Prevalence of Helicobacter pylori in the adolescent oral cavity: dependence on orthodontic therapy, oral flora and hygiene

BACKGROUND

Helicobacter pylori (HP) infection usually occurs in childhood. While there are various studies on the prevalence of HP in dental plaque, ours is the first to analyze its prevalence during orthodontic therapy and its interaction with competitive bacteria in adolescents.

SUBJECTS AND METHODS

The prevalence of HP was examined before and during the first 12 weeks of orthodontic therapy with fixed appliances in 11 patients with a mean age of 12.7 years. A total of 93 plaque samples were analyzed using PCR. The data acquired at every consultation were the following: PCR analysis of dental plaque and (13)C urea breath tests for HP, quantitative analyses of saliva for Lactobacilli and Streptococcus mutans, the interproximal plaque index (API), and sulcus bleeding index (SBI).

RESULTS

The prevalence of HP in plaque was 82% before orthodontic therapy, dropping to 54% during therapy (t test, p≤0.05). In contrast to HP's prevalence, the Lactobacilli count rose (p≤0.05). The number of Streptococcus mutans bacteria in saliva decreased during orthodontic therapy (p≤0.05).

CONCLUSION

The prevalence of HP in dental plaque amounted to 82%. Orthodontic treatment did not reduce its prevalence. The prevalence of Lactobacilli was inversely proportional to that of HP.

Possible counter effect in newborns of 1936A>G (I646V) polymorphism in the AKAP10 gene encoding A-kinase-anchoring protein 10

OBJECTIVE

Cyclic adenosine monophosphate/protein kinase A (PKA) is important in embryonic development. The human AKAP10 gene is polymorphic: 1936A>G results in changes to a PKA-binding domain and increased targeting to mitochondria. Previous studies found G1936 as 'deleterious' in adults, and this study investigates whether this holds true in preterm birth.

STUDY DESIGN

Study group consisted of 80 preterm newborns (PTNs) born before the 38th gestation week. Control group consisted of 123 full-term healthy newborns born after the 37th gestation week with uncomplicated pregnancies. Genomic DNA was extracted from umbilical blood and AKAP10 genotypes were identified by PCR/restriction enzyme.

RESULT

Significant differences in frequencies of 1936A>G genotypes/alleles between both groups were found. PTNs had increased frequency (55%) of AA homozygotes (odds ratio, AA versus AG+GG: 2.63 (95% confidence interval: 1.33 to 5.20), P=0.006) after adjustments: mothers with previous PTNs, smoking, first pregnancy, first delivery and Cesarean section.

CONCLUSION

Results suggest G1936 is preventative factor against preterm birth, in contrast with previously asserted negative effects in adults.

Hepcidin is localised in gastric parietal cells, regulates acid secretion and is induced by Helicobacter pylori infection

BACKGROUNDS AND AIMS

Hepcidin is an antimicrobial peptide and the central regulator of iron metabolism. Given that hepcidin was shown to be expressed in a variety of extrahepatic tissues and that stomach plays a role in iron absorption and in defence against infections, this study analysed the importance of hepcidin in the stomach.

METHODS

Expression and localisation of gastric hepcidin was studied by quantitative RT-PCR, western blot, immunofluorescence and in situ hybridisation. Regulation of gastric hepcidin expression was analysed both in vitro and in vivo. Hepcidin wild-type (WT) and knockout (KO) animals were used to determine the impact of hepcidin on gastric bacterial overgrowth as well as gastric acid secretion.

RESULTS

Hepcidin was abundantly expressed in the gastric fundus and corpus of all tested species. Treatment of AGS cells with ferric nitrilotriacetate solution downregulated hepcidin expression levels, while desferroxamine, interleukin 6 and Helicobacter pylori infection upregulated it. In humans, gastric hepcidin expression was elevated during H pylori infection and normalised after successful eradication. Gastric hepcidin is localised in parietal cells that are indispensable for gastric acid secretion. Comparisons of WT and hepcidin KO mice revealed that acid secretion in hepcidin-deficient mice is markedly reduced and is associated with gastric bacterial overgrowth, expression changes in multiple factors involved in acid secretion (Atp4a, Cck2r,Gas, Sst and Sst2r) and with reduced circulating gastrin levels. In WT mice, pantoprazole activated and histamine downregulated hepcidin expression levels.

CONCLUSIONS

Hepcidin is a product of parietal cells regulating gastric acid production and may contribute to development of gastric ulcers under stress conditions.

MBL2, MASP2, AMELX, and ENAM gene polymorphisms and dental caries in Polish children

OBJECTIVE

The aim of the study was to examine whether the MBL2 C(-290)G and G161A, MASP2 A359G, AMELX C287T and C522T, and ENAM C2452T polymorphisms are associated with dental caries.

SUBJECTS AND METHODS

Genomic DNA of 95 Polish children with 'higher caries experience' (HC) and 84 subjects with 'lower caries experience' (LC) belonging to two age-groups (5 and 13 years old) was extracted from the buccal mucosa. SNPs were genotyped with PCR-RFLP methods.

RESULTS

Among 5-year-old children, we found significantly higher percentage of subjects carrying MBL2 (-290)G allele in HC group compared with LC group (43.2%vs 17.6%, P = 0.023). MBL2 C(-290)G-G161A C-G haplotype was overrepresented in LC group in 5-year-olds (P = 0.01), while the opposite association was observed in 13-year-olds, where C-G was overrepresented in HC group (P = 0.028). In 5-year-old children, the frequency of MBL2 G-G haplotype was higher in HC group compared with LC subjects (P = 0.045), while the opposite association (with borderline significance) was observed in 13-year-old children (P = 0.057). SNPs in MASP2, AMELX, and ENAM were not associated with dental caries.

CONCLUSION

MBL2 gene polymorphism is associated with caries experience in Polish children, but the direction of this association seems to be opposite in primary and permanent dentition.

Protein kinase D2 is a novel regulator of glioblastoma growth and tumor formation

Glioblastoma multiforme, a highly aggressive tumor of the central nervous system, has a dismal prognosis that is due in part to its resistance to radio- and chemotherapy. The protein kinase C (PKC) family of serine threonine kinases has been implicated in the formation and proliferation of glioblastoma multiforme. Members of the protein kinase D (PKD) family, which consists of PKD1, -2 and, -3, are prominent downstream targets of PKCs and could play a major role in glioblastoma growth. PKD2 was highly expressed in both low-grade and high-grade human gliomas. The number of PKD2-positive tumor cells increased with glioma grading (P < .001). PKD2 was also expressed in CD133-positive glioblastoma stem cells and various glioblastoma cell lines in which the kinase was found to be constitutively active. Inhibition of PKDs by pharmacological inhibitors resulted in substantial inhibition of glioblastoma proliferation. Furthermore, specific depletion of PKD2 by siRNA resulted in a marked inhibition of anchorage-dependent and -independent proliferation and an accumulation of glioblastoma cells in G0/G1, accompanied by a down-regulation of cyclin D1 expression. In addition, PKD2-depleted glioblastoma cells exhibited substantially reduced tumor formation in vivo on chicken chorioallantoic membranes. These findings identify PKD2 as a novel mediator of glioblastoma cell growth in vitro and in vivo and thereby as a potential therapeutic target for this devastating disease.

B and T lymphocyte attenuator restricts the protective immune response against experimental malaria

The immune response against the blood stage of malaria has to be tightly regulated to allow for vigorous antiplasmodial activity while restraining potentially lethal immunopathologic damage to the host like cerebral malaria. Coinhibitory cell surface receptors are important modulators of immune activation. B and T lymphocyte attenuator (BTLA) (CD272) is a coinhibitory receptor expressed by most leukocytes, with the highest expression levels on T and B cells, and is involved in the maintenance of peripheral tolerance by dampening the activation of lymphocytes. The function of BTLA is described in several models of inflammatory disorders and autoimmunity, but its function in infectious diseases is less well characterized. Also, little is known about the influence of BTLA on non-T cells. In this study, we analyzed the function of BTLA during blood-stage malaria infection with the nonlethal Plasmodium yoelii strain 17NL. We show that BTLA knockout mice exhibit strongly reduced parasitemia and clear the infection earlier compared with wild-type mice. This increased resistance was seen before the onset of adaptive immune mechanisms and even in the absence of T and B cells but was more pronounced at later time points when activation of T and B cells was observed. We demonstrate that BTLA regulates production of proinflammatory cytokines in a T cell-intrinsic way and B cell intrinsically regulates the production of P. yoelii 17NL-specific Abs. These results indicate that the coinhibitory receptor BTLA plays a critical role during experimental malaria and attenuates the innate as well as the subsequent adaptive immune response.

[Shortage and need of physicians in Germany? Questions addressed to health services research]

The problem of shortage of physicians has been discussed controversially in Germany for years, and the different positions of the interest groups involved have not been resolved. The question of the present and anticipated future requirement of physicians is central for an appropriate and necessary medical care of the population. In the analysis, supply and demand of medical care have to be distinguished. Relatively reliable data do exist for the supply of physicians; however, the changing number of working hours that male and--in particular female--physicians are willing to contribute should be taken into consideration. Reliable data for the future demand are presently not available. Several variables (e.g., demography, disease spectrum of an aging society, medical progress, the changing rules of working hours, and the shift of medical care between hospital and practice care) depend on future developments. Considering the existing serious indicators of a growing shortage of physicians, it is recommended to put more effort into the scientific investigation of these factors. More profound data should improve the basis for decisions in health and education politics.

Intravenous ibandronate or sodium-fluoride--a 3.5 years study on bone density and fractures in Crohn's disease patients with osteoporosis

BACKGROUND AND AIM

Osteoporosis commonly afflicts Crohn's disease (CD) patients. Management remains unclear, with limited results for intravenous (i.v.) bisphosphonates and a follow-up longer than one year. Intravenous bisphosphonates bypass gastrointestinal-tract irritation offering an interesting alternative suitable for CD patients. We tested the long-term efficacy and safety of colecalciferol and calcium with sodium-fluoride or i.v. ibandronate for osteoporosis in CD.

METHODS

66 CD patients with lumbar osteoporosis (T-score<-2.5) were randomized to receive colecalciferol (1000 IU), calcium-citrate (800 mg) and intermittent sustained-release sodium-fluoride (50 mg) [groupA, n=33] or i.v. ibandronate (1 mg/3-monthly) [groupB, n=33]. Dual-energy X-ray absorptiometry of the lumbar-spine and right femur and X-rays of the spine were performed at baseline and after 1.0, 2.25 and 3.5 years. Fracture-assessment included visual reading and quantitative morphometry of X-rays.

RESULTS

55 (83.3%) patients completed at least the 1st year available for intention-to-treat (ITT) analysis, 42 (63.6%) completed the 2nd and 35 (53.0%) the 3rd year available for per-protocol analysis. Lumbar T-score increased by +0.23±0.43 (95%CI: 0.057-0.407, p<0.05), +0.71±1.05 (95%CI: 0.193-1.232, p<0.001) and +0.73±0.82 (95%CI: 0.340-1.336, p<0.001) (group A), and +0.28±0.41 (95%CI: 0.132-0.459, p<0.05), +0.43±0.55 (95%CI: 0.184-0.671, p<0.01) and +0.51±0.74 (95%CI: 0.145-0.882, p<0.001) (group B) during 1.0, 2.25 and 3.5 years follow-up time. In 2.71 years of follow-up, with the ITT analysis, the lumbar T-score increased by +0.66±0.97 (group A, p<0.001) and +0.46±0.67 (group B, p<0.001). One vertebral fracture with sodium-fluoride was not enough to detect differences between groups and the study was not powered for this. Study medication was well-tolerated and safe.

CONCLUSIONS

Sodium-fluoride and i.v. ibandronate improved osteoporosis. Keeping in mind bisphosphonates as a standard of osteoporosis care that reduce fracture-rate, data we do not have for sodium-fluoride, CD patients with osteoporosis can be treated safely with i.v. ibandronate.

A novel monoclonal antibody immunoassay for the detection of human serum hepcidin

BACKGROUND

Hepcidin is a liver-derived peptide hormone regulating iron metabolism. Changes in the expression of hepcidin are known to be the key pathogenic factors in hereditary hemochromatosis and are associated with infection and inflammation. To better understand the hormone's function in human disease, we aimed to establish an immunoassay to determine hepcidin concentrations in serum.

METHODS

Monoclonal antibodies mHK(8) and mHK(9) were generated and characterized by dot blot, Western blot, and immunofluorescence. A competitive enzyme-linked immunosorbent assay (ELISA) was established with mHK(9).

RESULTS

Both antibodies recognized hepcidin, by dot blot and Western blot, respectively. In human liver, mHK(8)/(9) showed an immunofluorescence staining pattern in hepatocytes identical to that of established prohepcidin antibodies. The developed immunoassay with mHK(9), reliably detecting mature hepcidin in serum over a large concentration range (0.9-140 ng ml⁻¹), showed high sensitivity and precision (intra-/interassay coefficients of variation: 4-5 and 7-11%; mean linearity: 85-112%; mean recovery: 87-114%). To test the clinical functionality of the developed assay we measured hepcidin serum concentrations in healthy volunteers, hepatitis C virus (HCV) patients, and two groups of hemochromatotic patients undergoing phlebotomy. The assay distinguished low hepcidin level in HCV and homozygous hemochromatosis patients from normal-range controls and compound heterozygous hemochromatosis patients. In healthy subjects and HCV patients, hepcidin levels were correlated with iron and transferrin saturation; no correlation was observed in the hemochromatotic patients.

CONCLUSION

We developed a monoclonal antibody ELISA that quantifies serum hepcidin levels with high sensitivity, robustness, and reliability of detection. The hepcidin ELISA should help to enhance our understanding of hepcidin-related human disorders.

A single dose of intravenous zoledronate prevents glucocorticoid therapy-associated bone loss in acute flare of Crohn's disease, a randomized controlled trial

OBJECTIVES

To assess the effectiveness and safety of zoledronate (ZOL) in preventing glucocorticoid therapy-associated bone loss in patients with acute flare of Crohn's disease (CD) in a randomized, double-blind, placebo-controlled trial.

METHODS

Forty CD patients starting a glucocorticoid therapy (60 mg prednisolone per day) for acute flare (CD activity index (CDAI) >220) were randomized to compare the effect of ZOL (4 mg intravenous, n=20) or placebo (n=20) on change in lumbar bone mineral density (BMD). All patients received calcium citrate (800 mg) and colecalciferol (1,000 IU) daily. Dual energy X-ray absorptiometry (DXA) of the lumbar spine (L1-L4) was performed at baseline and day 90. Follow-up examinations at day 1/7/14/30 and 90 included laboratory tests and adverse event/serious adverse events reports.

RESULTS

Thirty-six patients were available for per-protocol analysis. With placebo (n=18), a decrease in BMD was seen (T-score: -0.98 ± 0.8, day 0 and -1.25 ± 0.77, day 90, P=0.06), with ZOL (n=18) BMD increased (-1.15 ± 1.02, day 0 and -0.74 ± 1.09, day 90, P=0.03). The change in BMD under placebo (-0.26 ± 0.21) vs. ZOL (+0.41 ± 0.19) was highly significant (P=0.006). In all, 14 out of 18 patients with ZOL had an increase in BMD (+0.64 ± 0.48), 12 of 18 with placebo a decrease (-0.50 ± 0.39). Changes of clinical findings and laboratory results of inflammation (leukocytes, platelets, and C-reactive protein) were the same in- and between-groups throughout the study. With ZOL, serum bone degradation marker β-Cross-Laps decreased. Study medication was safe and well tolerated.

CONCLUSIONS

ZOL is effective in preventing glucocorticoid therapy-induced bone loss in patients with acute flare of CD and should be considered whenever a glucocorticoid therapy is started in CD patients.

A novel method of forceps biopsy improves the diagnosis of proximal biliary malignancies

BACKGROUND AND AIMS

Tissue specimen collection represents a cornerstone in diagnosis of proximal biliary tract malignancies offering great specificity, but only limited sensitivity. To improve the tumor detection rate, we developed a new method of forceps biopsy and compared it prospectively with endoscopic transpapillary brush cytology.

PATIENTS AND METHODS

43 patients with proximal biliary stenoses, which were suspect for malignancy, undergoing endoscopic retrograde cholangiography were prospectively recruited and subjected to both biopsy [using a double-balloon enteroscopy (DBE) forceps under a guidance of a pusher and guiding catheter with guidewire] and transpapillary brush cytology. The cytological/histological findings were compared with the final clinical diagnosis.

RESULTS

35 out of 43 patients had a malignant disease (33 cholangiocarcinomas, 1 hepatocellular carcinoma, 1 gallbladder carcinoma). The sensitivity of cytology and biopsy in these patients was 49 and 69%, respectively. The method with DBE forceps allowed a pinpoint biopsy of the biliary stenoses. Both methods had 100% specificity, and, when combined, 80% of malignant processes were detected. All patients with non-malignant conditions were correctly assigned by both methods. No clinically relevant complications were observed.

CONCLUSIONS

The combination of forceps biopsy and transpapillary brush cytology is safe and offers superior detection rates compared to both methods alone, and therefore represents a promising approach in evaluation of proximal biliary tract processes.

Protein kinase D2 is an essential regulator of murine myoblast differentiation

Muscle differentiation is a highly conserved process that occurs through the activation of quiescent satellite cells whose progeny proliferate, differentiate, and fuse to generate new myofibers. A defined pattern of myogenic transcription factors is orchestrated during this process and is regulated via distinct signaling cascades involving various intracellular signaling pathways, including members of the protein kinase C (PKC) family. The protein kinase D (PKD) isoenzymes PKD1, -2, and -3, are prominent downstream targets of PKCs and phospholipase D in various biological systems including mouse and could hence play a role in muscle differentiation. In the present study, we used a mouse myoblast cell line (C2C12) as an in vitro model to investigate the role of PKDs, in particular PKD2, in muscle stem cell differentiation. We show that C2C12 cells express all PKD isoforms with PKD2 being highly expressed. Furthermore, we demonstrate that PKD2 is specifically phosphorylated/activated during the initiation of mouse myoblast differentiation. Selective inhibition of PKCs or PKDs by pharmacological inhibitors blocked myotube formation. Depletion of PKD2 by shRNAs resulted in a marked inhibition of myoblast cell fusion. PKD2-depleted cells exhibit impaired regulation of muscle development-associated genes while the proliferative capacity remains unaltered. Vice versa forced expression of PKD2 increases myoblast differentiation. These findings were confirmed in primary mouse satellite cells where myotube fusion was also decreased upon inhibition of PKDs. Active PKD2 induced transcriptional activation of myocyte enhancer factor 2D and repression of Pax3 transcriptional activity. In conclusion, we identify PKDs, in particular PKD2, as a major mediator of muscle cell differentiation in vitro and thereby as a potential novel target for the modulation of muscle regeneration.

Hepcidin is an antibacterial, stress-inducible peptide of the biliary system

BACKGROUND/AIMS

Hepcidin (gene name HAMP), an IL-6-inducible acute phase peptide with antimicrobial properties, is the key negative regulator of iron metabolism. Liver is the primary source of HAMP synthesis, but it is also produced by other tissues such as kidney or heart and is found in body fluids such as urine or cerebrospinal fluid. While the role of hepcidin in biliary system is unknown, a recent study demonstrated that conditional gp130-knockout mice display diminished hepcidin levels and increased rate of biliary infections.

METHODS

Expression and localization of HAMP in biliary system was analyzed by real time RT-PCR, in-situ hybridization, immunostaining and -blotting, while prohepcidin levels in human bile were determined by ELISA.

RESULTS

Hepcidin was detected in mouse/human gallbladder and bile duct epithelia. Biliary HAMP is stress-inducible, in that it is increased in biliary cell lines upon IL-6 stimulation and in gallbladder mucosa of patients with acute cholecystitis. Hepcidin is also present in the bile and elevated prohepcidin levels were observed in bile of primary sclerosing cholangitis (PSC) patients with concurrent bacterial cholangitis compared to PSC subjects without bacterial infection (median values 22.3 vs. 8.9; p = 0.03). In PSC-cholangitis subjects, bile prohepcidin levels positively correlated with C-reactive protein and bilirubin levels (r = 0.48 and r = 0.71, respectively). In vitro, hepcidin enhanced the antimicrobial capacity of human bile (p<0.05).

CONCLUSION

Hepcidin is a stress-inducible peptide of the biliary epithelia and a potential marker of biliary stress. In the bile, hepcidin may serve local functions such as protection from bacterial infections.

Bones and Crohn's: no benefit of adding sodium fluoride or ibandronate to calcium and vitamin D

AIM

To compare the effect of calcium and cholecalciferol alone and along with additional sodium fluoride or ibandronate on bone mineral density (BMD) and fractures in patients with Crohn's disease (CD).

METHODS

Patients (n =148) with reduced BMD (T-score < -1) were randomized to receive cholecalciferol (1000 IU) and calcium citrate (800 mg) daily alone(group A, n = 32) or along with additional sodium fluoride (25 mg bid) (group B, n = 62) or additional ibandronate (1 mg iv/3-monthly) (group C, n = 54). Dual energy X-ray absorptiometry of the lumbar spine (L1-L4) and proximal right femur and X-rays of the spine were performed at baseline and after 1.0, 2.25 and 3.5 years. Fracture-assessment included visual reading of X-rays and quantitative morphometry of vertebral bodies (T4-L4).

RESULTS

One hundred and twenty three (83.1%) patients completed the first year for intention-to-treat (ITT) analysis. Ninety two (62.2%) patients completed the second year and 71 (47.8%) the third year available for per-protocol (PP) analysis. With a significant increase in T-score of the lumbar spine by +0.28 ± 0.35 [95% confidence interval (CI): 0.162-0.460, P < 0.01], +0.33 ± 0.49 (95% CI: 0.109-0.558, P < 0.01), +0.43 ± 0.47 (95% CI: 0.147-0.708, P < 0.01) in group A, +0.22 ± 0.33 (95% CI: 0.125-0.321, P < 0.01); +0.47 ± 0.60 (95% CI: 0.262-0.676, P < 0.01), +0.51 ± 0.44 (95% CI: 0.338-0.682, P < 0.01) in group B and +0.22 ± 0.38 (95% CI: 0.111-0.329, P < 0.01), +0.36 ± 0.53 (95% CI: 0.147-0.578, P < 0.01), +0.41 ± 0.48 (95% CI: 0.238-0.576, P < 0.01) in group C, respectively, during the 1.0, 2.25 and 3.5 year periods (PP analysis), no treatment regimen was superior in any in- or between-group analyses. In the ITT analysis, similar results in all in- and between-group analyses with a significant in-group but non-significant between-group increase in T-score of the lumbar spine by 0.38 ± 0.46 (group A, P < 0.01), 0.37 ± 0.50 (group B, P < 0.01) and 0.35 ± 0.49 (group C, P < 0.01) was observed. Follow-up in ITT analysis was still 2.65 years. One vertebral fracture in the sodium fluoride group was detected. Study medication was safe and well tolerated.

CONCLUSION

Additional sodium fluoride or ibandronate had no benefit over calcium and cholecalciferol alone in managing reduced BMD in CD.

Loss of Lsc/p115 protein leads to neuronal hypoplasia in the esophagus and an achalasia-like phenotype in mice

BACKGROUND & AIMS

Lsc/p115 originally was described as hematopoietic Ras homologous protein guanine exchange factor (Rho-GEF) regulating leukocyte migration, adhesion, and marginal zone B-cell homeostasis. Here we investigate the expression pattern of lsc/p115 in the gastrointestinal tract and the consequences of lsc/p115 deficiency in lsc/p115-knockout mice.

METHODS

The phenotype of lsc/p115-deficient mice was analyzed in vivo with small-animal computed tomography scans and esophageal manometry. The morphology and myenteric plexus were evaluated with immunohistochemistry, morphometry, Western blot analyses, and quantitative reverse-transcription polymerase chain reaction.

RESULTS

lsc/p115 is expressed in the gastrointestinal tract, sparing the segment of the small intestine. Immunohistochemical staining detects lsc/p115 in the muscle layer and the glial fibrillary acidic protein-positive glia in the esophagus. Esophageal manometry uncovers a severe motor dysfunction in lsc/p115-deficient mice. This achalasia-like phenotype is characterized by disturbed peristalsis, hypertension of the lower esophageal sphincter, and impaired relaxation of the lower esophageal sphincter. Lsc/p115-deficient mice develop a progressive dilatation of the esophagus and decrease of the muscle layer. The muscle cell differentiation is not altered in lsc/p115-deficient mice. However, the density of inhibitory and excitatory neurons and glia cells in the myenteric plexus and the muscle layer are reduced in morphometric analyses. This reduced number of glia cells is accompanied by reduced expression of the neurotrophic nerve growth factor.

CONCLUSIONS

lsc/p115 deficiency results in impaired neuronal innervation and in motor dysfunction recapitulating several aspects of esophageal achalasia. Reduced expression of nerve growth factor and a reduced number of glia cells most likely contribute to this phenotype.

Protein kinase D2 is a crucial regulator of tumour cell-endothelial cell communication in gastrointestinal tumours

BACKGROUND

Tumour angiogenesis is crucially dependent on the communication between the tumour and the associated endothelium. Protein kinase D (PKD) isoenzymes mediate vascular endothelial growth factor-A (VEGF-A) induced endothelial cell proliferation and migration and are also highly expressed in various tumours.

AIM

To examine the role of PKDs for tumour proliferation and angiogenesis selectively in pancreatic and gastric tumours and in tumour-associated endothelium in vitro and in vivo.

METHODS

PKD2 expression in human tumours was determined by immunohistochemistry. The effect of PKD2 depletion in endothelial cells by siRNAs was examined in sprouting assays, the chorioallantois model (CAM) and tumour xenografts. In murine endothelium in vivo PKD2 was knocked-down by splice switching oligonucleotides. Human PKD2 was depleted in xenografts by siRNAs and PKD2-miRs. PKD2 activation by hypoxia and its role for hypoxia-induced NR4/TR3- and VEGF-A promoter activity, expression and secretion was investigated in cell lines.

RESULTS

PKD2 is expressed in gastrointestinal tumours and in the tumour-associated endothelium. Tumour growth and angiogenesis in the CAM and in tumour xenografts require PKD expression in endothelial cells. Conversely, hypoxia activates PKD2 in pancreatic cancer cells and PKD2 was identified as the major mediator of hypoxia-stimulated VEGF-A promoter activity, expression and secretion in tumour cells. PKD2 depletion in pancreatic tumours inhibited tumour-driven blood vessel formation and tumour growth in the CAM and in orthotopic pancreatic cancer xenografts.

CONCLUSION

PKD2 regulates hypoxia-induced VEGF-A expression/secretion by tumour cells and VEGF-A stimulated blood vessel formation. PKD2 is a novel, essential mediator of tumour cell-endothelial cell communication and a promising therapeutic target to inhibit angiogenesis in gastrointestinal cancers.

The iron-regulatory peptide hepcidin is upregulated in the ischemic and in the remote myocardium after myocardial infarction

Recent evidence suggests that iron metabolism contributes to the ischemic damage after myocardial infarction. Hepcidin, a recently discovered peptide hormone, regulates iron uptake and metabolism, protecting the body from iron overload. In this study we analyzed the regulation of hepcidin in the heart and blood of rats after myocardial infarction. To induce a myocardial infarction in the rats, left anterior descending coronary artery ligation was performed. After 1-24h, biopsies from the ischemic and the non-ischemic myocardium were taken. In these biopsies, the mRNA levels and the protein expression of hepcidin were analyzed by quantitative RT-PCR and immunoblot analysis, respectively. In parallel, the serum levels of prohepcidin were measured by ELISA. Six hours after myocardial infarction, the hepcidin mRNA expression was temporally upregulated in the ischemic and in the non-ischemic myocardium. The upregulation was specific for hepcidin, since other iron-related genes (hemojuvelin, IREG-1) remained unchanged. Furthermore, the alteration of the hepcidin protein expression in the ischemic area was connected to the level of hepcidin in the serum of the infarcted rats, where hepcidin also raised up. Angiotensin receptor blockade with candesartan did not influence the mRNA regulation of hepcidin. Together, these data show a particular upregulation of the iron-regulatory peptide hepcidin in the ischemic and the non-ischemic myocardium after myocardial infarction. It is speculated that upregulation of hepcidin may reduce iron toxicity and thus infarct size expansion in an infarcted heart.

An age-related decrease in factor V Leiden frequency among Polish subjects

Factor V Leiden (G1691A FV mutation) is a widely acknowledged risk factor of deep vein thrombosis, including pulmonary embolism as the most serious complication. However, its high prevalence of ~5%in the Caucasian population might be related to an unknown evolutionary advantage. It might exert a beneficial effect on the carrier, e.g. protecting women from excessive bleeding during labour or allowing increased survival in severe sepsis or with other inflammatory diseases. The aim of our study was to verify or contradict the hypothesis of a favourable association between the A allele (A1691) and longevity in the Polish population. For this purpose, the G1691A mutation was analyzed by PCR-RFLP in 1016 Poles: 400 neonates (187 female and 312 male), 184 healthy adults (129 female and 55 male), and 432 long-lived individuals (age ≥95 years: 343 women and 89 men). Frequencies of G1691A carriers and the A1691 allele in long-lived individuals (0.2% and 0.1%, respectively) were significantly lower than in neonates (4.2% and 2.2%, respectively) and adults (3.3% and 1.6%). The frequency of the G1691A factor V Leiden mutation decreased with age, which indicates a shorter survival time among A1691 allele carriers in the Polish population.

[A prospective comparison of video colonoscopy and CT colonography in asymptomatic patients screened for colorectal cancer]

BACKGROUND AND OBJECTIVE

It was the aim of this study to compare the sensitivity and specificity of low-dose CT colonography (CTC) with that of optical colonoscopy (OC) in asymptomatic patients undergoing these tests in a screening program for colonic cancer.

PATIENTS AND METHODS

58 patients (mean age 62.6 years) were included. They underwent low dose CTC and, immediately afterwards, colonoscopy. The colonoscopists were unaware of the CTC findings. A "second look" was performed if a lesion seen in CTC had been missed in the first colonoscopy.

RESULTS

A total of 150 lesions were detected and histologically confirmed. 136 were found to be polypoid lesions, classified as either hyperplastic polyps (n = 66) or polyps with intraepithelial neoplasia (n = 70). In the per-patient analysis only 22.4 % of patients had no polypoid lesion, 27.6 % had at least one hyperplastic and 50.0 % had at least one adenomatous lesion. Sensitivity for adenomas of all size categories was calculated 55.7 % for CTC and 92.9 % for OC. This marked difference (both for the detection of individual lesions and the per-patient analyses) does not reach significance in the two-sided McNemar test.

CONCLUSIONS

There was a high prevalence of lesions with intraepithelial neoplasia in this screening group. OC had a higher sensitivity than CTC in the detection of lesions smaller than 10 mm.