A protein-truncating R179X variant in RNF186 confers protection against ulcerative colitis

Protein-truncating variants protective against human disease provide in vivo validation of therapeutic targets. Here we used targeted sequencing to conduct a search for protein-truncating variants conferring protection against inflammatory bowel disease exploiting knowledge of common variants associated with the same disease. Through replication genotyping and imputation we found that a predicted protein-truncating variant (rs36095412, p.R179X, genotyped in 11,148 ulcerative colitis patients and 295,446 controls, MAF=up to 0.78%) in RNF186, a single-exon ring finger E3 ligase with strong colonic expression, protects against ulcerative colitis (overall P=6.89 × 10(-7), odds ratio=0.30). We further demonstrate that the truncated protein exhibits reduced expression and altered subcellular localization, suggesting the protective mechanism may reside in the loss of an interaction or function via mislocalization and/or loss of an essential transmembrane domain.

COX-2 Is Associated with Periodontitis in Europeans

COX-2 plays an important role in periodontitis by mediating inflammatory reactions in periodontal tissues, and the COX-2 polymorphisms rs20417 and rs689466 have been reported to be associated with periodontitis in populations of Taiwanese and Chinese ethnicity. To test whether these variants were associated with periodontitis in populations of European ethnicity, we genotyped the single-nucleotide polymorphisms (SNPs) rs689466 and rs6681231, the latter a haplotype tagging SNP (htSNP) for rs20417 (r2>0.95), in our large-analysis population of individuals with aggressive (n = 532) and chronic periodontitis (n = 1052), and 2873 healthy control individuals. The rare G allele of htSNP rs6681231 was associated with aggressive periodontitis prior to and after adjustment for the covariates smoking, diabetes, and gender, with an odds ratio of 1.57 (95% confidence interval 1.18–2.08; p = 0.002). The validation of the association of rs20417 by the htSNP rs6681231 provides evidence for a general genetic risk of COX-2 variants in the pathogenesis of periodontitis.

A 3' UTR transition within DEFB1 is associated with chronic and aggressive periodontitis

Periodontal diseases are complex inflammatory diseases and affect up to 20% of the worldwide population. An unbalanced reaction of the immune system toward microbial pathogens is considered as the key factor in the development of periodontitis. Defensins have a strong antimicrobial function and are important contributors of the immune system toward maintaining health. Here, we present the first systematic association study of DEFB1. Using a haplotype-tagging single nucleotide polymorphism (SNP) approach, including described promoter SNPs of DEFB1, we investigated the associations of the selected variants in a large population (N=1337 cases and 2887 ethnically matched controls). The 3' untranslated region SNP, rs1047031, showed the most significant association signal for homozygous carriers of the rare A allele (P=0.002) with an increased genetic risk of 1.3 (95% confidence interval: 1.11-1.57). The association was consistent with the specific periodontitis forms: chronic periodontitis (odds ratio=2.2 (95% confidence interval: 1.16-4.35), P=0.02), and aggressive periodontitis (odds ratio=1.3 (95% confidence interval 1.04-1.68), P=0.02). Sequencing of regulatory and exonic regions of DEFB1 identified no other associated variant, pointing toward rs1047031 as likely being the causative variant. Prediction of microRNA targets identified a potential microRNA-binding site at the position of rs1047031.

Association of MICA-TM and MICB C1_2_A microsatellite polymorphisms with tumor progression in patients with colorectal cancer

Purpose

The major histocompatibility complex class I related A (MICA) and MICB molecules are ligands of NKG2D receptors on natural killer cells, gamma/delta T cells, and CD8aß T cells that mediate host antitumor immune response. The role of MICA-TM and MICB C1_2_A alleles in patients with colorectal cancer has not yet been investigated.

Methods

We have analyzed the MICA-TM and MICB C1_2_A polymorphisms in colorectal cancer patients (n = 79) by polymerase chain reaction amplification, subsequent electrophoresis, and sequencing in comparison to a previously analyzed cohort of healthy controls (n = 306). Allele frequencies obtained for MICA-TM and MICB C1_2_A were compared to histopathological data regarding tumor invasion, disease progression, microsatellite instability, and the presence of KRAS mutations (codon 12) and analyzed for possible impact on tumor-related survival (n = 61).

Results

Allele frequencies of MICA-TM and MICB C1_2_A polymorphisms were not different in patients with colorectal cancer in comparison to normal controls. In colorectal cancer patients, MICA-TM A4 allele was directly and MICA-TM A5 allele was inversely associated with lymph node involvement and advanced UICC stages. Tumor-related survival in colorectal cancer patients was significantly reduced in the presence of the MICA-TM A4 allele (p = 0.015). In patients with microsatellite stable tumors, survival was reduced in association with the MICA-TM A4 allele (p = 0.006) and MICA-TM A9 allele (p = 0.034), but increased in patients showing the MICA-TM A5 allele (p = 0.042).

Conclusions

Specific MICA-TM alleles seem to influence tumor progression and midterm survival of patients with colorectal cancer, indicating an important role of host innate immune predisposition involving NKG2D mediated antitumor response.

MICA*055: a new allele with eight GCT repeats in the exon 5 microsatellite

The new allele MICA*055 contains eight GCT repeats within the exon 5 MICA-TM microsatellite polymorphism.

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.

A645G (Lys216Glu) polymorphism of the bactericidal/permeability-increasing protein gene in periodontal disease

Bactericidal/permeability-increasing protein (BPI) is a member of the pattern recognition receptors of the innate immune system and recognizes lipopolysaccharides (LPS), a bacterial component belonging to the pathogen-associated molecular patterns (PAMPs). BPI mediates the neutralization of LPS and increases the phagocytosis and cytotoxicity against bacteria. Recently, the functionally effective polymorphism A645G resulting in the amino acid alteration Lys216Glu has been described. The aim of the study was to investigate the association of the A645G polymorphism with chronic periodontal disease. The study population comprised 123 patients with periodontal disease (36 with mild, 52 with moderate and 35 with severe periodontitis) and 122 healthy, unrelated control individuals. Genotyping of the BPI gene polymorphism A645G (Lys216Glu) was performed by polymerase chain reaction and restriction fragment length polymorphism analysis. Statistical analysis was carried out employing the chi(2) test with Yates correction. Genotype and allele frequencies of the polymorphism tested herein showed no significant differences between periodontal disease as compared to the control group. The frequencies of the G allele were 52.4% in patients with periodontal disease and 49.2% in the control individuals (P = 0.528). Moreover, no significant associations could be detected after stratification for disease severity and according to gender. The present study does not give evidence for the contribution of the BPI gene to the genetic background of chronic periodontal disease.

Serum antibodies in first-degree relatives of patients with IBD: a marker of disease susceptibility? A follow-up pilot-study after 7 years

INTRODUCTION

Various disease-specific serum antibodies were described in patients with inflammatory bowel disease and their yet healthy first-degree relatives. In the latter, serum antibodies are commonly regarded as potential markers of disease susceptibility. The present long-term follow-up study evaluated the fate of antibody-positive first-degree relatives.

PATIENTS AND METHODS

25 patients with Crohn's disease, 19 patients with ulcerative colitis and 102 first-degree relatives in whom presence of ASCA, pANCA, pancreatic- and goblet-cell antibodies had been assessed were enrolled. The number of incident cases with inflammatory bowel disease was compared between antibody-positive and antibody-negative first-degree relatives 7 years after storage of serum samples.

RESULTS

34 of 102 (33%) first-degree relatives were positive for at least one of the studied serum antibodies. In the group of first-degree relatives, one case of Crohn's disease and one case of ulcerative colitis were diagnosed during the follow-up period. However, both relatives did not display any of the investigated serum antibodies (p=1).

DISCUSSION

The findings of our pilot study argue against a role of serum antibodies as a marker of disease susceptibility in first-degree relatives of patients with inflammatory bowel disease. However, these data have to await confirmation in larger ideally prospective multicenter studies before definite conclusions can be drawn.

Prevalence of the -295 T-to-C promoter polymorphism of the interleukin (IL)-16 gene in periodontitis

Interleukin (IL)-16 is involved in the regulation of the expression of several proinflammatory cytokines, i.e. tumour necrosis factor (TNF)alpha and interleukin (IL)-1beta. The present study aimed to determine the prevalence of the -295 promoter polymorphism of the interleukin (IL)-16 gene in periodontal disease. A total of 123 patients with periodontal disease and 122 healthy controls were genotyped for the -295 IL-16 promoter polymorphism. Genotyping has been performed by PCR and restriction fragment length polymorphism (RFLP) analysis. The frequencies of alleles and genotypes as well of haplotypes within both study groups were compared using the Pearson chi(2) test at a level of significance of 5% (P < 0.05). The distribution of genotypes for the -295 IL-16 gene polymorphism showed no significant difference between periodontitis patients and healthy control subjects (P = 0.886). Also stratification analysis according to the disease severity revealed no significant difference regarding the genotype distribution among both study groups. Herein the IL-16 -295 gene polymorphism was not associated with chronic periodontitis.

The leukocyte count predicts the efficacy of treatment with azathioprine in inflammatory bowel disease

INTRODUCTION

Azathioprine has variable efficacy in inflammatory bowel disease. Previous studies suggested that either neutropenia, an increase in the mean corpuscular volume, the assessment of thiopurine methyl-transferase activity or erythrocyte 6-thioguanine values might predict the treatment response. However, due to the conflicting results of the preceding studies there are yet no established laboratory values which allow an estimation of the clinical response.

PATIENTS AND METHODS

45 patients with Crohn's disease and 39 patients with ulcerative colitis were enrolled in this retrospective evaluation. After a minimum of six months therapy with azathioprine patients in remission were compared with those who did not achieve a stable remission with respect to the number of leucocytes, lymphocytes, neutrophil granulocytes and the mean corpuscular volume.

RESULTS

Patients who went into remission during treatment with azathioprine displayed significantly lower leukocyte counts if compared to patients who were not in remission (p = 0.004 in Crohn's disease and 0.003 in ulcerative colitis). A similar tendency was also observed with respect to the granulocyte count (p = 0.007 in Crohn's disease and 0.004 in ulcerative colitis). The mean corpuscular volume did not correlate with the response to purine analogues.

DISCUSSION

The absolute leukocyte count and the percentage of granulocytes seem to predict the response to purine analogues in inflammatory bowel disease and possibly offers a feasible and cost effective diagnostic tool for the assessment of therapeutic efficacy. Subsequent preferably prospective studies should aim to define the optimal cut-off value for the leukocyte count.

Polymorphisms in the DLG5 and OCTN cation transporter genes in Crohn's disease

BACKGROUND AND AIMS

Recent data suggest identification of causal genetic variants for inflammatory bowel disease in the DLG5 gene and in the organic cation transporter (OCTN) cluster, both situated in previously described linkage regions.

PATIENTS AND METHODS

The polymorphisms in DLG5 (113 G-->A, 4136 C-->A, and DLG5_e26), SLC22A4 (1672 C-->T), and SLC22A5 (-207 G-->C) were assessed in 625 patients with Crohn's disease (CD), 363 patients with ulcerative colitis (UC), and 1012 healthy controls. Association with disease susceptibility, clinical phenotypes, and possible genetic interactions of these polymorphisms with disease associated CARD15/NOD2 mutations was analysed.

RESULTS

No significant association of DLG5 polymorphisms with CD or UC was observed. Homozygosity for the OCTN-TC haplotype was associated with an increased CD risk (OR = 1.65), which was even greater in the presence of CARD15 mutations. Genotype-phenotype analysis revealed that this association was particularly strong in patients with colonic disease. The TC haplotype was associated with non-fistulising non-fibrostenotic disease, an earlier age of disease onset, and reduced need for surgery.

CONCLUSION

Our observations argue against a role of DLG5 polymorphisms in the susceptibility for inflammatory bowel disease, whereas the OCTN polymorphisms are associated with CD. However, due to the comparable weak association observed herein, extended linkage disequilibrium analyses of these variants with the IBD5 haplotype tagged single nucleotide polymorphims might be advisable before definitive conclusions about their causative role in CD can be drawn.

Prognostic relevance of p53 and bcl-2 immunoreactivity for early invasive pT1/pT2 gastric carcinomas: indicators for limited gastric resections?

BACKGROUND

Laparoscopic or endoscopic limited resection is intended to be an additional therapeutic option for the treatment of early gastric cancer. However, tumorbiologic markers to predict the outcome for patients after limited resections are missing. This study therefore investigated the prognostic relevance of p53 and bcl-2 immunoreactivity as well as the percentage of apoptotic tumor cells in early invasive pT1/pT2 tumors managed with standard operations for gastric adenocarcinoma.

METHODS

Histologic slides of 65 pT1/pT2 gastric carcinomas were investigated for bcl-2 and p53 immunoreactivity. For 35 patients, DNA fragmentation of tumor cell nuclei was determined by the terminal uridine 5'-triphosphate (UTP) nick end-labeling (TUNEL) method. Follow-up evaluation of the patients was prospectively documented for 53.4 +/- 4.1 months.

RESULTS

Findings showed that bcl-2 immunoreactivity was associated with tumors of the intestinal type according to Lauren s classification (p = 0.042), and that p53 immunoreactivity was increased in more invasive tumors (pT1 vs pT2 tumors; p = 0.047). Mean survival time was significantly longer for patients with bcl-2-negative tumors (74.3 +/- 6.8 months) than for patients with bcl-2-positive tumors (50.8 +/- 7.6 months; p = 0.024). The percentage of apoptotic tumor cell nuclei did not have prognostic relevance in the population studied and was not associated with several histopathologic parameters or bcl-2 and p53 immunoreactivity. Subgroup analysis indicated that the survival of patients with differentiated G2 and bcl-2-negative/p53-negative tumors was significantly longer (82 +/- 6 months) than the survival of patients with G2 bcl-2- and/or p53-positive tumors (41.8 +/- 12.5 months; p = 0.005), with independent prognostic relevance determined by multivariate analysis (p = 0.024).

CONCLUSION

The data reported indicate that the analysis of bcl-2 and p53 immunoreactivity seems to have prognostic implications for early invasive (pT1/pT2) gastric adenocarcinomas and may subclassify patients for minimally invasive laparoscopic or endoscopic gastric resections.

Detection of occult high graded microsatellite instabilities in MMR gene mutation negative HNPCC tumors by addition of complementary marker analysis

BACKGROUND

Hereditary non-polyposis colorectal cancer (HNPCC) is an autosomal dominant tumor syndrome predisposing to predominantly colorectal and endometrial cancer. In 90% of the cases, molecular analyses reveal microsatellite instabilities due to germline mutations in DNA mismatch repair (MMR) genes, mainly MLH1, MSH2, among these tumors.

PATIENTS AND METHODS

Tumors from 40 HNPCC index patients (31 Amsterdam positive, 9 Bethesda positive; 21 females, 19 males; mean age 48.0 +/- 13.2 years) were examined. In contrast to the classical constellation, their tumors revealed only a microsatellite stable (MSS, n=31)--or low instable (MSI-L, n=9)--tumor phenotype following the international reference panel of 5 microsatellites. No MLH1 and MSH2 mutations were detectable. Complementary microsatellites (BAT40, D10S197, D13S153, D18S58, MYCL1) were investigated by PCR and fragment analysis to find other instabilities which might hint to the MIN-pathway of the tumors.

RESULTS

Due to ten microsatellites in total tumors were now reclassified in 4 MSI-H (10%), 24 MSI-L (60%) and 12 in MSS (30%) phenotypes. The mean age of onset for CRCs was the lowest in the MSI-H group with 45.7 +/- 9.6 years (vs. 48.7 +/- 14.3 and 49.0 +/- 12.9 years in MSI-L and MSS group). MSI-H-and MSI-L tumors were often localized in the proximal colon (50 and 52%), whereas MSS tumors were preferentially localized in the distal colon (77%). -

CONCLUSION

Complementary microsatellites help to subdive "non-classical" HNPCC in subgroups with different clinical appearance. It allows to detect occult MSI-H tumors with up to 10% and to confirm MSS tumors who seem to have a similar biological behaviour like sporadic CRC. Maybe that this genetic reclassification influence the decision of whether to offer patients chemotherapy or not, since it is known that patients with instable tumors do not benefit from chemotherapy as well as patients with microsatellite stable tumors.

Inflammatory bowel disease-specific autoantibodies in HLA-B27-associated spondyloarthropathies: increased prevalence of ASCA and pANCA

AIMS

An association between inflammatory bowel disease (IBD) and spondyloarthropathies (SpA) has repeatedly been reported. The aim of the present study was to investigate whether serologic markers of IBD, e.g. antibodies against Saccharomyces cerevisiae (ASCA), antibodies against exocrine pancreas (PAB) and perinuclear antineutrophil cytoplasmic antibodies (pANCA) are present in HLA-B27-associated SpA.

METHODS

87 patients with HLA-B27-positive SpA and 145 controls were tested for ASCA, PAB and pANCA employing ELISA or indirect immunofluorescence, respectively. Antibody-positive patients were interviewed regarding IBD-related symptoms using a standardized questionnaire.

RESULTS/CONCLUSION

When compared to the controls, ASCA IgA but not ASCA IgG levels were significantly increased in patients with SpA, in particular in ankylosing spondylitis (AS) and undifferentiated SpA (uSpA). pANCA were found in increased frequency in patients with SpA whereas PAB were not detected. The existence of autoantibodies was not associated with gastrointestinal symptoms but sustains the presence of a pathophysiological link between bowel inflammation and SpA.

No significant association between mutations in exons 6 and 8 of the autoimmune regulator (AIRE) gene and inflammatory bowel disease

Various autoantibodies have been described in patients with inflammatory bowel disease. The autoimmune regulator (AIRE) functions as a transcription factor in cells responsible for the induction and maintenance of immunological tolerance. In contrast to classic autoimmune disorders, polymorphisms of the AIRE gene are not associated with inflammatory bowel disease, despite the presence of disease-specific autoantibodies.

Toll-like receptor (TLR) 2 and 4 mutations in periodontal disease

Toll-like receptors (TLR) are signal molecules essential for the cellular response to bacterial cell wall components. Different functional effective polymorphisms for the TLR 4 gene (Asp299Gly; Thr399Ile) and for the TLR 2 gene (Arg677Trp, Arg753Gln) have recently been described that are associated with impaired lipopolysaccharide signal transduction. A total of 122 patients with chronic periodontal disease and 122 healthy unrelated controls were genotyped for the Asp299Gly and Thr399Ile polymorphism of the TLR 4 gene and the Arg677Trp and Arg753Gln mutation of the TLR 2 gene. The mutations were identified with polymerase chain reaction followed by restriction fragment length polymorphism (RFLP) analysis. The prevalence of the Asp299Gly and the Thr399Ile mutant allele was 4.1% (10/244) and 4.5% (11/244) among periodontitis patients. For the healthy controls the prevalence was 3.3% (8/244) for the Asp299Gly (P = 0.810) and 3.7% (9/244) for the Thr399Ile mutant allele (P = 0.819). The Arg753Gln mutant allele was found in 2.9% (7/244) of the periodontitis subjects as compared to 4.1% (10/244) in the control group (P = 0.622). The Arg677Trp mutant allele was not found in any of the study subjects. Unlike in ulcerative colitis there was not observed an association between chronic periodontitis and the various mutations of the TLR 2 and 4 gene.

Response to combination therapy with interferon alfa-2a and ribavirin in chronic hepatitis C according to a TNF-alpha promoter polymorphism

BACKGROUND

Tumor necrosis factor-alpha (TNF-alpha) is involved in the pathogenesis of chronic active hepatitis C. Polymorphisms in the promoter region of the TNF-alpha gene can alter the TNF-alpha expression and modify the host immune response. The present study aimed at the correlation of the G308A TNF-alpha polymorphism with the response to antiviral combination therapy in chronic hepatitis C.

PATIENTS AND METHODS

62 patients with HCV and 119 healthy unrelated controls were genotyped for the G308A TNF-alpha promoter polymorphism. The patients received 3 x 3 million units of interferon alfa-2a and 1,000-1,200 mg ribavirin daily according to their body weight. A response was defined as absence of HCV-RNA and normalization of S-ALT after 6 months of combination therapy.

RESULTS

With respect to the allele and genotype frequency, a significant difference was not observed between controls and patients with chronic hepatitis C. Furthermore, such a difference was also not observed if responders and non-responders to antiviral therapy were compared.

CONCLUSIONS

The promoter polymorphism of the TNF-alpha gene investigated herein is equally distributed in healthy individuals and patients with hepatitis C and does not seem to predict the response to therapy with interferon alfa-2a and ribavirin.

The Delta 32 mutation of the chemokine-receptor 5 gene neither is correlated with chronic hepatitis C nor does it predict response to therapy with interferon-alpha and ribavirin

Unlike in HIV, homozygosity for a 32-bp deletion (Delta 32) of the chemokine receptor 5 (CCR5) gene was recently described in increased frequency in patients with chronic hepatitis C (HCV). Thus, it was speculated that this mutation might be relevant for disease susceptibility and influence the response to antiviral therapy. The present study sought to confirm the association between HCV and the Delta 32 mutation of the CCR5 gene and to correlate it with the response to therapy with interferon-alpha-2a and ribavirin. Sixty-two patients with HCV and 119 healthy unrelated controls were genotyped for the Delta 32 mutation. For the correlation between the Delta 32 mutation and response to therapy, only patients (n = 59) who completed 6 months of combination therapy as part of a prospective study were evaluated. The Delta 32 mutation was not observed in increased frequency in HCV. Furthermore, a significant difference of the HCV load or aminotransferase concentrations was not observed in carriers versus noncarriers of the Delta 32 mutation. After stratification for potentially confounding factors such as gender or HCV genotype, a significant difference was also not detected with respect to treatment outcome. These observations argue strongly against a role of CCR5 for susceptibility to HCV infection or response to combination therapy.

Herpes simplex virus type 2-associated eosinophilic cellulitis (Wells' syndrome)

Eosinophilic cellulitis (Wells' syndrome) is a recurrent inflammatory dermatosis characterized by massive infiltration of eosinophils into the skin. Drugs and pathogens have been recognized causes of eosinophilic cellulitis. We report the repeated association of eosinophilic cellulitis with herpes simplex virus type 2 infections. Antiviral therapy led to a complete remission of eosinophilic cellulitis, indicating that causative treatment of underlying diseases can be effective in controlling eosinophilic cellulitis.

Anti-saccharomyces cerevisiae antibodies in patients with inflammatory bowel disease and their first-degree relatives: potential clinical value

Anti-Saccharomyces cerevisiae antibodies (ASCA) have been described as specific markers in Crohn's disease and their healthy first-degree relatives. 171 patients with Crohn's disease, their 105 first-degree relatives, 145 patients with ulcerative colitis and 101 first-degree relatives of patients with ulcerative colitis, 50 patients with infectious enterocolitis and 100 healthy controls were tested for ASCA employing the ELISA technique. When compared with the healthy controls (p < 0.0001) and patients with infectious enterocolitis (p < 0.0001) the prevalence of ASCA was significantly increased in patients with Crohn's disease and their first-degree relatives (p < 0.01). Further significant differences concerning the frequency of ASCA within the different groups of our study population were not observed. In particular, ASCA were not found in increased prevalence in infectious enterocolitis. These observations are compatible with a role of ASCA as a marker of genetic predisposition to Crohn's disease.

The -295T-to-C promoter polymorphism of the IL-16 gene is associated with Crohn's disease

Recently, a T-to-C polymorphism at position -295 in the promoter region of the human interleukin-16 (IL-16) gene was reported. The expression of IL-16 is increased in inflammatory bowel disease, in particular in Crohn's disease. However, data concerning the IL-16 promoter polymorphism in inflammatory bowel disease are lacking. Thus, the current study aimed at the assessment of this polymorphism in Crohn's disease and ulcerative colitis. One hundred three patients with Crohn's disease, 100 patients with ulcerative colitis, and 120 healthy unrelated controls were genotyped for the promoter polymorphism. Furthermore, patients with Crohn's disease were stratified according to disease localization and the respective clinical phenotype (fistulizing, fibrostenotic, or inflammatory). The frequencies of the T allele (P < 0.01) and the TT genotype (P < 0.01) were significantly increased in patients with Crohn's disease compared to the controls, regardless of the disease phenotype or the site of intestinal involvement. An association with ulcerative colitis was not observed. Herein a new association between a promoter polymorphism of the IL-16 gene and Crohn's disease was observed and correlates with the previously described increased mucosal expression of IL-16 in inflammatory bowel disease.

Linkage disequilibria between HLA-B, C1_4_1, MICA and MICB

The polymorphisms of MICA exon 5 (5 alleles), MICB intron 1 (13 alleles), C1_4_1 (6 alleles), HLA-B (29 alleles) and HLA-A (15 alleles) were investigated in a healthy German population. Sequencing was performed for the MICB alleles CA14, CA15, CA17, CA23 and CA26 isolated from different cell lines. Variation to the published sequence was observed for CA14, CA15 and for CA17. At the C1_4_1 locus a new allele (CAAA)9 was identified and confirmed by sequencing. Linkage disequilibria were investigated for two-point- and three-point-haplotypes. Although the average relative delta value correlates loosely with the physical distance from HLA-B to MICB: HLA-B-C1_4_1>HLA-B-MICA>HLA-B-MICB, there are several exceptions to this rule. Analyzing three-point-haplotypes for the segment MICB to HLA-A a wide variation of linkage disequilibria for some of the classical HLA-A, B haplotypes has been observed. While the HLA-A1, B8 haplotype displays strong relative delta values over the entire distance from HLA-A to MICB, other haplotypes have linkage disequilibria only in a limited region.

MICA, MICB and C1_4_1 polymorphism in Crohn's disease and ulcerative colitis

MICA and MICB belong to a multicopy gene family located in the major histocompatibility complex (MHC) class I region near the HLA-B gene. They encode for MHC class I molecules, which are induced by stress factors like infection, heat shock or neoplastic transformation and which are mainly expressed on gastrointestinal epithelium. They are recognized by gammadelta T lymphocytes and natural killer (NK) cells. Additionally they are located within a linkage region on chromosome 6p around HLA-B and TNFalpha. Thus the polymorphic MICA and MICB genes are excellent candidate genes for providing the genetic background of inflammatory bowel disease. A strong association of allele A6 of the MICA exon 5 trinucleotide microsatellite polymorphism with ulcerative colitis has been found in Japanese patients. Therefore, we have analysed the MICA exon 5 polymorphism, the MICB intron 1 dinucleotide polymorphism and in addition the tetranucleotide polymorphism C1_4_1, which is located between the MICA gene and the HLA-B gene, in patients of Caucasoid origin with Crohn's disease (n=94) and ulcerative colitis (n=94). In this study we could not find any associations of particular alleles of the MICA, MICB and C1_4_1 polymorphisms with Crohn's disease or ulcerative colitis. We could also not discover any associations of specific two-point or three-point haplotypes with these diseases. Thus it is unlikely that the MICA and MICB genes are involved in causing susceptibility for inflammatory bowel disease, although it cannot be excluded that a weak association could be identified in a larger patient sample.

Susceptibility contrast imaging of cerebral blood volume: human experience

Magnetic resonance (MR) can offer a unique window on the structure/function relationships in the brain, by utilizing the established link between tissue function, metabolism, and hemodynamics. This report focuses on recent applications of MR-based cerebral blood volume (CBV) imaging in humans. Our methodology uses high-speed "single-shot" or echo planar imaging techniques, which provide the necessary temporal resolution for mapping the rapid cerebral transit of contrast agents. These MR CBV mapping techniques have been used to study normal human brain task activation and in the clinical study of patients with brain tumors. In the latter, positron emission tomography imaging was used for functional metabolic and CBV correlation. Susceptibility contrast CBV imaging should allow us to improve our understanding of the relationship between the detailed physiology and morphology of the microvascular bed and functional attributes of the brain. These techniques can be applied to understanding fundamental questions of cognitive neuroscience and can aid in improving diagnostic sensitivity and specificity in various neuropathologies.

Open wound drainage versus wound excision in treating the modern assault rifle wound

Military dogma of the past 20 years preaches that excision of all injured tissue around the path of a penetrating projectile is essential in wound treatment. To find out whether excising injured muscle surrounding a bullet path benefits healing over and above the benefit provided by a simple release of tension by incision, two groups of 90 kg swine were shot in the hind leg with a replica of the AK-74 assault rifle projectile. One group was treated by excision of injured tissue around the projectile path; in the other group no tissue was excised. Both groups were given parenteral penicillin for 5 days, and simple gauze dressings were used to cover the wounds. No difference in healing time occurred; the wounds in both groups had closed, and no epithelial defect remained by 20 to 22 days. These results indicate that the simple extremity wound caused by the modern-generation assault rifle, provided with adequate open drainage and systemic penicillin, heals as rapidly when the body defense mechanisms handle the disrupted tissue as when an attempt is made to excise it surgically.

Purification and characterization of cloacin DF13 receptor from Enterobacter cloacae and its interaction with cloacin DF13 in vitro

Extraction of the crude cell envelope fraction of cloacin DF13-susceptible Enterobacter cloacae strain 02 with Triton X-100 and ethylenediaminetetraacetate solubilized an outer membrane fraction which neutralized the lethal activity of cloacin DF13. A similar fraction could not be isolated from strains known to be lacking functional cloacin DF13 receptors. On this basis the isolated outer membrane fraction was assumed to contain the specific cloacin DF13 receptor. The receptor was purified to homogeneity by acetone precipitation and affinity chromatography, using cloacin DF13 as a ligand. The purified receptor was identified as a protein which consisted of a single polypeptide chain with an apparent molecular weight of 90,000 and a preponderance of acidic amino acids (pI = 5.0). The interaction of equimolar amounts of purified receptor and cloacin DF13 in vitro resulted in a complete, irreversible neutralization of the lethal activity of the bacteriocin. This interaction showed a temperature optimum at 43 degrees C but was only slightly affected by variation of the pH between 5.0 and 8.5 or by increasing the ionic strength of the incubation buffer. The receptor had no neutralizing activity towards other bacteriocins, such as colicin E1 or colicin E3.