bluuebunny/crossref_metadata_2025 huggingface dataset:
Navigation of total knee arthroplasty: rotation of components and clinical results in a prospectively randomized study
Authors: Schmitt Jan , Hauk Carsten , Kienapfel Heino , Pfeiffer Michael , Efe Turgay , Fuchs-Winkelmann Susanne , Heyse Thomas J
Published: February 2011

Background

Navigation was introduced into total knee arthroplasty (TKA) to improve accuracy of component position, function and survival of implants. This study was designed to assess the outcome of navigated TKA in comparison with conventional implantation with the focus on rotational component position and clinical mid-term results.

Methods

In a prospectively randomized single-blinded approach, 90 patients with primary gonarthrosis were assigned to three different groups. Thirty patients each were assigned to NexGen LPS without and with navigation (groups 1 and 2), and 30 patients to navigation with the Stryker Scorpio PS (group 3). The navigation system used was the imageless Stryker KneeTrac, version 1.0. Clinical outcome was assessed by a blinded observer applying the Knee Society Score (KSS) and a visual analogue scale (VAS) for pain. CT scans and radiographs were conducted prior to and 12 weeks after index surgery.

Results

Seventy-nine patients were available for clinical evaluation at 3 ± 0.4 years follow-up. Four implants had to be revised for early loosening or infection (4.4%). Four patients had died and three patients were not able to follow the invitation for clinical assessment. Functional results in the KSS were significantly lower after navigated TKA. Operation time and incisions with navigation were significantly longer. Significantly less radiological outliers with navigation were found for coronal alignment of the femur, only.

Conclusion

In this series, no beneficial effect for navigation in TKA could be shown assessing clinical data, as functional results in the presented series seemed to be lower after first generation navigated TKA. The clinical mid- to long-term value of navigation remains to be evaluated in larger patient series or meta-analyses at longer follow-up.

Trial registration number

DRKS 00000430
Effect of nitric oxide on mitochondrial activity of human synovial cells
Authors: Cillero-Pastor Berta , Martin Miguel A , Arenas Joaquín , López-Armada María J , Blanco Francisco J
Published: February 2011

Background

Nitric oxide (NO) is a messenger implicated in the destruction and inflammation of joint tissues. Cartilage and synovial membrane from patients with rheumatoid arthritis (RA) and osteoarthritis (OA) have high levels of NO. NO is known to modulate various cellular pathways and, thus, inhibit the activity of the mitochondrial respiratory chain (MRC) of chondrocytes and induce the generation of reactive oxygen species (ROS) and cell death in multiple cell types. For these reasons, and because of the importance of the synovial membrane in development of OA pathology, we investigated the effects of NO on survival, mitochondrial function, and activity of fibroblastic human OA synovial cells.

Methods

Human OA synovia were obtained from eight patients undergoing hip joint replacement. Sodium nitroprusside (SNP) was used as a NO donor compound and cell viability was evaluated by MTT assays. Mitochondrial function was evaluated by analyzing the mitochondrial membrane potential (Δψm) with flow cytometry using the fluorofore DePsipher. ATP levels were measured by luminescence assays, and the activities of the respiratory chain complexes (complex I: NADH CoQ1 reductase, complex II: succinate dehydrogenase, complex III: ubiquinol-cytochrome c reductase, complex IV: cytochrome c oxidase) and citrate synthase (CS) were measured by enzymatic assay. Protein expression analyses were performed by western blot.

Results

SNP at a concentration of 0.5 mM induced cell death, shown by the MTT method at different time points. The percentages of viable cells at 24, 48 and 72 hours were 86.11 ± 4.9%, 74.31 ± 3.35%, and 43.88 ± 1.43%, respectively, compared to the basal level of 100% (*p < 0.05). SNP at 0.5 mM induced depolarization of the mitochondrial membrane at 12 hours with a decrease in the ratio of polarized cells (basal = 2.48 ± 0.28; SNP 0.5 mM = 1.57 ± 0.11; *p < 0.01). The time course analyses of treatment with SNP at 0.5 mM demonstrated that treatment reliably and significantly reduced intracellular ATP production (68.34 ± 14.3% vs. basal = 100% at 6 hours; *p < 0.05). The analysis of the MRC at 48 hours showed that SNP at 0.5 mM increased the activity of complexes I (basal = 36.47 ± 3.92 mol/min/mg protein, SNP 0.5 mM = 58.08 ± 6.46 mol/min/mg protein; *p < 0.05) and III (basal = 63.87 ± 6.93 mol/min/mg protein, SNP 0.5 mM = 109.15 ± 30.37 mol/min/mg protein; *p < 0.05) but reduced CS activity (basal = 105.06 ± 10.72 mol/min/mg protein, SNP at 0.5 mM = 66.88 ± 6.08 mol/min/mg protein.; *p < 0.05), indicating a decrease in mitochondrial mass. Finally, SNP regulated the expression of proteins related to the cellular cycle; the NO donor decreased bcl-2, mcl-1 and procaspase-3 protein expression.

Conclusions

This study suggests that NO reduces the survival of OA synoviocytes by regulating mitochondrial functionality, as well as the proteins controlling the cell cycle.
Quantification of HLA class I molecules on renal cell carcinoma using Edman degradation
Authors: Stickel Juliane S , Stickel Natalie , Hennenlotter Jörg , Klingel Karin , Stenzl Arnulf , Rammensee Hans-Georg , Stevanović Stefan
Published: February 2011

Background

Unimpaired HLA class I antigen presentation is a prerequisite for the recognition of tumor cells by cytotoxic T lymphocytes and thus essential for the success of anticancer immunotherapeutic concepts. Several approaches have been taken in the immunotherapy of metastatic renal cell carcinoma (RCC), however of limited success. HLA loss or down-regulation have often been reported and might interfere with immunotherapeutic approaches aimed at the recognition of HLA-presented peptides.

Methods

We employed a quantitative method of molecular analysis for the comparison of HLA amounts on primary tumor, normal kidney and metastases of RCC, using Edman degradation. We analyzed a series of 47 RCC samples including corresponding renal parenchyma, local lymph node metastases and distant metastases.

Results

Results of quantitative Edman degradation revealed significantly higher HLA yields on primary tumor and metastases compared to normal kidney tissue. This effect was shown not to result from infiltrating immune cells, since tumor-infiltrating lymphocytes had no influence on the overall HLA recovery from tumor tissue. Unexpectedly, we found a higher amount of HLA class I molecules on distant metastases compared to local lymph node metastases.

Conclusion

Edman degradation allows the direct quantitative comparison of HLA class I protein expression by tumor or normal tissue and metastases of RCC patients. Our results raise hopes for improving the success and effectiveness of future immunotherapeutic concepts for metastatic RCC.
Expression, secretion and surface display of a human alkaline phosphatase by the ciliate Tetrahymena thermophila
Authors: Aldag Ingo , Bockau Ulrike , Rossdorf Jan , Laarmann Sven , Raaben Willem , Herrmann Lutz , Weide Thomas , Hartmann Marcus WW
Published: February 2011

Background

Tetrahymena thermophila possesses many attributes that render it an attractive host for the expression of recombinant proteins. Surface proteins from the parasites Ichthyophthirius multifiliis and Plasmodium falciparum and avian influenza virus antigen H5N1 were displayed on the cell membrane of this ciliate. Furthermore, it has been demonstrated that T. thermophila is also able to produce a functional human DNase I. The present study investigates the heterologous expression of the functional human intestinal alkaline phosphatase (hiAP) using T. thermophila and thereby presents a powerful tool for the optimization of the ciliate-based expression system.

Results

Functional and full length human intestinal alkaline phosphatase was expressed by T. thermophila using a codon-adapted gene containing the native signal-peptide and GPI (Glycosylphosphatidylinositol) anchor attachment signal. HiAP activity in the cell extract of transformants suggested that the hiAP gene was successfully expressed. Furthermore, it was demonstrated that the enzyme was modified with N-glycosylation and localized on the surface membrane by the C-terminal GPI anchor. A C-terminally truncated version of hiAP lacking the GPI anchor signal peptide was secreted into the medium as an active enzyme. In a first approach to establish a high level expression system up to 14,000 U/liter were produced in a time frame of two days, which exceeds the production rate of other published expression systems for this enzyme.

Conclusions

With the expression of hiAP, not only a protein of commercial interest could be produced, but also a reporter enzyme that offers the possibility to analyze T. thermophila genes that play a role in the regulation of protein secretion. Additionally, the fact that ciliates do not secrete an endogenous alkaline phosphatase provides the possibility to use the truncated hiAP as a reporter enzyme, allowing the quantification of measures that will be necessary for further optimization of the host strains and the fermentation processes.
Modulation of sulfur metabolism enables efficient glucosinolate engineering
Authors: Møldrup Morten E , Geu-Flores Fernando , Olsen Carl E , Halkier Barbara A
Published: February 2011

Background

Metabolic engineering in heterologous organisms is an attractive approach to achieve efficient production of valuable natural products. Glucosinolates represent a good example of such compounds as they are thought to be the cancer-preventive agents in cruciferous plants. We have recently demonstrated that it is feasible to engineer benzylglucosinolate (BGLS) in the non-cruciferous plant Nicotiana benthamiana by transient expression of five genes from Arabidopsis thaliana. In the same study, we showed that co-expression of a sixth Arabidopsis gene, γ-glutamyl peptidase 1 (GGP1), resolved a metabolic bottleneck, thereby increasing BGLS accumulation. However, the accumulation did not reach the expected levels, leaving room for further optimization.

Results

To optimize heterologous glucosinolate production, we have in this study performed a comparative metabolite analysis of BGLS-producing N. benthamiana leaves in the presence or absence of GGP1. The analysis revealed that the increased BGLS levels in the presence of GGP1 were accompanied by a high accumulation of the last intermediate, desulfoBGLS, and a derivative thereof. This evidenced a bottleneck in the last step of the pathway, the transfer of sulfate from 3'-phosphoadenosine-5'-phosphosulfate (PAPS) to desulfoBGLS by the sulfotransferase AtSOT16. While substitution of AtSOT16 with alternative sulfotransferases did not alleviate the bottleneck, experiments with the three genes involved in the formation and recycling of PAPS showed that co-expression of adenosine 5'-phosphosulfate kinase 2 (APK2) alone reduced the accumulation of desulfoBGLS and its derivative by more than 98% and increased BGLS accumulation 16-fold.

Conclusion

Adjusting sulfur metabolism by directing sulfur from primary to secondary metabolism leads to a remarkable improvement in BGLS accumulation and thereby represents an important step towards a clean and efficient production of glucosinolates in heterologous hosts. Our study emphasizes the importance of considering co-substrates and their biological nature in metabolic engineering projects.
Cytochrome P450 diversity and induction by gorgonian allelochemicals in the marine gastropod Cyphoma gibbosum
Authors: Whalen Kristen E , Starczak Victoria R , Nelson David R , Goldstone Jared V , Hahn Mark E
Published: February 2011

Background

Intense consumer pressure strongly affects the structural organization and function of marine ecosystems, while also having a profound effect on the phenotype of both predator and prey. Allelochemicals produced by prey often render their tissues unpalatable or toxic to a majority of potential consumers, yet some marine consumers have evolved resistance to host chemical defenses. A key challenge facing marine ecologists seeking to explain the vast differences in consumer tolerance of dietary allelochemicals is understanding the biochemical and molecular mechanisms underlying diet choice. The ability of marine consumers to tolerate toxin-laden prey may involve the cooperative action of biotransformation enzymes, including the inducible cytochrome P450s (CYPs), which have received little attention in marine invertebrates despite the importance of allelochemicals in their evolution.

Results

Here, we investigated the diversity, transcriptional response, and enzymatic activity of CYPs possibly involved in allelochemical detoxification in the generalist gastropod Cyphoma gibbosum, which feeds exclusively on chemically defended gorgonians. Twelve new genes in CYP family 4 were identified from the digestive gland of C. gibbosum. Laboratory-based feeding studies demonstrated a 2.7- to 5.1-fold induction of Cyphoma CYP4BK and CYP4BL transcripts following dietary exposure to the gorgonian Plexaura homomalla, which contains high concentrations of anti-predatory prostaglandins. Phylogenetic analysis revealed that C. gibbosum CYP4BK and CYP4BL were most closely related to vertebrate CYP4A and CYP4F, which metabolize pathophysiologically important fatty acids, including prostaglandins. Experiments involving heterologous expression of selected allelochemically-responsive C. gibbosum CYP4s indicated a possible role of one or more CYP4BL forms in eicosanoid metabolism. Sequence analysis further demonstrated that Cyphoma CYP4BK/4BL and vertebrate CYP4A/4F forms share identical amino acid residues at key positions within fatty acid substrate recognition sites.

Conclusions

These results demonstrate differential regulation of CYP transcripts in a marine consumer feeding on an allelochemical-rich diet, and significantly advance our understanding of both the adaptive molecular mechanisms that marine consumers use to cope with environmental chemical pressures and the evolutionary history of allelochemical-metabolizing enzymes in the CYP superfamily.
Eriobotrya japonica hydrophilic extract modulates cytokines in normal tissues, in the tumor of Meth-A-fibrosarcoma bearing mice, and enhances their survival time
Authors: Alshaker Heba A , Qinna Nidal A , Qadan Fadi , Bustami Mona , Matalka Khalid Z
Published: February 2011

Background

Cytokines play a key role in the immune response to developing tumors, and therefore modulating their levels and actions provides innovative strategies for enhancing the activity of antigen presenting cells and polarizing towards T helper 1 type response within tumor microenvironment. One of these approaches could be the employment of plant extracts that have cytokine immunomodulation capabilities. Previously, we have shown that theEriobotrya japonicahydrophilic extract (EJHE) induces proinflammatory cytokinesin vitroandin vivo.

Methods

The present study explored thein vivoimmunomodulatory effect on interferon-gamma (IFN-γ), interleukin-17 (IL-17), and transforming growth factor-beta 1 (TGF-β1) evoked by two water-extracts prepared from EJ leaves in the tissues of normal and Meth-A-fibrosarcoma bearing mice.

Results

Intraperitoneal (i.p.) administration of 10 μg of EJHE and EJHE-water residue (WR), prepared from butanol extraction, increased significantly IFN-γ production in the spleen (p < 0.01) and lung (p < 0.03) tissues at 6-48 hours and suppressed significantly TGF-β1 production levels (p < 0.001) in the spleen for as long as 48 hours. The latter responses, however, were not seen in Meth-A fibrosarcoma-bearing mice. On the contrary, triple i.p. injections, 24 hours apart; of 10 μg EJHE increased significantly IFN-γ production in the spleen (p < 0.02) while only EJHE-WR increased significantly IFN-γ, TGF-β1 and IL-17 (p < 0.03 - 0.005) production within the tumor microenvironment of Meth-A fibrosarcoma. In addition, the present work revealed a significant prolongation of survival time (median survival time 72 days vs. 27 days of control, p < 0.007) of mice inoculated i.p. with Meth-A cells followed by three times/week for eight weeks of i.p. administration of EJHE-WR. The latter prolonged survival effect was not seen with EJHE.

Conclusions

The therapeutic value of EJHE-WR as an anticancer agent merits further investigation of understanding the effect of immunomodulators' constituents on the cellular components of the tissue microenvironment. This can lead to the development of improved strategies for cancer treatment and thus opening up a new frontier for future studies.
Health risks encountered by Dutch medical students during an elective in the tropics and the quality and comprehensiveness of pre-and post-travel care
Authors: Sharafeldin Elhadi , Soonawala Darius , Vandenbroucke Jan P , Hack Evelien , Visser Leo G
Published: February 2011

Background

Clinical and research electives abroad offer medical students many unique experiences. However, participating in an unfamiliar health-care setting combined with limited medical experience may place students at risk of illness. To improve pre-and post-travel care, we assessed the health risks and the quality and comprehensiveness of pre-and post-travel care in a cohort of Dutch medical students returning form an elective abroad.

Methods

All medical students who had performed an elective in the tropics between July 2006 and December 2008 were sent an informative email asking them to complete a web-based questionnaire.

Results

180 of 242 (74%) students completed the questionnaire. Regarding the risk of bloodborne viral infection: 67% of all students and 32% of junior students engaged in procedures that constitute a risk of exposure to bloodborne viral infection, often in countries with high HIV prevalence rates. None of nine students who experienced possible or certain mucosal or percutaneous exposure to potentially infectious body fluids reported the exposure at the time it occurred and none used PEP. Regarding other health risks: 8 of 40 (20%) students stopped using mefloquine due to adverse effects. This left a sizeable proportion unprotected in countries that are hyperendemic for malaria. Post-travel screening for schistosomiasis, tuberculosis (tuberculin skin test) and carriage of methicillin-resistant Staphylococcus aureus (MRSA) encompassed approximately half of all students who should have been screened.

Conclusions

Based on the results of this study we have adopted an integral set of measures to reduce the health risks associated with an elective abroad. The pre and post-travel consult has been centralized and standardized as well as the distribution of PEP. In addition we have developed a mandatory module on Global Health for all medical students planning an elective abroad.
Prevalence of resistance associated polymorphisms in Plasmodium falciparum field isolates from southern Pakistan
Authors: Ghanchi Najia Karim , Ursing Johan , Beg Mohammad A , Veiga Maria I , Jafri Sana , Mårtensson Andreas
Published: February 2011

Background

Scarce data are available on Plasmodium falciparum anti-malarial drug resistance in Pakistan. The aim of this study was, therefore, to determine the prevalence of P. falciparum resistance associated polymorphisms in field isolates from southern Pakistan.

Methods

Blood samples from 244 patients with blood-slide confirmed P. falciparum mono-infections were collected between 2005-2007. Single nucleotide polymorphisms in the P. falciparum chloroquine resistance transporter (pfcrt K76T), multi drug resistance (pfmdr1 N86Y), dihydrofolate reductase (pfdhfr A16V, N51I, C59R, S108N, I164L) and dihydropteroate synthetase (pfdhps A436S, G437A and E540K) genes and pfmdr1 gene copy numbers were determined using PCR based methods.

Results

The prevalence of pfcrt 76T and pfmdr1 86Y was 93% and 57%, respectively. The prevalence of pfdhfr double mutations 59R + 108N/51R + 108N was 92%. The pfdhfr triple mutation (51I, 59R, 108N) occurred in 3% of samples. The pfdhfr (51I, 59R, 108N) and pfdhps (437G, 540E) quintuple mutation was found in one isolate. Pfdhps 437G was observed in 51% and 540E in 1% of the isolates. One isolate had two pfmdr1 copies and carried the pfmdr1 86Y and pfcrt 76T alleles.

Conclusions

The results indicate high prevalence of in vivo resistance to chloroquine, whereas high grade resistance to sulphadoxine-pyrimethamine does not appear to be widespread among P. falciparum in southern Pakistan.
Dietary intake in the Personalized Medicine Research Project: a resource for studies of gene-diet interaction
Authors: Strobush Lacie , Berg Richard , Cross Deanna , Foth Wendy , Kitchner Terrie , Coleman Laura , McCarty Catherine A
Published: February 2011

Background

To describe the dietary intake of participants in the Personalized Medicine Research Project (PMRP), and to quantify differences in nutrient intake by smoking status and APOE4-a genetic marker that has been shown to modify the association between risk factors and outcomes.

Methods

The PMRP is a population-based DNA, plasma and serum biobank of more than 20,000 adults aged 18 years and older in central Wisconsin. A questionnaire at enrollment captures demographic information as well as self-reported smoking and alcohol intake. The protocol was amended to include the collection of dietary intake and physical activity via self-reported questionnaires: the National Cancer Institute 124-item Diet History Questionnaire and the Baecke Physical Activity Questionnaire. These questionnaires were mailed out to previously enrolled participants. APOE was genotyped in all subjects.

Results

The response rate to the mailed questionnaires was 68.2% for subjects who could still be contacted (alive with known address). Participants ranged in age from 18 to 98 years (mean 54.7) and 61% were female. Dietary intake is variable when comparing gender, age, smoking, and APOE4. Over 50% of females are dietary supplement users; females have higher supplement intake than males, but both have increasing supplement use as age increases. Food energy, total fat, cholesterol, protein, and alcohol intake decreases as both males and females age. Female smokers had higher macronutrient intake, whereas male nonsmokers had higher macronutrient intake. Nonsmokers in both genders use more supplements. In females, nonsmokers and smokers with APOE4 had higher supplement use. In males, nonsmokers with APOE4 had higher supplement use between ages 18-39 only, and lower supplement use at ages above 39. Male smokers with APOE4 had lower supplement use.

Conclusion

Dietary intake in PMRP subjects is relatively consistent with data from the National Health and Nutrition Examination Survey (NHANES). Findings suggest a possible correlation between the use of supplements and APOE4. The PMRP dietary data can benefit studies of gene-environment interactions and the development of common diseases.
Effect of nitrogen-rich cell culture surfaces on type X collagen expression by bovine growth plate chondrocytes
Authors: Petit Alain , Demers Caroline N , Girard-Lauriault Pierre-Luc , Stachura Dorothy , Wertheimer Michael R , Antoniou John , Mwale Fackson
Published: February 2011

Background

Recent evidence indicates that osteoarthritis (OA) may be a systemic disease since mesenchymal stem cells (MSCs) from OA patients express type X collagen, a marker of late stage chondrocyte hypertrophy (associated with endochondral ossification). We recently showed that the expression of type X collagen was suppressed when MSCs from OA patients were cultured on nitrogen (N)-rich plasma polymer layers, which we call "PPE:N" (N-doped plasma-polymerized ethylene, containing up to 36 atomic percentage (at.% ) of N.

Methods

In the present study, we examined the expression of type X collagen in fetal bovine growth plate chondrocytes (containing hypertrophic chondrocytes) cultured on PPE:N. We also studied the effect of PPE:N on the expression of matrix molecules such as type II collagen and aggrecan, as well as on proteases (matrix metalloproteinase-13 (MMP-13) and molecules implicated in cell division (cyclin B2). Two other culture surfaces, "hydrophilic" polystyrene (PS, regular culture dishes) and nitrogen-containing cation polystyrene (Primaria®), were also investigated for comparison.

Results

Results showed that type X collagen mRNA levels were suppressed when cultured for 4 days on PPE:N, suggesting that type X collagen is regulated similarly in hypertrophic chondrocytes and in human MSCs from OA patients. However, the levels of type X collagen mRNA almost returned to control value after 20 days in culture on these surfaces. Culture on the various surfaces had no significant effects on type II collagen, aggrecan, MMP-13, and cyclin B2 mRNA levels.

Conclusion

Hypertrophy is diminished by culturing growth plate chondrocytes on nitrogen-rich surfaces, a mechanism that is beneficial for MSC chondrogenesis. Furthermore, one major advantage of such "intelligent surfaces" over recombinant growth factors for tissue engineering and cartilage repair is potentially large cost-saving.
Area-aggregated assessments of perceived environmental attributes may overcome single-source bias in studies of green environments and health: results from a cross-sectional survey in southern Sweden
Authors: de Jong Kim , Albin Maria , Skärbäck Erik , Grahn Patrik , Wadbro John , Merlo Juan , Björk Jonas
Published: February 2011

Background

Most studies assessing health effects of neighborhood characteristics either use self-reports or objective assessments of the environment, the latter often based on Geographical Information Systems (GIS). While objective measures require detailed landscape data, self-assessments may yield confounded results. In this study we demonstrate how self-assessments of green neighborhood environments aggregated to narrow area units may serve as an appealing compromise between objective measures and individual self-assessments.

Methods

The study uses cross-sectional data (N = 24,847) from a public health survey conducted in the county of Scania, southern Sweden, in 2008 and validates the Scania Green Score (SGS), a new index comprising five self-reported green neighborhood qualities (Culture, Lush, Serene, Spacious and Wild). The same qualities were also assessed objectively using landscape data and GIS. A multilevel (ecometric) model was used to aggregate individual self-reports to assessments of perceived green environmental attributes for areas of 1,000 square meters. We assessed convergent and concurrent validity for self-assessments of the five items separately and for the sum score, individually and area-aggregated.

Results

Correlations between the index scores based on self-assessments and the corresponding objective assessments were clearly present, indicating convergent validity, but the agreement was low. The correlation was even more evident for the area-aggregated SGS. All three scores (individual SGS, area-aggregated SGS and GIS index score) were associated with neighborhood satisfaction, indicating concurrent validity. However, while individual SGS was associated with vitality, this association was not present for aggregated SGS and the GIS-index score, suggesting confounding (single-source bias) when individual SGS was used.

Conclusions

Perceived and objectively assessed qualities of the green neighborhood environment correlate but do not agree. An index score based on self-reports but aggregated to narrow area units can be a valid approach to assess perceived green neighborhood qualities in settings where objective assessments are not possible or feasible.
Lymphocyte deficiency limits Epstein-Barr virus latent membrane protein 1 induced chronic inflammation and carcinogenic pathology in vivo
Authors: Hannigan Adele , Qureshi Asif M , Nixon Colin , Tsimbouri Penelope M , Jones Sarah , Philbey Adrian W , Wilson Joanna B
Published: February 2011

Background

The importance of the malignant cell environment to its growth and survival is becoming increasingly apparent, with dynamic cross talk between the neoplastic cell, the leukocyte infiltrate and the stroma. Most cancers are accompanied by leukocyte infiltration which, contrary to an anticipated immuno-protective role, could be contributing to tumour development and cancer progression. Epstein-Barr virus (EBV) associated cancers, including nasopharyngeal carcinoma and Hodgkin's Disease, show a considerable leukocyte infiltration which surrounds the neoplastic cells, raising the questions as to what role these cells play in either restricting or supporting the tumour and what draws the cells into the tumour. In order to begin to address this we have studied a transgenic model of multistage carcinogenesis with epithelial expression of the EBV primary oncoprotein, latent membrane protein 1 (LMP1). LMP1 is expressed particularly in the skin, which develops a hyperplastic pathology soon after birth.

Results

The pathology advances with time leading to erosive dermatitis which is inflamed with a mixed infiltrate involving activated CD8+ T-cells, CD4+ T-cells including CD4+/CD25+/FoxP3+ Treg cells, mast cells and neutrophils. Also significant dermal deposition of immunoglobulin-G (IgG) is observed as the pathology advances. Along with NF-kappaB activation, STAT3, a central factor in inflammation regulation, is activated in the transgenic tissue. Several inflammatory factors are subsequently upregulated, notably CD30 and its ligand CD153, also leukocyte trafficking factors including CXCL10, CXCL13, L-selectin and TGFβ1, and inflammatory cytokines including IL-1β, IL-3 and the murine IL-8 analogues CXCL1, CXCL2 and CXCL5-6, amongst others. The crucial role of mature T- and/or B-lymphocytes in the advancing pathology is demonstrated by their elimination, which precludes mast cell infiltration and limits the pathology to an early, benign stage.

Conclusions

LMP1 can lead to the activation of several key factors mediating proliferation, angiogenesis and inflammationin vivo. With the initiation of an inflammatory programme, leukocyte recruitment follows which then itself contributes to the progressing pathology in these transgenic mice, with a pivotal role for B-and/or T-cells in the process. The model suggests a basis for the leukocyte infiltrate observed in EBV-associated cancer and its supporting role, as well as potential points for therapeutic intervention.
Cyr61/CCN1 signaling is critical for epithelial-mesenchymal transition and stemness and promotes pancreatic carcinogenesis
Authors: Haque Inamul , Mehta Smita , Majumder Monami , Dhar Kakali , De Archana , McGregor Douglas , Van Veldhuizen Peter J , Banerjee Sushanta K , Banerjee Snigdha
Published: February 2011

Background

Despite recent advances in outlining the mechanisms involved in pancreatic carcinogenesis, precise molecular pathways and cellular lineage specification remains incompletely understood.

Results

We show here that Cyr61/CCN1 play a critical role in pancreatic carcinogenesis through the induction of EMT and stemness. Cyr61 mRNA and protein were detected in the early precursor lesions and their expression intensified with disease progression. Cyr61/CCN1 expression was also detected in different pancreatic cancer cell lines. The aggressive cell lines, in which the expressions of mesenchymal/stem cell molecular markers are predominant; exhibit more Cyr61/CCN1 expression. Cyr61 expression is exorbitantly higher in cancer stem/tumor initiating Panc-1-side-population (SP) cells. Upon Cyr61/CCN1 silencing, the aggressive behaviors are reduced by obliterating interlinking pathobiological events such as reversing the EMT, blocking the expression of stem-cell-like traits and inhibiting migration. In contrast, addition of Cyr61 protein in culture medium augments EMT and stemness features in relatively less aggressive BxPC3 pancreatic cancer cells. Using a xenograft model we demonstrated that cyr61/CCN1 silencing in Panc-1-SP cells reverses the stemness features and tumor initiating potency of these cells. Moreover, our results imply a miRNA-based mechanism for the regulation of aggressive behaviors of pancreatic cancer cells by Cyr61/CCN1.

Conclusions

In conclusion, the discovery of the involvement of Cyr61/CCN1 in pancreatic carcinogenesis may represent an important marker for PDAC and suggests Cyr61/CCN1 can be a potential cancer therapeutic target.
High-fat diet and glucocorticoid treatment cause hyperglycemia associated with adiponectin receptor alterations
Authors: de Oliveira Cristiane , de Mattos Ana BM , Biz Carolina , Oyama Lila M , Ribeiro Eliane B , Oller do Nascimento Cláudia Maria
Published: February 2011

Background

Adiponectin is the most abundant plasma protein synthesized for the most part in adipose tissue, and it is an insulin-sensitive hormone, playing a central role in glucose and lipid metabolism. In addition, it increases fatty acid oxidation in the muscle and potentiates insulin inhibition of hepatic gluconeogenesis. Two adiponectin receptors have been identified: AdipoR1 is the major receptor expressed in skeletal muscle, whereas AdipoR2 is mainly expressed in liver. Consumption of high levels of dietary fat is thought to be a major factor in the promotion of obesity and insulin resistance. Excessive levels of cortisol are characterized by the symptoms of abdominal obesity, hypertension, glucose intolerance or diabetes and dyslipidemia; of note, all of these features are shared by the condition of insulin resistance. Although it has been shown that glucocorticoids inhibit adiponectin expression in vitro and in vivo, little is known about the regulation of adiponectin receptors. The link between glucocorticoids and insulin resistance may involve the adiponectin receptors and adrenalectomy might play a role not only in regulate expression and secretion of adiponectin, as well regulate the respective receptors in several tissues.

Results

Feeding of a high-fat diet increased serum glucose levels and decreased adiponectin and adipoR2 mRNA expression in subcutaneous and retroperitoneal adipose tissues, respectively. Moreover, it increased both adipoR1 and adipoR2 mRNA levels in muscle and adipoR2 protein levels in liver. Adrenalectomy combined with the synthetic glucocorticoid dexamethasone treatment resulted in increased glucose and insulin levels, decreased serum adiponectin levels, reduced adiponectin mRNA in epididymal adipose tissue, reduction of adipoR2 mRNA by 7-fold in muscle and reduced adipoR1 and adipoR2 protein levels in muscle. Adrenalectomy alone increased adiponectin mRNA expression 3-fold in subcutaneous adipose tissue and reduced adipoR2 mRNA expression 2-fold in liver.

Conclusion

Hyperglycemia as a result of a high-fat diet is associated with an increase in the expression of the adiponectin receptors in muscle. An excess of glucocorticoids, rather than their absence, increase glucose and insulin and decrease adiponectin levels.
Differential patterns of histone acetylation in inflammatory bowel diseases
Authors: Tsaprouni Loukia G , Ito Kazuhiro , Powell Jonathan J , Adcock Ian M , Punchard Neville
Published: February 2011

Post-translational modifications of histones, particularly acetylation, are associated with the regulation of inflammatory gene expression. We used two animal models of inflammation of the bowel and biopsy samples from patients with Crohn's disease (CD) to study the expression of acetylated histones (H) 3 and 4 in inflamed mucosa. Acetylation of histone H4 was significantly elevated in the inflamed mucosa in the trinitrobenzene sulfonic acid model of colitis particularly on lysine residues (K) 8 and 12 in contrast to non-inflamed tissue. In addition, acetylated H4 was localised to inflamed tissue and to Peyer's patches (PP) in dextran sulfate sodium (DSS)-treated rat models. Within the PP, H3 acetylation was detected in the mantle zone whereas H4 acetylation was seen in both the periphery and the germinal centre. Finally, acetylation of H4 was significantly upregulated in inflamed biopsies and PP from patients with CD. Enhanced acetylation of H4K5 and K16 was seen in the PP. These results demonstrate that histone acetylation is associated with inflammation and may provide a novel therapeutic target for mucosal inflammation.
A nanocomplex that is both tumor cell-selective and cancer gene-specific for anaplastic large cell lymphoma
Authors: Zhao Nianxi , Bagaria Hitesh G , Wong Michael S , Zu Youli
Published: February 2011

Background

Manyin vitrostudies have demonstrated that silencing of cancerous genes by siRNAs is a potential therapeutic approach for blocking tumor growth. However, siRNAs are not cell type-selective, cannot specifically target tumor cells, and therefore have limitedin vivoapplication for siRNA-mediated gene therapy.

Results

In this study, we tested a functional RNA nanocomplex which exclusively targets and affects human anaplastic large cell lymphoma (ALCL) by taking advantage of the abnormal expression of CD30, a unique surface biomarker, and the anaplastic lymphoma kinase (ALK) gene in lymphoma cells. The nanocomplexes were formulated by incorporating both ALK siRNA and a RNA-based CD30 aptamer probe onto nano-sized polyethyleneimine-citrate carriers. To minimize potential cytotoxicity, the individual components of the nanocomplexes were used at sub-cytotoxic concentrations. Dynamic light scattering showed that formed nanocomplexes were ~140 nm in diameter and remained stable for more than 24 hours in culture medium. Cell binding assays revealed that CD30 aptamer probes selectively targeted nanocomplexes to ALCL cells, and confocal fluorescence microscopy confirmed intracellular delivery of the nanocomplex. Cell transfection analysis showed that nanocomplexes silenced genes in an ALCL cell type-selective fashion. Moreover, exposure of ALCL cells to nanocomplexes carrying both ALK siRNAs and CD30 RNA aptamers specifically silenced ALK gene expression, leading to growth arrest and apoptosis.

Conclusions

Taken together, our findings indicate that this functional RNA nanocomplex is both tumor cell type-selective and cancer gene-specific for ALCL cells.
Down-regulation of phosphoglucomutase 3 mediates sulforaphane-induced cell death in LNCaP prostate cancer cells
Authors: Lee Chan-Hee , Jeong Soo-Jin , Yun Sun-Mi , Kim Ji-Hyun , Lee Hyo-Jung , Ahn Kwang Seok , Won Suk-Hyun , Kim Hyun Seok , Lee Hyo-Jeong , Ahn Kyoo-Seok , Zhu Shudong , Chen Chang-Yan , Kim Sung-Hoon
Published: February 2011

Background

Sulforaphane (SFN) is an isothiocyanate found in cruciferous vegetables that exerts anti-oxidant, anti-inflammatory, anti-cancer and radio-sensitizing activities. Nonetheless, the mechanism responsible for SFN-induced cell death is not fully understood. In the present study, anti-cancer mechanism of SFN was elucidated in LNCaP prostate cancer cells.

Results

SFN exerted cytotoxicity and increased TUNEL positive cells in a concentration-dependent manner in LNCaP cells. Proteomics study revealed that levels of nine proteins including tubulin β-2, phosphoglucomutase-3 (PGM3), melanoma-derived leucine zipper containing extra-nuclear factor, activin A type I receptor precursor, smoothelin-A, KIA0073, hypothetical protein LOC57691 and two unnamed proteins were changed over 8 folds in SFN treated LNCaP cells compared to untreated control. We have further confirmed that SFN reduced PGM3 expression with western blotting and showed that PGM3 siRNA enhanced cytotoxicity demonstrated by cell morphology and TUNEL assays in LNCaP cells.

Conclusion

Taken together, these findings suggest that PGM3 plays a role in mediating SFN-induced cell death in LNCaP cells, and is a potential molecular therapeutic target for prostate cancer.
Gastrointestinal stromal tumors: correlation between symptoms at presentation, tumor location and prognostic factors in 47 consecutive patients
Authors: Caterino Salvatore , Lorenzon Laura , Petrucciani Niccolò , Iannicelli Elsa , Pilozzi Emanuela , Romiti Adriana , Cavallini Marco , Ziparo Vincenzo
Published: February 2011

Background

Gastrointestinal stromal tumors (GIST) are mesenchymal tumors of the gastrointestinal tract, usually kit-positive, that are believed to originate from interstitial cell of Cajal, or their related stem cells. The most common clinical presentation of these tumors is gastrointestinal bleeding, otherwise they may cause intestinal obstruction, abdominal pain, a palpable mass, or can be incidentally detected during surgery or endoscopic/radiological procedures. Prognosis is related to the size of the tumor and to the mitotic rate; other prognostic factors are tumor location, tumor resection margins, tumor rupture, and c-kit mutation that may interfere with molecular target therapy efficacy.

Aim

Primary aim of this study was to report our experience regarding GIST patients, correlating symptoms at presentation with tumor localization and risk factors.

Patients and methods

47 consecutive patients undergone to surgical resection for GISTs were enrolled in a prospective study from December 1999 to March 2009. Patient's clinical and pathological features were collected and analysed.

Results

The most common symptom was abdominal pain. Bleeding in the digestive tract and abdominal pain were more frequent in gastric GISTs (58% and 61%); acute abdominal symptoms were more frequent in jejunal and ileal GISTs (40% and 60%), p < 0.05. We reported a mild correlation between the mitotic rate index and symptoms at presentation (p 0.074): this correlation was stronger if GISTs causing "acute abdominal symptoms" were compared with GISTs causing "abdominal pain" as main symptom (p 0.039) and with "incidental" GISTs (p 0.022).

We observed an higher prevalence of symptomatic patients in the "high risk/malignant group" of both the Fletcher's and Miettines's classification (p < 0.05).

Conclusion

According with our findings symptoms correlate to tumor location, to class risk criteria as mitotic index and risk classifications, however we cannot conclude that symptoms are per se predictive of survival or patient's outcome.
Impaired desensitization of a human polymorphic α2B-adrenergic receptor variant enhances its sympatho-inhibitory activity in chromaffin cells
Authors: Nguyen Kristy , Kassimatis Theodoros , Lymperopoulos Anastasios
Published: February 2011

Background

α2-adrenergic receptors (ARs) mediate many cellular actions of epinephrine and norepinephrine and inhibit their secretion from adrenal chromaffin cells. Like many other G-protein coupled receptors (GPCRs), they undergo agonist-dependent phopshorylation and desensitization by GPCR Kinases (GRKs), a phenomenon recently shown to play a major role in the sympathetic overdrive that accompanies and aggravates chronic heart failure. A deletion polymorphism in the human α2B-AR gene (Glu301-303) causes impaired agonist-promoted receptor phosphorylation and desensitization in heterologous cell lines. Given the importance of α2-ARs in regulation of catecholamine secretion from chromaffin cells, we sought to investigate, in the present study, the desensitization properties and the sympatho-inhibitory activity of this variant in a chromaffin cell line. For this purpose, we expressed this variant and its wild type counterpart in the well-established chromaffin cell line PC12, and performed receptor phosphorylation and desensitization studies, as well as in vitro catecholamine secretion assays.

Results

Both the agonist-induced phosphorylation and agonist-dependent desensitization of the human Glu301-303 deletion polymorphic α2B-AR are significantly impaired in PC12 cells, resulting in enhanced signaling to inhibition of cholinergic-induced catecholamine secretion in vitro.

Conclusion

This α2B-AR gene polymorphism (Glu301-303 deletion) might confer better protection against conditions characterized and aggravated by sympathetic/catecholaminergic overstimulation in vivo.
Prevalence of exercise and non-exercise physical activity in Chinese adolescents
Authors: Mak Kwok-Kei , Ho Sai-Yin , Lo Wing-Sze , McManus Alison M , Lam Tai-Hing
Published: February 2011

Non-exercise physical activity (NEPA) is an important part of energy expenditure. This study aimed to investigate the prevalence of exercise and NEPA among adolescents. In the HKSOS project 2006-2007, the proportions of Hong Kong Chinese adolescents (N = 32,005) achieving 60-minute exercise and 60-minute NEPA per day were analyzed. Exercise was defined as structured and planned physical activities, and NEPA was defined as unstructured and unplanned physical activities including walking for transportation and climbing stairs. The prevalence of exercise was higher in boys than girls (after school: 63.8% vs 39.6%; holidays: 78.7% vs 60.0%), but the prevalence of NEPA in boys was similar to that in girls (after school: 72.2% vs 68.0%; holidays: 80.3% vs 79.4%). In general, the prevalence of both exercise and NEPA decreased with age in boys and girls, but was more marked for exercise than NEPA. In conclusion, the prevalence of exercise was lower in adolescent girls than boys, and decreased more rapidly with age than NEPA. NEPA seems to be easier to accumulate than exercise among adolescents regardless of sex and age.
Conformational HIV-1 Envelope on particulate structures: a tool for chemokine coreceptor binding studies
Authors: Tagliamonte Maria , Tornesello Maria Lina , Buonaguro Franco M , Buonaguro Luigi
Published: February 2011

The human immunodeficiency virus type 1 (HIV-1) external envelope glycoprotein gp120 presents conserved binding sites for binding to the primary virus receptor CD4 as well as the major HIV chemokine coreceptors, CCR5 and CXCR4.

Concerted efforts are underway to understand the specific interactions between gp120 and coreceptors as well as their contribution to the subsequent membrane fusion process.

The present review summarizes the current knowledge on this biological aspect, which represents one of the key and essential points of the HIV-host cell interplay and HIV life cycle. The relevance of conformational HIV-1 Envelope proteins presented on Virus-like Particles for appropriate assessment of this molecular interaction, is also discussed.
Coreceptor use in nonhuman primate models of HIV infection
Authors: Sina Silvana Tasca , Ren Wuze , Cheng-Mayer Cecilia
Published: February 2011

SIV or SHIV infection of nonhuman primates (NHP) has been used to investigate the impact of coreceptor usage on the composition and dynamics of the CD4+ T cell compartment, mechanisms of disease induction and development of clinical syndrome. As the entire course of infection can be followed, with frequent access to tissue compartments, infection of rhesus macaques with CCR5-tropic SHIVs further allows for study of HIV-1 coreceptor switch after intravenous and mucosal inoculation, with longitudinal and systemic analysis to determine the timing, anatomical sites and cause for the change in envelope glycoprotein and coreceptor preference. Here, we review our current understanding of coreceptor use in NHPs and their impact on the pathobiological characteristics of the infection, and discuss recent advances in NHP studies to uncover the underlying selective pressures for the change in coreceptor preference in vivo.