritis were investigated. NOD1 G796A was detected by using polymerase chain reaction/restriction fragment length polymorphism. Detailed clinical phenotypes were determined by reviewing the medical charts.

RESULTS

The frequencies of the variant alleles of NOD1 G796A differed significantly between the Crohn's disease patients and both healthy (GG 49.5% vs. 67%; AG 41.5% vs. 28%; and AA 9.0% vs. 5.2%; p<0.0001) and non-inflammatory bowel disease controls with chronic gastritis. Carriage of the single nucleotide polymorphism of NOD1 G796A proved to be a highly significant risk factor for Crohn's disease compared to both healthy (p<0.0001, OR: 2.1, 95% CI: 1.5-2.9) and non-inflammatory bowel disease controls with chronic gastritis (p=0.008). Significant associations were not found between the different genotypes and the demographic data on the patients or the clinical characteristics of Crohn's disease. The different polymorphisms of pattern-recognition receptors (e.g. NOD2/CARD15 SNP8, SNP12 and SNP13 mutations, the TLR4 D299G polymorphism and NOD1 G796A) did not reveal a mutual basis.

CONCLUSIONS

Our results suggest that carriage of the NOD1 G796A mutation increases susceptibility for Crohn's disease in the Hungarian population.

Gender-stratified analysis of DLG5 R30Q in 4707 patients with Crohn disease and 4973 controls from 12 Caucasian cohorts

BACKGROUND

DLG5 p.R30Q has been reported to be associated with Crohn disease (CD), but this association has not been replicated in most studies. A recent analysis of gender-stratified data from two case-control studies and two population cohorts found an association of DLG5 30Q with increased risk of CD in men but not in women and found differences between 30Q population frequencies for males and females. Male-female differences in population allele frequencies and male-specific risk could explain the difficulty in replicating the association with CD.

METHODS

DLG5 R30Q genotype data were collected for patients with CD and controls from 11 studies that did not include gender-stratified allele counts in their published reports and tested for male-female frequency differences in controls and for case-control frequency differences in men and in women.

RESULTS

The data showed no male-female allele frequency differences in controls. An exact conditional test gave marginal evidence that 30Q is associated with decreased risk of CD in women (p = 0.049, OR = 0.87, 95% CI 0.77 to 1.00). There was also a trend towards reduced 30Q frequencies in male patients with CD compared with male controls, but this was not significant at the 0.05 level (p = 0.058, OR = 0.87, 95% CI 0.74 to 1.01). When data from this study were combined with previously published, gender-stratified data, the 30Q allele was found to be associated with decreased risk of CD in women (p = 0.010, OR = 0.86, 95% CI 0.76 to 0.97), but not in men.

CONCLUSION

DLG5 30Q is associated with a small reduction in risk of CD in women.

The NS3 protein of Rice hoja blanca tenuivirus suppresses RNA silencing in plant and insect hosts by efficiently binding both siRNAs and miRNAs

RNA silencing plays a key role in antiviral defense as well as in developmental processes in plants and insects. Negative strand RNA viruses such as the plant virus Rice hoja blanca tenuivirus (RHBV) replicate in plants and in their insect transmission vector. Like most plant-infecting viruses, RHBV encodes an RNA silencing suppressor, the NS3 protein, and here it is demonstrated that this protein is capable of suppressing RNA silencing in both plants and insect cells. Biochemical analyses showed that NS3 efficiently binds siRNA as well as miRNA molecules. Binding of NS3 is greatly influenced by the size of small RNA molecules, as 21 nucleotide (nt) siRNA molecules are bound > 100 times more efficiently than 26 nt species. Competition assays suggest that the activity of NS3 is based on binding to siRNAs prior to strand separation during the assembly of the RNA-induced silencing complex. In addition, NS3 has a high affinity for miRNA/miRNA* duplexes, indicating that its activity might also interfere with miRNA-regulated gene expression in both insects and plants.

Is the incidence and prevalence of inflammatory bowel diseases increasing in Eastern Europe?

Limited data are available on the frequency of inflammatory bowel diseases in East European countries. A recent study from Hungary reported an increasing incidence rate for ulcerative colitis (from 1.6 to 11.0) and for Crohn's disease (from 0.4 to 4.7) from 1977 to 2001. A similar trend was seen in Croatia. In contrast, other countries (for example, Czech Republic, Poland, Romania, Slovakia, and Baltic countries) reported low incidence and prevalence rates. This review will discuss the available data on the epidemiology of inflammatory bowel diseases in Eastern Europe, as well as consider the possible factors responsible for the differences seen between countries and epidemiological trends.

Management of inflammatory bowel diseases in Eastern Europe

Limited data are available on the management of inflammatory bowel diseases (IBD) in East European countries. The diagnostic tools and most treatment options are also available in Eastern Europe. The diagnostic procedures commonly used became more sophisticated in the past few years, with a greater use of computed tomography/magnetic resonance imaging and serology testing; however, double contrast barium enema, enteroclysis, and endoscopy remained standard. The medical therapy and surgical strategies are also somewhat different from those applied in Western countries. In ulcerative colitis, besides mesalazine, the use of sulphasalazine is still frequent, while azathioprine is only used in a minority of patients. The use of conventional corticosteroids is common and the rate of non-colorectal cancer associated colectomies is low. In contrast, 5-aminosalicylates are still used for maintenance in Crohn's disease and azathioprine is generally less frequently given compared with Western Europe. Biological agents have also become available about five years ago, yet their use is restricted mainly to specialised centres.

Double-stranded RNA binding may be a general plant RNA viral strategy to suppress RNA silencing

In plants, RNA silencing (RNA interference) is an efficient antiviral system, and therefore successful virus infection requires suppression of silencing. Although many viral silencing suppressors have been identified, the molecular basis of silencing suppression is poorly understood. It is proposed that various suppressors inhibit RNA silencing by targeting different steps. However, as double-stranded RNAs (dsRNAs) play key roles in silencing, it was speculated that dsRNA binding might be a general silencing suppression strategy. Indeed, it was shown that the related aureusvirus P14 and tombusvirus P19 suppressors are dsRNA-binding proteins. Interestingly, P14 is a size-independent dsRNA-binding protein, while P19 binds only 21-nucleotide ds-sRNAs (small dsRNAs having 2-nucleotide 3' overhangs), the specificity determinant of the silencing system. Much evidence supports the idea that P19 inhibits silencing by sequestering silencing-generated viral ds-sRNAs. In this study we wanted to test the hypothesis that dsRNA binding is a general silencing suppression strategy. Here we show that many plant viral silencing suppressors bind dsRNAs. Beet yellows virus Peanut P21, clump virus P15, Barley stripe mosaic virus gammaB, and Tobacco etch virus HC-Pro, like P19, bind ds-sRNAs size-selectively, while Turnip crinkle virus CP is a size-independent dsRNA-binding protein, which binds long dsRNAs as well as ds-sRNAs. We propose that size-selective ds-sRNA-binding suppressors inhibit silencing by sequestering viral ds-sRNAs, whereas size-independent dsRNA-binding suppressors inactivate silencing by sequestering long dsRNA precursors of viral sRNAs and/or by binding ds-sRNAs. The findings that many unrelated silencing suppressors bind dsRNA suggest that dsRNA binding is a general silencing suppression strategy which has evolved independently many times.

Small RNA binding is a common strategy to suppress RNA silencing by several viral suppressors

RNA silencing is an evolutionarily conserved system that functions as an antiviral mechanism in higher plants and insects. To counteract RNA silencing, viruses express silencing suppressors that interfere with both siRNA- and microRNA-guided silencing pathways. We used comparative in vitro and in vivo approaches to analyse the molecular mechanism of suppression by three well-studied silencing suppressors. We found that silencing suppressors p19, p21 and HC-Pro each inhibit the intermediate step of RNA silencing via binding to siRNAs, although the molecular features required for duplex siRNA binding differ among the three proteins. None of the suppressors affected the activity of preassembled RISC complexes. In contrast, each suppressor uniformly inhibited the siRNA-initiated RISC assembly pathway by preventing RNA silencing initiator complex formation.

Plant virus-derived small interfering RNAs originate predominantly from highly structured single-stranded viral RNAs

RNA silencing is conserved in a broad range of eukaryotes and includes the phenomena of RNA interference in animals and posttranscriptional gene silencing (PTGS) in plants. In plants, PTGS acts as an antiviral system; a successful virus infection requires suppression or evasion of the induced silencing response. Small interfering RNAs (siRNAs) accumulate in plants infected with positive-strand RNA viruses and provide specificity to this RNA-mediated defense. We present here the results of a survey of virus-specific siRNAs characterized by a sequence analysis of siRNAs from plants infected with Cymbidium ringspot tombusvirus (CymRSV). CymRSV siRNA sequences have a nonrandom distribution along the length of the viral genome, suggesting that there are hot spots for virus-derived siRNA generation. CymRSV siRNAs bound to the CymRSV p19 suppressor protein have the same asymmetry in strand polarity as the sequenced siRNAs and are imperfect double-stranded RNA duplexes. Moreover, an analysis of siRNAs derived from two other nonrelated positive-strand RNA viruses showed that they displayed the same asymmetry as CymRSV siRNAs. Finally, we show that Tobacco mosaic virus (TMV) carrying a short inverted repeat of the phytoene desaturase (PDS) gene triggered more accumulation of PDS siRNAs than the corresponding antisense PDS sequence. Taken together, these results suggest that virus-derived siRNAs originate predominantly by direct DICER cleavage of imperfect duplexes in the most folded regions of the positive strand of the viral RNA.

Molecular mechanism of RNA silencing suppression mediated by p19 protein of tombusviruses

RNA silencing is an evolutionarily conserved surveillance system that occurs in a broad range of eukaryotic organisms. In plants, RNA silencing acts as an antiviral system; thus, successful virus infection requires suppression of gene silencing. A number of viral suppressors have been identified so far; however, the molecular bases of silencing suppression are still poorly understood. Here we show that p19 of Cymbidium ringspot virus (CymRSV) inhibits RNA silencing via its small RNA-binding activity in vivo. Small RNAs bound by p19 in planta are bona fide double-stranded siRNAs and they are silencing competent in the in vitro RNA-silencing system. p19 also suppresses RNA silencing in the heterologous Drosophila in vitro system by preventing siRNA incorporation into RISC. During CymRSV infection, p19 markedly diminishes the amount of free siRNA in cells by forming p19-siRNA complexes, thus making siRNAs inaccessible for effector complexes of RNA-silencing machinery. Furthermore, the obtained results also suggest that the p19-mediated sequestration of siRNAs in virus-infected cells blocks the spread of the mobile, systemic signal of RNA silencing.

Low temperature inhibits RNA silencing-mediated defence by the control of siRNA generation

Temperature dramatically affects plant-virus interactions. Outbreaks of virus diseases are frequently associated with low temperature, while at high temperature viral symptoms are often attenuated (heat masking) and plants rapidly recover from virus diseases. However, the underlying mechanisms of these well-known observations are not yet understood. RNA silencing is a conserved defence system of eukaryotic cells, which operates against molecular parasites including viruses and transgenes. Here we show that at low temperature both virus and transgene triggered RNA silencing are inhibited. Therefore, in cold, plants become more susceptible to viruses, and RNA silencing-based phenotypes of transgenic plants are lost. Consistently, the levels of virus- and transgene-derived small (21-26 nucleotide) interfering (si) RNAs-the central molecules of RNA silencing-mediated defence pathways-are dramatically reduced at low temperature. In contrast, RNA silencing was activated and the amount of siRNAs gradually increased with rising temperature. However, temperature does not influence the accumulation of micro (mi) RNAs, which play a role in developmental regulation, suggesting that the two classes of small (si and mi) RNAs are generated by different nuclease complexes.

Immunology of inflammatory bowel diseases

The pathogenesis of inflammatory diseases involves complex interactions among genetic, environmental and immunologic factors, where the immune system plays a crucial role. The initiating factor may be a commonly present environmental antigen, but the defective mucosal immune response can't downregulate the inflammatory process, the resulting in chronic inflammation and tissue damage. The abnormal amplification of the immune system seems more likely to be a secondary and not a primary factor in the disease. IBD patients exhibit abnormalities in epithelial antigen presentation, and in the cellular and humoral immune system. The role of autoimmunity is unclear in IBD. The inflammatory mediator production and balance is also altered in IBD. Crohn's disease is characterised by a Th1 cytokine profile, while ulcerative colitis is characterised rather by a Th2 cytokine profile. Recent advances in the understanding of the pathogenesis of IBD led to major changes in the treatment of the disease. The newer agents target the key mediators involved in the inflammatory process.

[Molecular genetics and gene therapy in diseases of the esophagus, stomach, colon and pancreas]

There has been a major improvement in our knowledge in the area of molecular genetics in the past 20 years. It has become evident that genetic factors are important in the initiation, progression and prognosis of most diseases. Many studies addressed the issue of tumorigenesis, which provided insight into the molecular basis of the sequencional development of cancer, driven by the accumulation of genomic defects. Most of the neoplasms are genetically heterogeneous, independent pathways and simultaneous tumorigenesis may exist within the same organ. As some mutations exist in benignant and also in malignant conditions, it is an important challenge to define the molecular characteristics of significant versus non-significant lesions. A new form of therapeutic intervention is gene therapy. During the next decade it will likely play an increasing role in clinical practice and particularly in the treatment of cancer.

[Epstein-Barr virus genome positive lymphoepithelioma-like carcinoma of the stomach]

EBV is associated with a high number of tumours and non-tumourous conditions. The rare lymphoepithelioma like carcinoma of the stomach,--just as similar tumours of foregut origin (thymus, lung, salivary gland)--are frequently EBV genom positive with the expression of only a few genes (EBV nuclear antigen 1, EBV encoded ribonucleoproteins/EBER/, latency I). On the basis of the clinicopathological analysis of two cases and literature data the authors point out the male predominance and the relatively favourable prognosis of the patients, furthermore the frequent cardial-subcardial localization of these tumours. Since the frequent non-lymphoepithelioma like stomach tumours,--adenocarcinomas,--show EBV genom positivity in about 1% of the cases, it is concluded that the characteristic lymphoepithelioma like histological pattern is not a sine qua non condition of EBV genom positivity. It may also be assumed, that the CD8 and TIA 1 cytotoxic lymphocytes are not virus but tumour cell specific, however not efficient, perhaps not activated. The low level of apoptotic tumour cells supports this assumption. In one of the cases a double tumour, a genom positive lymphoepithelioma like carcinoma and a genom negative adenocarcinoma, adjacent to each other was seen which speaks in favour of common carcinogenetic factors and shows that microscopic neighbourhood is not a necessary condition in viral association. The origin of the possible oncogenic effect of EBV in the absence of the transforming gene products latent membrane protein 1 and EBNA 2 in genom positive stomach carcinomas is uncertain. The significance of the presence in both cases of CD 5+ tumour cells is not clear, the study of further cases is indicated.

Tissue-specific signal(s) activate the promoter of a metallocarboxypeptidase inhibitor gene family in potato tuber and berry

The molecular basis of the differential expression of the GM7-type metallocarboxypeptidase inhibitor (MCPI) genes in tuberizing (StMCPI) and non-tuberizing Solanum species (SbMCPI) was investigated. It was shown that the StMCPI is encoded by a gene family in Solanum tuberosum (potato), but SbMCPI might be a single-copy gene in the non-tuberizing species Solanum brevidens. The StMCPI promoter shows evolutionary relatedness to the S. brevidens-derived SbMCPI and to the fruit-specific tomato promoter 2A11. Both StMCPI and SbMCPI promoter regions were able to confer tuber- and berry-specific expression for the beta-glucuronidase reporter gene in potato suggesting that the difference in MCPI gene expression is in trans regulatory factors between the tuberizing and the non-tuberizing Solanum species. The MCPI promoters did not respond to metabolic, environmental or hormonal signals in leaves. Thus, the MCPI genes are regulated in a different way than the other known tuber-specific genes and potentially are suitable for biotechnological application in potato to provide specific transgene expression in tuber and berry.

TBP is not universally required for zygotic RNA polymerase II transcription in zebrafish

General transcription factors TFIIA, B, D, E, F, H, and RNA polymerase II (Pol II) are required for accurate initiation of Pol II transcription. The TATA binding protein (TBP), a subunit of TFIID, is responsible for recognition of the TATA box, a core element shared by a category of class II promoters [1]. Recently, novel TBP-like factors (TLFs) have been described in metazoan organisms [2]. In spite of the numerous in vitro studies describing the general role of TBP in RNA polymerase II (Pol lI) transcription initiation, the precise function of TBP and the newly described TLF is poorly understood in vivo. We inhibited TBP and TLF function in zebrafish embryos to study the role of these factors during zygotic transcription. A dominant-negative variant of TLF mRNA and a TBP morpholino antisense oligo was used to block either TLF or TBP function. Both TBP- or TLF-blocked embryos developed normally until the midblastula stage; however, they then failed to gastrulate. Several zygotic regulatory genes were downregulated by a block in either TBP or TLF function, while others were differentially affected. These results suggest that TBP is not universally required for Pol II transcription in vertebrates and that there is a differential requirement for TBP and TLF during early embryogenesis.

TBP-like factor is required for embryonic RNA polymerase II transcription in C. elegans

Recently, a novel family of TATA binding protein (TBP)-like factors (TLFs) have been described in metazoan organisms; however, their function has not yet been elucidated. Using Caenorhabditis elegans (Ce) as a model, we demonstrate that CeTLF is required in vivo for zygotic transcription during embryogenesis. Elimination of CeTLF expression by RNA interference caused embryonic lethality either due to the lack of expression of early patterning genes or to their ectopic expression. Moreover, the absence of CeTLF in vivo prevented the correct soma-specific phosphorylation of RNA polymerase II (Pol II). Thus, CeTLF may positively or negatively regulate Pol II transcription, depending on the developmental stage of the embryo.

D-Penicillamine for preventing retinopathy of prematurity in preterm infants

BACKGROUND

This section is under preparation and will be included in the next issue.

OBJECTIVES

To answer the question: Among very low birth weight infants, what is the effect of prophylactic administration of d-penicillamine on the incidence of acute ROP or severe ROP, and side effects including death?

SEARCH STRATEGY

Searches were made of multiple electronic databases, previous reviews including cross references, abstracts, conference/symposia proceedings, and expert informants.

SELECTION CRITERIA

Randomized or quasi-randomized controlled trials that administered d-penicillamine to infants less than 2000g birth weight within the day following birth were considered relevant to this review. Additional case series were examined for potential side effects.

DATA COLLECTION AND ANALYSIS

Data on clinical outcomes were excerpted by 3 reviewers independently, and consensus reached. Data analysis was conducted according to the standards of the Neonatal Cochrane Review Group.

MAIN RESULTS

Two randomized trials on the effects on ROP were identified. When combined, they showed a significantly lower incidence of acute ROP in the treated infants, relative risk of 0.09, 95% CI [0.01,0.71]. Severe stages of ROP could not be analyzed. There was no effect on death rates, relative risk 0.99 95% CI [0.70,1.39]. No side effects were reported, and follow up at one year revealed no significant differences in spasticity or developmental delay, although there were more rehospitalizations among the controls. In other reports of using d-penicillamine in over 140 infants for hyperbilirubinemia, skin rashes were reported in 2 infants and one had vomiting that may have been related.

REVIEWER'S CONCLUSIONS

D-penicillamine is unlikely to affect survival, and may reduce the incidence of acute ROP among survivors. Studies to date justify further investigation of this drug in a broader population; careful attention to possible side effects is needed.

[Helicobacter pylori infection and cancer of the stomach]

Although the incidence of gastric cancer has declined in the past few decades in developed countries, it has remained one of the most frequent malignomas with high mortality. Epidemiological, clinical and basic research studies confirm the role of Helicobacter pylori in the pathogenesis of the tumors of the distal stomach and low-grade MALT lymphomas. On the contrary more and more data suggest a possible protective role of the infection in the gastro-oesophageal reflux disease, tumors of the cardia and adenocarcinoma of the distal oesophagus. The intensive research being done in the past few years prove our previous concept, that the pathogenesis of gastric cancer is a multifactorial process, which is affected by Helicobacter pylori ("a major environmental factor") together with distinct environmental, social and genetic factors. The interaction of these factors and the importance of them urge further investigations, which may differ in different populations.

"Bloodless" treatment of a Jehovah's Witness infant with ABO hemolytic disease

An ABO-incompatible term infant girl born to parents who are Jehovah's Witnesses was admitted to our neonatal unit with a high serum bilirubin level necessitating exchange transfusion. The parents signed a request that blood should not be administered under any circumstances. However, they authorized us to apply the possible alternative treatments of orally administered D-penicillamine (300 mg/kg per day divided in three doses for 3 days), phototherapy, intravenous fluids, and recombinant human erythropoietin (200 U/kg subcutaneously on every second day for 2 weeks). Herein, we report the outcome of this baby, who was discharged from the our unit in good condition after treatment. Her physical growth and motor milestones at 14 months of age revealed no red flags for neurodevelopmental maturation. To our knowledge, this is the first case of an infant who received such a combined alternative (and "bloodless") treatment of serious ABO hemolytic disease of the newborn.

[Pathophysiology of Helicobacter pylori infection]

The (re)discovery of the gastric pathogen Helicobacter pylori almost one and a half decade ago completely changed our conception on gastroduodenal ulcer disease and gastric cancer. The most important issue is that Helicobacter pylori induces a mild, antrum dominant chronic pangastritis without increased risk of severe diseases in most of the cases. A smaller part of the infected develops antrum dominant gastritis with increased risk of duodenal ulcer. In a few cases the corpus is also affected, pangastritis occurs with increased risk to develop gastric ulcer and gastric cancer. Until now it is not quite obvious why some of the infected patients get ill while others not, and why different diseases develop in different patients. 1. From the bacterial point of view it is ascertained that toxin-producing strains (VacA, CagA positive) are more likely to induce ulcer formation and gastric carcinoma. 2. Genetic phenotype of the infected patients (blood-group and HLA antigens) may also be of importance. 3. Environmental factors may affect (promote or inhibit) disease development. All of these factors determine the complex immunological, functional and morphological changes characteristic for the developing disease.

Potato StubSNF1 interacts with StubGAL83: a plant protein kinase complex with yeast and mammalian counterparts

StubSNF1 is a potato cDNA that encodes a protein kinase similar to the yeast SNF1 gene involved in transcriptional regulation of glucose-repressible genes. The yeast SNF1 functions in a complex with GAL83/SIP1/SIP2 and SNF4 proteins. We have used StubSNF1 as bait in a yeast two-hybrid system to screen for potato cDNAs encoding proteins that bind to StubSNF1. Three overlapping cDNAs, two different in size, were isolated. DNA sequence analysis revealed that they were orthologues of the yeast GAL83/SIP1/SIP2 genes and their mammalian counterparts, AMPK beta-subunits. The direct interaction between the potato proteins StubGAL83 and StubSNF1 was shown by an in vitro binding assay. Southern and Northern hybridisations revealed that StubGAL83 exists in a low copy number in the potato genome and is highly (but organ-specifically) expressed in potato. In contrast, StubSNF1 possesses low transcript levels in each organ, except in flowers where high amounts of StubSNF1 mRNA could be detected. We demonstrate here that StubGAL83 can also interact with yeast SNF4 in a yeast two-hybrid system suggesting that plant SNF1 kinases may function in complexes similar to those detected in yeast and mammals.