391 research outputs found

    Sonographic evaluation of cervical lymphadenopathy; Comparison of metastatic and reactive lymph nodes in patients with head and neck squamous cell carcinoma using gray scale and doppler techniques

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    Background: Cervical lymphadenopathy could be seen in several pathologic processes. An accurate differentiation between these conditions is of utmost importance to select an appropriate therapy and assess the prognosis. Gray scale and Doppler are appropriate sonographic techniques for evaluating internal and external features of lymph nodes. Although, various criteria have been proposed to differentiate metastatic lymph nodes from benign ones, the most valuable and specific sonographic features are still under dispute. Objectives: The present study was designed to determine valuable sonographic features for differentiating metastasis from benign nodes using gray scale and Doppler sonography. Patients and Methods: A prospective diagnostic study was performed on 63 patients with head and neck squamous cell carcinoma (SCC) treated and referred to surgery clinic of Hazrat Rasoul Akram hospital from November 2010 to June 2012 with complaint of palpable cervical lymph node. All patients� necks were scanned multidirectionally by gray-scale and Doppler techniques. After sonography, lymph nodes were biopsied and investigated to find out whether they were metastatic or reactive. Finally, demographic, sonographic and pathologic data were statistically analyzed by SPSS ver. 16 software using t-test, a nonparametric test and ROC analysis. Ninety five percent confidence interval was considered for all parameters. Results: The study included 41 males and 22 females with a mean age of 57.56 ± 13.79 years. The number of metastatic lymph nodes was 47, while the remaining 16 were reactive. There were significant differences in length (P = 0.037), width (P = 0.001), resistance index (P < 0.001), pulsatility index (P < 0.001) and systolic velocity (P < 0.001) of metastatic and reactive lymph nodes. Cut points for resistive and pulsatility indexes and systolic velocity were calculated as 0.695, 1.35 and 16.5, respectively. The most valuable factor for defining a lymph node as metastatic was circulation pattern with accuracy, sensitivity and specificity of 94, 85 and 93, respectively. Conclusion: Gray scale sonography in combination with Doppler sonography could be a trustworthy technique in differentiating metastatic lymph nodes from reactive ones. Although, circulation pattern had a higher diagnostic accuracy in the present study, combination of sonographic characteristics could be more beneficial in differentiating metastatic cervical nodes from reactive ones. © 2015, Tehran University of Medical Sciences and Iranian Society of Radiology

    Bacterial Heat Shock Protein Activity

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    Bacteria are exposed to different types of stress in their growth conditions. They have developed appropriate responses, modulated by the re-modeling of protein complexes and by phosphorylation dependent signal transduction systems, to adapt and to survive in a variety range of nature. Proteins are essential components for biologic activity in the eukaryotic and prokaryotic cell. Heat Shock Proteins (HSP) have been identified from various organisms and have critical role in cell hemostasis. Chaperone can sense environment and have different potential role in the organism evolution

    The Antibacterial Effect of Low Temperature Stored Amnion on Growth of Escherichia Coli, Staphylococcus Aureus and Pseudomonas Aeruginosa

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    BACKGROUND AND OBJECTIVE: Amniotic membrane (AM) has a lot of applied properties like anti-bacterial characteristic mediated by peptides such as elafin. Because of limitations in use of freshly prepared tissue, there are various methods for long-term preservation of amniotic membrane. This study was conducted to determine the effect of cryopreservation, as one of the common methods of preservation of amniotic membrane, on its antibacterial property against the growth of commonly occurring bacteria in the clinic. METHODS: In this experimental study, the effect of fresh AM (from elective Cesarean) and cryopreserved (by 10% DMSO) AM on the growth of three standard bacterial strains including Escherichia coli ATCC 25922, Staphylococcus aureus, Pseudomonas aeruginosa and two clinical isolated strains of E.coli were evaluated using disk diffusion test. In this method, pieces of fresh or cryopreserved AM was placed in the culture plate after bacterial culturing. After incubation, the number of plates with inhibition zone and amount of inhibition zone were measured. The amount of elafin was measured in AM samples using ELISA. RESULTS: Fresh AM inhibit the growth of Pseudomonas aeruginosa and two clinical isolated strains of E.coli. However, it has no effect on the growth of standard strain of Escherichia coli and Staphylococcus aureus strain. There is no difference in the number of plates including inhibition zone between fresh and cryopreserved AM. The amount of elafin decreased significantly in cryopreserved AM (p<0.01). CONCLUSION: The results of this study showed that the anti-bacterial property of the AM depends on bacterial species. In addition, the cryopreservation process maintains anti-bacterial properties of amniotic stem cells

    Serum 25-hydroxy Vitamin D levels in patients with acne vulgaris and its association with disease severity

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    Background. Since Vitamin D is a recent known immunoregulatory factor in some diseases which are addressed in immune system disorders such as SLE, psoriasis and others. Objective. To determine the serum levels of 25-hydroxy Vitamin D3 25(OH)D in patients with acne vulgaris and its association with clinical features. Methods. This cross-sectional study was conducted over months. This study included 39 patients with acne vulgaris and 40 healthy controls. Subjects who did not use alcohol, Vitamin D supplements, oral steroids or PUVA and/or NBUVB for more than three months were included. Serum 25(OH)D levels were measured. Baseline demographics, family history and comorbidities like PCO were recorded. Statistical analyses were performed using SPSS 16.0.0. Results. The median concentration of 25(OH)D was 8.4 ng/mL (range: 1.4-99) in patients and 10.4 ng/mL (range: 3.1-56.7) in controls, with no statistical significant difference. PCOS was a significant predictor of the occurrence of acne vulgaris (OR=6.25; 95% CI: 1.52-25.66; p=0.01). There were no significant associations between severity of disease and serum 25(OH)D levels (rs=-0.12, p=0.45), age (rs=-0.28, p=0.09), BMI (rs=-0.12, p=0.46), age at onset of disease (rs=-0.08, p=0.63) and duration of disease (rs=-0.10, p=0.54). Conclusion. Based on the previous studies this is highly suspected that Vitamin D would be a prominent factor in acne patients and more performances with bigger sample size could be useful to get positive results

    Allopurinol mouthwash for prevention or alleviation radiotherapy induced oral mucositis: A randomized, placebo-controlled trial

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    Background and the purpose of the study: A randomized, double-blind, placebo-controlled trial was conducted to evaluate the effectiveness of an allopurinol mouthwash in prevention and alleviation of the oral radiotherapy induced mucositis. Methods: An allopurinol suspension mouthwash having proper physical stability at least for 6 weeks was prepared. A total of 24 patients with oral, nasopharynx or hypopharynx cancer were enrolled in the study. They were randomly allocated to receive either an allopurinol suspension or normal saline as placebo that were identical in appearance. Patients were instructed to use the suspension as a mouthwash 3 times a day for 3 minutes after beginning of each radiotherapy cycle. Patients were graded on the basis of severity of their own symptoms on a weekly basis by using WHO scale. Results: There were no differences in the severity of mucosits between the allopurinol and placebo-treated groups in first and second weeks of treatment (p =0.227, p = 0.121 respectively). In the third, fourth, fifth and sixth weeks, there were significant differences between two groups (p< 0.05 in each weeks separately). Major conclusion: Result of this study support the hypothesis that an allopurinol mouthwash may prevents or alleviate oral mucositis induced by radiotherapy

    Arylmethylene hydrazine derivatives containing 1,3-dimethylbarbituric moiety as novel urease inhibitors

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    A new series of arylmethylene hydrazine derivatives bearing 1,3-dimethylbarbituric moiety 7a�o were designed, synthesized, and evaluated for their in vitro urease inhibitory activity. All the title compounds displayed high anti-urease activity, with IC50 values in the range of 0.61 ± 0.06�4.56 ± 0.18 µM as compared to the two standard inhibitors hydroxyurea (IC50 = 100 ± 0.15 μM) and thiourea (IC50 = 23 ± 1.7 μM). Among the synthesized compounds, compound 7h with 2-nitro benzylidene group was found to be the most potent compound. Kinetic study of this compound revealed that it is a mix-mode inhibitor against urease. Evaluation of the interaction modes of the synthesized compounds in urease active site by molecular modeling revealed that that compounds with higher urease inhibitor activity (7h, 7m, 7c, 7l, 7i, and 7o, with IC50 of 0.61, 0.86, 1.2, 1.34, 1.33, 1.94 μM, respectively) could interact with higher number of residues, specially Arg609, Cys592 (as part of urease active site flap) and showed higher computed free energy, while compounds with lower urease activity (7f, 7n, 7g, and 7a with IC50 of 3.56, 4.56, 3.62 and 4.43 μM, respectively) and could not provide the proper interaction with Arg609, and Cys592 as the key interacting residues along with lower free binding energy. MD investigation revealed compound 7h interacted with Arg609 and Cys592 which are of the key residues at the root part of mobile flap covering the active site. Interacting with the mentioned residue for a significant amount of time, affects the flexibility of the mobile flap covering the active site and causes inhibition of the ureolytic activity. Furthermore, in silico physico-chemical study of compounds 7a�o predicted that all these compounds are drug-likeness with considerable orally availability. © 2021, The Author(s)

    The Antioxidant Activity of New Coumarin Derivatives

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    The antioxidant activity of two synthesized coumarins namely, N-(4,7-dioxo-2- phenyl-1,3-oxazepin-3(2H,4H,7H)-yl)-2-(2-oxo-2H-chromen-4-yloxy)acetamide 5 and N-(4-oxo-2-phenylthiazolidin-3-yl)-2-(2-oxo-2H-chromen-4-yloxy)acetamide 6 were studied with the DPPH, hydrogen peroxide and nitric oxide radical methods and compared with the known antioxidant ascorbic acid. Compounds 5 and 6 were synthesized in a good yield from the addition reaction of maleic anhydride or mercaptoacetic acid to compound 4, namely N′-benzylidene-2-(2-oxo-2H-chromen-4-yloxy)acetohydrazide. Compound 4 was synthesized by the condensation of compound 3, namely 2-(2-oxo-2H-chromen-4-yloxy) acetohydrazide, with benzaldehyde. Compound 3, however, was synthesized from the addition of hydrazine to compound 2, namely ethyl 2-(2-oxo-2H-chromen-4-yloxy)acetate, which was synthesized from the reaction of ethyl bromoacetate with 4-hydroxycoumarin 1. Structures for the synthesized coumarins 2–6 are proposed on the basis of spectroscopic evidence

    2018 Robotic Scene Segmentation Challenge

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    In 2015 we began a sub-challenge at the EndoVis workshop at MICCAI in Munich using endoscope images of ex-vivo tissue with automatically generated annotations from robot forward kinematics and instrument CAD models. However, the limited background variation and simple motion rendered the dataset uninformative in learning about which techniques would be suitable for segmentation in real surgery. In 2017, at the same workshop in Quebec we introduced the robotic instrument segmentation dataset with 10 teams participating in the challenge to perform binary, articulating parts and type segmentation of da Vinci instruments. This challenge included realistic instrument motion and more complex porcine tissue as background and was widely addressed with modifications on U-Nets and other popular CNN architectures. In 2018 we added to the complexity by introducing a set of anatomical objects and medical devices to the segmented classes. To avoid over-complicating the challenge, we continued with porcine data which is dramatically simpler than human tissue due to the lack of fatty tissue occluding many organs
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