Apmis

SUN, QINGZHU; YANG, XUDONG; ASIM, M. B. RAZA; JIAO, FANGFANG; HE, XIAOJING; ZHONG, BO; LI, DONGMIN; LU, SHEMIN

doi: 10.1111/j.1600-0463.2011.02721.xpmid: 21492222

Sun Q, Yang X, Asim MBR, Jiao F, He X, Zhong B, Li D, Lu S. Different challenge terms determine disease patterns of antigen‐induced pulmonary inflammation in E3 rats. APMIS 2011; 119: 229–38. Antigen induced pulmonary inflammation (AIPI) in rats, a classic animal model for asthma, has greatly contributed to the understanding of the disease pathogenesis, especially for the inflammation process. E3 rats are recently used to induce AIPI model for its susceptibility to pulmonary inflammation, but the features of AIPI with different antigen challenge terms on E3 rats require to be elucidated systemically. The aim of this study was to compare AIPI disease patterns in E3 rats with different challenge terms. E3 rats were immunized and challenged with ovalbumin (OVA) for 1, 4, and 8 weeks. Histological methods were used to determine morphological changes in lungs and cell types in bronchoalveolar lavage fluid. Nitric oxide (NO) concentration was assayed by Griess method. IL‐4 and TGF‐β expression were detected by real‐time PCR. ELISA was used for the determination of serum IgE and OVA‐specific IgG1. The results showed that all the sensitized E3 rats had a strong influx of eosinophils into the airway. In 1‐week challenge group, the rats showed stronger inflammation, such as elevated levels of NO, delayed type hypersensitivity, IL‐4 expression, and inflammatory cell infiltration; while in 8‐week challenge group, rats manifested significant tissue destruction, accumulation of collagen and mucus production, and higher levels of antibody production, and TGF‐β expression. Hence, the detail characterizations of AIPI model challenged for different terms demonstrated that E3 rats challenged with antigen for 1 week are suitable for studying acute pulmonary inflammation; meanwhile, the model established in the rats challenged for 8 weeks is appropriate for understanding pathogenesis of lung remodelling in chronic inflammation.

BERG, KASPER DRIMER; TOFT, BIRGITTE GRØNKÆR; RØDER, MARTIN ANDREAS; BRASSO, KLAUS; VAINER, BEN; IVERSEN, PETER

doi: 10.1111/j.1600-0463.2011.02723.xpmid: 21492223

Berg KD, Toft BG, Røder MA, Brasso K, Vainer B, Iversen P. Prostate needle biopsies: interobserver variation and clinical consequences of histopathological re‐evaluation. APMIS 2011; 119: 239–46. Histopathological grading of prostate cancer (PCa) is associated with significant interobserver variability. This, as well as clinical consequences of histopathological re‐evaluation, was investigated. In 350 patients, histopathological re‐evaluations of prostate biopsies were compared with primary pathology reports and with histopathology of the radical prostatectomy specimen. The consequences of re‐evaluation for clinical workup and treatment of patients according to local algorithms were determined. For Gleason score (GS), complete agreement between primary report and re‐evaluation was found in 76.9%. The cancers were assessed with higher GS at re‐evaluation in 25.0% of patients in cases with primary GS ≤ 6, while scores were devaluated in 3.0% and 10.3% of the patients with primary GS = 7 and ≥8, respectively. Strategies for clinical evaluation and treatment were changed as a result of the biopsy re‐evaluations in 19.7% and 13.1% of patients, respectively. Gleason scoring based on the radical prostatectomy specimen was higher than in both primary reports and re‐evaluation of biopsies. Although a relatively high degree of concordance was found between biopsy assessments, the significant trend towards higher Gleason scoring at re‐evaluation, leading to frequent changes in clinical assessments and surgical strategy, justifies re‐evaluation of PCa biopsies in patients with primary GS ≤ 6.

BJØRKENG, EVA; RASMUSSEN, GUNLÖG; SUNDSFJORD, ARNFINN; SJÖBERG, LENNART; HEGSTAD, KRISTIN; SÖDERQUIST, BO

doi: 10.1111/j.1600-0463.2011.02724.xpmid: 21492224

Bjørkeng E, Rasmussen G, Sundsfjord A, Sjöberg L, Hegstad K, Söderquist B. Clustering of polyclonal VanB‐type vancomycin‐resistant Enterococcus faecium in a low‐endemic area was associated with CC17‐genogroup strains harbouring transferable vanB2‐Tn5382 and pRUM‐like repA containing plasmids with axe‐txe plasmid addiction systems. APMIS 2011; 119: 247–58. VanB‐type vancomycin‐resistant Enterococcus faecium isolates (n = 17) from 15 patients at the Örebro University hospital in Sweden during a span of 18 months was characterized. All patients had underlying disorders and received broad‐spectrum antimicrobial therapy. Pulsed‐field gel electrophoresis (PFGE) grouped 14 isolates in three PFGE types and three isolates in unique PFGE patterns. All isolates had multi‐locus sequence types (ST17 (n = 5); ST18 (n = 3); ST125 (n = 7); ST262 (n = 1); ST460 (n = 1)) belonging to the successful hospital‐adapted clonal complex 17 (CC17), harboured CC17‐associated virulence genes, were vanB2‐positive and expressed diverse vancomycin minimum inhibitory concentration (MICs; 8 to >256 mg/L). Isolate 1 had a unique PFGE type and a chromosomal transferable vanB2‐Tn5382 element. Interestingly, the other five PFGE types had Tn5382 located on plasmids containing pRUM‐like repA and a plasmid addiction system (axe‐txe) shown by co‐hybridization analysis of PFGE‐separated S1‐nuclease digested total DNA. The resistance plasmids were mainly of 120‐kb and supported intraspecies vanB transfer. Two strains were isolated from patient 6 and we observed a possible transfer of the vanB2‐resistance genes from PFGE type III ST460 to a more successful PFGE type I ST125. This latter PFGE type I ST125 became the predominant type afterwards. Our observations support the notion that vanB‐type vancomycin‐resistant Enterococcus faecium can persist in a low‐endemic area through successful clones and plasmids with stability functions in hospital patients with known risk factors.

WINTHER, CHARLOTTE; GRÆM, NIELS

doi: 10.1111/j.1600-0463.2011.02725.xpmid: 21492225

Winther C, Græm N. Accuracy of frozen section diagnosis: a retrospective analysis of 4785 cases. APMIS 2011; 119: 259–62. During a 1‐year period 4785 intraoperative consultations were performed. The pathology reports were retrospectively reviewed to determine the accuracy of frozen section diagnosis in various tissue types. Skin for evaluation of section margins and axillary sentinel lymph nodes for evaluation of metastatic disease were most frequently sent for frozen section diagnosis. The number of discordant cases were 182, 178 were false negative and four were false positive. When frozen section diagnoses were compared with permanent section diagnoses, the overall diagnostic concordance was 95.1%. The number of deferred specimens was 57. The accuracy of frozen section diagnosis varied between tissue types, and axillary sentinel lymph nodes accounted for the greatest number of discordances. In conclusion, the frozen section diagnosis is a reliable method with varying concordance and deferral rates between tissue types. We suggest regular monitoring of the performance in frozen section diagnosis.

LEE, BAOLERI; SCHJERLING, CHARLOTTE K.; KIRKBY, NIKOLAI; HOFFMANN, NADINE; BORUP, REHANNAH; MOLIN, SØREN; HØIBY, NIELS; CIOFU, OANA

doi: 10.1111/j.1600-0463.2011.02726.xpmid: 21492226

Lee B, Schjerling CK, Kirkby N, Hoffmann N, Borup R, Molin S, Høiby N, Ciofu O. Mucoid Pseudomonas aeruginosa isolates maintain the biofilm formation capacity and the gene expression profiles during the chronic lung infection of CF patients. APMIS 2011; 119: 263–74. Phenotypic and genotypic diversifications of Pseudomonas aeruginosa in the airways of patients with cystic fibrosis (CF) promote long‐term survival of bacteria during chronic lung infection. Twelve clonally related, sequential mucoid and non‐mucoid paired P. aeruginosa isolates obtained from three Danish CF patients were investigated. The in vitro biofilm formation capacity was studied under static and flow through conditions and the global gene expression profiles were investigated by Affymetrix GeneChip. Regulatory genes of alginate production and quorum sensing (QS) system were sequenced and measurements of the alginate production and the detection of the QS signal molecules were performed. Comparisons of mucoid and non‐mucoid isolates from early and late stages of the infection showed that the mucoid phenotype maintained over a decade the capacity to form in vitro biofilm and showed an unaltered transcriptional profile, whereas substantial alterations in the transcriptional profiles and loss of the capacity to form in vitro biofilms were observed in corresponding isolates of the non‐mucoid phenotype. The conserved gene expression pattern in the mucoid isolates vs the diversity of changes in non‐mucoid isolates observed in this particular P. aeruginosa clone reflects different adaptation strategies used by these two phenotypes in the different niches of the CF lung environment.

LARSEN, INGE KRISTINE; PEDERSEN, GITTE; SCHØNHEYDER, HENRIK C.

doi: 10.1111/j.1600-0463.2011.02727.xpmid: 21492227

Larsen IK, Pedersen G, Schønheyder HC. Bacteraemia with an unknown focus: is the focus de facto absent or merely unreported? A one‐year hospital‐based cohort study. APMIS 2011; 119: 275–9. An unknown focus of infection is associated with an increased risk of death in patients with bacteraemia. However, the implications for patient management remain uncertain, and to our knowledge, the validity of an unknown focus has not been evaluated. Therefore, we conducted a retrospective record review of bacteraemias with an unknown focus recorded in a regional bacteraemia database. The study cohort comprised 645 cases of bacteraemia diagnosed in 537 hospitalized patients at Aalborg Hospital, Denmark, in 2003. The focus was unknown in 184 (29%) bacteraemia episodes (162 patients). The record review pointed conclusively to a focus in 39 episodes. The positive predictive value of an unknown focus was 79% and the proportion of bacteraemias with a focus increased from 71% to 78%. Among the 145 cases of bacteraemia with a de facto unknown focus, there were 36 incidents of febrile neutropenia and 20 additional incidents of early death which precluded a search for a focus. The study confirmed the focus to be de facto absent in most patients classified with an unknown focus. The distribution of foci changed only marginally by the disclosure of a focus in one of five patients in the ‘unknown’ group.

BELLANGER, ANNE‐PAULINE; GRENOUILLET, FREDERIC; HENON, THIERRY; SKANA, FLORENCE; LEGRAND, FAEZEH; DECONINCK, ERIC; MILLON, LAURENCE

doi: 10.1111/j.1600-0463.2011.02728.xpmid: 21492228

Bellanger A‐P, Grenouillet F, Henon T, Skana F, Legrand F, Deconinck E, Millon L. Retrospective assessment of β‐d‐(1,3)‐glucan for presumptive diagnosis of fungal infections. APMIS 2011; 119: 280–6. β‐d‐(1,3)‐glucan (BG) is a component of the cell walls of many fungal organisms. Our aims were to investigate the feasibility of the BG assay and its contribution to early diagnosis of different types of invasive fungal infections (IFI) commonly diagnosed in a tertiary care centre. The BG serum levels of 28 patients diagnosed with six IFI (13 probable invasive aspergillosis (IA), 2 proven IA, 2 zygomycosis, 3 fusariosis, 3 cryptococcosis, 3 candidaemia and 2 pneumocystosis) were retrospectively evaluated. The kinetic variations in BG serum levels from the 15 patients diagnosed with IA were compared with those of the galactomannan antigen (GM). In 5/15 cases of IA, BG was positive earlier than GM (time lapse from 4 to 30 days), in 8/15 cases, BG was positive at the same time as GM and, in 2/15 cases, BG was positive after GM. For the five other fungal diseases, BG was highly positive at the period of diagnosis except for the two cases of zygomycosis and one of the three cases of fusariosis. This study, which reflects the common activity of a tertiary care centre, confirms that BG detection could be of interest for IFI screening in patients with haematological malignancies.

ÖNNBERG, ANNA; MÖLLING, PAULA; ZIMMERMANN, JOHANNA; SÖDERQUIST, BO

doi: 10.1111/j.1600-0463.2011.02730.xpmid: 21492229

Önnberg A, Mölling P, Zimmermann J, Söderquist B. Molecular and phenotypic characterization of Escherichia coli and Klebsiella pneumoniae producing extended‐spectrum β‐lactamases with focus on CTX‐M in a low‐endemic area in Sweden. APMIS 2011; 119: 287–95. During the last decade increasing prevalence of extended‐spectrum β‐lactamase (ESBL)‐producing Enterobacteriaceae has been detected worldwide, mainly due to dissemination of Escherichia coli and Klebsiella pneumoniae producing CTX‐M‐type ESBLs. CTX‐M‐15 is the most widespread CTX‐M type, and the predominant type in various countries. Dissemination of ESBL‐producing organisms is caused not only by horizontal transfer of plasmids, but also by clonal spread of ESBL‐producing strains. In this study, the molecular epidemiology of class A ESBL (ESBLA)‐producing E. coli and K. pneumoniae isolated in Örebro County, Sweden, was investigated. Out of 200 ESBLA‐producing E. coli and K. pneumoniae isolates, collected over a 10‐year period, 87% were producing CTX‐M, belonging to subgroup CTX‐M‐1 (64%), CTX‐M‐9 (34%), or CTX‐M‐2 (2%). The remaining isolates were producing variants of SHV and TEM. Sequencing of the blaCTX‐M genes revealed 10 different CTX‐M types, with a dominance of CTX‐M‐15 (E. coli 54%, K. pneumoniae 50%) followed by CTX‐M‐14 (E. coli 28%, K. pneumoniae 27%). Phenotypic characterization of the CTX‐M‐producing isolates was performed using the PhenePlate system. Although a few minor clusters of CTX‐M‐15 and CTX‐M‐14 producers were identified, the majority of the isolates did not appear to be clonally related.

OLESEN, UFFE HØGH; HASTRUP, NINA; SEHESTED, MAXWELL

doi: 10.1111/j.1600-0463.2011.02733.xpmid: 21492230

Olesen UH, Hastrup N, Sehested M. Expression patterns of nicotinamide phosphoribosyltransferase and nicotinic acid phosphoribosyltransferase in human malignant lymphomas. APMIS 2011; 119: 296–303. The purpose of the study was to determine in human malignant lymphomas the expression patterns of nicotinamide phosphoribosyltransferase (NAMPT) and nicotinic acid phosphoribosyltransferase (NAPRT), the primary, rate‐limiting enzymes in the synthesis of NAD+. NAMPT is a potential biomarker for sensitivity to NAMPT inhibitors and NAPRT is a biomarker for the use of nicotinic acid as a chemoprotectant in treatment with NAMPT inhibitors. The NAMPT inhibitor, APO866, is currently in clinical phase II trials in lymphomas. The expression of NAMPT and NAPRT was investigated in 53 samples of malignant lymphomas (diffuse large B‐cell lymphoma, follicular B‐cell lymphoma, Hodgkin’s lymphoma and peripheral T‐cell lymphoma). The expression of NAMPT was generally high in the more aggressive malignant lymphomas, with >80% strong expression, whereas the expression in the more indolent follicular lymphoma (FL) was significantly lower (>75% moderate or low expression, p = 0.0002). NAMPT was very highly expressed in Hodgkin Reed‐Sternberg cells in Hodgkin’s lymphoma. NAPRT expression was more varied (p > 0.0001) with 30–50% low expression except for Hodgkin’s lymphoma where 85% displayed low expression (p = 0.0024). In conclusion, FL are a promising target for NAMPT inhibitors whereas substantial subsets of malignant lymphomas especially in Hodgkin lymphoma may be suitable for a combination treatment with nicotinic acid and NAMPT inhibitors.

CREMADES, ROSA; RODRÍGUEZ, JUAN CARLOS; GARCIA‐PACHÓN, EDUARDO; GALIANA, ANTONIO; RUIZ‐GARCÍA, MONTSERRAT; LÓPEZ, PILAR; ROYO, GLORIA

doi: 10.1111/j.1600-0463.2011.02735.xpmid: 21492231

Cremades R, Rodríguez JC, Garcia‐Pachón E, Galiana A, Ruiz‐García M, López P, Royo G. Interaction between linezolid and Mycobacterium tuberculosis in an experimental in vitro model. APMIS 2011; 119: 304–8. As linezolid is emerging as a useful alternative in the treatment of multi‐resistant tuberculosis, we developed an in vitro model to elucidate certain aspects of the interaction that takes place between the microorganism and the antibiotic. We found that the drug does not generate resistant mutants following repeated exposure at subinhibitory concentrations and that it exhibits bactericidal activity against most of the susceptible strains in vitro at high concentrations (83.3% of the strains at concentrations of 50 μg/mL) in the exponential growth phase. This bactericidal activity is much less if the microorganism is in nonreplicating phase, even in the case of susceptible strains in vitro. Therefore, linezolid appears to be an alternative as far as generation of resistance is concerned in the treatment of multi‐resistant tuberculosis. However, it has limited bactericidal capacity against strains in nonreplicant phase, which makes it necessary to use linezolid in combination with other drugs that act on these microorganisms.