Search results for: interferon gamma

Authors: Shishen Xie, Yingda L. Xie

Abstract:

Tuberculosis (TB) is a potentially serious infectious disease that remains a health concern. The Interferon Gamma Release Assay (IGRA) is a blood test to find out if an individual is tuberculous positive or negative. This study applies statistical analysis to the clinical data of interferon-gamma levels of seventy-three subjects who diagnosed pulmonary TB in an anti-tuberculous treatment. Data analysis is performed to determine if there is a significant decline in interferon-gamma levels for the subjects during a period of six months, and to infer if the anti-tuberculous treatment is effective.

Keywords: data analysis, interferon gamma release assay, statistical methods, tuberculosis infection

Procedia PDF Downloads 276

Authors: Yulistiani Yulistiani, Zamrotul Izzah, Lintang Bismantara, Wenny Putri Nilamsari, Arif Bachtiar, Budi Suprapti

Abstract:

Interferon-gamma (IFN-γ) and interleukin-6 (IL-6) are pro-inflammatory cytokines, which have the protective immune response against Tuberculosis (TB). Indeed, pro-inflammatory cytokines Mycobacterium tuberculosis antigen-specific CD4+ and CD8+ T cells and NK cells increase the level of production of IFN-γ, a cytokine critical for augmenting the microbicidal activity of phagocytes. On the other hand, M. tuberculosis reduces the effects of IFN-γ by inhibiting the transcription of IFN-γ- responsive genes and by inducing the secretion of IL-6, which inhibits IFN-γ signaling. Probiotics Lactobacillus sp. and Bifidobacterium sp. were known to increase IFN-γ production in vivo, while vitamin B1, B6, and B12 worked on macrophages and releasing cytokines. Therefore, the present study was to evaluate the effect of probiotics and vitamin B supplement on changes of plasma cytokine levels in active pulmonary TB. From October to November 2016, twelve M. tuberculosis-infected patients starting anti-TB drugs were recruited, then divided into two groups. Seven patients were given a combination of probiotics and vitamin B, while five patients were in the control group. Plasma IFN-γ and IL-6 levels were measured by the ELISA kit before and a month after treatment. IFN-γ levels raised in four patients receiving the supplement (P = 0.743), while IL-6 increased in three patients in this group until day 30 of treatment (P = 0.298). Taken together, these results show the promising effect of probiotics and vitamin B on stimulation of IFN-γ and IL-6 production during intensive therapy of TB.

Keywords: interferon-gamma, interleukin-6, probiotic, tuberculosis

Procedia PDF Downloads 321

Authors: Saad Khalid Niaz, Arif Mahmood Siddiqui, Afzal Haqi

Abstract:

Background: Estimated prevalence of Hepatitis C in Pakistan is 5% of which 78 % are Genotype 3, in which Response to conventional interferon is reported to be 70%. Objective: To determine the efficacy of pegylated interferon 20 kDa (Unipeg) plus ribavirin (Ribazole) in HCV genotype 3 patients who relapsed to conventional interferon. Methods: This is an ongoing study of 20 enrolled patients. Pegylated interferon alfa-2a 20 kDa 180 mcg weekly with ribavirin, were administered for a period of 24 weeks. Virological Responses were measured by Qualitative HCV RNA at weeks 4, 12, 24 and 48 to determine Rapid Virological Response (RVR), Early Virological Response (EVR), End of Treatment (ETR) and Sustained Virological Response (SVR), respectively. EVR was done for those who didn’t achieve RVR. Results: Males were 12 (60%) and mean age was 38.5 ±7.62 years. Out of 20 recruited patients, all completed 4 weeks therapy; RVR was achieved in 8 (40%) patients. One patient was lost to follow up and one yet to visit at 12 weeks. From 10 patients, 8 (80%) patients achieved EVR. Out of intent-to-treat patients, 15 completed 24 weeks therapy, ETR was achieved in 14 (93%) patients and 9 patients completed post therapy follow-up, of which, 8 (89%) patients achieved SVR. Conclusion: Our interim data demonstrates that Pegylated Interferon alfa-2a 20 kDa 180 mcg (Unipeg) in combination with Ribavirin (Ribazole) has shown promising results in treating HCV Genotype 3 patients who relapsed to conventional interferon. We recommend use of Pegylated Interferon in Relapsers with Genotype 3 when financial constraints limit the use of oral antivirals.

Keywords: pegylated interferon (unipeg), hepatitis c, relapsers, Pakistan

Procedia PDF Downloads 275

Authors: Syeda Kiran Shahzadi, Nasir Mahmood, Muhammad Abdul Qadir

Abstract:

In the current research, three recombinant human interferon alpha-2b proteins (two modified and one normal form) were produced and Pegylated with an aim to produce more effective drugs against viral infections and cancers. The modified recombinant human interferon alpha-2b proteins were produced by site-directed modifications of interferon alpha 2b gene, targeting the amino acids at positions ‘R23’ and ‘H34’. The resulting chemically modified and unmodified forms of human interferon alpha 2b were conjugated with methoxy-polyethylene glycol propanealdehyde (400 KDa) and methoxy-polyethylene glycol succinimidyl succinate (400 KDa). Pegylation of normal and modified forms of Interferon alpha-2b prolong their release time and enhance their efficacy. The conjugation of PEG with modified and unmodified human interferon alpha 2b protein drugs was also characterized with 1H-NMR, HPLC, and SDS-PAGE. Antiproliferative assays of modified and unmodified forms of drugs were performed in cell based bioassays using MDBK cell lines. The results indicated that experimentally produced recombinant human interferon alpha-2b proteins were biologically active and resulted in significant inhibition of cell growth.

Keywords: protein refolding, antiproliferative activities, biomedical applications, human interferon alpha-2b, pegylation, mPEG-propionaldehyde, site directed mutagenesis, E. coli expression

Procedia PDF Downloads 147

Authors: Muhammad Imran Hussain, Ramisha Ibtisam, Tayyaba Fatima, Huba Khalid, Ayesha Aziz, Khansa, Adan Sitara, Anam Shahzad, Aymen Jabeen

Abstract:

Vitamin D supports the immune system fight TB by inhibiting Interferon-gamma (IFN-γ) and lowering host inflammation. The purpose of the research was to see if giving the vitamin D supplements to TB patients affected their prognosis. A randomized placebo control study of 200 TB patients was performed among which 106 received 400,000 IU of injectable vitamin D3 and 94 received placebo for 2 doses. Assessment was carried out at the end of every month for 3 months. IFN-γ responses to whole blood stimulation generated by the Mycobacterium tuberculosis sonicate (MTBs) antigen and early secreted and T cell activated 6 kDa (ESAT6) were assessed at 0 and 12 weeks. The statistical analysis used descriptive statistics (mean and standard deviation), Friedman's test and Fisher's test. The vitamin D group gained significantly more weight (+3.90 pounds) and had less persistent lung disease on imaging (1.33 zones vs. 1.84 zones). They also had a 50% decrease in cavity size. Additionally, patients with low baseline serum concentrations of 25-(OH)D had a significant increase in MTB-induced IFN-γ production after taking vitamin D supplements. Vitamin D administration in large amounts can hasten the recovery of TB patients. The findings point is a therapeutically useful activity of Vitamin D's in the management for tuberculosis.

Keywords: tuberculosis, vitamin D, interferon gamma, protein, infection

Procedia PDF Downloads 14

Authors: Wen-Yu Lin, Yi-Ching Chung, Tzyy-Rong Jinn

Abstract:

It is well known that enterovirus 71 (EV71) causes recurring outbreaks of hand, foot and mouth disease (HFMD) and encephalitis leading to complications or death in young children. And, several HFMD of EV71 with high mortalities occurred in Asia countries, such as Malaysia (1997), Taiwan (1998) and China (2008). Thus, more effective antiviral drugs are needed to prevent or reduce EV71-related complications. As reported, interferon-α protects mice from lethal EV71 challenge by the modulation of innate immunity and then degrade enterovirus protease 3Cᵖʳᵒ. On the other side, pleconaril by targeting enterovirus VP1 protein and then block virus entry and attachment. Thus, the aim of this study was to evaluate the synergistic antiviral activity of interferon-α and pleconaril against enterovirus 71 infection. In a preliminary study showed that pleconaril at concentrations of 50, 100 and 300 µg/mL reduced EV71-induced CPE to 52.0 ± 2.5%, 40.2 ± 3.5% and 26.5 ± 1.5%, respectively, of that of the EV71-infected RD control cells (taken as 100%). Notably, 1000 IU/mL of interferon-α in combination with pleconaril at concentrations of 50, 100 and 300µg/mL suppressed EV71-induced CPE by 30.2 ± 3.8%, 16.5 ± 1.3% and 2.8 ± 2.0%, respectively, of that of the pleconaril alone treated with the infected RD cells. These results indicated that interferon-α 1000 IU/mL combination with pleconaril (50, 100 and 300µg/mL) inhibited EV71-induced CPE more effectively than treated with pleconaril alone in the infected RD cells.

Keywords: enterovirus 71, interferon-α, pleconaril, RD cells

Procedia PDF Downloads 112

Authors: Muhammad Sameer Ahmed, Piotr Remlein, Tansal Gucluoglu

Abstract:

The technique called as Generalized frequency division multiplexing (GFDM) used in the free space optical channel can be a good option for implementation free space optical communication systems. This technique has several strengths e.g. good spectral efficiency, low peak-to-average power ratio (PAPR), adaptability and low co-channel interference. In this paper, the impact of weather conditions such as haze, rain and fog on GFDM over the gamma-gamma channel model is discussed. A Trade off between link distance and system performance under intense weather conditions is also analysed. The symbol error probability (SEP) of GFDM over the gamma-gamma turbulence channel is derived and verified with the computer simulations.

Keywords: free space optics, generalized frequency division multiplexing, weather conditions, gamma gamma distribution

Procedia PDF Downloads 142

Authors: F. Abbas Pour Khotbehsara, B. Salehpour, A. Kianvash

Abstract:

Many industrial materials like magnets need to be tested for the radiation environment expected at linear colliders (LC) where the accelerator and detectors will be subjected to large influences of beta, neutron and gamma’s over their life Gamma irradiation of the permanent sample magnets using a 60Co source was investigated up to an absorbed dose of 700Mrad shows a negligible effect on some magnetic properties of Nd-Fe-B. In this work, it has been tried to investigate the change of some important properties of Barium hexa ferrite. Results showed little decreases of magnetic properties at doses rang of 0.5 to 2.5 Mrad. But at the gamma irradiation dose up to 10 Mrad it is showed a few increase of properties. Also study of gamma irradiation of Nd-Fe-B showed considerably increase of magnetic properties.

Keywords: gamma ray irradiation, hard ferrite, magnetic coefficient, magnetic material, radiation dose

Procedia PDF Downloads 211

Authors: Jibon Sharma, Alakjyoti Patowary, Moirangthem Nara Singh

Abstract:

In experimental research it is very much essential to obtain the quality control of the system used for the experiment. NaI (Tl) scintillation detector is the most commonly used in radiation and medical physics for measurement of the gamma ray activity of various samples. In addition, the scintillation detector has a lot of applications in the elemental analysis of various compounds, alloys using activation analysis. In each application for quantitative analysis, it is very much essential to know the detection efficiency and resolution for different gamma energies. In this work, the energy dependence of efficiency and resolution of NaI (Tl) detector using gamma-ray spectroscopy are investigated. Different photon energies of 356.01 keV,511keV,661.60keV,1170 keV,1274.53 keV and 1330 keV are obtained from four radioactive sources (133Ba,22Na,137Cs and 60 Co) used in these studies. Values of full energy peak efficiencies of these gamma energies are found to be respectively 58.46%,10.15%,14.39%,1.4%,3.27% and 1.31%. The values of percent resolution for above different gamma ray energies are found to be 11.27%,7.27%,6.38%,5.17%,4.86% and 4.74% respectively. It was found that the efficiency of the detector exponentially decreases with energy and the resolution of the detector is directly proportional to the energy of gamma-ray.

Keywords: naI (Tl) gamma-ray spectrometer, resolution, full energy peak efficiency, radioactive sources

Procedia PDF Downloads 77

Authors: Abeer N. Alshukairi, Abdulrahman A. Alrajhi, Abdulfattah W. Alamri, Adel F. Alothman

Abstract:

We described the nosocomial transmission of a pre-XDR or an MDR case of pulmonary tuberculosis in a HIV negative health care worker in an area endemic for MDR & XDR tuberculosis. With inadequate therapy and non-compliance, his strain developed acquired resistance and he presented with extra-pulmonary XDR tuberculosis in the form of multi-focal osteomyelitis and encysted pleural effusion. He was cured after 2 years of therapy with various anti-tuberculous drugs in addition to interferon gamma.

Keywords: osteomyelitis, treatment, XDR tuberculosis, successful treatment

Procedia PDF Downloads 444

Authors: Azuraida Amat, Halimah Mohamed Kamari, Che Azurahanim Che Abdullah, Ishak Mansor

Abstract:

The changes of the optical and structural properties of Bismuth-Boro-Tellurite glasses pre and post gamma irradiation were studied. Six glass samples, with different compositions [(TeO2)0.7 (B2O3)0.3]1-x (Bi2O3)x prepared by melt quenching method were irradiated with 25kGy gamma radiation at room temperature. The Fourier Transform Infrared Spectroscopy (FTIR) was used to explore the structural bonding in the prepared glass samples due to exposure, while UV-VIS Spectrophotometer was used to evaluate the changes in the optical properties before and after irradiation. Gamma irradiation causes a profound changes in the peak intensity as shown by FTIR spectra which is due to the breaking of the network bonding. Before gamma irradiation, the optical band gap, Eg value decreased from 2.44 eV to 2.15 eV with the addition of Bismuth content. The value kept decreasing (from 2.18 eV to 2.00 eV) following exposure to gamma radiation due to the increase of non-bridging oxygen (NBO) and the increase of defects in the glass. In conclusion, the glass with high content of Bi2O3 (0.30Bi) give the smallest Eg and show less changes in FTIR spectra after gamma irradiation, which indicate that this glass is more resistant to gamma radiation compared to other glasses.

Keywords: boro-tellurite, bismuth, gamma radiation, optical properties

Procedia PDF Downloads 392

Authors: Samira Berenji Ardestani, Hamid Reza Akhavan

Abstract:

Gamma irradiation greatly reduces the potential microbiological risk of fresh fruits, resulting in improved microbial safety as well as extending their shelf life. The effects of 0.5-2 kGy gamma doses on some physicochemical, microbial and sensory properties of fresh barberry fruits (Berberis vulgaris) during refrigerated storage for 40 days were evaluated. The total anthocyanin and total phenolic contents of barberry fruits decreased in a dose-dependent manner immediately after irradiation and after subsequent storage. In general, it is recommended that, according to the effect of gamma radiation on physicochemical, microbial and sensorial characteristics, doses of 1.25-2 kGy could be used.

Keywords: antioxidant property, barberry fruit, chemical properties, gamma irradiation

Procedia PDF Downloads 246

Authors: Young Gil Kim, Hye Min Park, Chan Jong Park, Koan Sik Joo

Abstract:

A personal gamma spectrometer has to be sensitive, pocket-sized, and carriable on the users. To serve these requirements, we developed the SiPM-based portable radiation detectors. The prototype uses a Ce:GAGG scintillator coupled to a silicon photomultiplier and a radio frequency(RF) module to measure gamma-ray, and can be accessed wirelessly or remotely by mobile equipment. The prototype device consumes roughly 4.4W, weighs about 180g (including battery), and measures 5.0 7.0. It is able to achieve 5.8% FWHM energy resolution at 662keV.

Keywords: Ce:GAGG, gamma-ray, radio frequency, silicon photomultiplier

Procedia PDF Downloads 300

Authors: Hechmi Saidi, Noureddine Hamdi

Abstract:

The performance of hybrid amplify and forward - decode and forward (AF-DF) hybrid radio frequency/free space optical (RF/FSO) communication system, that adopts M-ary pulse position modulation (MPPM) techniques, is analyzed. Both exact and approximate symbol-error rates (SERs) are derived. The random variations of the received optical irradiance, produced by the atmospheric turbulence, is modeled by the gamma-gamma (GG) statistical distribution. A closed-form expression for the probability density function (PDF) is derived for the whole above system is obtained. Thanks to the use of hybrid AF-DF hybrid RF/FSO configuration and MPPM, the effects of atmospheric turbulence is mitigated; hence the capacity of combating atmospheric turbulence and the transmissitted signal quality are improved.

Keywords: free space optical, gamma gamma channel, radio frequency, decode and forward, error pointing, M-ary pulse position modulation, symbol error rate

Procedia PDF Downloads 254

Authors: Hechmi Saidi, Noureddine Hamdi

Abstract:

The performance of Decode and Forward (DF) multihop Free Space Optical ( FSO) scheme deploying Multiple Input Multiple Output (MIMO) configuration under Gamma-Gamma (GG) statistical distribution, that adopts M-ary Pulse Position Modulation (MPPM) coding, is investigated. We have extracted exact and estimated values of Symbol-Error Rates (SERs) respectively. A closed form formula related to the Probability Density Function (PDF) is expressed for our designed system. Thanks to the use of DF multihop MIMO FSO configuration and MPPM signaling, atmospheric turbulence is combatted; hence the transmitted signal quality is improved.

Keywords: free space optical, multiple input multiple output, M-ary pulse position modulation, multihop, decode and forward, symbol error rate, gamma-gamma channel

Procedia PDF Downloads 173

Authors: K. Sowri Babu, P. Srinath, N. Rajeswara Rao, K. Venugopal Reddy

Abstract:

The effect of gamma ray irradiation on morphology and optical properties of ZnO/Mesoporous silica (MPS) nanocomposite was studied. The ZnO/MPS nanocomposite was irradiated with gamma rays of doses 30, 60, and 90 kGy and dose-rate of irradiation was 0.15 kGy/hour. Irradiated samples are characterized with FE-SEM, FT-IR, UV-vis, and Photoluminescence (PL) spectrometers. SEM pictures showed that morphology changed from spherical to flake like morphology. UV-vis analysis showed that the band gap increased with increase of gamma ray irradiation dose. This enhancement of the band gap is assigned to the depletion of oxygen vacancies with irradiation. The intensity of PL peak decreased gradually with increase of gamma ray irradiation dose. The decrease in PL intensity is attributed to the decrease of oxygen vacancies at the interface due to poor interface and improper passivation between ZnO/MPS.

Keywords: ZnO nanoparticles, nanocomposites, mesoporous silica, photoluminescence

Procedia PDF Downloads 199

Authors: Masaki Yamaguchi, Daimei Sasayama, Shinsuke Washizuka

Abstract:

The goal of this study was to examine the possibility of salivary cytokines for the screening of attention deficit hyperactivity disorder (ADHD) in children. We carried out a case-control study, including 19 children with ADHD and 17 healthy children (controls). A multiplex bead array immunoassay was used to conduct a multi-analysis of 27 different salivary cytokines. Six salivary cytokines (interleukin (IL)-1β, IL-8, IL12p70, granulocyte colony-stimulating factor (G-CSF), interferon gamma (IFN-γ), and vascular endothelial growth factor (VEGF)) were significantly associated with the presence of ADHD (p < 0.05). An informative salivary cytokine panel was developed using VEGF by logistic regression analysis (odds ratio: 0.251). Receiver operating characteristic analysis revealed that assessment of a panel using VEGF showed “good” capability for discriminating between ADHD patients and controls (area under the curve: 0.778). ADHD has been hypothesized to be associated with reduced cerebral blood flow in the frontal cortex, due to reduced VEGF levels. Our study highlights the possibility of utilizing differential salivary cytokine levels for point-of-care testing (POCT) of biomarkers in children with ADHD.

Keywords: cytokine, saliva, attention deficit hyperactivity disorder, child

Procedia PDF Downloads 101

Authors: Sukumar Namineni, Tracy O'Connor, Ulrich Kalinke, Percy Knolle, Mathias Heikenwaelder

Abstract:

The liver is one of the pivotal organs in vertebrate animals, serving a multitude of functions such as metabolism, detoxification and protein synthesis and including a predominant role in innate immunity. The innate immune mechanisms pertaining to liver in controlling viral infections have largely been attributed to the Kupffer cells, the locally resident macrophages. However, all the cells of liver are equipped with innate immune functions including, in particular, the hepatocytes. Hence, our aim in this study was to elucidate the innate immune contribution of hepatocytes in viral clearance using mice lacking Ikkβ specifically in the hepatocytes, termed IkkβΔᴴᵉᵖ mice. Blockade of Ikkβ activation in IkkβΔᴴᵉᵖ mice affects the downstream signaling of canonical NF-κB signaling by preventing the nuclear translocation of NF-κB, an important step required for the initiation of innate immune responses. Interestingly, infection of IkkβΔᴴᵉᵖ mice with lymphocytic choriomeningitis virus (LCMV) led to strongly increased hepatic viral titers – mainly confined in clusters of infected hepatocytes. This was due to reduced interferon stimulated gene (ISG) expression during the onset of infection and a reduced CD8+ T-cell-mediated response. Decreased ISG production correlated with increased liver LCMV protein and LCMV in isolated hepatocytes from IkkβΔᴴᵉᵖ mice. A similar phenotype was found in LCMV-infected mice lacking interferon signaling in hepatocytes (IFNARΔᴴᵉᵖ) suggesting a link between NFkB and interferon signaling in hepatocytes. We also observed a failure of interferon-mediated inhibition of HBV replication in HepaRG cells treated with NF-kB inhibitors corroborating our initial findings with LCMV infections. Collectively, these results clearly highlight a previously unknown and influential role of hepatocytes in the induction of innate immune responses leading to viral clearance during a systemic viral infection with LCMV-WE.

Keywords: CD8+ T cell responses, innate immune mechanisms in the liver, interferon signaling, interferon stimulated genes, NF-kB signaling, viral clearance

Procedia PDF Downloads 165

Authors: Ghaleb Bin Huraib

Abstract:

Atopic dermatitis (AD), also known as atopic eczema, is a chronic inflammatory skin disease characterized by severe itching and recurrent, relapsing eczema-like skin lesions, affecting up to 20% of children and 10% of adults in industrialized countries. AD is a complex multifactorial disease, and its exact etiology and pathogenesis have not been fully elucidated. The aim of this study was to investigate the impact of gene polymorphisms of T helper cell subtype Th1 and Th2 cytokines, interferon-gamma (IFN-γ), interleukin-6 (IL-6) and transforming growth factor (TGF)-β1on AD susceptibility in a Saudi cohort. One hundred four unrelated patients with AD and 195 healthy controls were genotyped for IFN-γ (874A/T), IL-6 (174G/C) and TGF-β1 (509C/T) polymorphisms using ARMS-PCR and PCR-RFLP technique. The frequency of genotypes AA and AT of IFN-γ (874A/T) differed significantly among patients and controls (P 0.001). The genotype AT was increased while genotype AA was decreased in AD patients as compared to controls. AD patients also had a higher frequency of T-containing genotypes (AT+TT) than controls (P = 0.001). The frequencies of alleles T and A were statistically different in patients and controls (P = 0.04). The frequencies of genotype GG and allele G of IL-6 (174G/C) were significantly higher, while genotype GC and allele C were lower in AD patients than in controls. There was no significant difference in the frequencies of alleles and genotypes of TGF-β1 (509C/T) polymorphism between the patient and control groups. These results showed that susceptibility to AD is influenced by the presence or absence of genotypes of IFN-γ (874A/T) and IL-6 (174G/C) polymorphisms. It is concluded T-allele and T-containing genotypes (AT+TT) of IFN-γ (874A/T) and G-allele and GG genotype ofIL-6 (174G/C) polymorphisms are susceptible to AD in Saudis. On the other hand, the TGF-β1 (509C/T) polymorphism may not be associated with AD risk in our population; however, further studies with large sample sizes are required to confirm these results.

Keywords: atopic dermatitis, Polymorphism, Interferon, IL-6

Procedia PDF Downloads 37

Authors: Pui Hong Chung, Wing Chi Ho, Jun Li, Cyrus Leung, Ek Yeoh

Abstract:

Background: Cigarette smoking is associated with poor tuberculosis (TB) outcomes in terms of progression of active TB, relapse of TB and TB-related mortality, but the association with latent tuberculosis infection (LTBI) is unclear. The systematic review conducted aimed at studying the association between active smoking and LTBI, and likelihood of dose-response relationship. Methods: Two independent reviewers searched three electronic databases comprising PudMed, Medline by EBSCOHOST, ExcerptaMedica Database (EMBASE), from inception up to 31st Dec 2015 for studies reporting data on current smoking and the LTBI with tuberculin skin test (TST) or interferon-γ release assays (IGRAs) results, comparing the odds ratios (ORs) of outcome measure of TST or IGRAs among current smokers with 95% confidence intervals (CI). Results: Seven studies were identified, including six cross-sectional studies and one longitudinal cohort study. The outcome measures from three studies were in TST, three studies in IGRAs and one for both tests. For TST, OR ranging from 1.39 to 3.40 (95% CI) with all studies shown positive association between cigarette smoking and LTBI. For IGRAs, OR ranging from 0.47 to 1.89 (95% CI) with one study shown the negative association that might be related to impaired interferon-gamma production in immunosuppressive persons. One identified study demonstrated positive dose-response relationship in TST result. Conclusions: Cigarette smoking is likely to be a risk factor of LTBI. There is the important implication for TB and tobacco control program to halt TB by empowering public health policy. Further study is also needed to provide more evidence of the dose-response model/relationship.

Keywords: latent tuberculosis infection, systematic review, active smoking, model

Procedia PDF Downloads 223

Authors: Ghaleb Bin Huraib, Fahad Al Harthi, Misbahul Arfin, Abdulrahman Al-Asmari

Abstract:

Atopic dermatitis (AD), also known as atopic eczema, is a chronic inflammatory skin disease characterized by severe itching and recurrent relapsing eczema-like skin lesions, affecting up to 20% of children and 10% of adults in industrialized countries. AD is a complex multifactorial disease, and its exact etiology and pathogenesis have not been fully elucidated. The aim of this study was to investigate the impact of gene polymorphisms of T helper cell subtype Th1 and Th2 cytokines, interferon-gamma (IFN-γ), interleukin-6 (IL-6) and transforming growth factor (TGF)-β1on AD susceptibility in a Saudi cohort. One hundred four unrelated patients with AD and 195 healthy controls were genotyped for IFN-γ (874A/T), IL-6 (174G/C) and TGF-β1 (509C/T) polymorphisms using ARMS-PCR and PCR-RFLP technique. The frequency of genotypes AA and AT of IFN-γ (874A/T) differed significantly among patients and controls (P 0.001). The genotype AT was increased while genotype AA was decreased in AD patients as compared to controls. AD patients also had higher frequency of T containing genotypes (AT+TT) than controls (P = 0.001). The frequencies of allele T and A were statistically different in patients and controls (P = 0.04). The frequencies of genotype GG and allele G of IL-6 (174G/C) were significantly higher while genotype GC and allele C were lower in AD patients than controls. There was no significant difference in the frequencies of alleles and genotypes of TGF-β1 (509C/T) polymorphism between patient and control groups. These results showed that susceptibility to AD is influenced by presence or absence of genotypes of IFN-γ (874A/T) and IL-6 (174G/C) polymorphisms. It is concluded that T-allele and T-containing genotypes (AT+TT) of IFN-γ (874A/T) and G-allele and GG genotype ofIL-6 (174G/C) polymorphisms are susceptible to AD in Saudis.On the other hand, the TGF-β1 (509C/T) polymorphism may not be associated with AD risk in Saudi population however further studies with large sample size are required to confirm these findings.

Keywords: atopic dermatitis, interferon-γ, interleukin-6, transforming growth factor-β1, polymorphism

Procedia PDF Downloads 76

Authors: Carlos G. Santos, Frederico A. Genezini, A. P. Dos Santos, H. Yorivaz, P. T. D. Siqueira

Abstract:

The Prompt-Gamma Activation Analysis (PGAA) is a valuable technique for investigating the elemental composition of various samples. However, the installation of a PGAA system entails specific conditions such as filtering the neutron beam according to the target and providing adequate shielding for both users and detectors. These requirements incur substantial costs, exceeding $100,000, including manpower. Nevertheless, a cost-effective approach involves leveraging an existing neutron beam facility to create a hybrid system integrating PGAA and Neutron Tomography (NT). The IEA-R1 nuclear reactor at IPEN/USP possesses an NT facility with suitable conditions for adapting and implementing a PGAA device. The NT facility offers a thermal flux slightly colder and provides shielding for user protection. The key additional requirement involves designing detector shielding to mitigate high gamma ray background and safeguard the HPGe detector from neutron-induced damage. This study employs Monte Carlo simulations with the MCNP6 code to optimize the collimator plug for PGAA within the IEA-R1 NT facility. Three collimator models are proposed and simulated to assess their effectiveness in shielding gamma and neutron radiation from nucleon fission. The aim is to achieve a focused prompt-gamma signal while shielding ambient gamma radiation. The simulation results indicate that one of the proposed designs is particularly suitable for the PGAA-NT hybrid system.

Keywords: MCNP6.1, neutron, prompt-gamma ray, prompt-gamma activation analysis

Procedia PDF Downloads 30

Authors: A. Amar

Abstract:

Analysis of the elastic scattering of protons on ¹⁰B nuclei has been done in the framework of the optical model and single folding model at the beam energies up to 17 MeV. We could enhance the optical potential parameters using Esis88 Code, as well as SPI GENOA Code. Linear relationship between volume real potential (V₀) and proton energy (E_p) has been obtained. Also, surface imaginary potential W_D is proportional to the proton energy (E_p) in the range 0.400 and 17 MeV. The radiative reaction ¹⁰B(p,γ)¹¹C has been analyzed using potential model. A comparison between ¹⁰B(p,γ)¹¹C and ⁶Li(p,γ)⁷Be has been made. Good agreement has been found between theoretical and experimental results in the whole range of energy. The radiative resonance reaction ⁷Li(p,γ)⁸Be has been studied.

Keywords: elastic scattering of protons on 10B nuclei, optical potential parameters, potential model, radiative reaction

Procedia PDF Downloads 181

Authors: Hani Baek, Gwang Min Sun, Chansun Shin, Sung Ho Ahn

Abstract:

Fast neutron irradiation using nuclear reactors is an effective method to improve switching loss and short circuit durability of power semiconductor (insulated gate bipolar transistors (IGBT) and insulated gate transistors (IGT), etc.). However, not only fast neutrons but also thermal neutrons, epithermal neutrons and gamma exist in the nuclear reactor. And the electrical properties of the IGBT may be deteriorated by the irradiation of gamma. Gamma irradiation damages are known to be caused by Total Ionizing Dose (TID) effect and Single Event Effect (SEE), Displacement Damage. Especially, the TID effect deteriorated the electrical properties such as leakage current and threshold voltage of a power semiconductor. This work can confirm the effect of the gamma irradiation on the electrical properties of 600 V NPT-IGBT. Irradiation of gamma forms lattice defects in the gate oxide and Si-SiO₂ interface of the IGBT. It was confirmed that this lattice defect acts on the center of the trap and affects the threshold voltage, thereby negatively shifted the threshold voltage according to TID. In addition to the change in the carrier mobility, the conductivity modulation decreases in the n-drift region, indicating a negative influence that the forward voltage drop decreases. The turn-off delay time of the device before irradiation was 212 ns. Those of 2.5, 10, 30, 70 and 100 kRad(Si) were 225, 258, 311, 328, and 350 ns, respectively. The gamma irradiation increased the turn-off delay time of the IGBT by approximately 65%, and the switching characteristics deteriorated.

Keywords: NPT-IGBT, gamma irradiation, switching, turn-off delay time, recombination, trap center

Procedia PDF Downloads 127

Authors: Priyanka R. Oberoi, Chandra B. Maurya, Prakash A. Mahanwar

Abstract:

Ionizing radiation can cause a drastic change in the physical and chemical properties of the material exposed. Numerous medical devices are sterilized by ionizing radiation. In the current research paper, an attempt was made to develop precise and inexpensive polymeric film dosimeter which can be used for controlling radiation dosage. Polymeric film containing (pH sensitive dye) indicator dye Bromophenol blue (BPB) was casted to check the effect of Gamma radiation on its optical and physical properties. The film was exposed to gamma radiation at 4 kGy/hr in the range of 0 to 300 kGy at an interval of 50 kGy. Release of vinyl acetate from an emulsion on high radiation reacts with the BPB fading the color of the film from blue to light blue and then finally colorless, indicating a change in pH from basic to acidic form. The change was characterized by using CIE l*a*b*, ultra-violet spectroscopy and FT-IR respectively.

Keywords: bromophenol blue, dosimeter, gamma radiation, polymer

Procedia PDF Downloads 256

Authors: Thomais Tsoulia, Arvind Y. M. Sundaram, Stine Braaen, Øyvind Haugland, Espen Rimstad, Øystein Wessel, Maria K. Dahle

Abstract:

Fish red blood cells (RBC) are nucleated, and in addition to their function in gas exchange, they have been characterized as mediators of immune responses. Salmonid RBC are the major target cells of Piscineorthoreovirus (PRV), a virus associated with heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon. The activation of antiviral response genesin RBChas previously been described in ex vivo and in vivo PRV-infection models, but not explored in the initial virus encounter phase. In the present study, mRNA transcriptome responses were explored in erythrocytes from individual fish, kept ex vivo, and exposed to purified PRV for 24 hours. The responses were compared to responses in macrophage-like salmon head kidney (SHK-1) and endothelial-like Atlantic salmon kidney (ASK) cells, none of which support PRV replication. The comparative analysis showed that the antiviral response to PRV was strongest in the SHK-1 cells, with a set of 80 significantly induced genes (≥ 2-fold upregulation). In RBC, 46 genes were significantly upregulated, while ASK cells were not significantly responsive. In particular, the transcriptome analysis of RBC revealed that PRV significantly induced interferon regulatory factor 1 (IRF1) and interferon-induced protein with tetratricopeptide repeats 5-like (IFIT9). However, several interferon-regulated antiviral genes which have previously been reported upregulated in PRV infected RBC in vivo (myxovirus resistance (Mx), interferon-stimulated gene 15 (ISG15), toll-like receptor 3 (TLR3)), were not significantly induced after 24h of virus stimulation. In contrast to RBC, these antiviral response genes were significantly upregulated in SHK-1. These results confirm that RBC are involved in the innate immune response to viruses, but with a delayed antiviral response compared to SHK-1. A notable difference is that interferon regulatory factor 1 (IRF-1) is the most strongly induced gene in RBC, but not among the significantly induced genes in SHK-1. Putative differences in the binding, recognition, and response to PRV, and any link to effects on the ability of PRV to replicate remains to be explored.

Keywords: antiviral responses, atlantic salmon, piscine orthoreovirus-1, red blood cells, RNA-seq

Procedia PDF Downloads 155

Authors: S. Nouri

Abstract:

In this study, the Si-aluminide coating was prepared on gamma-TiAl [Ti-45Al-2Nb-2Mn-1B (at. %)] via liquid-phase slurry procedure. The high temperature oxidation resistance of this diffusion coating was evaluated at 1100 °C for 400 hours. The results of the isothermal oxidation showed that the formation of Si-aluminide coating can remarkably improve the high temperature oxidation of bare gamma-TiAl alloy. The identification of oxide scale microstructure showed that the formation of protective Al₂O₃+SiO₂ mixed oxide scale along with a continuous, compact and uniform layer of Ti₅Si₃ beneath the surface oxide scale can act as an oxygen diffusion barrier during the high temperature oxidation. The other possible mechanisms related to the formation of Si-aluminide coating and oxide scales were also discussed.

Keywords: Gamma-TiAl alloy, high temperature oxidation, Si-aluminide coating, slurry procedure

Procedia PDF Downloads 146

Authors: Chodidjah, Edi Dharmana, Hardhono, Sarjadi

Abstract:

Breast cancer treatment options including surgery, radiation therapy, chemotherapy, and immunotherapy have not been effective. Besides, they have side effects. Keladi Tikus (Typhonium flagelliforme) has been shown to improve immune system, suppress tumor growth and induce apoptosis. One of the parameters for immune system, tumor growth and apoptosis is IFNγ (Interferon γ), VEGF (Vascular Endothelial Growth Factor) and Caspase 3 respectively. The aim of this study was to examine the effect of the administration of Keladi Tikus tuber extract at the dose of 200 mg/kgBW, 400 mg/KgBW, and 800 mg/kgBW on the level of IFNγ, VEGF and caspase 3 expression. In this experimental study using post test randomized control group design, 24 CH3 mice with tumor were randomly divided into 4 groups including control group and treated groups: Treated with 0.2 cc extract of Keladi Tikus at the dose of 200 mg/kgBW, 400 mg/kgBW, 800 mg/kgBW, respectively for 30 days. On day 31 the lymphatic tissue was taken and evaluated for its level of IFNγ, using ELISA. The tumor tissue was taken and subjected to immunohistochemistry staining for VEGF and caspase 3 expression evaluation. The data on IFNγ, VEGF and Caspase 3 expression were analyzed using One Way Anova with significant level of 0.05. One Way Anova resulted in p<0.05. LSD test showed that the level of IFNγ and Caspase 3 for control group was different from that of treated groups. There was no significant different between the treated group of 400 mg/KgBW and 800mg/KgBW. VEGF expressions for all the treated groups were significant. In conclusion, the oral administration of ethanolic extract of Keladi Tikus (Typhonium flagelliforme) at the dose of 200mg/kgBW, 400 mg/kgBW,800 mg/kgBW increases IFNγ, Caspase 3 and decreases VEGF expression in C3H mice with adenocarsinoma mamma.

Keywords: Typhonium flagelliforme, IFNγ, caspase 3, VEGF

Procedia PDF Downloads 400

Authors: Shoroog Alraddadi

Abstract:

In this study, the effect of gamma irradiation on the structural and transport properties of Bismuth Telluride (Bi₂Te₃) thin films was investigated. Bi₂Te₃ thin films with thicknesses varying from 100 nm to 500 nm were grown using thermal evaporation in vacuum 10⁻⁵ Torr. The films were irradiated by Gamma radiation with different doses (50, 200, and 500 kGy). The crystal structure of Bi₂Te₃ thin films was studied by XRD diffraction. It was showed that the degree of crystallinity of films increases as the doses increase. Furthermore, it was found that the electrical conductivity of Bi₂Te₃ increase as the doses increase. From these results, it can be concluding that the effect of radiation on the structural and transport properties was positive at the levels of irradiation used.

Keywords: bismuth telluride, gamma irradiation, thin film, transport properties

Procedia PDF Downloads 121

Authors: J. Constanzo, B. Paquette, G. Charest, L. Masson-Côté, M. Guillot

Abstract:

Targeted and whole-brain irradiation in humans can result in significant side effects causing decreased patient quality of life. To adequately investigate structural and functional alterations after stereotactic radiosurgery, preclinical studies are needed. The first step is to establish a robust standardized method of targeted irradiation on small regions of the rat brain. Eleven euthanized male Fischer rats were imaged in a stereotactic bed, by computed tomographic (CT), to estimate positioning variations regarding to the bregma skull reference point. Using a rat brain atlas and the stereotactic bregma coordinates assessed from CT images, various regions of the brain were delimited and a treatment plan was generated. A dose of 37 Gy at 30% isodose which corresponds to 100 Gy in 100% of the target volume (X = 98.1; Y = 109.1; Z = 100.0) was set by Leksell Gamma Plan using sectors number 4, 5, 7, and 8 of the Gamma Knife unit with the 4-mm diameter collimators. Effects of positioning accuracy of the rat brain on the dose deposition were simulated by Gamma Plan and validated with dosimetric measurements. Our results showed that 90% of the target volume received 110 ± 4.7 Gy and the maximum of deposited dose was 124 ± 0.6 Gy, which corresponds to an excellent relative standard deviation of 0.5%. This dose deposition calculated with the Gamma Plan was validated with the dosimetric films resulting in a dose-profile agreement within 2%, both in X- and Z-axis,. Our results demonstrate the feasibility to standardize the irradiation procedure of a small volume in the rat brain using a Gamma Knife.

Keywords: brain irradiation, dosimetry, gamma knife, small-animal irradiation, stereotactic radiosurgery (SRS)

Procedia PDF Downloads 379