598 research outputs found

    Comparative study of imaging at 3.0 T versus 1.5 T of the knee

    Get PDF
    The objectives of the study were to compare MR imaging at 1.5 and 3.0 T in the same patients concerning image quality and visualization of cartilage pathology and to assess diagnostic performance using arthroscopy as a standard of reference. Twenty-six patients were identified retrospectively as having comparative 1.5 and 3.0 T MR studies of the knee within an average of 102 days. Standard protocols included T1-weighted and fat-saturated intermediate-weighted fast spin-echo sequences in three planes; sequence parameters had been adjusted to account for differences in relaxation at 3.0 T. Arthroscopy was performed in 19 patients. Four radiologists reviewed each study independently, scored image quality, and analyzed pathological findings. Sensitivities, specificities, and accuracies in diagnosing cartilage lesions were calculated in the 19 patients with arthroscopy, and differences between 1.5 and 3.0 T exams were compared using paired Student’s t tests with a significance threshold of p < 0.05. Each radiologist scored the 3.0 T studies higher than those obtained at 1.5 T in visualizing anatomical structures and abnormalities (p < 0.05). Using arthroscopy as a standard of reference, diagnosis of cartilage abnormalities was improved at 3.0 T with higher sensitivity (75.7% versus 70.6%), accuracy (88.2% versus 86.4%), and correct grading of cartilage lesions (51.3% versus 42.9%). Diagnostic confidence scores were higher at 3.0 than 1.5 T (p < 0.05) and signal-to-noise ratio at 3.0 T was approximately twofold higher than at 1.5 T. MRI at 3.0 T improved visualization of anatomical structures and improved diagnostic confidence compared to 1.5 T. This resulted in significantly better sensitivity and grading of cartilage lesions at the knee

    Four year experience of sarcoma of soft tissues and bones in a tertiary care hospital and review of literature

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Sarcoma encompasses an uncommon group of cancer and the data is insufficient from Pakistan. We report our four years experience of Sarcoma of soft tissues and bones.</p> <p>Methods</p> <p>This cross sectional study was carried out at Aga Khan University Hospital from 2004 to 2008. The patients were divided into two groups from the outset i.e. initially diagnosed and relapsed group and separate sub group analysis was conducted.</p> <p>Results</p> <p>Out of 93 newly diagnosed patients, 58 belonged to bone sarcoma and 35 to soft tissue sarcoma group. While for relapsed patients, 5 had soft tissue sarcoma and 9 had bone sarcoma. Mean age was 32.5 years. At presentation, approximately two third patients had localised disease while remaining one third had metastatic disease. The Kaplan Meier estimate of median recurrence free survival was 25 months, 35 months, and 44 months for Osteogenic sarcoma, Ewing's sarcoma and Chondrosarcoma respectively. For Leiomyosarcoma and Synovial sarcoma, it was 20 and 19 months respectively. The grade of the tumour (p = 0.02) and surgical margin status (p = 0.001) were statistically significant for determination of relapse of disease.</p> <p>Conclusion</p> <p>The median recurrence free survival of patients in our study was comparable to the reported literature but with significant lost to follow rate. Further large-scale, multi centre studies are needed to have a more comprehensive understanding of this heterogeneous disease in our population.</p

    Shotgun Mass Spectrometry Workflow Combining IEF and LC-MALDI-TOF/TOF

    Get PDF
    We present a high throughput shotgun mass spectrometry workflow using a bidimensional peptide fractionation procedure consisting of isoelectric focusing and RP-HPLC prior to mass spectrometric analysis, with the aim of optimizing peptide separation and protein identification. As part of the workflow we used the ‘Isotope-Coded Protein Labeling’ (ICPL) method for accurate relative quantitation of protein expression. Such workflow was successfully applied to a comparative proteome analysis of schizophrenia versus healthy control brain tissues and can be an alternative to proteome researches

    Proteomic analysis of the Plasmodium male gamete reveals the key role for glycolysis in flagellar motility.

    Get PDF
    BACKGROUND: Gametogenesis and fertilization play crucial roles in malaria transmission. While male gametes are thought to be amongst the simplest eukaryotic cells and are proven targets of transmission blocking immunity, little is known about their molecular organization. For example, the pathway of energy metabolism that power motility, a feature that facilitates gamete encounter and fertilization, is unknown. METHODS: Plasmodium berghei microgametes were purified and analysed by whole-cell proteomic analysis for the first time. Data are available via ProteomeXchange with identifier PXD001163. RESULTS: 615 proteins were recovered, they included all male gamete proteins described thus far. Amongst them were the 11 enzymes of the glycolytic pathway. The hexose transporter was localized to the gamete plasma membrane and it was shown that microgamete motility can be suppressed effectively by inhibitors of this transporter and of the glycolytic pathway. CONCLUSIONS: This study describes the first whole-cell proteomic analysis of the malaria male gamete. It identifies glycolysis as the likely exclusive source of energy for flagellar beat, and provides new insights in original features of Plasmodium flagellar organization

    Inequalities in colorectal cancer screening participation in the first round of the national screening programme in England

    Get PDF
    BACKGROUND: Introduction of organised, population-based, colorectal cancer screening in the United Kingdom using the faecal occult blood test (FOBT) has the potential to reduce overall colorectal cancer mortality. However, socio-economic variation in screening participation could exacerbate existing inequalities in mortality.METHODS: This study examined FOBT uptake rates in London, England in relation to area-level socio-economic deprivation over the first 30 months of the programme during which 401 197 individuals were sent an FOBT kit. Uptake was defined as return of a completed test kit within 3 months. Area-level deprivation in each postcode sector was indexed with the Townsend Material Deprivation Index. Analyses controlled for area-level household mobility, ethnic diversity and poor health, each of which was associated with lower return rates.RESULTS: The results showed a strong socio-economic gradient in FOBT uptake, which declined from 49% in the least deprived quintile of postcodes to 38% in the middle quintile and 32% in the most deprived quintile. Variation in socio-economic deprivation between sectors accounted for 62% of the variance in return rates, with little attenuation as a result of controlling for ethnic diversity, household mobility or health status.CONCLUSION: These results highlight the need to understand the causes of socio-economic gradients in screening participation and address barriers that could otherwise increase disparities in colorectal cancer survival

    Results of the Scandinavian Sarcoma Group XIV protocol for classical osteosarcoma: 63 patients with a minimum follow-up of 4 years

    Get PDF
    Background and purpose The Scandinavian Sarcoma Group (SSG) XIV protocol is based on experience from previous SSG trials and other osteosarcoma intergroup trials, and has been considered the best standard of care for patients with extremity localized, non-metastatic osteosarcoma. We analyzed the outcome in 63 consecutive patients. Patients and methods From 2001 through 2005, 63 patients recruited from centers in Sweden, Norway, and Finland were included. They received preoperative chemotherapy consisting of 2 cycles of paired methotrexate (12 g/m(2)), cisplatin (90 mg/m(2)), and doxorubicin (75 mg/m(2)). 3 cycles were administered post-operatively, and poor histological responders were given 3 additional cycles of ifosfamide (10-12 g/m(2)) as a salvage strategy. Results With a median follow-up of 77 months for survivors, the estimated metastasis-free and sarcoma-related survival at 5 years was 70% and 76%, respectively. 53 patients were treated with limb salvage surgery or rotationplasty and 2 patients experienced a local recurrence. 3 toxic deaths were recorded, all related to acute toxicity from chemotherapy. The 5-year metastasis-free survival of poor histological responders receiving add-on treatment with ifosfamide was 47%, as compared to 89% for good histological responders. Interpretation Outcome from the SSG XIV protocol compares favorably with the results of previous SSG trials and other published osteosarcoma trials. However, salvage therapy given to poor responders did not improve outcome to a similar degree as for good responders. In a multi-institutional setting, more than four-fifths of the patients were operated with limb salvage surgery or rotationplasty, with few local recurrences

    Identification of alternative splice variants in Aspergillus flavus through comparison of multiple tandem MS search algorithms

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Database searching is the most frequently used approach for automated peptide assignment and protein inference of tandem mass spectra. The results, however, depend on the sequences in target databases and on search algorithms. Recently by using an alternative splicing database, we identified more proteins than with the annotated proteins in <it>Aspergillus flavus</it>. In this study, we aimed at finding a greater number of eligible splice variants based on newly available transcript sequences and the latest genome annotation. The improved database was then used to compare four search algorithms: Mascot, OMSSA, X! Tandem, and InsPecT.</p> <p>Results</p> <p>The updated alternative splicing database predicted 15833 putative protein variants, 61% more than the previous results. There was transcript evidence for 50% of the updated genes compared to the previous 35% coverage. Database searches were conducted using the same set of spectral data, search parameters, and protein database but with different algorithms. The false discovery rates of the peptide-spectrum matches were estimated < 2%. The numbers of the total identified proteins varied from 765 to 867 between algorithms. Whereas 42% (1651/3891) of peptide assignments were unanimous, the comparison showed that 51% (568/1114) of the RefSeq proteins and 15% (11/72) of the putative splice variants were inferred by all algorithms. 12 plausible isoforms were discovered by focusing on the consensus peptides which were detected by at least three different algorithms. The analysis found different conserved domains in two putative isoforms of UDP-galactose 4-epimerase.</p> <p>Conclusions</p> <p>We were able to detect dozens of new peptides using the improved alternative splicing database with the recently updated annotation of the <it>A. flavus </it>genome. Unlike the identifications of the peptides and the RefSeq proteins, large variations existed between the putative splice variants identified by different algorithms. 12 candidates of putative isoforms were reported based on the consensus peptide-spectrum matches. This suggests that applications of multiple search engines effectively reduced the possible false positive results and validated the protein identifications from tandem mass spectra using an alternative splicing database.</p

    Water-Driven Assembly of Laser Ablation-Induced Au Condensates as Mesomorphic Nano- and Micro-Tubes

    Get PDF
    Reddish Au condensates, predominant atom clusters and minor amount of multiply twinned particles and fcc nanoparticles with internal compressive stress, were produced by pulsed laser ablation on gold target in de-ionized water under a very high power density. Such condensates were self-assembled as lamellae and then nano- to micro-diameter tubes with multiple walls when aged at room temperature in water for up to 40 days. The nano- and micro-tubes have a lamellar- and relaxed fcc-type wall, respectively, both following partial epitaxial relationship with the co-existing multiply twinned nanoparticles. The entangled tubes, being mesomorphic with a large extent of bifurcation, flexibility, opaqueness, and surface-enhanced Raman scattering, may have potential encapsulated and catalytic/label applications in biomedical systems

    Arthroscopy vs. MRI for a detailed assessment of cartilage disease in osteoarthritis: diagnostic value of MRI in clinical practice

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>In patients with osteoarthritis, a detailed assessment of degenerative cartilage disease is important to recommend adequate treatment. Using a representative sample of patients, this study investigated whether MRI is reliable for a detailed cartilage assessment in patients with osteoarthritis of the knee.</p> <p>Methods</p> <p>In a cross sectional-study as a part of a retrospective case-control study, 36 patients (mean age 53.1 years) with clinically relevant osteoarthritis received standardized MRI (sag. T1-TSE, cor. STIR-TSE, trans. fat-suppressed PD-TSE, sag. fat-suppressed PD-TSE, Siemens Magnetom Avanto syngo MR B 15) on a 1.5 Tesla unit. Within a maximum of three months later, arthroscopic grading of the articular surfaces was performed. MRI grading by two blinded observers was compared to arthroscopic findings. Diagnostic values as well as intra- and inter-observer values were assessed.</p> <p>Results</p> <p>Inter-observer agreement between readers 1 and 2 was good (kappa = 0.65) within all compartments. Intra-observer agreement comparing MRI grading to arthroscopic grading showed moderate to good values for readers 1 and 2 (kappa = 0.50 and 0.62, respectively), the poorest being within the patellofemoral joint (kappa = 0.32 and 0.52). Sensitivities were relatively low at all grades, particularly for grade 3 cartilage lesions. A tendency to underestimate cartilage disorders on MR images was not noticed.</p> <p>Conclusions</p> <p>According to our results, the use of MRI for precise grading of the cartilage in osteoarthritis is limited. Even if the practical benefit of MRI in pretreatment diagnostics is unequivocal, a diagnostic arthroscopy is of outstanding value when a grading of the cartilage is crucial for a definitive decision regarding therapeutic options in patients with osteoarthritis.</p
    corecore