Displaying all 14 publications

Abstract:
Sort:
  1. Osahor AN, Narayanan K
    Methods Mol Biol, 2021;2211:15-27.
    PMID: 33336267 DOI: 10.1007/978-1-0716-0943-9_2
    Gene delivery using invasive bacteria as vectors is a robust method that is feasible for plasmid and artificial chromosome DNA construct delivery to human cells presenting β1 integrin receptors. This technique is relatively underutilized owing to the inefficiency of gene transfer to targeted cell populations. Bacterial vectors must successfully adhere to the cell membrane, internalize into the cytoplasm, undergo lysis, and deliver DNA to the nucleus. There are limited studies on the use of exogenous reagents to improve the efficiency of bacteria-mediated gene delivery to mammalian cells. In this chapter, we describe how cationic lipids, conventionally used for DNA and protein transfection, as well as antimicrobial compounds, can be used to synergistically enhance the adherence of invasive bacterial vectors to the cell membrane and improve their predisposition to internalize into the cytoplasm to deliver DNA. Using simple combinatorial methods, functional DNA transfer can be improved by up to four-fold of invaded cell populations. These methods are easy to perform and are likely to be applicable for other bacterial vectors including Listeria and Salmonella.
  2. Osahor AN, Ng AWR, Narayanan K
    Methods Mol Biol, 2021;2211:29-40.
    PMID: 33336268 DOI: 10.1007/978-1-0716-0943-9_3
    Visual analysis of the gene delivery process when using invasive bacteria as a vector has been conventionally performed using standard light and fluorescence microscopy. These microscopes can provide basic information on the invasiveness of the bacterial vector including the ability of the vector to successfully adhere to the cell membrane. Standard microscopy techniques however fall short when finer details including membrane attachment as well as internalization into the cytoplasm are desired. High-resolution visual analysis of bacteria-mediated gene delivery can allow accurate measurement of the adherence and internalization capabilities of engineered vectors. Here, we describe the use of scanning electron microscopy (SEM) to directly quantify vectors when they are external to the cell wall, and confocal microscopy to evaluate the vectors when they have internalized into the cytoplasm. By performing the invasion procedure on microscope coverslips, cells can be easily prepared for analysis using electron or confocal microscopes. Imaging the invasion complexes in high resolution can provide important insights into the behavior of bacterial vectors including E. coli, Listeria, and Salmonella when invading their target cells to deliver DNA and other molecules.
  3. Osahor AN, Tan CY, Sim EU, Lee CW, Narayanan K
    Anal Biochem, 2014 Oct 1;462:26-8.
    PMID: 24929088 DOI: 10.1016/j.ab.2014.05.030
    When recombineering bacterial artificial chromosomes (BACs), it is common practice to design the ends of the donor molecule with 50 bp of homology specifying its insertion site. We demonstrate that desired recombinants can be produced using intermolecular homologies as short as 15 bp. Although the use of shorter donor end regions decreases total recombinants by several fold, the frequency of recombinants with correctly inserted donor molecules was high enough for easy detection by simple polymerase chain reaction (PCR) screening. This observation may have important implications for the design of oligonucleotides for recombineering, including significant cost savings, especially for high-throughput projects that use large quantities of primers.
  4. Kampan NC, Xiang SD, McNally OM, Stephens AN, Quinn MA, Plebanski M
    Curr Med Chem, 2018;25(36):4785-4806.
    PMID: 28707587 DOI: 10.2174/0929867324666170712160621
    Interleukin 6 (IL-6), a well-known pro-inflammatory cytokine with pleiotropic activity is a central player in chronic inflammatory diseases including cancers. Therefore, blockade of the IL-6 signalling pathway has become a target for the therapy of diverse cancers such as multicentric Castleman's disease (CD), multiple myeloma and solid tumours including renal, prostate, lung, colorectal and ovarian cancers. Monoclonal antibodies against IL-6 (Siltuximab) and the IL-6 receptor (IL-6R) (Tocilizumab) have emerged as potential immunotherapies, alone or in combination with conventional chemotherapy. Human trials have demonstrated the ability to block IL-6 activity and in multicentric CD lead to durable clinical response and longer disease stabilisation. However, the efficacy of these treatments is still debatable for other cancers. New generation therapeutics in development such as Clazakizumab, Sarilumab, and soluble gp130-Fc have the additional features of improved binding affinity, better specificity with reduced adverse effects. A deeper understanding of the immunological basis of these agents, as well as of the challenges that are faced by immunotherapy-based products in clinical trials, will help select the most promising anti-IL-6/IL-6R therapies for large scale use. Concurrently, current research efforts to personalize treatments may help in the treatment of patients that would greatly benefit from IL-6 blocking therapies.
  5. Moody R, Wilson K, Kampan NC, McNally OM, Jobling TW, Jaworowski A, et al.
    Cancers (Basel), 2021 Aug 20;13(16).
    PMID: 34439354 DOI: 10.3390/cancers13164201
    Autoantibodies recognising phosphorylated heat shock factor 1 (HSF1-PO4) protein are suggested as potential new diagnostic biomarkers for early-stage high-grade serous ovarian cancer (HGSOC). We predicted in silico B-cell epitopes in human and murine HSF1. Three epitope regions were synthesised as peptides. Circulating immunoglobulin A (cIgA) against the predicted peptide epitopes or HSF1-PO4 was measured using ELISA, across two small human clinical trials of HGSOC patients at diagnosis. To determine whether chemotherapy would promote changes in reactivity to either HSF1-PO4 or the HSF-1 peptide epitopes, IgA responses were further assessed in a sample of patients after a full cycle of chemotherapy. Anti-HSF1-PO4 responses correlated with antibody responses to the three selected epitope regions, regardless of phosphorylation, with substantial cross-recognition of the corresponding human and murine peptide epitope variants. Assessing reactivity to individual peptide epitopes, compared to HSF1-PO4, improved assay sensitivity. IgA responses to HSF1-PO4 further increased significantly post treatment, indicating that HSF1-PO4 is a target for immunity in response to chemotherapy. Although performed in a small cohort, these results offer potential insights into the interplay between autoimmunity and ovarian cancer and offer new peptide biomarkers for early-stage HGSOC diagnosis, to monitor responses to chemotherapy, and widely for pre-clinical HGSOC research.
  6. Kampan NC, Madondo MT, McNally OM, Stephens AN, Quinn MA, Plebanski M
    Front Immunol, 2017;8:1482.
    PMID: 29163543 DOI: 10.3389/fimmu.2017.01482
    Background: Epithelial ovarian cancer (EOC) remains a highly lethal gynecological malignancy. Ascites, an accumulation of peritoneal fluid present in one-third of patients at presentation, is linked to poor prognosis. High levels of regulatory T cells (Tregs) in ascites are correlated with tumor progression and reduced survival. Malignant ascites harbors high levels of Tregs expressing the tumor necrosis factor receptor 2 (TNFR2), as well as pro-inflammatory factors such as interleukin 6 (IL-6) and tumor necrosis factor (TNF). IL-6 is also associated with poor prognosis. Herein, we study the effect of IL-6 and TNF present in ascites on the modulation of TNFR2 expression on T cells, and specifically Tregs.

    Methods: Ascites and respective peripheral blood sera were collected from 18 patients with advanced EOC and soluble biomarkers, including IL-6, sTNFR2, IL-10, TGF-β, and TNF, were quantified using multiplexed bead-based immunoassay. Peripheral blood mononuclear cells (PBMC) from healthy donors were incubated with cell-free ascites for 48 h (or media as a negative control). In some experiments, IL-6 or TNF within the ascites were neutralized by using monoclonal antibodies. The phenotype of TNFR2(+) Tregs and TNFR2(-) Tregs were characterized post incubation in ascites. In some experiments, cell sorted Tregs were utilized instead of PBMC.

    Results: High levels of immunosuppressive (sTNFR2, IL-10, and TGF-β) and pro-inflammatory cytokines (IL-6 and TNF) were present in malignant ascites. TNFR2 expression on all T cell subsets was higher in post culture in ascites and highest on CD4(+)CD25(hi)FoxP3(+) Tregs, resulting in an increased TNFR2(+) Treg/effector T cell ratio. Furthermore, TNFR2(+) Tregs conditioned in ascites expressed higher levels of the functional immunosuppressive molecules programmed cell death ligand-1, CTLA-4, and GARP. Functionally, TNFR2(+) Treg frequency was inversely correlated with interferon-gamma (IFN-γ) production by effector T cells, and was uniquely able to suppress TNFR2(+) T effectors. Blockade of IL-6, but not TNF, within ascites decreased TNFR2(+) Treg frequency. Results indicating malignant ascites promotes TNFR2 expression, and increased suppressive Treg activity using PBMC were confirmed using purified Treg subsets.

    Conclusion: IL-6 present in malignant ovarian cancer ascites promotes increased TNFR2 expression and frequency of highly suppressive Tregs.

  7. Kampan NC, Madondo MT, Reynolds J, Hallo J, McNally OM, Jobling TW, et al.
    Sci Rep, 2020 02 10;10(1):2213.
    PMID: 32042020 DOI: 10.1038/s41598-020-59009-z
    Pre-operative discrimination of malignant masses is crucial for accurate diagnosis and prompt referral to a gynae oncology centre for optimal surgical intervention. HGSOC progression is correlated with local and systemic inflammation. We hypothesised that inclusion of inflammatory biomarkers in sera may improve diagnostic tests. In the training cohort, we tested four existing clinical tests (RMI score and ROMA, CA125 and HE4) and a panel of 28 immune soluble biomarkers in sera from 66 patients undergoing surgery for suspected ovarian cancer. Six promising immune biomarkers alone, or in combination with conventional tests, were subsequently analysed in an independent validation cohort (n = 69). IL-6 was identified as the main driver of variability followed closely by conventional diagnostic tests. Median sera IL-6 was higher in HGSOC patients compared to those with a benign mass or controls with normal ovaries (28.3 vs 7.3 vs 1.2 pg/ml, p  3.75 pg/ml as primary triage followed by conventional tests (CA125 or RMI score) identified ovarian cancer in patients with a misclassification rate of 4.54-3.03%, superior to the use of CA125 or RMI alone (9.09 to 10.60). The validation cohort demonstrated a similar improvement in the diagnostic sensitivity following addition of IL-6. IL-6 in combination with conventional tests may be a useful clinical biomarker for triage of patients with a suspected malignant ovarian mass.
  8. Collins JM, Stout JE, Ayers T, Hill AN, Katz DJ, Ho CS, et al.
    Clin Infect Dis, 2021 11 02;73(9):e3468-e3475.
    PMID: 33137172 DOI: 10.1093/cid/ciaa1662
    BACKGROUND: Most tuberculosis (TB) disease in the United States (US) is attributed to reactivation of remotely acquired latent TB infection (LTBI) in non-US-born persons who were likely infected with Mycobacterium tuberculosis in their countries of birth. Information on LTBI prevalence by country of birth could help guide local providers and health departments to scale up the LTBI screening and preventive treatment needed to advance progress toward TB elimination.

    METHODS: A total of 13 805 non-US-born persons at high risk of TB infection or progression to TB disease were screened for LTBI at 16 clinical sites located across the United States with a tuberculin skin test, QuantiFERON Gold In-Tube test, and T-SPOT.TB test. Bayesian latent class analysis was applied to test results to estimate LTBI prevalence and associated credible intervals (CrIs) for each country or world region of birth.

    RESULTS: Among the study population, the estimated LTBI prevalence was 31% (95% CrI, 26%-35%). Country-of-birth-level LTBI prevalence estimates were highest for persons born in Haiti, Peru, Somalia, Ethiopia, Vietnam, and Bhutan, ranging from 42% to 55%. LTBI prevalence estimates were lowest for persons born in Colombia, Malaysia, and Thailand, ranging from 8% to 13%.

    CONCLUSIONS: LTBI prevalence in persons born outside the US varies widely by country. These estimates can help target community outreach efforts to the highest-risk groups.

  9. Olusanya BO, Gulati S, Berman BD, Hadders-Algra M, Williams AN, Smythe T, et al.
    Nat Med, 2023 May;29(5):1056-1060.
    PMID: 37055569 DOI: 10.1038/s41591-023-02291-x
  10. Martinaud C, Scorer T, Lozano M, Miles A, Fitchett G, Ba A, et al.
    Vox Sang, 2021 09;116(8):e44-e70.
    PMID: 33939177 DOI: 10.1111/vox.13102
  11. Olusanya BO, Gladstone M, Wright SM, Hadders-Algra M, Boo NY, Nair MKC, et al.
    Front Public Health, 2022;10:894546.
    PMID: 36091559 DOI: 10.3389/fpubh.2022.894546
    OBJECTIVE: Children with developmental disabilities are associated with a high risk of poor school enrollment and educational attainment without timely and appropriate support. Epidemiological data on cerebral palsy and associated comorbidities required for policy intervention in global health are lacking. This paper set out to report the best available evidence on the global and regional prevalence of cerebral palsy (CP) and developmental intellectual disability and the associated "years lived with disability" (YLDs) among children under 5 years of age in 2019.

    METHODS: We analyzed the collaborative 2019 Rehabilitation Database of the Global Burden of Disease (GBD) Study and World Health Organization for neurological and mental disorders available for 204 countries and territories. Point prevalence and YLDs with 95% uncertainty intervals (UI) are presented.

    RESULTS: Globally, 8.1 million (7.1-9.2) or 1.2% of children under 5 years are estimated to have CP with 16.1 million (11.5-21.0) or 2.4% having intellectual disability. Over 98% resided in low-income and middle-income countries (LMICs). CP and intellectual disability accounted for 6.5% and 4.5% of the aggregate YLDs from all causes of adverse health outcomes respectively. African Region recorded the highest prevalence of CP (1.6%) while South-East Asia Region had the highest prevalence of intellectual disability. The top 10 countries accounted for 57.2% of the global prevalence of CP and 62.0% of the global prevalence of intellectual disability.

    CONCLUSION: Based on this Database, CP and intellectual disability are highly prevalent and associated with substantial YLDs among children under 5 years worldwide. Universal early detection and support services are warranted, particularly in LMICs to optimize school readiness for these children toward inclusive education as envisioned by the United Nations' Sustainable Development Goals.

  12. Cros A, Ahamad Fatan N, White A, Teoh SJ, Tan S, Handayani C, et al.
    PLoS One, 2014;9(6):e96332.
    PMID: 24941442 DOI: 10.1371/journal.pone.0096332
    In this paper we describe the construction of an online GIS database system, hosted by WorldFish, which stores bio-physical, ecological and socio-economic data for the 'Coral Triangle Area' in South-east Asia and the Pacific. The database has been built in partnership with all six (Timor-Leste, Malaysia, Indonesia, The Philippines, Solomon Islands and Papua New Guinea) of the Coral Triangle countries, and represents a valuable source of information for natural resource managers at the regional scale. Its utility is demonstrated using biophysical data, data summarising marine habitats, and data describing the extent of marine protected areas in the region.
  13. Olusanya BO, Wright SM, Nair MKC, Boo NY, Halpern R, Kuper H, et al.
    Pediatrics, 2020 07;146(1).
    PMID: 32554521 DOI: 10.1542/peds.2019-2623
    BACKGROUND: Estimates of children and adolescents with disabilities worldwide are needed to inform global intervention under the disability-inclusive provisions of the Sustainable Development Goals. We sought to update the most widely reported estimate of 93 million children <15 years with disabilities from the Global Burden of Disease Study 2004.

    METHODS: We analyzed Global Burden of Disease Study 2017 data on the prevalence of childhood epilepsy, intellectual disability, and vision or hearing loss and on years lived with disability (YLD) derived from systematic reviews, health surveys, hospital and claims databases, cohort studies, and disease-specific registries. Point estimates of the prevalence and YLD and the 95% uncertainty intervals (UIs) around the estimates were assessed.

    RESULTS: Globally, 291.2 million (11.2%) of the 2.6 billion children and adolescents (95% UI: 249.9-335.4 million) were estimated to have 1 of the 4 specified disabilities in 2017. The prevalence of these disabilities increased with age from 6.1% among children aged <1 year to 13.9% among adolescents aged 15 to 19 years. A total of 275.2 million (94.5%) lived in low- and middle-income countries, predominantly in South Asia and sub-Saharan Africa. The top 10 countries accounted for 62.3% of all children and adolescents with disabilities. These disabilities accounted for 28.9 million YLD or 19.9% of the overall 145.3 million (95% UI: 106.9-189.7) YLD from all causes among children and adolescents.

    CONCLUSIONS: The number of children and adolescents with these 4 disabilities is far higher than the 2004 estimate, increases from infancy to adolescence, and accounts for a substantial proportion of all-cause YLD.

  14. Lundgren JD, Babiker AG, Sharma S, Grund B, Phillips AN, Matthews G, et al.
    NEJM Evid, 2023 Mar;2(3).
    PMID: 37213438 DOI: 10.1056/evidoa2200302
    BACKGROUND: For people with HIV and CD4+ counts >500 cells/mm3, early initiation of antiretroviral therapy (ART) reduces serious AIDS and serious non-AIDS (SNA) risk compared with deferral of treatment until CD4+ counts are <350 cells/mm3. Whether excess risk of AIDS and SNA persists once ART is initiated for those who defer treatment is uncertain.

    METHODS: The Strategic Timing of AntiRetroviral Treatment (START) trial, as previously reported, randomly assigned 4684 ART-naive HIV-positive adults with CD4+ counts .500 cells/mm3 to immediate treatment initiation after random assignment (n = 2325) or deferred treatment (n= 2359). In 2015, a 57% lower risk of the primary end point (AIDS, SNA, or death) for the immediate group was reported, and the deferred group was offered ART. This article reports the follow-up that continued to December 31, 2021. Cox proportional-hazards models were used to compare hazard ratios for the primary end point from randomization through December 31, 2015, versus January 1, 2016, through December 31, 2021.

    RESULTS: Through December 31, 2015, approximately 7 months after the cutoff date from the previous report, the median CD4+ count was 648 and 460 cells/mm3 in the immediate and deferred groups, respectively, at treatment initiation. The percentage of follow-up time spent taking ART was 95% and 36% for the immediate and deferred groups, respectively, and the time-averaged CD4+ difference was 199 cells/mm3. After January 1, 2016, the percentage of follow-up time on treatment was 97.2% and 94.1% for the immediate and deferred groups, respectively, and the CD4+ count difference was 155 cells/mm3. After January 1, 2016, a total of 89 immediate and 113 deferred group participants experienced a primary end point (hazard ratio of 0.79 [95% confidence interval, 0.60 to 1.04] versus hazard ratio of 0.47 [95% confidence interval, 0.34 to 0.65; P<0.001]) before 2016 (P=0.02 for hazard ratio difference).

    CONCLUSIONS: Among adults with CD4+ counts >500 cells/mm3, excess risk of AIDS and SNA associated with delaying treatment initiation was diminished after ART initiation, but persistent excess risk remained. (Funded by the National Institute of Allergy and Infectious Diseases and others.).

Related Terms
Filters
Contact Us

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

External Links