282 research outputs found

    Anatomizing extracellular polymer of Calothrix desertica with its anti-oxidation and anti-nutrient profiling

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    Calothrix desertica having a semilunar apical heterocyst is proficient at excreting 1.2 g/L of extracellular polymers (EPsC) in 45 days. The refined EPsC constitutes 430 mg/g of glycogen, 390 mg/g of protein, and 14.6 mg/g of glycoproteins (GPs). The glycoprotein estimation of EPsC was performed by two step hydrolysis methods with H2SO4. The peak between 10 mAU to 20 mAU in HPLC, 1400 cm-1 to 1700 cm-1 in FTIR, and 40kDa- 35kDa bands in SDS-PAGE authenticates the presence of glycoproteins in the EPsC. The EPsC agglomerate of 1000 nm to 3000 nm size with a Zeta potential of -20 mV to 5 mV was determined using DLS. Further EPsC of nanosizes of 30 nm to 150 nm in 50,000 X and 20 nm to 40 nm in 60,000 X was measured using FE- SEM. The DPPH assay and H2O2 scavenging assay showed 73.1% and 70.8% of anti-oxidant activity in EPsC, which is coequally efficient as standard gallic acid. EPsC biopolymer can also be used as a potential reducing agent, as per the anti-nutrient activity studies

    Cytotoxic Effect and Antioxidant Activity of Bioassay-guided Fractions from Solanum nigrum Extracts

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    Purpose: To evaluate the cytotoxic effect and antioxidant activity of bioassay-guided fractions from Malaysian species of Solanum nigrum.Methods: Methanol leaf and ethanol fruit extracts of Solanum nigrum were subjected to bioassay-guided fractionation using column chromatography. The semi-purified fractions were investigated for their in vitro cytotoxic effect against various cancer cell lines using 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay, and for antioxidant activity using 2, 2-diphenyl-1- picryhydrazyl (DPPH) assay.Results: From bioassay-guided fractionation, 13 and 17 fractions were obtained from the methanol leaf and ethanol fruit extracts, respectively. In MTT assay, fractions 1, 2 and 4 from methanol extract showed the highest cytotoxic effect against the cancer cells with IC50 of 13.0 μg/mL at 48 h incubation. For the ethanol extract, fractions 14 and 15 showed the highest cytotoxic effect with IC50 of 12.0 μg/mL against K-562 cells, while fractions 13, 14 and 17 showed IC50 of 13.0 μg/mL against HeLa cells. Doxorubicin hydrochloride and vinblastine sulfate inhibited the cancer cells with IC50 range of 1.3 to 17.0 μg/mL. The highest radical scavenging activity was exhibited by fraction 2 from methanol extract with ED50 value of 0.10 mg/ml, while fraction 15 from ethanol extract showed ED50 of 0.79 mg/mL. Ascorbic acid and α-tocopherol exhibited radical scavenging activity of 95.0 ± 0.01 % (ED50 = 0.05 mg/mL) and 93.0 ± 0.01 % (ED50 = 0.10 mg/mL), respectively.Conclusion: Solanum nigrum leaves and fruits are potential sources of cytotoxic and antioxidant agents.Keywords: Solanum nigrum, Cytotoxic Activity, Anti-oxidant Activity, Bioassay-guided Fractionation, Doxorubicin, Vinblastin

    Comparison of habitual visual acuity and stereoacuity between children attending KEMAS and urban private preschools

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    The assessment of a preschooler’s visual status is important as it forms part of the measure to assess the child’s school readiness. However, not all children attending preschools have equal opportunity to undergo vision screening programmes. In this study, we measured presenting habitual near and distance visual acuity and stereoacuity in 6-year-old children (n=385). These parameters were measured in and compared between preschoolers attending urban, privately-run kindergartens and those attending KEMAS preschools, which were typically from suburban and rural areas with families of very low income. Seven percent of KEMAS preschoolers failed the distance visual acuity test while the failure rate for private preschoolers was 6.0%. For near visual acuity, a higher percentage of private preschoolers failed the test (8.7%) than KEMAS preschoolers (4.9%). A slightly higher percentage of private preschoolers had weak stereopsis (3.3%) compared to KEMAS preschoolers (2.5%). However, the differences found between the two preschooler groups were not statistically significant (all p>0.05). The proportion of children who failed each of the screening criteria for distance vision, near vision, and stereopsis was similar between KEMAS and private preschools. Therefore, an universally inclusive vision screening programme should be conducted for all preschool types to detect, diagnose, treat, and potentially prevent any visual impairment

    Comparison of low contrast sensitivity among multi-slice CT units using various mAs setting for the potential benefit of non-MRI compatible, stereotactic radiosurgery (SRS) patients

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    Purpose: To evaluate the low contrast detectability sensitivity among 4-slice, 8-slice and 16-slice CT units using various mAs settings. Findings of the study may elucidate the most optimal imaging parameter for stereotactic radiosurgery (SRS) patients who are not MRI compatible.Methods and Materials: Low contrast targets in the CATPHAN phantom (model: CTP 504, The Phantom Laboratory) were imaged on a 4-slice LightSpeed Advantage™ GE CT scanner (GE Healthcare, WI) and a 16- slice LightSpeed Advantage™ GE CT scanner (GE Healthcare, WI) in 8-slice and 16-slice mode. The CATPHAN CTP515 low contrast targets of size 15, 9, 8, 7, 6, 5, 4, 3 and 2 mm for each contrast difference of 1%, 0.5% and 0.3% from the water-equivalent background was imaged using a SRS protocol. Two image sets per setting were acquired for mAs parameters of 300, 350 and 440. Images were evaluated in a blind study by three independent reviewers.Results: Using 300,350 and 440mAs settings on the 4-slice scanner, the average smallest diameters recorded at 1% contrast were 5 ± 1 mm, 5 ± 1 mm and 5 ± 0 mm and at 0.5% were 7 ± 2 mm, 7 ± 1 mm and 6 ± 1 mm. For the 8 - slice scanner, the average smallest diameters recorded at 1% contrast were 7 ± 0 mm, 6 ± 0 mm and 5 ± 0 mm, and at 0.5% were 12 ± 3 mm, 9 ± 1 mm and 6 ± 1 mm. For the 16 - slice scanner, the average smallest diameters recorded at 1% contrast were 7 ± 1 mm, 7 ± 1 mm and 6 ± 1 mm, and at 0.5% were 11 ± 3 mm, 8 ± 1 mm and 8 ± 1 mm. A difference was observed between the 4 and 8 - slice scanners at 300mAs (p &lt; 0.01) for each contrast level as well as the 4 and 16 slice at 440 (p &lt; 0.01) and 350 (p &lt; 0.01) mAs. Additionally, a difference was observed between each mAs for the 8 slice at 1% (p &lt; 0.01) and 0.5% (p &lt; 0.01) contrast.Conclusion: Results demonstrate consistently improved low contrast detectability as mAs was increased. CT simulation imaging parameters can be optimized to improve low contrast sensitivity for non MRI compatible SRS patients.----------------Cite this article as: Stanley D, Narayanasamy G, Breton C, Papanikolaou N, Gutierrez AN. Comparison of low contrast sensitivity among multi-slice CT units using various mAs setting for the potential benefit of non-MRI compatible, stereotactic radiosurgery (SRS) patients. Int J Cancer Ther Oncol 2014; 2(2):020237. DOI: 10.14319/ijcto.0202.37</p

    Comparison of low contrast sensitivity among multi-slice CT units using various mAs setting for the potential benefit of non-MRI compatible, stereotactic radiosurgery (SRS) patients

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    Purpose: To evaluate the low contrast detectability sensitivity among 4-slice, 8-slice and 16-slice CT units using various mAs settings. Findings of the study may elucidate the most optimal imaging parameter for stereotactic radiosurgery (SRS) patients who are not MRI compatible.Methods and Materials: Low contrast targets in the CATPHAN phantom (model: CTP 504, The Phantom Laboratory) were imaged on a 4-slice LightSpeed Advantage™ GE CT scanner (GE Healthcare, WI) and a 16- slice LightSpeed Advantage™ GE CT scanner (GE Healthcare, WI) in 8-slice and 16-slice mode. The CATPHAN CTP515 low contrast targets of size 15, 9, 8, 7, 6, 5, 4, 3 and 2 mm for each contrast difference of 1%, 0.5% and 0.3% from the water-equivalent background was imaged using a SRS protocol. Two image sets per setting were acquired for mAs parameters of 300, 350 and 440. Images were evaluated in a blind study by three independent reviewers.Results: Using 300,350 and 440mAs settings on the 4-slice scanner, the average smallest diameters recorded at 1% contrast were 5 ± 1 mm, 5 ± 1 mm and 5 ± 0 mm and at 0.5% were 7 ± 2 mm, 7 ± 1 mm and 6 ± 1 mm. For the 8 - slice scanner, the average smallest diameters recorded at 1% contrast were 7 ± 0 mm, 6 ± 0 mm and 5 ± 0 mm, and at 0.5% were 12 ± 3 mm, 9 ± 1 mm and 6 ± 1 mm. For the 16 - slice scanner, the average smallest diameters recorded at 1% contrast were 7 ± 1 mm, 7 ± 1 mm and 6 ± 1 mm, and at 0.5% were 11 ± 3 mm, 8 ± 1 mm and 8 ± 1 mm. A difference was observed between the 4 and 8 - slice scanners at 300mAs (p &lt; 0.01) for each contrast level as well as the 4 and 16 slice at 440 (p &lt; 0.01) and 350 (p &lt; 0.01) mAs. Additionally, a difference was observed between each mAs for the 8 slice at 1% (p &lt; 0.01) and 0.5% (p &lt; 0.01) contrast.Conclusion: Results demonstrate consistently improved low contrast detectability as mAs was increased. CT simulation imaging parameters can be optimized to improve low contrast sensitivity for non MRI compatible SRS patients.----------------Cite this article as: Stanley D, Narayanasamy G, Breton C, Papanikolaou N, Gutierrez AN. Comparison of low contrast sensitivity among multi-slice CT units using various mAs setting for the potential benefit of non-MRI compatible, stereotactic radiosurgery (SRS) patients. Int J Cancer Ther Oncol 2014; 2(2):020237. DOI: 10.14319/ijcto.0202.3

    Radiobiological Evaluation of Intensity Modulated Radiation Therapy Treatments of Patients with Head and Neck Cancer: A Dual-Institutional Study

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    In clinical practice, evaluation of clinical efficacy of treatment planning stems from the radiation oncologist\u27s experience in accurately targeting tumors, while keeping minimal toxicity to various organs at risk (OAR) involved. A more objective, quantitative method may be raised by using radiobiological models. The purpose of this work is to evaluate the potential correlation of OAR-related toxicities to its radiobiologically estimated parameters in simultaneously integrated boost (SIB) intensity modulated radiation therapy (IMRT) plans of patients with head and neck tumors at two institutions. Lyman model for normal tissue complication probability (NTCP) and the Poisson model for tumor control probability (TCP) models were used in the Histogram Analysis in Radiation Therapy (HART) analysis. In this study, 33 patients with oropharyngeal primaries in the head and neck region were used to establish the correlation between NTCP values of (a) bilateral parotids with clinically observed rates of xerostomia, (b) esophagus with dysphagia, and (c) larynx with dysphagia. The results of the study indicated a strong correlation between the severity of xerostomia and dysphagia with Lyman NTCP of bilateral parotids and esophagus, respectively, but not with the larynx. In patients without complications, NTCP values of these organs were negligible. Using appropriate radiobiological models, the presence of a moderate to strong correlation between the severities of complications with NTCP of selected OARs suggested that the clinical outcome could be estimated prior to treatment

    Improvement over time in outcomes for patients undergoing endoscopic therapy for Barrett's oesophagus-related neoplasia: 6-year experience from the first 500 patients treated in the UK patient registry.

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    BACKGROUND: Barrett's oesophagus (BE) is a pre-malignant condition leading to oesophageal adenocarcinoma (OAC). Treatment of neoplasia at an early stage is desirable. Combined endoscopic mucosal resection (EMR) followed by radiofrequency ablation (RFA) is an alternative to surgery for patients with BE-related neoplasia. METHODS: We examined prospective data from the UK registry of patients undergoing RFA/EMR for BE-related neoplasia from 2008 to 2013. Before RFA, visible lesions were removed by EMR. Thereafter, patients had RFA 3-monthly until all BE was ablated or cancer developed (endpoints). End of treatment biopsies were recommended at around 12 months from first RFA treatment or when endpoints were reached. Outcomes for clearance of dysplasia (CR-D) and BE (CR-IM) at end of treatment were assessed over two time periods (2008-2010 and 2011-2013). Durability of successful treatment and progression to OAC were also evaluated. RESULTS: 508 patients have completed treatment. CR-D and CR-IM improved significantly between the former and later time periods, from 77% and 56% to 92% and 83%, respectively (p<0.0001). EMR for visible lesions prior to RFA increased from 48% to 60% (p=0.013). Rescue EMR after RFA decreased from 13% to 2% (p<0.0001). Progression to OAC at 12 months is not significantly different (3.6% vs 2.1%, p=0.51). CONCLUSIONS: Clinical outcomes for BE neoplasia have improved significantly over the past 6 years with improved lesion recognition and aggressive resection of visible lesions before RFA. Despite advances in technique, the rate of cancer progression remains 2-4% at 1 year in these high-risk patients. TRIAL REGISTRATION NUMBER: ISRCTN93069556

    Engaging fringe stakeholders in business and society research: applying visual participatory research methods

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    Business and society (B&S) researchers, as well as practitioners, have been critiqued for ignoring those with less voice and power (e.g. women, non-literate or indigenous peoples) often referred to as ‘fringe stakeholders’. Existing methods used in B&S research often fail to address issues of meaningful participation, voice and power, especially in developing countries. In this article we stress the utility of visual participatory research (VPR) methods in B&S research to fill this gap. Through a case study on engaging Ghanaian cocoa farmers on gender inequality issues we explore how VPR methods may be used by researchers to achieve more inclusive, and thus more credible, stakeholder research that can improve decision-making within businesses. Furthermore, we argue that ingrained social and environmental problems tackled by B&S research and the unique context in which they occur may open up new opportunities to develop participatory visual methods for social change
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