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2.
Am J Hum Genet ; 102(5): 731-743, 2018 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-29706352

RESUMO

Large-scale, population-based genomic studies have provided a context for modern medical genetics. Among such studies, however, African populations have remained relatively underrepresented. The breadth of genetic diversity across the African continent argues for an exploration of local genomic context to facilitate burgeoning disease mapping studies in Africa. We sought to characterize genetic variation and to assess population substructure within a cohort of HIV-positive children from Botswana-a Southern African country that is regionally underrepresented in genomic databases. Using whole-exome sequencing data from 164 Batswana and comparisons with 150 similarly sequenced HIV-positive Ugandan children, we found that 13%-25% of variation observed among Batswana was not captured by public databases. Uncaptured variants were significantly enriched (p = 2.2 × 10-16) for coding variants with minor allele frequencies between 1% and 5% and included predicted-damaging non-synonymous variants. Among variants found in public databases, corresponding allele frequencies varied widely, with Botswana having significantly higher allele frequencies among rare (<1%) pathogenic and damaging variants. Batswana clustered with other Southern African populations, but distinctly from 1000 Genomes African populations, and had limited evidence for admixture with extra-continental ancestries. We also observed a surprising lack of genetic substructure in Botswana, despite multiple tribal ethnicities and language groups, alongside a higher degree of relatedness than purported founder populations from the 1000 Genomes project. Our observations reveal a complex, but distinct, ancestral history and genomic architecture among Batswana and suggest that disease mapping within similar Southern African populations will require a deeper repository of genetic variation and allelic dependencies than presently exists.


Assuntos
População Negra/genética , Sequenciamento do Exoma , Variação Genética , Botsuana , Estudos de Coortes , Pool Gênico , Genética Populacional , Genoma Humano , Geografia , Humanos , Filogenia , Análise de Componente Principal
3.
BMC Infect Dis ; 21(1): 1218, 2021 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-34872511

RESUMO

BACKGROUND: Several repurposed drugs such as hydroxychloroquine (HCQ) have been investigated for treatment of COVID-19, but none was confirmed to be efficacious. While in vitro studies have demonstrated antiviral properties of HCQ, data from clinical trials were conflicting regarding its benefit for COVID-19 treatment. Drugs that limit viral replication may be beneficial in the earlier course of the disease thus slowing progression to severe and critical illness. DESIGN: We conducted a randomized open label Phase II clinical trial from October-December 2020. METHODS: Patients diagnosed with COVID-19 using RT-PCR were included in the study if they were 18 years and above and had a diagnosis of COVID-19 made in the last 3 days. Patients were randomized in blocks, to receive either HCQ 400 mg twice a day for the first day followed by 200 mg twice daily for the next 4 days plus standard of care (SOC) treatment or SOC treatment alone. SARS COV-2 viral load (CT values) from RT-PCR testing of samples collected using nasal/orapharyngeal swabs was performed at baseline, day 2, 4, 6, 8 and 10. The primary outcome was median time from randomization to SARS COV-2 viral clearance by day 6. RESULTS: Of the 105 participants enrolled, 55 were assigned to the intervention group (HCQ plus SOC) and 50 to the control group (SOC only). Baseline characteristics were similar across treatment arms. Viral clearance did not differ by treatment arm, 20 and 19 participants respectively had SARS COV-2 viral load clearance by day 6 with no significant difference, median (IQR) number of days to viral load clearance between the two groups was 4(3-4) vs 4(2-4): p = 0.457. There were no significant differences in secondary outcomes (symptom resolution and adverse events) between the intervention group and the control group. There were no significant differences in specific adverse events such as elevated alkaline phosphatase, prolonged QTc interval on ECG, among patients in the intervention group as compared to the control group. CONCLUSION: Our results show that HCQ 400 mg twice a day for the first day followed by 200 mg twice daily for the next 4 days was safe but not associated with reduction in viral clearance or symptom resolution among adults with COVID-19 in Uganda. TRIAL REGISTRATION:  NCT04860284.


Assuntos
Tratamento Farmacológico da COVID-19 , Hidroxicloroquina , Adulto , Humanos , Hidroxicloroquina/efeitos adversos , SARS-CoV-2 , Resultado do Tratamento , Uganda
4.
Adv Exp Med Biol ; 1339: 131-137, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35023100

RESUMO

The Ebola virus disease is a severe hemorrhagic fever that affects humans and other primates. Ebola virus, the causative agent of the disease, is transmitted to humans from wild animals and is highly contagious and aggressive with an estimated fatality rate to be around 50%. Since 1976, 11 outbreaks of Ebola virus disease have been reported in total, affecting mostly sub-Saharan Africa, while the most recent ongoing outbreak in the Democratic Republic of the Congo has more than 3000 reported cases and 72 deaths. Although an effective vaccine against Ebola virus disease has become available, no targeted treatment with proven efficacy upon infection is developed. Herein, we review the epidemiology of Ebola virus and the current situation in terms of prevention, diagnosis, and treatment of the disease.


Assuntos
Ebolavirus , Doença pelo Vírus Ebola , Animais , Animais Selvagens , Surtos de Doenças , Febre , Doença pelo Vírus Ebola/diagnóstico , Doença pelo Vírus Ebola/epidemiologia , Doença pelo Vírus Ebola/prevenção & controle
5.
Retrovirology ; 17(1): 19, 2020 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-32631377

RESUMO

BACKGROUND: Tripartite Motif Containing 5 alpha (TRIM5α), a restriction factor produced ubiquitously in cells and tissues of the body plays an important role in the immune response against HIV. TRIM5α targets the HIV capsid for proteosomal destruction. Cyclophilin A, an intracellular protein has also been reported to influence HIV infectivity in a cell-specific manner. Accordingly, variations in TRIM5α and Cyclophilin A genes have been documented to influence HIV-1 disease progression. However, these variations have not been documented among Elite controllers in Uganda and whether they play a role in viral suppression remains largely undocumented. Our study focused on identifying the variations in TRIM5α and Cyclophilin A genes among HIV-1 Elite controllers and non-controllers in Uganda. RESULTS: From the sequence analysis, the rs10838525 G > A mutation in exon 2 of TRIM5α was only found among elite controllers (30%) while the rs3824949 in the 5'UTR was seen among 25% of the non-controllers. In the Cyclophilin A promoter, rs6850 was seen among 62.5% of the non-controllers and only among 10% elite controllers. Furthermore, rs17860048 in the Cyclophillin A promoter was predominantly seen among elite controllers (30%) and 12.5% non-controllers. From gene expression analysis, we noted that the respective genes were generally elevated among elite controllers, however, this difference was not statistically significant (TRIM5α p = 0.6095; Cyclophilin A p = 0.6389). CONCLUSION: Variations in TRIM5α and Cyclophillin A promoter may influence HIV viral suppression. The rs10838525 SNP in TRIM5α may contribute to viral suppression among HIV-1 elite controllers. The rs6850 in the cyclophillin A gene may be responsible for HIV-1 rapid progression among HIV-1 non-controllers. These SNPs should be investigated mechanistically to determine their precise role in HIV-1 viral suppression.


Assuntos
Infecções por HIV/genética , Peptidilprolil Isomerase/genética , Proteínas com Motivo Tripartido/genética , Ubiquitina-Proteína Ligases/genética , Adulto , Fatores de Restrição Antivirais , Estudos Transversais , Feminino , Expressão Gênica , Variação Genética , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Uganda
6.
BMC Infect Dis ; 18(1): 133, 2018 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-29548281

RESUMO

BACKGROUND: Precise designation of high risk forms of latent Mycobacterium tuberculosis-M.tb infections (LTBI) is impossible. Delineation of high-risk LTBI can, however, allow for chemoprophylaxis and curtail majority cases of active tuberculosis (ATB). There is epidemiological evidence to support the view that LTBI in context of HIV-1 co-infection is high-risk for progression to ATB relative to LTBI among HIV-ve persons. We recently showed that assays of M.tb thymidylate kinase (TMKmt) antigen and host specific IgG can differentiate ATB from LTBI and or no TB (NTB, or healthy controls). In this study, we aimed to expose the differential levels of TMKmt Ag among HIV+ve co-infected LTBI relative to HIV-ve LTBI as a strategy to advance these assays for designating incipient LTBI. METHODS: TMKmt host specific IgM and IgG detection Enzyme Immuno-Assays (EIA) were conducted on 40 TB exposed house-hold contacts (22 LTBI vs. 18 no TB (NTB) by QunatiFERON-TB GOLD®); and TMKmt Ag detection EIA done on 82 LTBI (46 HIV+ve vs 36 HIV-ve) and 9 NTB (American donors). Purified recombinant TMKmt protein was used as positive control for the Ag assays. RESULTS: IgM levels were found to be equally low across QuantiFERON-TB GOLD® prequalified NTB and TB exposed house-hold contacts. Higher TMKmt host specific IgG trends were found among TB house-hold contacts relative to NTB controls. TMKmt Ag levels among HIV+ve LTBI were 0.2676 ± 0.0197 (95% CI: 0.2279 to 0.3073) relative to 0.1069 ± 0.01628 (95% CI: 0.07385 to 0.14) for HIV-ve LTBI (supporting incipient nature of LTBI in context of HIV-1 co-infection). NTB had TMKmt Ag levels of 0.1013 ± 0.02505 (5% CI: 0.0421 to 0.1606) (intimating that some were indeed LTBI). CONCLUSIONS: TMKmt Ag levels represent a novel surrogate biomarker for high-risk LTBI, while host-specific IgG can be used to designate NTB from LTBI.


Assuntos
Progressão da Doença , Tuberculose Latente/diagnóstico , Mycobacterium tuberculosis/enzimologia , Núcleosídeo-Fosfato Quinase/metabolismo , Teste Tuberculínico/métodos , Adulto , Anticorpos Antibacterianos/análise , Biomarcadores/análise , Coinfecção , Feminino , Infecções por HIV/complicações , HIV-1 , Humanos , Imunoglobulina G/análise , Imunoglobulina M/análise , Tuberculose Latente/complicações , Tuberculose Latente/microbiologia , Masculino , Mycobacterium tuberculosis/isolamento & purificação , Medição de Risco
7.
BMC Infect Dis ; 18(1): 498, 2018 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-30285648

RESUMO

BACKGROUND: Ebolavirus and Marburgvirus are genera of the virus family Filoviridae. Filoviruses cause rare but fatal viral hemorrhagic fevers (VHFs) in remote villages of equatorial Africa with potential for regional and international spread. Point-of-care (POC) rapid diagnostic tests (RDTs) are critical for early epidemic detection, reponse and control. There are 2 RDTs for Zaire ebolavirus (EBOV), but not other Ebolavirus spp. or Marburg marburgvirus (MARV). We validate 3 conserved B cell epitopes of filovirus glycoprotein (GP) using ebola virus diseases (EVD) survivor samples, towards devising pan-filovirus RDTs. METHODS: In-silico Immuno-informatics:- (a) multiple and basic local alignments of amino-acid sequences of filovirus (4 Ebolavirus spp. & MARV) Gp1, 2 and epitope prediction and conservation analyses within context of ClusterW, BLAST-P and the immune epitope database analysis resource (IEDB-AR); alongside (b) in-vitro enzyme immuno-assays (EIAs) for SUDV Gp1, 2 antigen and host-specific antibodies (IgM and IgG) among 94 gamma irradiated EVD survivor serum and 9 negative controls. RESULTS: Linear B cell epitopes were present across the entire length of all Gp1, 2, most lying in the region between amino acids positioned 350 and 500. Three seperate epitopes 97/80_GAFFLYDRLAST, 39_YEAGEWAENCY and 500_CGLRQLANETTQALQLFLRATTELR (designated UG-Filo-Peptide- 1, 2 and 3 respectively) were conserved within all studied filovirus species Gp1, 2. Gp1, 2 host specific IgM levels were comparably low (av. ODs < 0.04 [95% CI: 0.02837 to 0.04033]) among the 9 negative controls and 57 survivor samples analyzed. Host specific IgG levels, on the other hand, were elevated (av. ODs > 1.7525 [95% CI: 0.3010 to 3.1352]) among the 92 survivor samples relative to the 9 negative controls (av. ODs < 0.2.321 [95% CI: -0.7596 to 0.5372]). Filovirus Gp1, 2 antigen was not detected [av. ODs < 0.20] within EVD survivor serum relative to recombinant protein positive controls [av. ODs = 0.50]. CONCLUSIONS: These conserved B cell epitopes of filovirus Gp1, 2 and their derivative antibodies are promising for research and development of RDTs for EVD, with potential for extension to detect MVD.


Assuntos
Ebolavirus/imunologia , Epitopos de Linfócito B/imunologia , Glicoproteínas/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Antivirais/imunologia , Sequência Conservada , Doença pelo Vírus Ebola/diagnóstico , Doença pelo Vírus Ebola/virologia , Humanos , Imunoglobulina G , Imunoglobulina M , Doença do Vírus de Marburg/diagnóstico , Doença do Vírus de Marburg/virologia , Marburgvirus/imunologia , Kit de Reagentes para Diagnóstico , Proteínas Virais/genética , Proteínas Virais/imunologia
8.
Genet Med ; 19(7): 826-833, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28383545

RESUMO

PURPOSE: The Collaborative African Genomics Network (CAfGEN) aims to establish sustainable genomics research programs in Botswana and Uganda through long-term training of PhD students from these countries at Baylor College of Medicine. Here, we present an overview of the CAfGEN PhD training program alongside trainees' perspectives on their involvement. BACKGROUND: Historically, collaborations between high-income countries (HICs) and low- and middle-income countries (LMICs), or North-South collaborations, have been criticized for the lack of a mutually beneficial distribution of resources and research findings, often undermining LMICs. CAfGEN plans to address this imbalance in the genomics field through a program of technology and expertise transfer to the participating LMICs. METHODS: An overview of the training program is presented. Trainees from the CAfGEN project summarized their experiences, looking specifically at the training model, benefits of the program, challenges encountered relating to the cultural transition, and program outcomes after the first 2 years. CONCLUSION: Collaborative training programs like CAfGEN will not only help establish sustainable long-term research initiatives in LMICs but also foster stronger North-South and South-South networks. The CAfGEN model offers a framework for the development of training programs aimed at genomics education for those for whom genomics is not their "first language." Genet Med advance online publication 06 April 2017.


Assuntos
Educação de Pós-Graduação/métodos , Educação/métodos , Genômica/educação , Pesquisa Biomédica/educação , Pesquisa Biomédica/métodos , Botsuana , Biologia Computacional/educação , Currículo , Feminino , Humanos , Cooperação Internacional , Masculino , Estudantes , Uganda , Universidades
9.
Brief Funct Genomics ; 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38605526

RESUMO

Intermolecular interactions of protein-protein complexes play a principal role in the process of discovering new substances used in the diagnosis and treatment of many diseases. Among such complexes of proteins, we have to mention antibodies; they interact with specific antigens of two genera of single-stranded RNA viruses belonging to the family Filoviridae-Ebolavirus and Marburgvirus; both cause rare but fatal viral hemorrhagic fever in Africa, with pandemic potential. In this research, we conduct studies aimed at the design and evaluation of antibodies targeting the filovirus glycoprotein precursor GP-1,2 to develop potential targets for the pan-filovirus easy-to-use rapid diagnostic tests. The in silico research using the available 3D structure of the natural antibody-antigen complex was carried out to determine the stability of individual protein segments in the process of its formation and maintenance. The computed free binding energy of the complex and its decomposition for all amino acids allowed us to define the residues that play an essential role in the structure and indicated the spots where potential antibodies can be improved. Following that, the study involved targeting six epitopes of the filovirus GP1,2 with two polyclonal antibodies (pABs) and 14 monoclonal antibodies (mABs). The evaluation conducted using Enzyme Immunoassays tested 62 different sandwich combinations of monoclonal antibodies (mAbs), identifying 10 combinations that successfully captured the recombinant GP1,2 (rGP). Among these combinations, the sandwich option (3G2G12* - (rGP) - 2D8F11) exhibited the highest propensity for capturing the rGP antigen.

10.
Int J Infect Dis ; 139: 132-140, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38036259

RESUMO

OBJECTIVES: We utilize a large retrospective study cohort derived from electronic medical records to estimate the prevalence of long-term non-progression (LTNP) and determine the factors associated with progression among children infected with HIV in Botswana and Uganda. METHODS: Electronic medical records from large tertiary HIV clinical centers in Botswana and Uganda were queried to identify LTNP children 0-18 years enrolled between June 2003 and May 2014 and extract demographic and nutritional parameters. Multivariate subdistribution hazard analyses were used to examine demographic factors and nutritional status in progression in the pre-antiretroviral therapy era. RESULTS: Between the two countries, 14,246 antiretroviral therapy-naïve children infected with HIV were enrolled into clinical care. The overall proportion of LTNP was 6.3% (9.5% in Botswana vs 5.9% in Uganda). The median progression-free survival for the cohort was 6.3 years, although this was lower in Botswana than in Uganda (6.6 vs 8.8 years; P <0.001). At baseline, the adjusted subdistribution hazard ratio (aHRsd) of progression was increased among underweight children (aHRsd 1.42; 95% confidence interval [CI]: 1.32-1.53), enrolled after 2010 (aHRsd 1.32; 95% CI 1.22-1.42), and those from Botswana (aHRsd 2; 95% CI 1.91-2.10). CONCLUSIONS: In our study, the prevalence of pediatric LTNP was lower than that observed among adult populations, but progression-free survival was higher than expected. Underweight, year of enrollment into care, and country of origin are independent predictors of progression among children.


Assuntos
Infecções por HIV , Magreza , Adulto , Humanos , Criança , Estudos Retrospectivos , Magreza/complicações , Botsuana/epidemiologia , Uganda/epidemiologia , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Infecções por HIV/complicações , Fatores de Risco , Progressão da Doença
11.
Transplant Proc ; 55(10): 2319-2325, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37923573

RESUMO

BACKGROUND: Uganda's Health Sector Development Plan (2015/16 through 2019/2020) noted that most referrals for treatment abroad were for organ transplant services that cost the government >5.6 million USD. The government of Uganda has invested in building the capacity for organ donation and transplantation services by training human resources personnel and setting up infrastructure in Kampala, where these services can be accessed. However, there is no information on the readiness of communities and the scientific community to embrace (communities) or undertake (science) organ transplantation in the country. We set out to assess knowledge and attitudes about organ donation and transplantation among the urban population in Kampala. METHODS: We conducted a cross-sectional survey among 395 participants from the urban population of Kampala at Garden City Mall, Wandegeya market, and Nakawa market from 28 May through 7 June 2021. We asked about knowledge of organ donation and transplantation, collected sociodemographic data, and performed a sentiment analysis of participants' attitudes toward organ donation and transplantation. RESULTS: The M:F ratio of participants was 1:1; the majority (55.9%) of participants were Baganda, two-thirds of participants knew about organ donation, and 90% of participants did not know of any government policy on organ donation and transplantation. Radio/television was the most common source of information, and the kidney was the most frequently transplanted organ. Overall, there were 94.3% and 93.2% positive sentiments toward organ transplantation and organ donation, respectively. The need for stricter laws governing organ donation and transplantation, corruption, and fear were the main negative sentiments expressed by participants. CONCLUSIONS: Sensitization of the community is required regarding government policy on organ donation and transplantation, and this should be communicated through radio/television and social media. There was a positive attitude toward organ donation and transplantation.


Assuntos
Turismo Médico , Transplante de Órgãos , Obtenção de Tecidos e Órgãos , Humanos , Estudos Transversais , População Urbana , Conhecimentos, Atitudes e Prática em Saúde , Uganda , Inquéritos e Questionários
12.
Am J Stem Cells ; 12(5): 98-111, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38213639

RESUMO

BACKGROUND: Keloids and hypertrophic scars are some of the most common skin conditions globally, associated with poor treatment response and high recurrence rates. Autologous adipose-derived stromal vascular fraction (SVF) is increasingly recognized as an emerging therapy albeit limited literature on its outcome in scar treatment. This review aimed to describe the current practices and outcomes of adipose-derived stromal Vascular Fraction in scar treatment. METHODS: This systematic review assessed articles describing the use of SVF in scar treatment published between 2000 and 2023. Article searches of Medline/PubMed, Cochrane Library, and Embase databases using Mesh terms and the Boolean operators ("AND", "OR") by two independent researchers were done whilst following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Clinical studies assessing SVF in scar treatment with a primary outcome measure being an improvement in scar characteristics including the thickness, scar assessment scores were included. RESULTS: Among the 1425 studies identified in the search, 20 studies met the inclusion criteria with a total of 493 patients included. Eight of these were clinical trials with the rest being observational studies. Follow-up ranged from 3 months to 24 months. In all studies, there was an improvement in scar characteristics following single-dose treatment with SVF or its equivalent. All studies reported SVF to be safe. CONCLUSION: The review found that autologous adipose-derived SVF is a clinically effective therapy for keloids and scar treatment.

13.
Am J Stem Cells ; 12(2): 23-36, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37215278

RESUMO

INTRODUCTION: Autologous adipose-derived stromal vascular fraction (SVF) has been described to have therapeutic benefits in the treatment of keloids. However, most of the evidence on its efficacy is based on observational studies the majority of which are conducted in high-income countries and yet the highest burden of keloids is in low- and middle-income countries (LMICs). OBJECTIVES: We set out to determine the safety and feasibility of using autologous adipose derived stromal vascular fraction in the treatment of keloids in LMICs. METHODS: In this phase II randomized controlled pilot clinical trial conducted in the Plastic Surgery Unit of Kirruddu National Referral Hospital in Kampala Uganda, 8 patients were assigned a 1:1 ratio to either SVF or triamcinolone acetonide (TAC) arms. In the SVF arm, a median (Inter quartile range) amount of stromal cell infiltration of 2.7×106 (11×106) was administered, while the controls received 10 mg/ml TAC at a ratio of 1:1 TAC to keloid volume. Primary endpoints were adverse event development based on the Common Terminology Criteria for Adverse Events (CTCAE) v5.0 tool and feasibility assessment based on ≥ 70% recruitment feasibility and ≥ 80% interventional feasibility rates. RESULTS: The participants' mean age was 27.9 (±6.5) years, with a female predilection of 5 (63%). Overall, no adverse events were reported in the SVF arm, while ulceration in a single patient in the TAC arm, which was a grade II adverse event, was reported. Recruitment feasibility of 80% and interventional feasibility with 100% completion were reported. CONCLUSION: Based on our findings, an autologous adipose-derived stromal vascular fraction is feasible and safe for the treatment of keloids in LMICs.

14.
J Public Health Afr ; 14(9): 2735, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37881727

RESUMO

On 20th September 2022, Uganda declared the 7th outbreak of Ebola virus disease (EVD) caused by the Sudan Ebola strain following the confirmation of a case admitted at Mubende Regional Referral Hospital. Upon confirmation, the Government of Uganda immediately activated the national incident management system to initiate response activities. Additionally, a multi-country emergency stakeholder meeting was held in Kampala; convening Ministers of Health from neighbouring Member States to undertake cross-border preparedness and response actions. The outbreak spanned 69 days and recorded 164 cases (142 confirmed, 22 probable), 87 recoveries and 77 deaths (case fatality ratio of 47%). Nine out of 136 districts were affected with transmission taking place in 5 districts but spilling over in 4 districts without secondary transmission. As part of the response, the Government galvanised robust community mobilisation and initiated assessment of medical counter measures including therapeutics, new diagnostics and vaccines. This paper highlights the response actions that contributed to the containment of this outbreak in addition to the challenges faced with a special focus on key recommendations for better control of future outbreaks.

15.
Genet Vaccines Ther ; 10(1): 8, 2012 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-22938508

RESUMO

BACKGROUND: Malaria causes immense human morbidity and mortality globally. The plasmodium species vivax and falciparum cause over 75 % clinical malaria cases. Until now, gene-based strategies against malaria have only been applied to plasmodium species and their mosquito-vector. Merozoites of these two respective plasmodium species target and invade red blood cells (RBCs) by using the duffy antigen receptor for chemokines (DARC), and Sialic Acid (SLC4A1) residues of the O-linked glycans of Glycophorin A. RBCs of naturally selected duffy-negative blacks are resistant to P.vivax tropism. We hypothesized that artificial aberration of the host-pathway by target mutagenesis of either RBC -receptors, may abolish or reduce susceptibility of the host to malaria. As a first step towards the experimental actualization of these concepts, we aimed to identify zinc finger arrays (ZFAs) for constructing ZFNs that target genes of either wild-type host-RBC- receptors. METHODS: In-Silico Gene & Genome Informatics RESULTS: Using the genomic contextual nucleotide-sequences of homo-sapiens darc and glycophorin-a, and the ZFN-consortia software- CoDA-ZiFiT-ZFA and CoDA-ZiFiT-ZFN: we identified 163 and over 1,000 single zinc finger arrays (sZFAs) that bind sequences within the genes for the two respective RBC-receptors. Second, 2 and 18 paired zinc finger arrays (pZFAs) that are precursors for zinc finger nucleases (ZFNs) capable of cleaving the genes for darc and glycophorin-a were respectively assembled. Third, a mega-BLAST evaluation of the genome-wide cleavage specificity of this set of ZFNs was done, revealing alternate homologous nucleotide targets in the human genome other than darc or glycophorin A. CONCLUSIONS: ZFNs engineered with these ZFA-precursors--with further optimization to enhance their specificity to only darc and glycophorin-a, could be used in constructing an experimental gene-based-malaria vaccine. Alternatively, meganucleases and transcription activator-like (TAL) nucleases that target conserved stretches of darc and glycophorin-a DNA may serve the purpose of abrogating invasion of RBCs by falciparam and vivax plasmodia species.

16.
BMC Blood Disord ; 12: 5, 2012 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-22583379

RESUMO

BACKGROUND: Sickle cell disease (or simply, SCD) is an inherited hemoglobinopathy which is mostly prevalent among persons of African descent. SCD results from a monogenic (Hemoglobin, beta) point-mutation (substitution of the base Adenine with Thymine at position six) that leads to replacement of the amino acid glutamic acid (E) with valine (V). Management of SCD within resource-poor settings is largely syndromic, since the option of cure offered by bone-marrow transplantation (BMT) is risky and unaffordable by most affected individuals. Despite previous reports of repair and inhibition of the sickle beta-globin gene and messenger ribonucleic acids (mRNAs), respectively in erythrocyte precursor cells via gene-targeting using an oligomer-restriction enzyme construct and either ribozyme- or RNA-DNA chimeric oligonucleotides (or simply third strand binding), gene-therapy to treat SCD still remains largely preclinical. In the wake of the advances in target- gene- mutagenesis and repair wrought by zinc finger nuclease (ZFN) technology, it was hypothesized that SCD may be cured by the same. The goal of this study thus, was constructing a database of zinc finger arrays (ZFAs) and engineering ZFNs, that respectively bind and cleave within or around specific sequences in the sickle hemoglobin, beta (-ßS) gene. METHODS AND RESULTS: First, using the complete 1606 genomic DNA base pair (bp) sequences of the normal hemoglobin-beta (ßA) chain gene, and the ZiFiT-CoDA-ZFA software preset at default, 57 three-finger arrays (ZFAs) that specifically bind 9 base-pair sequences within the normal hemoglobin-beta chain, were computationally assembled. Second, by serial linkage of these ZFAs to the Flavobacterium okeanokoites endonuclease Fok I- four ZFNs with unique specificity to >24 bp target-sequences at the genomic contextual positions 82, 1333, 1334, and 1413 of the ßA chain-gene were constructed in-silico. Third, localizing the point-mutation of SCD at genomic contextual position -69-70-71- bp (a position corresponding to the 6th codon) of the ßA chain-gene, inspired the final design of five more ZFNs specific to >24 bp target-sequences within the 8,954 bp that are genomically adjacent to the 5' end of the ßA chain-gene. CONCLUSIONS: This set of 57 ZFAs and 9 ZFNs offers us gene-therapeutic precursors for the targeted mutagenesis and repair of the SCD mutation or genotype.

17.
Theor Biol Med Model ; 9: 30, 2012 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-22840184

RESUMO

BACKGROUND: Human papillomavirus (HPV) types 16 and 18 are the high-risk, sexually transmitted infectious causes of most cervical intraepithelial neoplasias (CIN) or cancers. While efficacious vaccines to reduce the sexual acquisition of these high-risk HPVs have recently been introduced, no virus-targeted therapies exist for those already exposed and infected. Considering the oncogenic role of the transforming (E6 and E7) genes of high-risk HPVs in the slow pathogenesis of cervical cancer, we hypothesize that timely disruption or abolition of HPV genome expression within pre-cancerous lesions identified at screening may reverse neoplasia. We aimed to derive model zinc finger nucleases (ZFNs) for mutagenesis of the genomes of two high-risk HPV (types 16 & 18). METHODS AND RESULTS: Using ZiFiT software and the complete genomes of HPV types16 and 18, we computationally generated the consensus amino acid sequences of the DNA-binding domains (F1, F2, & F3) of (i) 296 & 327 contextually unpaired (or single) three zinc-finger arrays (sZFAs) and (ii) 9 & 13 contextually paired (left and right) three- zinc-finger arrays (pZFAs) that bind genomic DNA of HPV-types 16 and 18 respectively, inclusive of the E7 gene (s/pZFAHpV/E7). In the absence of contextually paired three-zinc-finger arrays (pZFAs) that bind DNA corresponding to the genomic context of the E6 gene of either HPV type, we derived the DNA binding domains of another set of 9 & 14 contextually unpaired E6 gene-binding ZFAs (sZFAE6) to aid the future quest for paired ZFAs to target E6 gene sequences in both HPV types studied (pZFAE6). This paper presents models for (i) synthesis of hybrid ZFNs that cleave within the genomic DNA of either HPV type, by linking the gene sequences of the DNA-cleavage domain of the FokI endonuclease FN to the gene sequences of a member of the paired-HPV-binding ZFAs (pZFAHpV/E7 + FN), and (ii) delivery of the same into precancerous lesions using HPV-derived viral plasmids or vectors. CONCLUSIONS: With further optimization, these model ZFNs offer the opportunity to induce target-mutagenesis and gene-therapeutic reversal of cervical neoplasia associated with HPV types 16 & 18.


Assuntos
Papillomavirus Humano 16/genética , Papillomavirus Humano 16/metabolismo , Papillomavirus Humano 18/genética , Papillomavirus Humano 18/metabolismo , Neoplasias do Colo do Útero/terapia , Dedos de Zinco , Sequência de Bases , DNA Viral/genética , Bases de Dados Factuais , Desoxirribonucleases/metabolismo , Feminino , Regulação Viral da Expressão Gênica/fisiologia , Terapia Genética , Genoma Viral/genética , Humanos , Modelos Biológicos , Mutagênese , Neoplasias do Colo do Útero/virologia
18.
Am J Stem Cells ; 11(4): 56-63, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36189175

RESUMO

BACKGROUND: Autologous adipose-derived stromal vascular fraction (SVF) is an emerging therapy that is being pioneered as a potential treatment for keloids and hypertrophic scars. Up to this point, there isn't a cure for keloids and hypertrophic scars yet they comprise the commonest benign skin disorders. Despite published studies reporting potential therapeutic benefits of SVF, their use and efficacy on scar improvement are not clearly described. The aim of this review is to describe the clinical practice involved in harvesting, processing, utilization of SVF, and associated efficacy in scar treatment. METHODS: We shall include published clinical articles evaluating the efficacy of SVF on improving scar characteristics and assessment scores among adults with keloids or hypertrophic scars. Article search of Medline/PubMed, Cochrane Library and Embase using Mesh terms of "scars" and "stromal vascular fraction" combined with the Boolean operators ("AND", "OR") will be performed by two independent researchers following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) statement. The primary outcome measure will be the mean difference in the Scar characteristics including Scar assessment scores, scar thickness among others. DATA SYNTHESIS: Descriptive data synthesis and mean differences between treatment arms will be calculated for the primary outcome of the scar assessment scores. In case more than three studies provide consistent characteristics of the scar assessment scores, a meta-analysis will be conducted. DISCUSSION: Evidence obtained from the systematic review will form the foundation upon which further clinical trials research will be conducted in evaluating the efficacy of autologous adipose-derived stromal vascular fraction in keloid and hypertrophic scar. The systematic review has been submitted to the PROSPERO database and is currently under review.

19.
Theor Biol Med Model ; 8: 26, 2011 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-21781315

RESUMO

BACKGROUND: Infection with HIV, which culminates in the establishment of a latent proviral reservoir, presents formidable challenges for ultimate cure. Building on the hypothesis that ex-vivo or even in-vivo abolition or disruption of HIV-gene/genome-action by target mutagenesis or excision can irreversibly abrogate HIV's innate fitness to replicate and survive, we previously identified the isoschizomeric bacteria restriction enzymes (REases) AcsI and ApoI as potent cleavers of the HIV-pol gene (11 and 9 times in HIV-1 and 2, respectively). However, both enzymes, along with others found to cleave across the entire HIV-1 genome, slice (SX) at palindromic sequences that are prevalent within the human genome and thereby pose the risk of host genome toxicity. A long-term goal in the field of R-M enzymatic therapeutics has thus been to generate synthetic restriction endonucleases with longer recognition sites limited in specificity to HIV. We aimed (i) to assemble and construct zinc finger arrays and nucleases (ZFN) with either proviral-HIV-pol gene or proviral-HIV-1 whole-genome specificity respectively, and (ii) to advance a model for pre-clinically testing lentiviral vectors (LV) that deliver and transduce either ZFN genotype. METHODS AND RESULTS: First, we computationally generated the consensus sequences of (a) 114 dsDNA-binding zinc finger (Zif) arrays (ZFAs or ZifHIV-pol) and (b) two zinc-finger nucleases (ZFNs) which, unlike the AcsI and ApoI homeodomains, possess specificity to >18 base-pair sequences uniquely present within the HIV-pol gene (ZifHIV-polFN). Another 15 ZFNs targeting >18 bp sequences within the complete HIV-1 proviral genome were constructed (ZifHIV-1FN). Second, a model for constructing lentiviral vectors (LVs) that deliver and transduce a diploid copy of either ZifHIV-polFN or ZifHIV-1FN chimeric genes (termed LV- 2xZifHIV-polFN and LV- 2xZifHIV-1FN, respectively) is proposed. Third, two preclinical models for controlled testing of the safety and efficacy of either of these LVs are described using active HIV-infected TZM-bl reporter cells (HeLa-derived JC53-BL cells) and latent HIV-infected cell lines. CONCLUSION: LV-2xZifHIV-polFN and LV- 2xZifHIV-1FN may offer the ex-vivo or even in-vivo experimental opportunity to halt HIV replication functionally by directly abrogating HIV-pol-gene-action or disrupting/excising over 80% of the proviral HIV DNA from latently infected cells.


Assuntos
Endonucleases/metabolismo , Genes pol/genética , Terapia Genética , Genoma Viral/genética , HIV-1/genética , Provírus/genética , Dedos de Zinco/genética , Sequência de Bases , DNA Viral/genética , Vetores Genéticos , Humanos , Lentivirus/genética , Especificidade por Substrato , Transdução Genética
20.
Theor Biol Med Model ; 8: 23, 2011 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-21702927

RESUMO

BACKGROUND: Herpes simplex type II (HSV-2) is a member of the family herpesviridae. Human infection with this double stranded linear DNA virus causes genital ulcerative disease and existing treatment options only serve to resolve the symptomatology (ulcers) associated with active HSV-2 infection but do not eliminate latent virus. As a result, infection with HSV-2 follows a life-long relapsing (active versus latent) course. On the basis of a primitive bacterium anti-phage DNA defense, the restriction modification (R-M) system, we previously identified the Escherichia coli restriction enzyme (REase) EcoRII as a novel peptide to excise or irreversibly disrupt latent HSV-2 DNA from infected cells. However, sequences of the site specificity palindrome of EcoRII 5'-CCWGG-3' (W = A or T) are equally present within the human genome and are a potential source of host-genome toxicity. This feature has limited previous HSV-2 EcoRII based therapeutic models to microbicides only, and highlights the need to engineer artificial REases (zinc finger nucleases-ZFNs) with specificity to HSV-2 genomic-DNA only. Herein, the therapeutic-potential of zinc finger arrays (ZFAs) and ZFNs is identified and modeled, with unique specificity to the HSV-2 genome. METHODS AND RESULTS: Using the whole genome of HSV-2 strain HG52 (Dolan A et al.,), and with the ZFN-consortium's CoDA-ZiFiT software pre-set at default, more than 28,000 ZFAs with specificity to HSV-2 DNA were identified. Using computational assembly (through in-silico linkage to the Flavobacterium okeanokoites endonuclease Fok I of the type IIS class), 684 ZFNs with specificity to the HSV-2 genome, were constructed. Graphic-analysis of the HSV-2 genome-cleavage pattern using the afore-identified ZFNs revealed that the highest cleavage-incidence occurred within the 30,950 base-pairs (~between the genomic context coordinates 0.80 and 1.00) at the 3' end of the HSV-2 genome. At approximately 3,095 bp before and after the 5' and 3' ends of the HSV-2 genome (genomic context coordinates 0.02 and 0.98, respectively) were specificity sites of ZFNs suited for the complete excision of over 60% of HSV-2 genomic material from within infected human cells, through the process of non-homologous end joining (NHEJ). Furthermore, a model concerning a recombinant (ICP10-PK mutant) replication competent HSV-2 viral vector for delivering and transducing a diploid copy (or pair) of the HSV-2-genome-specific ZFN genotype within neuronal tissue, is presented. CONCLUSION: ZFNs with specificity to HSV-2 genomic DNA that are precursors of novel host-genome expressed HSV-2 gene-therapeutics or vaccines were identified.


Assuntos
DNA Viral/genética , Desoxirribonucleases/metabolismo , Genoma Viral/genética , Vacinas contra o Vírus do Herpes Simples/imunologia , Herpesvirus Humano 2/genética , Herpesvirus Humano 2/imunologia , Dedos de Zinco/genética , Pareamento de Bases/genética , Sequência de Bases , Vetores Genéticos/genética , Genótipo , Humanos , Modelos Genéticos , Recombinação Genética/genética , Especificidade por Substrato , Transdução Genética
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