"pathology" via Stockport Education Centre Library

by Zsuzsanna Varga, Joachim Diebold, Corina Dommann-Scherrer, Harald Frick, Daniela Kaup, Aurelia Noske, Ellen Obermann, Christian Ohlschlegel, Barbara Padberg, Christiane Rakozy, Sara Sancho Oliver, Sylviane Schobinger-Clement, Heide Schreiber-Facklam, Gad Singer, Coya Tapia, Urs Wagner, Mauro G. Mastropasqua, Giuseppe Viale, Hans-Anton Lehr

Adjuvant chemotherapy decisions in breast cancer are increasingly based on the pathologist's assessment of tumor proliferation. The Swiss Working Group of Gyneco- and Breast Pathologists has surveyed inter- and intraobserver consistency of Ki-67-based proliferative fraction in breast carcinomas.

Methods

Five pathologists evaluated MIB-1-labeling index (LI) in ten breast carcinomas (G1, G2, G3) by counting and eyeballing. In the same way, 15 pathologists all over Switzerland then assessed MIB-1-LI on three G2 carcinomas, in self-selected or pre-defined areas of the tumors, comparing centrally immunostained slides with slides immunostained in the different laboratoires. To study intra-observer variability, the same tumors were re-examined 4 months later.

Results

The Kappa values for the first series of ten carcinomas of various degrees of differentiation showed good to very good agreement for MIB-1-LI (Kappa 0.56–0.72). However, we found very high inter-observer variabilities (Kappa 0.04–0.14) in the read-outs of the G2 carcinomas. It was not possible to explain the inconsistencies exclusively by any of the following factors: (i) pathologists' divergent definitions of what counts as a positive nucleus (ii) the mode of assessment (counting vs. eyeballing), (iii) immunostaining technique, and (iv) the selection of the tumor area in which to count. Despite intensive confrontation of all participating pathologists with the problem, inter-observer agreement did not improve when the same slides were re-examined 4 months later (Kappa 0.01–0.04) and intra-observer agreement was likewise poor (Kappa 0.00–0.35).

Conclusion

Assessment of mid-range Ki-67-LI suffers from high inter- and intra-observer variability. Oncologists should be aware of this caveat when using Ki-67-LI as a basis for treatment decisions in moderately differentiated breast carcinomas.

by Abhijit Sau, Anup Kumar Misra

Background

Extraintestinal pathogenic E. coli are mostly responsible for a diverse spectrum of invasive human and animal infections leading to the urinary tract infections. Bacterial lipopolysaccharides are responsible for their pathogenicity and their interactions with host immune responses. In spite of several breakthroughs in the development of therapeutics to combat urinary tract infections and related diseases, the emergence of multidrug-resistant bacterial strains is a serious concern. Lipopolysaccharides are attractive targets for the development of long-term therapeutic agents to eradicate the infections. Since the natural sources cannot provide the required amount of oligosaccharides, development of chemical synthetic strategies for their synthesis is relevant to gain access to a reservoir of oligosaccharides and their close analogs.

Methodology

Two tetrasaccharide derivatives were synthesized from a single disaccharide intermediate. β-d-mannoside moiety was prepared from β-d-glucoside moiety following oxidation–reduction methodology. A [2+2] stereoselective block glycosylation strategy has been adopted for the preparation of tetrasaccharide derivative. α-d-Glucosamine moiety was prepared from α-d-mannosidic moiety following triflate formation at C-2 and S_N² substitution. A one-pot iterative glycosylation exploiting the orthogonal property of thioglycoside was carried out during the synthesis of tetrasaccharide analog.

Results

Synthesis of the tetrasaccharide motif (1) and its structural analog (2) corresponding to the lipopolysaccharide of Escherichia coli O75 was successfully achieved in excellent yield. Most of the reactions are clean and high yielding. Both compounds 1 and 2 were synthesized as their 4-methoxyphenyl glycoside, which can act as a temporary anomeric protecting group for further use of these tetrasaccharides in the preparation of glycoconjugates.

by Martin H. de Borst, Ferdau L. Nauta, Liffert Vogt, Gozewijn D. Laverman, Ron T. Gansevoort, Gerjan Navis

Under specific conditions non-steroidal anti-inflammatory drugs (NSAIDs) may be used to lower therapy-resistant proteinuria. The potentially beneficial anti-proteinuric, tubulo-protective, and anti-inflammatory effects of NSAIDs may be offset by an increased risk of (renal) side effects. We investigated the effect of indomethacin on urinary markers of glomerular and tubular damage and renal inflammation. We performed a post-hoc analysis of a prospective open-label crossover study in chronic kidney disease patients (n = 12) with mild renal function impairment and stable residual proteinuria of 4.7±4.1 g/d. After a wash-out period of six wks without any RAAS blocking agents or other therapy to lower proteinuria (untreated proteinuria (UP)), patients subsequently received indomethacin 75 mg BID for 4 wks (NSAID). Healthy subjects (n = 10) screened for kidney donation served as controls. Urine and plasma levels of total IgG, IgG4, KIM-1, beta-2-microglobulin, H-FABP, MCP-1 and NGAL were determined using ELISA. Following NSAID treatment, 24 h -urinary excretion of glomerular and proximal tubular damage markers was reduced in comparison with the period without anti-proteinuric treatment (total IgG: UP 131[38–513] vs NSAID 38[17–218] mg/24 h, p<0.01; IgG4: 50[16–68] vs 10[1–38] mg/24 h, p<0.001; beta-2-microglobulin: 200[55–404] vs 50[28–110] ug/24 h, p = 0.03; KIM-1: 9[5]–[14] vs 5[2]–[9] ug/24 h, p = 0.01). Fractional excretions of these damage markers were also reduced by NSAID. The distal tubular marker H-FABP showed a trend to reduction following NSAID treatment. Surprisingly, NSAID treatment did not reduce urinary excretion of the inflammation markers MCP-1 and NGAL, but did reduce plasma MCP-1 levels, resulting in an increased fractional MCP-1 excretion. In conclusion, the anti-proteinuric effect of indomethacin is associated with reduced urinary excretion of glomerular and tubular damage markers, but not with reduced excretion of renal inflammation markers. Future studies should address whether the short term glomerulo- and tubulo-protective effects as observed outweigh the possible side-effects of NSAID treatment on the long term.

by Claudia Schillinger, Annett Petrich, Renate Lux, Birgit Riep, Judith Kikhney, Anton Friedmann, Lawrence E. Wolinsky, Ulf B. Göbel, Holger Daims, Annette Moter

The polymicrobial nature of periodontal diseases is reflected by the diversity of phylotypes detected in subgingival plaque and the finding that consortia of suspected pathogens rather than single species are associated with disease development. A number of these microorganisms have been demonstrated in vitro to interact and enhance biofilm integration, survival or even pathogenic features. To examine the in vivo relevance of these proposed interactions, we extended the spatial arrangement analysis tool of the software daime (digital image analysis in microbial ecology). This modification enabled the quantitative analysis of microbial co-localization in images of subgingival biofilm species, where the biomass was confined to fractions of the whole-image area, a situation common for medical samples. Selected representatives of the disease-associated red and orange complexes that were previously suggested to interact with each other in vitro (Tannerella forsythia with Fusobacterium nucleatum and Porphyromonas gingivalis with Prevotella intermedia) were chosen for analysis and labeled with specific fluorescent probes via fluorescence in situ hybridization. Pair cross-correlation analysis of in vivo grown biofilms revealed tight clustering of F. nucleatum/periodonticum and T. forsythia at short distances (up to 6 µm) with a pronounced peak at 1.5 µm. While these results confirmed previous in vitro observations for F. nucleatum and T. forsythia, random spatial distribution was detected between P. gingivalis and P. intermedia in the in vivo samples. In conclusion, we successfully employed spatial arrangement analysis on the single cell level in clinically relevant medical samples and demonstrated the utility of this approach for the in vivo validation of in vitro observations by analyzing statistically relevant numbers of different patients. More importantly, the culture-independent nature of this approach enables similar quantitative analyses for “as-yet-uncultured” phylotypes which cannot be characterized in vitro.

by Wenyan Hu, Gang Zhao, Chunyou Wang, Jungang Zhang, Ling Fu

Background

Pancreatic cancer is a lethal disease with a 5-year survival rate of only 1–5%. The acceleration of intraoperative histological examination would be beneficial for better management of pancreatic cancer, suggesting an improved survival. Nonlinear optical methods based on two-photon excited fluorescence (TPEF) and second harmonic generation (SHG) of intrinsic optical biomarkers show the ability to visualize the morphology of fresh tissues associated with histology, which is promising for real-time intraoperative evaluation of pancreatic cancer.

Methodology/Principal Findings

In order to investigate whether the nonlinear optical imaging methods have the ability to characterize pancreatic histology at cellular resolution, we studied different types of pancreatic tissues by using label-free TPEF and SHG. Compared with other routine methods for the preparation of specimens, fresh tissues without processing were found to be most suitable for nonlinear optical imaging of pancreatic tissues. The detailed morphology of the normal rat pancreas was observed and related with the standard histological images. Comparatively speaking, the preliminary images of a small number of chemical-induced pancreatic cancer tissues showed visible neoplastic differences in the morphology of cells and extracellular matrix. The subcutaneous pancreatic tumor xenografts were further observed using the nonlinear optical microscopy, showing that most cells are leucocytes at 5 days after implantation, the tumor cells begin to proliferate at 10 days after implantation, and the extracellular collagen fibers become disordered as the xenografts grow.

Conclusions/Significance

In this study, nonlinear optical imaging was used to characterize the morphological details of fresh pancreatic tissues for the first time. We demonstrate that it is possible to provide real-time histological evaluation of pancreatic cancer by the nonlinear optical methods, which present an opportunity for the characterization of the progress of spontaneous pancreatic cancer and further application in a non-invasive manner.

by Felipe Vaca-Paniagua, Rosa María Alvarez-Gomez, Verónica Fragoso-Ontiveros, Silvia Vidal-Millan, Luis Alonso Herrera, David Cantú, Enrique Bargallo-Rocha, Alejandro Mohar, César López-Camarillo, Carlos Pérez-Plasencia

Hereditary breast cancer comprises 10% of all breast cancers. The most prevalent genes causing this pathology are BRCA1 and BRCA2 (breast cancer early onset 1 and 2), which also predispose to other cancers. Despite the outstanding relevance of genetic screening of BRCA deleterious variants in patients with a history of familial cancer, this practice is not common in Latin American public institutions. In this work we assessed mutations in the entire exonic and splice-site regions of BRCA in 39 patients with breast and ovarian cancer and with familial history of breast cancer or with clinical features suggestive for BRCA mutations by massive parallel pyrosequencing. First we evaluated the method with controls and found 41–485 reads per sequence in BRCA pathogenic mutations. Negative controls did not show deleterious variants, confirming the suitability of the approach. In patients diagnosed with cancer we found 4 novel deleterious mutations (c.2805_2808delAGAT and c.3124_3133delAGCAATATTA in BRCA1; c.2639_2640delTG and c.5114_5117delTAAA in BRCA2). The prevalence of BRCA mutations in these patients was 10.2%. Moreover, we discovered 16 variants with unknown clinical significance (11 in exons and 5 in introns); 4 were predicted as possibly pathogenic by in silico analyses, and 3 have not been described previously. This study illustrates how massive pyrosequencing technology can be applied to screen for BRCA mutations in the whole exonic and splice regions in patients with suspected BRCA-related cancers. This is the first effort to analyse the mutational status of BRCA genes on a Mexican-mestizo population by means of pyrosequencing.

by Pedro Albuquerque, Cristina M. R. Caridade, Arlete S. Rodrigues, Andre R. S. Marcal, Joana Cruz, Leonor Cruz, Catarina L. Santos, Marta V. Mendes, Fernando Tavares

Background

Bacterial spot-causing xanthomonads (BSX) are quarantine phytopathogenic bacteria responsible for heavy losses in tomato and pepper production. Despite the research on improved plant spraying methods and resistant cultivars, the use of healthy plant material is still considered as the most effective bacterial spot control measure. Therefore, rapid and efficient detection methods are crucial for an early detection of these phytopathogens.

Methodology

In this work, we selected and validated novel DNA markers for reliable detection of the BSX Xanthomonas euvesicatoria (Xeu). Xeu-specific DNA regions were selected using two online applications, CUPID and Insignia. Furthermore, to facilitate the selection of putative DNA markers, a customized C program was designed to retrieve the regions outputted by both databases. The in silico validation was further extended in order to provide an insight on the origin of these Xeu-specific regions by assessing chromosomal location, GC content, codon usage and synteny analyses. Primer-pairs were designed for amplification of those regions and the PCR validation assays showed that most primers allowed for positive amplification with different Xeu strains. The obtained amplicons were labeled and used as probes in dot blot assays, which allowed testing the probes against a collection of 12 non-BSX Xanthomonas and 23 other phytopathogenic bacteria. These assays confirmed the specificity of the selected DNA markers. Finally, we designed and tested a duplex PCR assay and an inverted dot blot platform for culture-independent detection of Xeu in infected plants.

Significance

This study details a selection strategy able to provide a large number of Xeu-specific DNA markers. As demonstrated, the selected markers can detect Xeu in infected plants both by PCR and by hybridization-based assays coupled with automatic data analysis. Furthermore, this work is a contribution to implement more efficient DNA-based methods of bacterial diagnostics.

by Helge Røsjø, Mats Stridsberg, Geir Florholmen, Kåre-Olav Stensløkken, Anett Hellebø Ottesen, Ivar Sjaastad, Cathrine Husberg, Mai Britt Dahl, Erik Øie, William E. Louch, Torbjørn Omland, Geir Christensen

Background

Several beneficial effects have been demonstrated for secretogranin II (SgII) in non-cardiac tissue. As cardiac production of chromogranin A and B, two related proteins, is increased in heart failure (HF), we hypothesized that SgII could play a role in cardiovascular pathophysiology.

Methodology/Principal Findings

SgII production was characterized in a post-myocardial infarction heart failure (HF) mouse model, functional properties explored in experimental models, and circulating levels measured in mice and patients with stable HF of moderate severity. SgII mRNA levels were 10.5 fold upregulated in the left ventricle (LV) of animals with myocardial infarction and HF (p<0.001 vs. sham-operated animals). SgII protein levels were also increased in the LV, but not in other organs investigated. SgII was produced in several cell types in the myocardium and cardiomyocyte synthesis of SgII was potently induced by transforming growth factor-β and norepinephrine stimulation in vitro. Processing of SgII to shorter peptides was enhanced in the failing myocardium due to increased levels of the proteases PC1/3 and PC2 and circulating SgII levels were increased in mice with HF. Examining a pathophysiological role of SgII in the initial phase of post-infarction HF, the SgII fragment secretoneurin reduced myocardial ischemia-reperfusion injury and cardiomyocyte apoptosis by 30% and rapidly increased cardiomyocyte Erk1/2 and Stat3 phosphorylation. SgII levels were also higher in patients with stable, chronic HF compared to age- and gender-matched control subjects: median 0.16 (Q1–3 0.14–0.18) vs. 0.12 (0.10–0.14) nmol/L, p<0.001.

Conclusions

We demonstrate increased myocardial SgII production and processing in the LV in animals with myocardial infarction and HF, which could be beneficial as the SgII fragment secretoneurin protects from ischemia-reperfusion injury and cardiomyocyte apoptosis. Circulating SgII levels are also increased in patients with chronic, stable HF and may represent a new cardiac biomarker.

by Bernice L. Y. Cheuk, Y. C. Chan, Stephen W. K. Cheng

This present study aims to investigate the changes in the inflammatory markers after elective endovascular treatment of Type B aortic dissection with aneurysm, as related to different anatomical features of the dissection flap in the paravisceral perfusion. Consecutive patients with type B aortic dissections with elective endovascular stent graft repair were recruited and categorized into different groups. Serial plasma levels of cytokines (Interleukin-1β, -6, -8, -10, TNF-α), chemokines (MCP-1), and serum creatinine were monitored at pre-, peri- and post-operative stages. The length of stent graft employed in each surgery was retrieved and correlated with the change of all studied biochemical parameters. A control group of aortic dissected patients with conventional medication management was recruited for comparing the baseline biochemical parameters. In total, 22 endovascular treated and 16 aortic dissected patients with surveillance were recruited. The endovascular treated patients had comparable baseline levels as the non-surgical patients. There was no immediate or thirty day-mortality, and none of the surgical patients developed post-operative mesenteric ischaemia or clinically significant renal impairment. All surgical patients had detectable pro-inflammatory mediators, but none of the them showed any statistical significant surge in the peri-operative period except IL-1β and IL-6. Similar results were obtained when categorized into different groups. IL-1β and IL-6 showed maximal levels within hours of the endovascular procedure (range, 3.93 to 27.3 higher than baseline; p = 0.001), but returned to baseline 1 day post-operatively. The change of IL-1β and IL-6 at the stent graft deployment was statistically greater in longer stent graft (p>0.05). No significant changes were observed in the serum creatinine levels. In conclusion, elective endovascular repair of type B aortic dissection associated with insignificant changes in inflammatory mediators and creatinine. All levels fell toward basal levels post-operatively suggesting that thoracic endovascular aortic repair is rather less aggressive with insignificant inflammatory modulation.