Displaying publications 861 - 880 of 1059 in total

Abstract:
Sort:
  1. Shaharuddin B, Ahmad S, Md Latar N, Ali S, Meeson A
    Stem Cells Transl Med, 2017 03;6(3):761-766.
    PMID: 28297580 DOI: 10.5966/sctm.2016-0175
    Limbal stem cell (LSC) deficiency is a visually debilitating condition caused by abnormal maintenance of LSCs. It is treated by transplantation of donor-derived limbal epithelial cells (LECs), the success of which depends on the presence and quality of LSCs within the transplant. Understanding the immunobiological responses of these cells within the transplants could improve cell engraftment and survival. However, human corneal rings used as a source of LSCs are not always readily available for research purposes. As an alternative, we hypothesized that a human telomerase-immortalized corneal epithelial cell (HTCEC) line could be used as a model for studying LSC immunobiology. HTCEC constitutively expressed human leukocyte antigen (HLA) class I but not class II molecules. However, when stimulated by interferon-γ, HTCECs then expressed HLA class II antigens. Some HTCECs were also migratory in response to CXCL12 and expressed stem cell markers, Nanog, Oct4, and Sox2. In addition because both HTCECs and LECs contain side population (SP) cells, which are an enriched LSC population, we used these SP cells to show that some HTCEC SP cells coexpressed ABCG2 and ABCB5. HTCEC SP and non-side population (NSP) cells also expressed CXCR4, but the SP cells expressed higher levels. Both were capable of colony formation, but the NSP colonies were smaller and contained fewer cells. In addition, HTCECs expressed ΔNp63α. These results suggest the HTCEC line is a useful model for further understanding LSC biology by using an in vitro approach without reliance on a supply of human tissue. Stem Cells Translational Medicine 2017;6:761-766.
    Matched MeSH terms: HLA Antigens/metabolism
  2. Lai LL, Chan WK, Sthaneshwar P, Nik Mustapha NR, Goh KL, Mahadeva S
    PLoS One, 2017;12(4):e0174982.
    PMID: 28369100 DOI: 10.1371/journal.pone.0174982
    Wisteria floribunda agglutinin-positive Mac-2 binding protein (WFA+-M2BP) has been suggested to be useful for the assessment of disease severity in non-alcoholic fatty liver disease (NAFLD). Consecutive adult NAFLD patients who had a liver biopsy were included. Serum WFA+-M2BP level was measured using a lectin-antibody sandwich immunoassay using a chemiluminescence enzyme immunoassay machine (HISCL-5000, Sysmex, Kobe, Japan). The measured levels were indexed using the following equation: Cut-off index (COI) = ([WFA+-M2BP]sample-[WFA+-M2BP]NC) / ([WFA+-M2BP]PC-[WFA+-M2BP]NC), where PC = positive control and NC = negative control. Histopathological examination of liver biopsy specimen was reported according to Non-Alcoholic Steatohepatitis (NASH) Clinical Research Network Scoring System. Data for 220 cases were analyzed. The AUROC of the COI for the diagnosis of NASH was 0.65. The AUROC of the COI for the diagnosis of steatosis grade ≥2 and 3 was 0.64 and 0.53, respectively. The AUROC of the COI for the diagnosis of lobular inflammation grade ≥1, ≥2 and 3 was 0.57, 0.68 and 0.59, respectively. The AUROC of the COI for the diagnosis of hepatocyte ballooning grade ≥1 and 2 was 0.64 and 0.65, respectively. The AUROC of the COI for the diagnosis of fibrosis stage ≥1, ≥2, ≥3 and 4 was 0.61, 0.71, 0.74 and 0.84, respectively. Out of the 220 cases, 152 cases were the same 76 patients who had a repeat liver biopsy after 48 weeks of intervention. The AUROC of the change in the COI to detect improvement in steatosis, lobular inflammation, hepatocyte ballooning and fibrosis was 0.57, 0.54, 0.59 and 0.52, respectively. In conclusion, serum WFA+-M2BP was most useful for the diagnosis of significant fibrosis, advanced fibrosis and cirrhosis in NAFLD patients. However, it was less useful for differentiating NASH from non-NASH, and for diagnosis and follow-up of the individual histopathological components of NASH.
    Matched MeSH terms: Antigens, Neoplasm/blood*
  3. Biabanikhankahdani R, Alitheen NBM, Ho KL, Tan WS
    Sci Rep, 2016 11 24;6:37891.
    PMID: 27883070 DOI: 10.1038/srep37891
    Multifunctional nanocarriers harbouring specific targeting moieties and with pH-responsive properties offer great potential for targeted cancer therapy. Several synthetic drug carriers have been studied extensively as drug delivery systems but not much information is available on the application of virus-like nanoparticles (VLNPs) as multifunctional nanocarriers. Here, we describe the development of pH-responsive VLNPs, based on truncated hepatitis B virus core antigen (tHBcAg), displaying folic acid (FA) for controlled drug delivery. FA was conjugated to a pentadecapeptide containing nanoglue bound on tHBcAg nanoparticles to increase the specificity and efficacy of the drug delivery system. The tHBcAg nanoparticles loaded with doxorubicin (DOX) and polyacrylic acid (PAA) demonstrated a sustained drug release profile in vitro under tumour tissue conditions in a controlled manner and improved the uptake of DOX in colorectal cancer cells, leading to enhanced antitumour effects. This study demonstrated that DOX-PAA can be packaged into VLNPs without any modification of the DOX molecules, preserving the pharmacological activity of the loaded DOX. The nanoglue can easily be used to display a tumour-targeting molecule on the exterior surface of VLNPs and can bypass the laborious and time-consuming genetic engineering approaches.
    Matched MeSH terms: Hepatitis B Core Antigens/chemistry*
  4. Qiang S, Alsaeedi HA, Yuhong C, Yang H, Tong L, Kumar S, et al.
    J. Photochem. Photobiol. B, Biol., 2018 Jun;183:127-132.
    PMID: 29704860 DOI: 10.1016/j.jphotobiol.2018.04.003
    BACKGROUND: Retinal degeneration is a condition ensued by various ocular disorders such as artery occlusion, diabetic retinopathy, retrolental fibroplasia and retinitis pigmentosa which cause abnormal loss of photoreceptor cells and lead to eventual vision impairment. No efficient treatment has yet been found, however, the use of stem cell therapy such as bone marrow and embryonic stem cells has opened a new treatment modality for retinal degenerative diseases. The major goal of this study is to analyze the potential of endothelial progenitor cells derived from bone marrow to differentiate into retinal neural cells for regenerative medicine purposes.

    METHODS: In this study, endothelial progenitor cells were induced in-vitro with photoreceptor growth factor (taurine) for 21 days. Subsequently, the morphology and gene expression of CRX and RHO of the photoreceptors-induced EPCs were examined through immunostaining assay.

    FINDINGS: The results indicated that the induced endothelial progenitor cells demonstrated positive gene expression of CRX and RHO. Our findings suggested that EPC cells may have a high advantage in cell replacement therapy for treating eye disease, in addition to other neural diseases, and may be a suitable cell source in regenerative medicine for eye disorders.

    Matched MeSH terms: Antigens, CD34/metabolism
  5. Yong YK, Tan HY, Jen SH, Shankar EM, Natkunam SK, Sathar J, et al.
    J Transl Med, 2017 05 31;15(1):121.
    PMID: 28569153 DOI: 10.1186/s12967-017-1226-4
    BACKGROUND: Currently, several assays can diagnose acute dengue infection. However, none of these assays can predict the severity of the disease. Biomarkers that predicts the likelihood that a dengue patient will develop a severe form of the disease could permit more efficient patient triage and allows better supportive care for the individual in need, especially during dengue outbreaks.

    METHODS: We measured 20 plasma markers i.e. IFN-γ, IL-10, granzyme-B, CX3CL1, IP-10, RANTES, CXCL8, CXCL6, VCAM, ICAM, VEGF, HGF, sCD25, IL-18, LBP, sCD14, sCD163, MIF, MCP-1 and MIP-1β in 141 dengue patients in over 230 specimens and correlate the levels of these plasma markers with the development of dengue without warning signs (DWS-), dengue with warning signs (DWS+) and severe dengue (SD).

    RESULTS: Our results show that the elevation of plasma levels of IL-18 at both febrile and defervescence phase was significantly associated with DWS+ and SD; whilst increase of sCD14 and LBP at febrile phase were associated with severity of dengue disease. By using receiver operating characteristic (ROC) analysis, the IL-18, LBP and sCD14 were significantly predicted the development of more severe form of dengue disease (DWS+/SD) (AUC = 0.768, P 

    Matched MeSH terms: Antigens, CD14/blood
  6. Chan WK, Yeoh KY, Lim CY, Lai SM, Lee JL, Leow AHR, et al.
    Med J Malaysia, 2018 06;73(3):137-140.
    PMID: 29962496 MyJurnal
    INTRODUCTION: There have been no published data on the transmission of hepatitis B virus (HBV) infection among children of hepatitis B surface antigen (HBsAg) positive mothers in Malaysia.

    METHODS: This is a cross-sectional study of all the children of HBsAg-positive mothers who delivered at the University of Malaya Medical Centre between 1993 and 2000.

    RESULTS: A total of 60 HBsAg-positive mothers and their 154 children participated in the study. HBsAg was detected in four children (2.6%) while IgG antibody to the hepatitis B core antigen (anti-HBc IgG) was detected in seventeen children (11.0%). The mother's age at childbirth was significantly lower in the children with detectable HBsAg (22.5±6.1 years vs. 29.7±4.5 years, p=0.043) and anti-HBc IgG (26.6±6.1 years vs. 30.0±4.3 years, p=0.004). Children born in the 1980s were significantly more likely to have detectable HBsAg (18.8% vs. 0.7%, p=0.004) and anti-HBc IgG (37.5% vs. 8.0%, p=0.000) compared with those born later. All children with detectable HBsAg were born via spontaneous vaginal delivery, and hepatitis B immunoglobulin was either not given or the administration status was unknown. The majority of mothers with chronic HBV infection (70.4%) were not under any regular follow-up for their chronic HBV infection and the main reason was the lack of awareness of the need to do so (47.4%).

    CONCLUSION: Transmission of HBV infection among children of HBsAg-positive mothers in Malaysia is low. However, attention needs to be given to the high rate of HBsAgpositive mothers who are not on any regular follow-up.

    Matched MeSH terms: Hepatitis B Surface Antigens/blood*
  7. Kang AY, Park AY, Shin HJ, Khan NA, Maciver SK, Jung SY
    Exp Parasitol, 2018 Sep;192:19-24.
    PMID: 30031120 DOI: 10.1016/j.exppara.2018.07.009
    Amoebae from the genus Acanthamoeba are facultative pathogens of humans and other animals. In humans they most frequently infect the eye causing a sight threatening infection known as Acanthamoeba keratitis (AK), and also cause an often fatal encephalitis (GAE). A mannose-binding protein (MBP) has been identified as being important for Acanthamoeba infection especially in AK. This lectin has previously been characterized from Acanthamoeba castellanii as consisting of multiple 130 kDa subunits. MBP expression correlates with pathogenic potential and is expressed in a number of Acanthamoeba species. Here we report the purification of a similar lectin from Acanthamoeba culbertsoni and the production of a monoclonal antibody to it. The A. culbertsoni MBP was isolated by affinity chromatography using α-D-mannose agarose and has an apparent molecular weight of 83 kDa. The monoclonal antibody is an IgM that is useful in both western blots and immunofluorescence. We expect that this antibody will be useful in the study of the pathology of A. culbertsoni and in its identification in clinical samples.
    Matched MeSH terms: Antigens, Protozoan/immunology
  8. Saidin S, Yunus MH, Othman N, Lim YA, Mohamed Z, Zakaria NZ, et al.
    Pathog Glob Health, 2017 May;111(3):128-136.
    PMID: 28335696 DOI: 10.1080/20477724.2017.1300421
    Entamoeba histolytica infection remains a public health concern in developing countries. Early diagnosis of amoebiasis can avoid disease complications, thus this study was aimed at developing a test that can rapidly detect the parasite antigens in stool samples. Rabbits were individually immunized with recombinant pyruvate phosphate dikinase (rPPDK) and E. histolytica excretory-secretory antigens to produce polyclonal antibodies. A rapid dipstick test was produced using anti-rPPDK PAb lined on the dipstick as capture reagent and anti-EhESA PAb conjugated to colloidal gold as the detector reagent. Using E. histolytica-spiked in stool sample of a healthy individual, the detection limit of the dipstick test was found to be 1000 cells ml-1. Meanwhile when rPPDK was spiked in the stool sample, the minimum concentration detected by the dipstick test was 0.1 μg ml-1. The performances of the dipstick, commercial Techlab E. histolytica II enzyme-linked immunosorbent assays (ELISA) and real-time PCR were compared using 70 stool samples from patients infected with Entamoeba species (n = 45) and other intestinal pathogens (n = 25). When compared to real-time PCR, the diagnostic sensitivity of the dipstick for detection of E. histolytica was 65.4% (n = 17/26); while the diagnostic specificity when tested with stool samples containing other intestinal pathogens was 92% (23/25). In contrast, Techlab E. histolytica II ELISA detected 19.2% (5/26) of the E. histolytica-positive samples as compared to real-time PCR. The lateral flow dipstick test produced in this study enabled rapid detection of E. histolytica, thus it showed good potential to be further developed into a diagnostic tool for intestinal amoebiasis.
    Matched MeSH terms: Antigens, Protozoan/immunology*
  9. Sultan S, Irfan SM, Zaidi SM
    Med J Malaysia, 2018 08;73(4):185-189.
    PMID: 30121679
    BACKGROUND: It is being increasingly recognised that thalassemia major patients, like intermedia, have increased propensity for thromboembolism. Deficiency of natural anticoagulants is more recently defined finding contributing to the hypercoagulable state. The aim this study is to determine natural anticoagulants levels and their correlation with maternal characteristics, haematological and biochemical markers.

    METHODS: This is a prospective case-control study. We registered 80 patients and 60 healthy controls from Jan 2009 to Dec 2013. Complete blood counts, prothrombin time, activated partial thromboplastin time, protein C, protein S, antithrombin, serum ferritin, liver enzymes; HbsAg and Anti- HCV were evaluated.

    RESULT: There were 42 males and 38 females with mean age of 12.30±5.50 years. The mean protein C, protein S and antithrombin in patients and control were 58.25±22.5 versus 110.67±22.60, 67.90±19.58 versus 98.70±21.54 and 89.73±18.09 versus 104.0±10.98 (p<0.001) respectively. Protein C was predominantly deficient in 65% followed by protein S and antithrombin in 35% and 20% respectively. Protein C deficiency divulged positive correlation with protein S deficiency (p = 0.035) and antithrombin deficiency with hemoglobin of ≤8gm% (p<0.0025). No significant correlation of prothrombotic markers was established with maternal characteristics, hepatic dysfunction, hepatitis and serum ferritin.

    CONCLUSION: Substantial decrement in prothrombotic markers, primarily protein C, may be implicated in elevated thrombosis; however follow-up data is required to establish definitive thromboembolic events.

    Matched MeSH terms: Hepatitis B Surface Antigens/blood
  10. Chai SJ, Fong SCY, Gan CP, Pua KC, Lim PVH, Lau SH, et al.
    Hum Vaccin Immunother, 2019;15(1):167-178.
    PMID: 30193086 DOI: 10.1080/21645515.2018.1520584
    Peptide vaccines derived from tumour-associated antigens have been used as an immunotherapeutic approach to induce specific cytotoxic immune response against tumour. We previously identified that MAGED4B and FJX1 proteins are overexpressed in HNSCC patients; and further demonstrated that two HLA-A2-restricted 9-11 amino acid peptides derived from these proteins were able to induce anti-tumour immune responses in vitro independently using PBMCs isolated from these patients. In this study, we evaluated the immunogenicity and efficacy of a dual-antigenic peptide vaccine (PV1), comprised of MAGED4B and FJX1 peptides in HNSCC patients. We first demonstrated that 94.8% of HNSCC patients expressed MAGED4B and/or FJX1 by immunohistochemistry, suggesting that PV1 could benefit the majority of HNSCC patients. The presence of pre-existing MAGED4B and FJX1-specific T-cells was detected using a HLA-A2 dimer assay and efficacy of PV1 to induce T-cell to secrete cytotoxic cytokine was evaluated using ELISPOT assay. Pre-existing PV1-specific T-cells were detected in all patients. Notably, we demonstrated that patients' T-cells were able to secrete cytotoxic cytokines upon exposure to target cells expressing the respective antigen post PV1 stimulation. Furthermore, patients with high expression of MAGED4B and FJX1 in their tumours were more responsive to PV1 stimulation, demonstrating the specificity of the PV1 peptide vaccine. Additionally, we also demonstrated the expression of MAGED4B and FJX1 in breast, lung, colon, prostate and rectal cancer suggesting the potential use of PV1 in these cancers. In summary, PV1 could be a good vaccine candidate for the treatment of HNSCC patients and other cancers expressing these antigens.
    Matched MeSH terms: Antigens, Neoplasm/immunology*
  11. Yu SP, Ong KC, Perera D, Wong KT
    Virology, 2019 01 15;527:107-115.
    PMID: 30481615 DOI: 10.1016/j.virol.2018.10.015
    Japanese encephalitis virus (JEV) causes central nervous system neuronal injury and inflammation. A clear understanding of neuronal responses to JEV infection remains elusive. Using the Affymetrix array to investigate the transcriptome of infected SK-N-MC cells, 1316 and 2737 dysregulated genes (≥ 2/-2 fold change, P 
    Matched MeSH terms: Antigens, Viral/metabolism
  12. Mussa A, Talib M, Mohamed Z, Hajissa K
    BMC Res Notes, 2019 Jun 11;12(1):334.
    PMID: 31186056 DOI: 10.1186/s13104-019-4361-6
    OBJECTIVE: Rapid diagnostic tests (RDTs) play a crucial role in the management and control of malaria infection. The histidine-rich protein 2 (PfHRP-2) based RDTs are the most commonly used RDTs for malaria diagnosis in Sudan. Deletion of pfhrp2 in Plasmodium falciparum genome affect the accuracy of PfHRP-2 based RDT kits. This study aimed to identify molecular variation of pfhrp2 among suspected malaria patients from different clinics in Omdurman, Sudan.

    RESULTS: A noticeable variation between the RDT (Alltest Biotech, China) and nPCR results was observed, for RDT 78% (46/59) were P. falciparum positive, 6.8% (4/59) were co-infected with both P. falciparum and Plasmodium vivax, 15.3% (9/59) were negative by the RDT. However, when the nPCR was applied only 44.1% (26/59) and 55.9% (33/59) was P. falciparum positive and negative respectively. The pfhrp2 was further amplified form all nPCR positive samples. Only 17 DNA samples were positive from the 26 positive P. falciparum, interestingly, variation in band sizes was observed and further confirmed by DNA sequencing, and sequencing analysis revealed a high-level of genetic diversity of the pfhrp2 gene in the parasite population from the study area. However, despite extreme sequence variation, diversity of PfHRP2 does not appear to affect RDT performance.

    Matched MeSH terms: Antigens, Protozoan/genetics*
  13. Oyong DA, Wilson DW, Barber BE, William T, Jiang J, Galinski MR, et al.
    J Infect Dis, 2019 11 06;220(12):1950-1961.
    PMID: 31419296 DOI: 10.1093/infdis/jiz407
    BACKGROUND: Complement-fixing antibodies are important mediators of protection against Plasmodium falciparum malaria. However, complement-fixing antibodies remain uncharacterized for Plasmodium vivax malaria. P. vivax merozoite surface protein 3α (PvMSP3α) is a target of acquired immunity and a potential vaccine candidate.

    METHODS: Plasma from children and adults with P. vivax malaria in Sabah, Malaysia, were collected during acute infection, 7 and 28 days after drug treatment. Complement-fixing antibodies and immunoglobulin M and G (IgM and IgG), targeting 3 distinctive regions of PvMSP3α, were measured by means of enzyme-linked immunosorbent assay.

    RESULTS: The seroprevalence of complement-fixing antibodies was highest against the PvMSP3α central region (77.6%). IgG1, IgG3, and IgM were significantly correlated with C1q fixation, and both purified IgG and IgM were capable of mediating C1q fixation to PvMSP3α. Complement-fixing antibody levels were similar between age groups, but IgM was predominant in children and IgG3 more prevalent in adults. Levels of functional antibodies increased after acute infection through 7 days after treatment but rapidly waned by day 28.

    CONCLUSION: Our study demonstrates that PvMSP3α antibodies acquired during P. vivax infection can mediate complement fixation and shows the important influence of age in shaping these specific antibody responses. Further studies are warranted to understand the role of these functional antibodies in protective immunity against P. vivax malaria.

    Matched MeSH terms: Antigens, Protozoan/immunology*
  14. Crane M, Avihingsanon A, Rajasuriar R, Velayudham P, Iser D, Solomon A, et al.
    J Infect Dis, 2014 Sep 1;210(5):745-51.
    PMID: 24585898 DOI: 10.1093/infdis/jiu119
    We investigated the relationship between microbial translocation, immune activation, and liver disease in human immunodeficiency virus (HIV)/hepatitis B virus (HBV) coinfection. Lipopolysaccharide (LPS), soluble CD14, CXCL10, and CCL-2 levels were elevated in patients with HIV/HBV coinfection. Levels of LPS, soluble CD14, and CCL-2 declined following receipt of HBV-active combination antiretroviral therapy (cART), but the CXCL10 level remained elevated. No markers were associated with liver disease severity on liver biopsy (n = 96), but CXCL10, interleukin 6 (IL-6), interleukin 10 (IL-10), tumor necrosis factor α, and interferon γ (IFN-γ) were all associated with elevated liver enzyme levels during receipt of HBV-active cART. Stimulation of hepatocyte cell lines in vitro with IFN-γ and LPS induced a profound synergistic increase in the production of CXCL10. LPS may contribute to liver disease via stimulating persistent production of CXCL10.
    Matched MeSH terms: Antigens, CD14/blood
  15. Goh KGK, Phan MD, Forde BM, Chong TM, Yin WF, Chan KG, et al.
    mBio, 2017 10 24;8(5).
    PMID: 29066548 DOI: 10.1128/mBio.01558-17
    Uropathogenic Escherichia coli (UPEC) is a major cause of urinary tract and bloodstream infections and possesses an array of virulence factors for colonization, survival, and persistence. One such factor is the polysaccharide K capsule. Among the different K capsule types, the K1 serotype is strongly associated with UPEC infection. In this study, we completely sequenced the K1 UPEC urosepsis strain PA45B and employed a novel combination of a lytic K1 capsule-specific phage, saturated Tn5 transposon mutagenesis, and high-throughput transposon-directed insertion site sequencing (TraDIS) to identify the complement of genes required for capsule production. Our analysis identified known genes involved in capsule biosynthesis, as well as two additional regulatory genes (mprA and lrhA) that we characterized at the molecular level. Mutation of mprA resulted in protection against K1 phage-mediated killing, a phenotype restored by complementation. We also identified a significantly increased unidirectional Tn5 insertion frequency upstream of the lrhA gene and showed that strong expression of LrhA induced by a constitutive Pcl promoter led to loss of capsule production. Further analysis revealed loss of MprA or overexpression of LrhA affected the transcription of capsule biosynthesis genes in PA45B and increased sensitivity to killing in whole blood. Similar phenotypes were also observed in UPEC strains UTI89 (K1) and CFT073 (K2), demonstrating that the effects were neither strain nor capsule type specific. Overall, this study defined the genome of a UPEC urosepsis isolate and identified and characterized two new regulatory factors that affect UPEC capsule production.IMPORTANCE Urinary tract infections (UTIs) are among the most common bacterial infections in humans and are primarily caused by uropathogenic Escherichia coli (UPEC). Many UPEC strains express a polysaccharide K capsule that provides protection against host innate immune factors and contributes to survival and persistence during infection. The K1 serotype is one example of a polysaccharide capsule type and is strongly associated with UPEC strains that cause UTIs, bloodstream infections, and meningitis. The number of UTIs caused by antibiotic-resistant UPEC is steadily increasing, highlighting the need to better understand factors (e.g., the capsule) that contribute to UPEC pathogenesis. This study describes the original and novel application of lytic capsule-specific phage killing, saturated Tn5 transposon mutagenesis, and high-throughput transposon-directed insertion site sequencing to define the entire complement of genes required for capsule production in UPEC. Our comprehensive approach uncovered new genes involved in the regulation of this key virulence determinant.
    Matched MeSH terms: Antigens, Bacterial/biosynthesis*
  16. Rahumatullah A, Abdul Karim IZ, Noordin R, Lim TS
    Int J Mol Sci, 2017 Nov 22;18(11).
    PMID: 29165352 DOI: 10.3390/ijms18112376
    Helminth parasite infections are significantly impacting global health, with more than two billion infections worldwide with a high morbidity rate. The complex life cycle of the nematodes has made host immune response studies against these parasites extremely difficult. In this study, we utilized two phage antibody libraries; the immune and naïve library were used to identify single chain fragment variable (scFv) clones against a specific filarial antigen (BmR1). The V-gene analysis of isolated scFv clones will help shed light on preferential VDJ gene segment usage against the filarial BmR1 antigen in healthy and infected states. The immune library showed the usage of both lambda and kappa light chains. However, the naïve library showed preferential use of the lambda family with different amino acid distributions. The binding characteristics of the scFv clones identified from this work were analyzed by immunoassay and immunoaffinity pull down of BmR1. The work highlights the antibody gene usage pattern of a naïve and immune antibody library against the same antigen as well as the robust nature of the enriched antibodies for downstream applications.
    Matched MeSH terms: Antigens, Helminth/immunology
  17. Abas FS, Shana'ah A, Christian B, Hasserjian R, Louissaint A, Pennell M, et al.
    Cytometry A, 2017 06;91(6):609-621.
    PMID: 28110507 DOI: 10.1002/cyto.a.23049
    The advance of high resolution digital scans of pathology slides allowed development of computer based image analysis algorithms that may help pathologists in IHC stains quantification. While very promising, these methods require further refinement before they are implemented in routine clinical setting. Particularly critical is to evaluate algorithm performance in a setting similar to current clinical practice. In this article, we present a pilot study that evaluates the use of a computerized cell quantification method in the clinical estimation of CD3 positive (CD3+) T cells in follicular lymphoma (FL). Our goal is to demonstrate the degree to which computerized quantification is comparable to the practice of estimation by a panel of expert pathologists. The computerized quantification method uses entropy based histogram thresholding to separate brown (CD3+) and blue (CD3-) regions after a color space transformation. A panel of four board-certified hematopathologists evaluated a database of 20 FL images using two different reading methods: visual estimation and manual marking of each CD3+ cell in the images. These image data and the readings provided a reference standard and the range of variability among readers. Sensitivity and specificity measures of the computer's segmentation of CD3+ and CD- T cell are recorded. For all four pathologists, mean sensitivity and specificity measures are 90.97 and 88.38%, respectively. The computerized quantification method agrees more with the manual cell marking as compared to the visual estimations. Statistical comparison between the computerized quantification method and the pathologist readings demonstrated good agreement with correlation coefficient values of 0.81 and 0.96 in terms of Lin's concordance correlation and Spearman's correlation coefficient, respectively. These values are higher than most of those calculated among the pathologists. In the future, the computerized quantification method may be used to investigate the relationship between the overall architectural pattern (i.e., interfollicular vs. follicular) and outcome measures (e.g., overall survival, and time to treatment). © 2017 International Society for Advancement of Cytometry.
    Matched MeSH terms: Antigens, CD3/genetics
  18. Hooi YT, Ong KC, Tan SH, Perera D, Wong KT
    Lab Invest, 2020 Sep;100(9):1262-1275.
    PMID: 32601355 DOI: 10.1038/s41374-020-0456-x
    Coxsackievirus A16 (CV-A16) is one of the major causes of mild and self-limiting hand-foot-and-mouth disease (HFMD) in young children, which may occasionally leads to serious neurological complications. In this study, we had developed a novel, consistent, orally infected CV-A16 HFMD hamster model with encephalomyelitis. Four groups of 7-day-old hamsters in a kinetic study were orally infected with mouse-adapted CV-A16 strains and sacrificed at 1-4 days post infection (dpi), respectively. Tissues were studied by light microscopy, immunohistochemistry to detect viral antigens, in situ hybridization to detect viral RNA, and by viral titration. In a separate transmission experiment, orally infected index hamsters were housed together with contact hamsters to investigate oral and fecal viral shedding by virus culture and reverse transcription polymerase chain reaction (RT-PCR). At severe infection/death endpoints, index and contact hamster infection were also histopathologically analyzed. In the kinetic study, infected hamsters developed signs of infection at 4 dpi. Viral antigens/RNA were localized to brainstem (medulla/pons; reticular formation and motor trigeminal nucleus) and spinal cord anterior horn neurons, oral squamous epithelia and epidermis from 3 to 4 dpi. Salivary and lacrimal glands, myocardium, brown adipose tissue, intestinal smooth muscle, and skeletal muscle infection was also demonstrated. Viremia at 1 dpi and increasing viral titers in various tissues were observed from 2 dpi. In the transmission study, all contact hamsters developed disease 3-5 days later than index hamsters, but demonstrated similar histopathological findings at endpoint. Viral culture and RT-PCR positive oral washes and feces confirmed viral shedding. Our hamster model, orally infected by the natural route for human infection, confirmed CV-A16 neurotropism and demonstrated squamous epitheliotropism reminiscent of HFMD, attributes not found in other animal models. It should be useful to investigate neuropathogenesis, model person-to-person transmission, and for testing antiviral drugs and vaccines.
    Matched MeSH terms: Antigens, Viral/metabolism
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links