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2.
Cognit Comput ; 13(4): 873-881, 2021.
Article in English | MEDLINE | ID: mdl-33680210

ABSTRACT

Coronavirus disease (COVID-19) has infected over more than 28.3 million people around the globe and killed 913K people worldwide as on 11 September 2020. With this pandemic, to combat the spreading of COVID-19, effective testing methodologies and immediate medical treatments are much required. Chest X-rays are the widely available modalities for immediate diagnosis of COVID-19. Hence, automation of detection of COVID-19 from chest X-ray images using machine learning approaches is of greater demand. A model for detecting COVID-19 from chest X-ray images is proposed in this paper. A novel concept of cluster-based one-shot learning is introduced in this work. The introduced concept has an advantage of learning from a few samples against learning from many samples in case of deep leaning architectures. The proposed model is a multi-class classification model as it classifies images of four classes, viz., pneumonia bacterial, pneumonia virus, normal, and COVID-19. The proposed model is based on ensemble of Generalized Regression Neural Network (GRNN) and Probabilistic Neural Network (PNN) classifiers at decision level. The effectiveness of the proposed model has been demonstrated through extensive experimentation on a publicly available dataset consisting of 306 images. The proposed cluster-based one-shot learning has been found to be more effective on GRNN and PNN ensembled model to distinguish COVID-19 images from that of the other three classes. It has also been experimentally observed that the model has a superior performance over contemporary deep learning architectures. The concept of one-shot cluster-based learning is being first of its kind in literature, expected to open up several new dimensions in the field of machine learning which require further researching for various applications.

3.
Asian Pac J Cancer Prev ; 22(2): 523-530, 2021 Feb 01.
Article in English | MEDLINE | ID: mdl-33639669

ABSTRACT

BACKGROUND: Early diagnosis of a brain tumor is important for improving the treatment possibilities. Manually segmenting the tumor from the volumetric data is time-consuming, and the visualization of the tumor is rather challenging. METHODS: This paper proposes a user-guided brain tumour segmentation from MRI (Magnetic Resonance Imaging) images developed using Medical Imaging Interaction Toolkit (MITK) and printing the segmented object using the 3D printer for tumour quantification. The proposed method includes segmenting the tumour interactively using connected threshold method, then printing the physical object from the segmented volume of interest. Then the distance between two voxels was measured using electronic callipers on the 3D volume in a specific direction. And next, the same distance was measured in the same direction on the 3D printed object. RESULTS: The technique was tested with n=5 samples (20 readings) of brain MRI images from RIDER Neuro MRI dataset of National Cancer Institute. MITK provides various tools that enable image visualization, registration, and contouring. We were able to achieve the same measurements using both the approaches and this has been tested statistically with paired t-test method. Through this and the observer's opinion, the accuracy of the segmentation was proved. CONCLUSION: When the difference in measurement of tumor volume through the electronic calipers and with 3D printed object equates to zero, proves that the segmentation technique is accurate. This helps to delineate the tumor more accurately during radio therapy.


Subject(s)
Brain Neoplasms/diagnostic imaging , Glioblastoma/diagnostic imaging , Imaging, Three-Dimensional , Magnetic Resonance Imaging , Printing, Three-Dimensional , Algorithms , Brain Neoplasms/pathology , Glioblastoma/pathology , Humans , Reproducibility of Results , Tumor Burden
4.
Asian Pac J Cancer Prev ; 22(2): 537-546, 2021 Feb 01.
Article in English | MEDLINE | ID: mdl-33639671

ABSTRACT

BACKGROUND: Obtaining the right image dataset for the medical image research systematically is a tedious task. Anatomy segmentation is the key step before extracting the radiomic features from these images. OBJECTIVE: The purpose of the study was to segment the 3D colon from CT images and to measure the smaller polyps using image processing techniques. This require huge number of samples for statistical analysis. Our objective was to systematically classify and arrange the dataset based on the parameters of interest so that the empirical testing becomes easier in medical image research. MATERIALS AND METHODS: This paper discusses a systematic approach of data collection and analysis before using it for empirical testing. In this research the image were considered from National Cancer Institute (NCI). TCIA from NCI has a vast collection of diagnostic quality images for the research community. These datasets were classified before empirical testing of the research objectives. The images in the TCIA collection were acquired as per the standard protocol defined by the American College of Radiology. Patients in the age group of 50-80 years were involved in various clinical trials (multicenter). The dataset collection has more than 10 billion of DICOM images of various anatomies. In this study, the number of samples considered for empirical testing was 300 (n) acquired from both supine and prone positions. The datasets were classified based on the parameters of interest. The classified dataset makes the dataset selection easier during empirical testing. The images were validated for the data completeness as per the DICOM standard of the 2020b version. A case study of CT Colonography dataset is discussed. CONCLUSION: With this systematic approach of data collection and classification, analysis will be become more easier during empirical testing.
.


Subject(s)
Colonic Polyps/diagnostic imaging , Colonography, Computed Tomographic/statistics & numerical data , Data Management/organization & administration , Image Processing, Computer-Assisted/statistics & numerical data , Aged , Aged, 80 and over , Colonic Polyps/epidemiology , Datasets as Topic , Female , Humans , Male , Middle Aged
5.
Asian Pac J Cancer Prev ; 22(1): 185-193, 2021 Jan 01.
Article in English | MEDLINE | ID: mdl-33507698

ABSTRACT

BACKGROUND: While transmitting the medical images in radiology information systems the adversary effect can break the CIA (Confidentiality, Integrity, and Availability) triads of information security. The objective of the study was to transmit the complete set of image objects in a dataset without data integrity violation. METHODS: In this paper a hybrid cryptographic technique which combines the prime details from the patient dataset (stack of axial 2D images) and the Advanced Encryption Standard (AES) method has been proposed. The steps include a) Creating an artificial X-ray image (DRR) from the 3D volume, b) dividing the DRR image in x and y directions equally into four regions, c) applying the zig-zag pattern to each quadrant, and d) encryption of each quadrant with block cipher mode using the AES algorithm. After dataset transmission the DRR image was regenerated at the receiver and compared each of the deciphered blocks (transmitted ones) using the histogram technique. RESULTS: The technique was tested on CT and MRI scans of sixty datasets. The image injection techniques, such as adding and deleting an image from the dataset and modifying the image pixels, were tested. The results were validated statistically using mean square error and histogram matching techniques. CONCLUSION: The combination of the DRR and the AES technique has ensured the secured transmission of the entire dataset and not an individual image.


Subject(s)
Algorithms , Computer Security , Image Processing, Computer-Assisted/standards , Magnetic Resonance Imaging/standards , Neoplasms/pathology , Radiology/standards , Tomography, X-Ray Computed/standards , Humans , Internet/standards , Neoplasms/diagnostic imaging , Prognosis
6.
Int J Surg Case Rep ; 63: 113-117, 2019.
Article in English | MEDLINE | ID: mdl-31585320

ABSTRACT

INTRODUCTION: Typically a patient with acute aortic dissection presents with severe chest pain radiating to the back, tearing in nature. Rarely it can present as painless acute aortic dissection this is seen in iatrogenic cases or when associated with atherosclerosis, diabetes, or aortic aneurysm. CASE PRESENTATION: We hereby present a case of a 32-year aged female who presented with dyspnoea & palpitations (NYHA III) from last 6 months, diagnosed to have Aortic Aneurysm with Type A dissection & Severe AR. She eventually underwent BENTALL'S procedure with CABG and had an uneventful recovery. DISCUSSION: Clinical manifestation of Aortic dissection can be variable, therefore its diagnosis is challenging. 25% of cases, may have associated ECG changes suggestive of acute coronary syndrome leading to a possible misdiagnosis especially if associated ST elevation in ECG. Aorto arteritis is a non-atherosclerotic chronic inflammatory vascular disease of unknown etiology that affects the aorta, proximal parts of its major branches. In this case, there is a possibility that there was underlying spontaneous coronary artery dissection which in turn could be cause for silent ischemia in young women. CONCLUSION: Acute aortic dissection is a life-threatening disease with a high rate of cardiovascular morbidity and mortality. The most important and common risk factor is systemic hypertension which has been reported in the 70% of the patients with aortic dissection. Most of the aortic dissection observed in young women has been reported to be related to pregnancy. Dissection should be suspected during any acute coronary syndrome, particularly Inferior wall MI.

7.
Invest Educ Enferm ; 37(1)2019 Feb.
Article in English | MEDLINE | ID: mdl-31083843

ABSTRACT

OBJECTIVES: To assess nurses' knowledge and perceptions towards mental illness. METHODS: This was a cross-sectional descriptive study conducted among 126 randomly selected nurses those are working under District Mental Health program in Karnataka (India). The data was collected through self-reported questionnaires Using the modified version of Public perception of mental illness questionnaire and Attitude Scale for Mental Illness. RESULTS: The findings revealed that majority of the subjects were women (74.4%), Hindus (92.1%) and were from rural background (69.8%). The mean Knowledge score 10.8±1.6 adequate knowledge (maximum possible =12) among 91% of the subjects, and 52% of them hold negative attitudes towards people with mental illness (88.9±13.6). While majority of the subjects hold negative attitudes in 'Separatism' (53.5%), 'Stereotyping' (73%), 'Benevolence' (54%), 'Pessimistic prediction' (53%) domains, they hold positive attitudes in 'Restrictiveness' (88%) and 'Stigmatization' (72%) domains. Women than men endorsed positive attitudes towards persons with mental illness in Stereotyping' (p<0.001), 'Restrictiveness' (p<0.01), 'Benevolence' (p<0.001) and 'Pessimistic prediction' (t= 2.22, p<0.05) domains. Similarly, Auxiliary Nursing Midwifery found to be less restrictive (p<0.05), more benevolent (p<0.001) and less pessimistic (p<0.05) compared to nurses with higher education (General Nursing and Midwifery and Bachelor of Science in Nursing). CONCLUSIONS: The present study showed adequate knowledge on mental illness among nurses. Yet they hold stigmatizing and negative attitudes towards mental illness. Hence, it is an urgent priority to develop and implement educational programs to inculcate positive attitudes towards people with mental illness to provide optimal care to this vulnerable population.


Subject(s)
Attitude of Health Personnel , Health Knowledge, Attitudes, Practice , Mental Disorders/nursing , Primary Care Nursing/statistics & numerical data , Adult , Cross-Sectional Studies , Female , Humans , India , Male , Middle Aged , Primary Care Nursing/psychology , Sex Factors , Stereotyping , Surveys and Questionnaires
8.
Asian Pac J Cancer Prev ; 20(2): 629-637, 2019 Feb 26.
Article in English | MEDLINE | ID: mdl-30806070

ABSTRACT

Background: The purpose of the research was to improve the polyp detection accuracy in CT Colonography (CTC) through effective colon segmentation, removal of tagged fecal matter through Electronic Cleansing (EC), and measuring the smaller polyps. Methods: An improved method of boundary-based semi-automatic colon segmentation with the knowledge of colon distension, an adaptive multistep method for the virtual cleansing of segmented colon based on the knowledge of Hounsfield Units, and an automated method of smaller polyp measurement using skeletonization technique have been implemented. Results: The techniques were evaluated on 40 CTC dataset. The segmentation method was able to delineate the colon wall accurately. The submerged colonic structures were preserved without soft tissue erosion, pseudo enhanced voxels were corrected, and the air-contrast layer was removed without losing the adjacent tissues. The smaller polyp of size less than <10mm was detected correctly. The results were statistically validated qualitatively and quantitatively. Segmented colons were validated through volumetric overlap computation, and accuracy of 95.826±0.6854% was achieved. In polyp measurement, the paired t-test method was applied to compare the difference with ground truth and at α=5%, t=0.9937 and p=0.098 was achieved. The statistical values of TPR=90%, TNR=82.3% and accuracy=88.31% were achieved. Conclusion: An automated system of polyp measurement has been developed starting from colon segmentation to improve the existing CTC solutions. The analysis of domain-based approach of polyp has given good results. A prototype software, which can be used as a low-cost polyp diagnosis tool, has been developed.


Subject(s)
Algorithms , Colonic Polyps/pathology , Colonography, Computed Tomographic/methods , Image Processing, Computer-Assisted/methods , Pattern Recognition, Automated/methods , Radiographic Image Interpretation, Computer-Assisted/methods , Colonic Polyps/diagnostic imaging , Feces/chemistry , Humans , Imaging, Three-Dimensional/methods , Prognosis
9.
Invest. educ. enferm ; 37(1): [E06], Febrero 2019.
Article in English | LILACS, BDENF - Nursing, COLNAL | ID: biblio-982204

ABSTRACT

Objective. To assess nurses' knowledge and perceptions towards mental illness. Methods. This was a crosssectional descriptive study conducted among 126 randomly selected nurses those are working under District Mental Health program in Karnataka (India). The data was collected through self-reported questionnaires Using the modified version of Public perception of mental illness questionnaire and Attitude Scale for Mental Illness. Results. The findings revealed that majority of the subjects were women (74.4%), Hindus (92.1%) and were from rural background (69.8%). The mean Knowledge score 10.8±1.6 adequate knowledge (maximum possible =12) among 91% of the subjects, and 52% of them hold negative attitudes towards people with mental illness (88.9±13.6). While majority of the subjects hold negative attitudes in 'Separatism' (53.5%), 'Stereotyping' (73%), 'Benevolence' (54%), 'Pessimistic prediction' (53%) domains, they hold positive attitudes in 'Restrictiveness'(88%) and 'Stigmatization' (72%) domains. Women than men endorsed positive attitudes towards persons with mental illness in Stereotyping' (p<0.001), 'Restrictiveness' (p<0.01), 'Benevolence' (p<0.001) and 'Pessimistic prediction' (t= 2.22, p<0.05) domains. Similarly, Auxiliary Nursing Midwifery found to be less restrictive (p<0.05), more benevolent (p<0.001) and less pessimistic (p<0.05) compared to nurses with higher education (General Nursing and Midwifery and Bachelor of Science in Nursing). Conclusion. The present study showed adequate knowledge on mental illness among nurses. Yet they hold stigmatizing and negative attitudes towards mental illness. Hence, it is an urgent priority to develop andimplement educational programs to inculcate positive attitudes towards people with mental illness to provide optimal care to this vulnerable population.


Objetivo. Evaluar los conocimientos y percepciones de las enfermeras de atención primaria hacia la enfermedad mental. Métodos. Se realizó un estudio descriptivo transversal con 126 enfermeras que trabajan en el programa de Salud Mental del Distrito en Karnataka (India). Los datos se recolectaron a partir de cuestionarios contestados por autorreporte, empleando la versión modificada del cuestionario Percepción pública de la enfermedad mental y la Escala de Actitudes hacia la enfemedad mental. Resultados. Los hallazgos revelaron que la mayoría de los participantes eran mujeres (74.4%), hindúes (92.1%) y de origen rural (69.8%). El puntaje promedio de conocimiento fue de 10.8±1.6, que indica un conocimiento adecuado (máximo posible = 12). El 52% de los participantes tienen actitudes negativas hacia las personas con enfermedades mentales, siendo mayor este porcentaje en los dominios 'Estereotipos' (73%), 'Benevolencia' (54%), 'Separatismo' (53.5%), 'Predicción pesimista' (53%); mientras que tienen actitudes positivas en 'Restricción' (88%) y 'Estigmatización '(72%). Las mujeres, en mayor porcentaje que los hombres, tuvieron actitudes positivas hacia las personas con enfermedades mentales en los dominios 'Estereotipos' (p<0.001), 'Restricción' (p<0.01), 'Benevolencia' (p<0.001) y 'Predicción pesimista' (p<0.05). Del mismo modo, las enfermeras parteras auxiliares fueron menos restrictivas (p<0.05), más benévolas (p<0.001) y menos pesimista (p<0.05) en comparación con las enfermeras con mayor educación (enfermeras parteras generales y licenciadas en ciencias de la enfermería). Conclusión. El presente estudio mostró un conocimiento adecuado sobre las enfermedades mentales entre las enfermeras. Sin embargo, tienen actitudes estigmatizantes y negativas hacia la enfermedad mental. Por lo tanto, es una prioridad implementar programas educativos para la adquisición de actitudes positivas hacia las personas con enfermedades mentales con el fin de brindar una atención integral a esta población vulnerable.


Objetivo. Avaliar os conhecimentos e percepções à doença mental das enfermeiras de atenção primária. Métodos. Se realizou um estudo descritivo transversal com 126 enfermeiras que trabalham no programa de Saúde Mental do Distrito em Karnataka (Índia). Os dados foram recolhidos a través de questionários respondidos por autorreporte, empregando a versão modificada do questionário Percepção pública da doença mental e a Escala de Atitudes à doença mental. Resultados. As descobertas revelaram que a maioria dos participantes eram mulheres (74.4%), hindus (92.1%) e de origem rural (69.8%). A pontuação média de conhecimento foi de 10.8±1.6 indicando conhecimento adequado (máximo possível = 12). 52% dos participantes têm atitudes negativas às pessoas com doenças mentais, sendo maior esta porcentagem nos domínios 'Estereótipos' (73%), 'Benevolência' (54%), 'Separatismo' (53.5%), 'Predição pessimista' (53%); enquanto que têm atitudes positivas em 'Restrição' (88%) e 'Estigmas'(72%). As mulheres, em maior porcentagem que os homens, tiveram atitudes positivas às pessoas com doenças mentais nos domínios 'Estereótipos' (p<0.001), 'Restrição' (p<0.01), 'Benevolência' (p<0.001) e 'Predição pessimista' (p<0.05). Do mesmo modo, as enfermeiras parteiras auxiliares formam menos restritivas (p<0.05), mais benévolas (p<0.001) e menos pessimista (p<0.05) em comparação com as enfermeiras com maior educação (enfermeiras parteiras gerais e licenciadas em ciências da enfermagem). Conclusão. O presente estudo mostrou um conhecimento adequado sobre as doenças mentais entre as enfermeiras. Porém, tem atitudes de estigmas e negativas à doença mental. Por tanto, é uma prioridade implementar programas educativos para o melhoramento das atitudes positivas às pessoas com doenças mentais com o fim de brindar uma atenção integral a esta população vulnerável.


Subject(s)
Humans , Stereotyping , Attitude , Cross-Sectional Studies , Beneficence , Mentally Ill Persons , Primary Care Nursing , Self Report , Optimism , Pessimism
10.
J Cardiothorac Vasc Anesth ; 31(5): 1702-1706, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28826847

ABSTRACT

OBJECTIVE: The objective of the study was to investigate if the main pulmonary artery (mPA)-to-ascending aorta (AscAo), (mPA:AscAo) ratio could serve as a screening tool in identifying pulmonary artery hypertension (PAH). DESIGN: A prospective observational study. SETTING: Tertiary care center, university hospital. PARTICIPANTS: Fifty-four adult patients undergoing off-pump coronary artery bypass grafting surgery (OPCAB). INTERVENTIONS: mPA and AscAo transverse diameters were measured by transesophageal echocardiography (TEE) and the mean pulmonary arterial pressures (mPAP) were recorded simultaneously using a pulmonary artery catheter. MEASUREMENTS AND MAIN RESULTS: mPA:AscAo ratio demonstrated significant linear correlation with mPAP measured by pulmonary artery catheterization (ie, r = 0.61, confidence interval [CI] = 0.5352-0.6736, p < 0.0001). Receiver operating characteristic curves were performed to evaluate sensitivity and specificity of mPA:AscAo ratio ≥1 for diagnosing PAH (mPAP ≥25 mmHg). Area under the curve for mPA:AscAo ratio was 0.91 (95% CI, 0.869-0.936, p < 0.0001), with a sensitivity of 84.27%, specificity of 83.92%, positive-predictive value of 87.6% and negative-predictive value of 81.1% for a mPAP ≥25 mmHg. CONCLUSIONS: The ratio of mPA:AscAo is a simple, reliable, and reproducible method that can be obtained through TEE, which guides the clinician to screen patients with PAH.


Subject(s)
Aorta/diagnostic imaging , Coronary Artery Bypass, Off-Pump/methods , Echocardiography, Transesophageal/methods , Hypertension, Pulmonary/diagnostic imaging , Hypertension, Pulmonary/surgery , Pulmonary Artery/diagnostic imaging , Aged , Female , Humans , Male , Middle Aged , Prospective Studies
11.
Oncotarget ; 7(48): 78412-78420, 2016 Nov 29.
Article in English | MEDLINE | ID: mdl-27729616

ABSTRACT

Because endogenous interferon type I (IFN-I) produced by HIV-1 infection might complicate the analysis of therapeutically administered IFN-I, we tested different humanized mouse models for induction of IFN-I during HIV-1 infection. While HIV-1 induced high levels of IFN-α in BLT mice, IFN-I was undetectable following infection in the Hu-PBL mouse model, in which only T cells expand. We therefore tested the effect of treatment with Pegylated IFN-2 (pegasys), in Hu-PBL mice. Pegasys prevented CD4 T cell depletion and reduced the viral load for 10 days, but the effect waned thereafter. We next expressed IFN-I subsets (IFN-α2, -α6, -α8, -α14, and -ß) in Hu-PBL mice by hydrodynamic injection of plasmids encoding them and 2 days later infected the mice with HIV-1. CD4 T cell depletion was prevented in all subtypes of IFN-I-expressing mice by day 10. However, at day 40 post-infection, protection was seen in IFN-ß- and IFN-α14-expressing mice, but not the others. The viral load followed an inverse pattern and was highest in control mice and lowest in IFN-ß- and IFN-α14-expressing mice until day 40 after infection. These results show that gene therapy with plasmids encoding IFN-ß and -α14, but not the commonly used -α2, confers long-term suppression of HIV-1 replication.


Subject(s)
Adoptive Transfer , Genetic Therapy/methods , HIV Infections/prevention & control , HIV-1/immunology , Interferon-alpha/genetics , Interferon-beta/genetics , Leukocytes, Mononuclear/transplantation , Animals , Antiviral Agents/pharmacology , Disease Models, Animal , HIV Infections/genetics , HIV Infections/immunology , HIV Infections/virology , HIV-1/drug effects , HIV-1/growth & development , Humans , Interferon-alpha/biosynthesis , Interferon-alpha/immunology , Interferon-alpha/pharmacology , Interferon-beta/biosynthesis , Interferon-beta/immunology , Leukocytes, Mononuclear/immunology , Mice, Inbred NOD , Mice, SCID , Polyethylene Glycols/pharmacology , Recombinant Proteins/pharmacology , Time Factors , Viral Load , Virus Replication
12.
J Coll Physicians Surg Pak ; 26(3): 225-6, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26975958

ABSTRACT

Ebstein's anomaly is a rare form of congenital malformation of the heart, characterized by apical displacement of the septal and posterior tricuspid valve leaflets, leading to atrialisation of the right ventricle with a variable degree of malformation and displacement of the anterior leaflet. It may not be detected until late in adolescence or adulthood. The clinical manifestations of Ebstein's anomaly vary greatly. We are reporting a case of 35-year male who presented with generalized fatigue, palpitation and effort intolerance. Laboratory investigations confirmed the diagnosis of diabetes ketosis. Transthoracic echocardiography showed severe Ebstein's anomaly with severe tricuspid regurgitation, no residual atrial septal defect, but with severe right ventricular dysfunction. Though only few studies showed the high prevalence of abnormal glucose metabolism in young adult patients with complex congenital heart disease, but Epstein's anomaly with diabetes ketosis was nowhere mentioned.


Subject(s)
Diabetic Ketoacidosis/diagnosis , Ebstein Anomaly/diagnostic imaging , Tricuspid Valve Insufficiency/diagnostic imaging , Ventricular Dysfunction/diagnostic imaging , Adult , Diabetic Ketoacidosis/drug therapy , Diuretics/therapeutic use , Ebstein Anomaly/complications , Echocardiography , Echocardiography, Doppler , Heart Failure/complications , Humans , Insulin Infusion Systems , Insulin, Long-Acting/therapeutic use , Male , Treatment Outcome , Ventricular Dysfunction/drug therapy
13.
Mol Ther ; 18(11): 2028-37, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20648001

ABSTRACT

Dendritic cells (DCs) are potent antigen-presenting cells that play a critical role in the activation of T cells. RNA interference (RNAi)-mediated silencing of negative immunoregulatory molecules expressed by DCs may provide a strategy to enhance the potency of DC-based vaccines and immunotherapy. Ablation of suppressor of cytokine signaling-1 (SOCS-1) in antigen-presenting cells has been shown to enhance cellular immune response in mice. Here, we used a previously reported DC-targeting approach to deliver small interfering RNA (siRNA) against SOCS-1 to human myeloid-derived DCs (MDDCs). SOCS1-silencing in MDDCs resulted in enhanced cytokine responses to lipopolysaccharide (LPS) and a strong mixed-lymphocyte reaction. Moreover, only DCs treated with SOCS-1 siRNA, and not controls, elicited strong primary in vitro responses to well-characterized HLA-A*0201-restricted Melan-A/MART-1 and human immunodeficiency virus (HIV) Gag epitopes in naive CD8(+) T cells from healthy donors. Finally, stimulation of CD8(+) T cells from HIV-seropositive subjects with SOCS1-silenced DCs resulted in an augmented polyfunctional cytotoxic T-lymphocyte (CTL) response, suggesting that SOCS-1 silencing can restore functionally compromised T cells in HIV infection. Collectively, these results demonstrate the feasibility of DC3-9dR-mediated manipulation of DC function to enhance DC immunogenicity for potential vaccine or immunotherapeutic applications.


Subject(s)
Dendritic Cells/immunology , HIV/immunology , RNA, Small Interfering/genetics , Suppressor of Cytokine Signaling Proteins/metabolism , T-Lymphocytes, Cytotoxic/immunology , T-Lymphocytes/immunology , Apoptosis , Blotting, Western , Cell Proliferation , Cells, Cultured , Cytokines/metabolism , Flow Cytometry , HIV/genetics , HIV Infections/immunology , HIV Infections/virology , HLA-A Antigens/immunology , HLA-A2 Antigen , Humans , Lipopolysaccharides/pharmacology , Myeloid Cells/drug effects , Myeloid Cells/immunology , Myeloid Cells/metabolism , Peptide Fragments/pharmacology , RNA, Messenger/genetics , Reverse Transcriptase Polymerase Chain Reaction , Signal Transduction , Suppressor of Cytokine Signaling 1 Protein , Suppressor of Cytokine Signaling Proteins/antagonists & inhibitors , Suppressor of Cytokine Signaling Proteins/genetics , T-Lymphocytes/drug effects , T-Lymphocytes/metabolism
14.
J Virol ; 84(5): 2490-501, 2010 Mar.
Article in English | MEDLINE | ID: mdl-20015996

ABSTRACT

Dengue is a common arthropod-borne flaviviral infection in the tropics, for which there is no vaccine or specific antiviral drug. The infection is often associated with serious complications such as dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS), in which both viral and host factors have been implicated. RNA interference (RNAi) is a potent antiviral strategy and a potential therapeutic option for dengue if a feasible strategy can be developed for delivery of small interfering RNA (siRNA) to dendritic cells (DCs) and macrophages, the major in vivo targets of the virus and also the source of proinflammatory cytokines. Here we show that a dendritic cell-targeting 12-mer peptide (DC3) fused to nona-D-arginine (9dR) residues (DC3-9dR) delivers siRNA and knocks down endogenous gene expression in heterogenous DC subsets, (monocyte-derived DCs [MDDCs], CD34(+) hematopoietic stem cell [HSC])-derived Langerhans DCs, and peripheral blood DCs). Moreover, DC3-9dR-mediated delivery of siRNA targeting a highly conserved sequence in the dengue virus envelope gene (siFvE(D)) effectively suppressed dengue virus replication in MDDCs and macrophages. In addition, DC-specific delivery of siRNA targeting the acute-phase cytokine tumor necrosis factor alpha (TNF-alpha), which plays a major role in dengue pathogenesis, either alone or in combination with an antiviral siRNA, significantly reduced virus-induced production of the cytokine in MDDCs. Finally to validate the strategy in vivo, we tested the ability of the peptide to target human DCs in the NOD/SCID/IL-2Rgamma(-/-) mouse model engrafted with human CD34(+) hematopoietic stem cells (HuHSC mice). Treatment of mice by intravenous (i.v.) injection of DC3-9dR-complexed siRNA targeting TNF-alpha effectively suppressed poly(I:C)-induced TNF-alpha production by DCs. Thus, DC3-9dR can deliver siRNA to DCs both in vitro and in vivo, and this delivery approach holds promise as a therapeutic strategy to simultaneously suppress virus replication and curb virus-induced detrimental host immune responses in dengue infection.


Subject(s)
Cytokines/biosynthesis , Dendritic Cells , Dengue Virus , Dengue , RNA, Small Interfering/metabolism , RNA, Small Interfering/pharmacology , Animals , Cytokines/immunology , Dendritic Cells/drug effects , Dendritic Cells/immunology , Dendritic Cells/virology , Dengue/immunology , Dengue/therapy , Dengue Virus/drug effects , Dengue Virus/immunology , Gene Transfer Techniques , Humans , Macrophages/cytology , Macrophages/immunology , Mice , Mice, Knockout , Oligopeptides/genetics , Oligopeptides/immunology , Peptides/genetics , Peptides/metabolism , Poly I-C/immunology , RNA, Small Interfering/genetics , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Tumor Necrosis Factor-alpha/immunology , Virus Replication/drug effects
15.
Blood ; 106(3): 818-26, 2005 Aug 01.
Article in English | MEDLINE | ID: mdl-15831707

ABSTRACT

Viral heterogeneity is a major hurdle for potential therapeutic use of RNA interference (RNAi) against HIV-1. To determine the extent of RNAi tolerance to mutations, we tested 3 viral target sites with differing propensity for mutations: a highly variable rev sequence, a gag sequence conserved only among clade B isolates, and a vif sequence highly conserved across clades. Lentiviral expression of all 3 shRNAs inhibited replication of the homologous HIV(IIIB) strain. However, they differed in their ability to protect primary CD4 T cells against multiple isolates within and across HIV clades. The least conserved rev sequence inhibited only 2 of 5 clade B isolates. The gag sequence (conserved within clade B) protected 5 of 5 clade B isolates but not other clade viruses with 2 or 3 mutations in the central region. In contrast, the vif sequence, which was conserved across clades except for single mutations at positions 14 and 17, inhibited viruses from 5 different clades. Moreover, siRNAs with introduced mutations at sites of gag sequence polymorphisms showed reduced antiviral activity, whereas mutations in vif siRNA only modestly decreased silencing. Thus, although 1 or 2 mutations at peripheral sites are tolerated, mutations in the central target cleavage region abolish RNAi activity.


Subject(s)
CD4-Positive T-Lymphocytes/virology , HIV Infections/drug therapy , HIV-1/genetics , RNA, Small Interfering/administration & dosage , Antiviral Agents/administration & dosage , Antiviral Agents/pharmacology , Biological Therapy , CD4-Positive T-Lymphocytes/drug effects , Cell Line , Conserved Sequence , Genes, gag , Genes, rev , Genes, vif , HIV-1/drug effects , Humans , Lentivirus , Mutation , RNA Interference , RNA, Small Interfering/pharmacology , Transfection
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