Apmis

HSIEH, WEN‐SHYANG; SUNG, LING‐LING; TSAI, KUN‐CHOU; HO, HSIN‐TSUNG

doi: 10.1111/j.1600-0463.2009.02436.xpmid: 19343822

We evaluated VITEK 2 cards (NGNC and AST‐GN10) for the accuracy of identification (ID) and antimicrobial susceptibility testing (AST) of non‐glucose‐fermenting Gram‐negative bacilli (NGF‐GNB). In a total of 201 strains, 190 strains (94.5%) were correctly identified, seven strains (3.5%) showed low discrimination, four strains (2.0%) had discrepancies, and no strain remained unidentified. Reference AST of amikacin, aztreonam, cefepime, cefotaxime, ceftazidime, ciprofloxacin, imipenem, levofloxacin, piperacillin‐tazobactam, and trimethoprim‐sulfamethoxazole was performed by the agar dilution method. Approximately 82.5% of ID and 72.9% of AST were completed within 7 and 14 h, respectively. For NGF‐GNB, other than Pseudomonas aeruginosa, Acinetobacter spp., Stenotrophomonas maltophilia, and the Burkholderia cepacia group, essential agreements (EAs) were 93.6–100.0%. Severe disagreements (resistant by the reference method to susceptible by AST‐GN10) were observed for amikacin (0.9%), cefepime (1.8%), cefotaxime (1.8%), imipenem (0.9%), and piperacillin‐tazobactam (0.9%). One major disagreement (susceptible to resistant) was observed for ceftazidime (0.1%). For P. aeruginosa, EAs were 85.7–100%, with severe disagreements observed for cefepime (4.8%) and piperacillin‐tazobactam (4.8%). For Acinetobacter spp., EAs were 86.4–100% without disagreements. The VITEK 2 cards appear to be promising for rapid ID and reliable AST for most species of NGF‐GNB.

SARAFIAN, VICTORIA S.; MARINOVA, TSVETANA T.; GULUBOVA, MAYA V.

doi: 10.1111/j.1600-0463.2009.02437.xpmid: 19343823

Lysosome‐associated membrane proteins 1 and 2 (LAMP‐1 and LAMP‐2) are implicated in a variety of normal and pathological processes. LAMP‐2 is proposed to participate in chaperone‐mediated autophagy. Autophagy regulates T‐lymphocyte homeostasis by promoting both survival and proliferation. The biological importance of this process in the thymic gland and especially the involvement of LAMPs are far from being elucidated. The aim of the study was to examine the parallel expression of LAMPs and ubiquitin, a key molecule in autophagy, in normal human thymic glands and thymomas. The immunohistochemical expression of both markers was compared with that of cyclin D1 – an important regulator of cell cycle progression. Novel evidence for differential expression of LAMPs and ubiquitin is presented. Most Hassal's corpuscules in thymoma were negative for LAMPs, but positive in normal thymus. Both lymphocytes and epithelial cells in pathological thymus showed higher intensity for LAMP‐2 compared with LAMP‐1. In thymoma, ubiquitin was more intensively positive in these cell types compared with the normal thymus, suggesting activated autophagy in the course of this pathological state. A deregulation in cyclin D1 expression in thymoma is also reported. The functional importance of these molecules in autoghagy accompanying normal and pathological processes in the thymic gland is reviewed.

HAJEM, NEDAA; WEINTRAUB, ANDREJ; NIMTZ, MANFRED; RÖMLING, UTE; PÅHLSON, CARL

doi: 10.1111/j.1600-0463.2009.02435.xpmid: 19338513

Rickettsia helvetica is an obligate intracellular Gram‐negative microorganism found in Ixodes ricinus ticks. When R. helvetica was first discovered in 1979, little was known about its physiology and it fell into oblivion until it recently was suspected of being pathogenic to humans. However, all efforts to isolate R. helvetica from patients have been unsuccessful, although serological responses against R. helvetica can be demonstrated. The aim of our study was to investigate the protein profile of R. helvetica and study the antigenicity of its proteins using two‐dimensional (2D) immunoblot in order to characterize the immunological response against R. helvetica infection. Our results show that in addition to the known PS120 and OmpB antigenic R. helvetica proteins, three other antigens exist: a 60 kDa GroEL protein, a 10 kDa GroES protein and a hitherto unknown 35 kDa hypothetical protein that has similarities with ORF‐RC0799 of Rickettsia conorii. Furthermore, the lipopolysaccharide showed strong antigenicity. In this study, we present the first proteome map and the first 2D immunoblot profile of R. helvetica and finally we present the 35 kDa R. helvetica as an additional antigen to the previously known rickettsial antigens.

MATEE, MECKY; MFINANGA, SAYOKI; HOLM‐HANSEN, CAROL

doi: 10.1111/j.1600-0463.2008.02429.xpmid: 19338514

Anti‐tuberculosis drug resistance levels and patterns of Mycobacterium tuberculosis (Mtb) isolated from newly diagnosed tuberculosis (TB) patients in Temeke district in Dar es Salaam, Tanzania were investigated. A total of 226 Mtb isolates from 564 TB suspects with no previous history of anti‐TB treatment were tested for drug resistance against rifampicin, isoniazid, streptomycin and ethambutol on Lowenstein Jensen (LJ) medium using the proportion method. Of the 226 isolates, 22 (9.7%) were resistant to any one of the four anti‐TB drugs; nine (3.99%) isolates were isoniazid mono‐drug resistant and eight (3.54%) isolates were streptomycin mono‐drug resistant. Multi‐drug resistance, defined as resistance to both rifampicin and isoniazid, was observed in three (1.3%) isolates and two were also resistant to streptomycin and ethambutol. One (0.44%) isolate had poly resistance to isoniazid and streptomycin. The level of anti‐TB drug resistant Mtb in Temeke, an HIV endemic area, remained constant between 1995 and 2007. The level of resistance to any one of the four anti‐TB drugs was between 9.0% and 10%, resistance to individual drugs <4% and multi‐drug resistance <2%.

BRAUNSTEIN, THOMAS HARTIG; SORENSEN, CHARLOTTE MEHLIN; HOLSTEIN‐RATHLOU, NIELS‐HENRIK

doi: 10.1111/j.1600-0463.2009.02432.xpmid: 19338515

The expression of connexins in renal arterioles is believed to have a profound impact on conducted responses, regulation of arteriolar tonus and renal blood flow. We have previously shown that in renal preglomerular arterioles, conducted vasomotor responses are 40% greater in spontaneously hypertensive rats (SHR) than in normotensive Sprague–Dawley (SD) rats. Because conducted vasomotor responses depend on the cell–cell communication mediated through gap junctions, we hypothesized that the increased magnitude of conducted vasomotor response in SHR is associated with an increased amount of connexins in renal arterioles. To test this hypothesis, the amount of connexin 37 (Cx37), Cx40 and Cx43 was assessed in renal arterioles from normo‐ and hypertensive rats using quantitative immunofluorescence laser confocal miscroscopy. To account for differences in genetic background, we included both normotensive Wistar–Kyoto (WKY) and SD rats in the study. In all three strains of rats, and for all three isoforms, the expression of connexins was predominantly confined to the endothelial cells. We found a significantly increased abundance (240 ± 17.6%, p<0.05) of Cx37 in arterioles from WKY compared with SD and SHR. This high abundance of Cx37 was not related to blood pressure because normotensive SD demonstrated a level of Cx37 similar to that of SHR. Additionally, we found no evidence for an increased abundance of Cx40 and Cx43 in renal arterioles of SHR when compared with normotensive counterparts.

ABDOU, ASMAA GABER; EL‐WAHED, MOSHIRA MOHAMMED ABD; ASAAD, NANCY YOUSSEF; SAMAKA, REHAB MONIR; ABDALLAHA, RANIA

doi: 10.1111/j.1600-0463.2009.02448.xpmid: 19338516

Ephrin receptors and ephrin ligands constitute one of the largest groups of tyrosine kinases. The division of ephrin receptors into type A or type B is determined by their ligand‐binding specificities. Ephrin A4 as a ligand has a broad capacity to bind and stimulate different subtypes of ephrin A receptors. Little is known about the role of ephrins generally and ephrin A4 particularly in osteosarcoma. Ephrin A4 was immunohistochemically assessed on archival material from 46 primary osteosarcoma cases, 10 metastatic pulmonary lesions and 20 normal control bone specimens. Ephrin A4 was expressed in 100% of normal bone specimens, in 84.4% of primary osteosarcoma cases and in all metastatic pulmonary lesions. Cytoplasmic and nucleocytoplasmic patterns of ephrin A4 immunoreactivity were observed, with the predominance of the latter pattern in normal bone (100%), and in 43.5% of primary osteosarcoma cases, which showed a higher intensity of expression compared with normal bone (p<0.05). The cytoplasmic pattern is the only staining pattern seen in metastatic cases, which may suggest its role in enhancement of invasion and metastasis. The differences in the distribution of the two patterns of ephrin A4 may indicate a different biological activity of this molecule depending on its localization. The nuclear localization of ephrin A4 requires further investigation to clarify the mechanism and the significance of the nuclear trafficking of ephrin A4.

CHEUNOY, WATTANA; HAILE, MELLES; CHAIPRASERT, ANGKANA; PRAMMANANAN, THERDSAK; CRISTEA‐FERNSTRÖM, MARIANA; VONDRACEK, MARTIN; CHRYSSANTHOU, ERJA; HOFFNER, SVEN; PETRINI, BJÖRN

doi: 10.1111/j.1600-0463.2009.02438.xpmid: 19343824

SARAC, SINAN; AFZAL, SHOAIB; BROHOLM, HELLE; MADSEN, FLEMMING F.; PLOUG, THORKIL; LAURSEN, HENNING

doi: 10.1111/j.1600-0463.2009.02443.xpmid: 19338517

Intractable temporal lobe epilepsy (TLE) is an invalidating disease and many patients are resistant to medical treatment. Increased glutamate concentration has been found in epileptogenic foci and may induce local over‐excitation and cytotoxicity; one of the proposed mechanisms involves reduced extra‐cellular clearance of glutamate by excitatory amino acid transporters (EAAT‐1 to EAAT‐5). EAAT‐1 and EAAT‐2 are mainly expressed on astroglial cells for the reuptake of glutamate from the extra‐cellular space. We have studied the expression of EAAT‐1 and EAAT‐2 in the hippocampus and temporal lobe in 12 patients with TLE by immunhistochemistry and densitometry. The expression of EAAT‐1 and EAAT‐2 was reduced to approximately 40% and 25%, respectively, in CA1 of the hippocampus. In the same area, an increased expression of glial fibrillary acid protein (GFAP) at 90% reflected molecular rearrangements and upregulation of GFAP in the existing astrocytes as Ki‐67 staining failed to demonstrate any signs of astrocytic proliferation. The aetiology of the reduced expression of EAAT‐1 and EAAT‐2 remains unclear. The downregulation of EAAT‐1 and EAAT‐2 may be an adaptive response to neuronal death or it may be a causative event contributing to neuronal death. Further studies of the EAATs and their function are needed to clarify the mechanisms and significance of EAAT‐1 and EAAT‐2 disappearance in TLE.

KALUNGI, SAM; WABINGA, HENRY; BOSTAD, LEIF

doi: 10.1111/j.1600-0463.2009.02444.xpmid: 19338518

In Uganda, a large number of biopsied enlarged lymph nodes is diagnosed as reactive lymphoid hyperplasia (RLH) not indicative of a specific etiologic agent. The aim of this study was to examine the spectrum of RLH in lymph node biopsies in Ugandan patients and their possible association with HIV and EBV infection. Ninety biopsies were retrieved and included in the study. The predominant RLH type was follicular, found in 45 (50.0%) of the cases. Positive staining for LMP‐1 was found in six cases (6.7%), EBNA‐1 in 36 cases (40.0%) and HIV1‐p24 in 15 cases (16.7%), respectively. A combination of EBV and HIV positivity was found in 46 (52.2%) of the cases. EBV infection was associated with hyperplastic germinal centers (p<0.01). HIV1‐p24 positive staining was associated with follicle fragmentation (p<0.01) but not hyperplastic GC (p=0.08). In conclusion, RLH in Ugandan patients is frequently associated with EBV and HIV infection. The histologic features of the lymph nodes are not specific for any individual infection, but a high number of EBV‐positive cases are associated with hyperplastic GC, and follicular fragmentation is characteristic of HIV infection.