Helena Enroth | University of Skövde (original) (raw)

Papers by Helena Enroth

Cancer research, Jan 15, 2001

DNA and sera from 130 cases of gastric cancer and 263 population-based controls were analyzed to ... more DNA and sera from 130 cases of gastric cancer and 263 population-based controls were analyzed to study the association of HLA class II DR-DQ alleles with Helicobacter pylori (Hp) infection and the risk for gastric cancer. Presence of the DQA1*0102 allele was inversely and significantly associated with Hp seropositivity (P = 2 x 10(-5)), which is an independent replication of previous findings. However, this inverse relationship with Hp did not correspond with a reduced risk of gastric cancer. At the DRB1 locus, the *1601 allele was significantly associated with an increased gastric cancer risk with an odds ratio (95% confidence interval) of 8.7 (range, 2.7-28.0). The effect of *1601 was more pronounced among Hp-negative subjects, and the association was stronger with the diffuse, rather than with the intestinal, histological type of gastric cancer. Because none of the HLA alleles were associated with both Hp infection and gastric cancer, the HLA DR-DQ alleles are linked with gastric...

Journal of clinical microbiology, 1997

In this study, we evaluated a rapid whole-blood test, BM-test Helicobacter pylori, for detection ... more In this study, we evaluated a rapid whole-blood test, BM-test Helicobacter pylori, for detection of H. pylori infection in 144 and 48 patients with other gastrointestinal symptoms and with gastric cancer, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of the test correlated well with the standards used for the calculation, i.e., serology by enzyme-linked immunosorbent assay or culture and histology.

The aim of the study was to de te rmine inter-and intrapatie nt variation of Helicobacter pylori ... more The aim of the study was to de te rmine inter-and intrapatie nt variation of Helicobacter pylori strains base d on genomic ® nge rprinting and cagA (cytotoxin-associate d gene A) status. Ten bacte rial colonie s from e ach of 10 patie nts with gastric cance r (GC), 10 with duode nal ulcer (DU), and 10 with gastritis (GI) were use d. The prese nce of the putative adhe sin ge ne, the cagA gene , and the strain speci® c banding patte rn obtaine d by arbitrary primed (AP-) PCR was analyze d. Genomic ® nge rprinting showe d exte nsive inte rpatie nt variation, but the banding patte rns obtaine d from colonie s from the same patie nt were always identical (intrapatie nt variation) . In ® ve patie nts, the cagA status varie d betwee n the colonie s despite identical banding patte rns. Among patie nts in a de velope d country such as Swede n, the proportion with multiple -strain infe ction of H. pylori is low, but subclone s with diffe ring cagA status e xist within the strain.

Infection and Immunity, 2003

Helicobacter pylori infection is associated with a variety of outcomes ranging from seemingly asy... more Helicobacter pylori infection is associated with a variety of outcomes ranging from seemingly asymptomatic coexistence to peptic ulcer disease and gastric cancer. The cag pathogenicity island (PAI) contains genes associated with a more aggressive phenotype and has been suggested to be a determinant of severe disease outcome. The cagA gene has served as a marker for the cag PAI. However,

Scandinavian Journal of Infectious Diseases, 2009

In the present study, we have investigated 37 invasive Staphylococcus aureus strains (collected b... more In the present study, we have investigated 37 invasive Staphylococcus aureus strains (collected between 1997 and 2005) from 33 human episodes of septicaemia causing either endocarditis or vertebral osteomyelitis. All S. aureus strains were typed using pulsed field gel electrophoresis (PFGE), and most strains belonged to any of 4 different PFGE clusters. There was no correlation between any of the PFGE clusters with site of infection. All strains showed highly different expression patterns of extracellular proteins, i.e. we found a vast variation in the number of proteins and amount of individual proteins expressed by the different strains. There was no correlation between any cluster of exoprotein patterns with endocarditis or with vertebral osteomyelitis. We did not find any correlation between agr group and endocarditis, as previously reported. On the other hand, a correlation between some of the PFGE clusters with a certain agr group was found. Known risk factors for S. aureus infections were observed in a majority of the patients.

Scandinavian Journal of Gastroenterology, 2002

The exact role of Helicobacter pylori as a causative agent of gastric cancer is still under debat... more The exact role of Helicobacter pylori as a causative agent of gastric cancer is still under debate. The aim of this study was to determine how the use of different diagnostic methods for detection of H. pylori influences the measures of prevalence of the infection and thus the association with risk of gastric adenocarcinoma. We included 72 cases and 324 controls in an endoscopy clinic-based matched case-control study. Culture of H. pylori and immunohistochemical staining were performed on gastric biopsies. Serum samples were tested for H. pylori IgG by conventional ELISA and by immunoblotting. The overall prevalence of H. pylori was 68% based on all 4 diagnostic methods, 79% in the cases and 66% in the controls. Highest agreement, 91%, was observed between culture and immunohistochemistry with a Kappa value of 0.81. Immunoblotting detected the highest number of H. pylori-positive subjects in both cases and controls. The association of H. pylori positivity with gastric cancer was generally weaker and statistically non-significant using culture and immunohistochemistry compared with the serological tests, of which IgG ELISA yielded the higher odds ratio (OR 2.5, 95% confidence interval 1.4-4.4). The study shows that relative risk estimates for the association between H. pylori and gastric cancer risk are to some extent determined by the diagnostic method used to detect H. pylori infection.

Scandinavian Journal of Gastroenterology, 2009

Helicobacter pylori (H. pylori) infection stimulates the production of interleukin (IL)-1 beta, a... more Helicobacter pylori (H. pylori) infection stimulates the production of interleukin (IL)-1 beta, a pro-inflammatory cytokine and suppressor of gastric acid secretion. As both inflammation and hypochlorhydria, which might facilitate proximal colonization of H. pylori and other bacterial species alike, have been implicated in gastric carcinogenesis, much attention has been directed to functional genetic polymorphisms that affect the production of IL-1 beta. The purpose of this study was to clarify the role of these polymorphisms. We analysed a population-based, case-control study in 5 Swedish counties and a hospital-based, case-control study conducted in 8 Swedish hospitals, with a total of 351 gastric cancer cases and 539 controls. The IL1B-31, IL1B-511 and IL1B+3954 biallelic polymorphisms were genotyped using pyrosequencing. The variable number of tandem repeats (VNTR) polymorphism of IL1-RN was analysed using polymerase chain reaction (PCR) followed by gel electrophoresis. Relative risks were estimated by odds ratios with 95% confidence intervals, derived from unconditional logistic regression. The risk of gastric cancer was unrelated to genotype in all of the studied polymorphic loci, and the absence of any association was confirmed in both the population-based and hospital-based case-control studies. Analyses confined to histological subtypes (intestinal or diffuse) and site-specific tumours (cardia or distal stomach), as well as analyses stratified by H. pylori infection status and family history of gastric cancer, did not reveal any significant increases or decreases in risk. Our results do not lend support to the hypothesis that human genetic polymorphisms related to the production of IL-1 beta are associated with the risk of gastric cancer.

Journal of Medical Microbiology, 2009

Helicobacter, 2001

Background and Objectives. Intracellular location of Helicobacter pylori in human gastric epithel... more Background and Objectives. Intracellular location of Helicobacter pylori in human gastric epithelial cells has been observed in biopsies. Whether this reflects an ability to invade host cells and establish an intracellular niche remains to be determined. Methods. The interactions between a clinical isolate of H. pylori and primary cell cultures from human gastric epithelium or the human epithelial cell line HEp-2 were monitored using time-lapse photography. This technique allows studies of the dynamics of host-microbial interactions. Results. H. pylori cells readily approached and established close contacts with epithelial cells followed by uptake of the bacteria into the cellular cytoplasm. Entry into epithelial cells was achieved through an active pro-

FEMS Immunology & Medical Microbiology, 1999

The gastric bacterial flora and its influence on the IQ C-urea breath test (UBT) for detection of... more The gastric bacterial flora and its influence on the IQ C-urea breath test (UBT) for detection of Helicobacter pylori infection was studied in a pig model. Seven SPF minipigs were used. H. pylori or a mix of other urease positive bacteria were administered orally. UBT, serum and biopsies for histology and culture were collected. Our results show that UBT is not specific for H. pylori in pigs as the gastric bacterial flora is responsible for the high UBT values observed. Furthermore, the Ellegaard Go ë ttingen SPF minipigs are not useful in an animal model for H. pylori studies. z

Clinical and Vaccine Immunology, 2000

Strain variations of Helicobacter pylori have been tested by numerous methods and compared among ... more Strain variations of Helicobacter pylori have been tested by numerous methods and compared among different patient groups. The aim of this study was to investigate whether H. pylori expresses disease-specific proteins that can be detected by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). H. pylori strains isolated from duodenal ulcer, gastric cancer, and gastritis patients were analyzed. Extensive variation in spot patterns was observed between the strains, but a dendrogram analysis revealed that some strains within each disease group clustered together. Eight proteins were sequenced and found in the H. pylori genome sequence. 2-D PAGE is a useful method for studies of protein expression and for highlighting the extensive strain variation that H. pylori exhibits.

BMC Infectious Diseases, 2015

Background: Sepsis is a serious medical condition requiring timely administered, appropriate anti... more Background: Sepsis is a serious medical condition requiring timely administered, appropriate antibiotic therapy. Blood culture is regarded as the gold standard for aetiological diagnosis of sepsis, but it suffers from low sensitivity and long turnaround time. Thus, nucleic acid amplification tests (NAATs) have emerged to shorten the time to identification of causative microbes. The aim of the present study was to evaluate the clinical utility in everyday practice in the emergency department of two commercial NAATs in patients suspected with sepsis. Methods: During a six-week period, blood samples were collected consecutively from all adult patients admitted to the general emergency department for suspicion of a community-onset sepsis and treated with intravenous antibiotics. Along with conventional blood cultures, multiplex PCR (Magicplex™) was performed on whole blood specimens whereas portions from blood culture bottles were used for analysis by microarray-based assay (Prove-it™). The aetiological significance of identified organisms was determined by two infectious disease physicians based on clinical presentation and expected pathogenicity. Results: Among 382 episodes of suspected sepsis, clinically relevant microbes were detected by blood culture in 42 episodes (11%), by multiplex PCR in 37 episodes (9.7%), and by microarray in 32 episodes (8.4%). Although moderate agreement with blood culture (kappa 0.50), the multiplex PCR added diagnostic value by timely detection of 15 clinically relevant findings in blood culture-negative specimens. Results of the microarray corresponded very well to those of blood culture (kappa 0.90), but were available just marginally prior to blood culture results.