An investigation into the serological and molecular diagnosis of Jaagsiekte Sheep Retrovirus (JSRV)

Thesis (M.Med.)-University of KwaZulu-Natal, 2005.The Jaagsiekte Sheep Retrovirus (JSRV), an exogenous type B/D-retrovirus with about 10-15 endogenous counterparts in all normal sheep genomes, causes Jaagsiekte (JS) or ovine pulmonary adenocarcinoma (OPA), a contagious lung cancer of sheep. This sheep lung cancer has been identified as the best natural out-bred model that can be used to study human epithelial tumours. The close similarity between the pathology of the sheep disease and Human Bronchiolo-alveolar carcinoma are highly suggestive that the human disease could have a similar aetiology and mechanism to the sheep disease. However, in the case of sheep at the time of the study there was a need for an assay that could be used to screen for infected sheep. The isolation, cloning and subsequent sequencing of the first full-length exogenous and endogenous forms of JSRV contributed greatly towards JSRV research. Until recently the diagnosis of OPA was based mostly on clinical presentation with confirmation by micro and macro examination of the affected lungs by expert pathologists. In the absence of a specific humoral response no serology-based tests were available to diagnose the disease early in live animals. Control and management of the disease was primarily by regular flock inspections and prompt culling of the suspected cases. The objective of this research project was therefore to assess and investigate the serological and molecular diagnosis of JSRV. In an attempt to develop a serology based assay three proteins were identified as candidate diagnostic antigens, the group specific antigen JSRV p26, the transmembrane and the orf-X proteins. Genes coding for all three proteins were isolated, cloned and expressed. The JSRV p26 was sufficiently purified and its potential as a diagnostic antigen was evaluated in both a Western blot and ELISA. Our studies confirmed that there were no circulating antibodies to the JSRV capsid protein. Evidence suggested that the immune response was localised to the lungs. Lung lavage samples were therefore collected from infected and normal sheep and analysed for the presence of JSRV p26 antibodies using an in-house JSp26 peroxidase conjugate in an antigen capture assay. This assay lacked sensitivity but the results indicated that there was a specific localised immune response to JSRV in the lungs of OPA affected sheep. This was confirmed with an in-house antigen capture assay that we developed. JS antigen was detected in the lung and nasal fluid of affected sheep, but not in equivalent samples from normal sheep. Three molecular assays were investigated for their sensitivity and specificity, the LTR-gag PCR, U3/LTR hemi-nested PCR and the PCR that covered the V1/V2 region. The U3/LTR hemi-nested assay was 2 logs more sensitive than the LTR-gag PCR. However, it detected the endogenous JSRV5.9A1 loci at higher concentrations. This was overcome by designing a more specific primer P3M for the first step of the U3/LTR hemi-nested PCR and the use of the AmpliTaq Gold DNA polymerase. This assay proved to be both sensitive and specific enough to screen for the infectious exogenous JSRV in peripheral blood samples from individual sheep. It is now possible to use this assay to selectively eradicate the disease from a flock through a selective culling programme. Furthermore, the assay could be made quantitative by the inclusion of concentration standards

SYNTHESIS, CHARACTERIZATION AND IN VITRO ANTIMICROBIAL EVALUATION OF SOME NEW AMIDES OF THIOMORPHOLINE CARBOXYLATE

Objective: Synthesis and antimicrobial evaluation of some new amides of Thiomorpholine caboxylate.Methods: A series of new amides of Thiomorpholine caboxylate were synthesized by reacting 4-tert-butyl 2-methyl thiomorpholine-2,4-dicarboxylate 1,1-dioxide with primary amines in presence of Trimethyl aluminum in toluene at ambient temperature in good yields. 4-tert-butyl 2-methyl thiomorpholine-2,4-dicarboxylate 1,1-dioxide was synthesized by reacting tert-butyl thiomorpholine-4-carboxylate 1,1-dioxide with methyl chloroformate in presence of LiHMDS (1M in THF) at -78oC for the first time. The newly synthesized compounds were characterized by IR, 1HNMR, 13C NMR, Mass spectral studies and elemental analysis.Results: A series of new amides of Thiomorpholine carboxylate were synthesized in good yields and all the compounds were screened for their In-vitro antimicrobial activities. Conclusion: Preliminary results revealed that the synthesized compounds were showed moderate to good antibacterial and antifungal activity

One pot synthesis of 1-((1-aryl-1H-1,2,3-triazol-4-yl)methyl)-1H-benzo[d] imidazoles in ionic liquids: Evaluation of antioxidant and antimicrobial activities

In view of pharmacological importance of benzimidazole and 1,2,3-triazole nuclei, we made an effort to synthesize the bi-functional mimic 1,2,3-triazolyl-benzimidazoles through the copper catalyzed azide-alkyne 1,3-dipolar cycloaddition reaction in ionic liquids. The synthesized compounds were characterized by NMR, IR and Mass spectral analysis. The synthesized compounds were screened for antimicrobial and antioxidant activities. A good number of the compounds found to possess potent antioxidant and antimicrobial activities

Drug resistance and viral tropism in HIV-1 subtype C-infected patients in KwaZulu-Natal, South Africa: implications for future treatment options

Article approval pendingDrug resistance poses a significant challenge for the successful application of highly active antiretroviral therapy (HAART) globally. Furthermore, emergence of HIV-1 isolates that preferentially use CXCR4 as a coreceptor for cell entry, either as a consequence of natural viral evolution or HAART use, may compromise the efficacy of CCR5 antagonists as alternative antiviral therapy

If not now, when? Time for the European Union to define a global health strategy

Speakman, E. M., McKee, M., & Coker, R. (2017). If not now, when? Time for the European Union to define a global health strategy. Lancet Global Health, 5(4), e392-e393. https://doi.org/10.1016/S2214-109X%2817%2930085-

One-pot synthesis of novel 1,2,3-triazole-pyrimido[4,5-c]isoquinoline hybrids and evaluation of their antioxidant activity

<p>A series of novel pyrimido[4,5-<i>c</i>]isoquinolines (<b>3a–3h</b>) and 1,2,3-triazole-coupled pyrimido[4,5-<i>c</i>]isoquinolines (<b>4a–4h</b>) were synthesized in good to excellent yields in the one-pot method. The reaction of 6-amino-1,3-dimethyluracil with different 2-iodo benzoyl chlorides using Pd catalyst in dimethylformamide afforded corresponding pyrimido[4,5-<i>c</i>]isoquinolines (<b>3a–3h</b>). One-pot reaction of pyrimido[4,5-<i>c</i>]isoquinolines with propargyl bromide and benzyl azide in THF at room temperature furnished 1,2,3-triazole-coupled pyrimido[4,5-<i>c</i>]isoquinoline (<b>4a–4h</b>). In vitro antioxidant activity examination revealed that compounds <b>4d</b> and <b>4c</b> found to exhibit potent antioxidant activity as compared to the standard drug Trolox with IC₅₀ values 6.02 ± 0.6 and 12.18 ± 0.9 µM, respectively.</p

Synthesis and biological evaluation of (3-arylisoxazol-5-yl) methyl 6-fluoro-4-oxo-4H-chromene-2-carboxylates as antioxidant and antimicrobial agents

A series of novel (3-aryl-1,2-oxazol-5-yl) methyl 6-fluoro-4-oxo-4H- -chromene-2-carboxylate derivatives (C1-C12) were synthesized by Cu (I) catalyzed reaction of in situ generated nitrile oxides with prop-2-yn-1-yl 6-fluoro-4-oxo-4H-chromene-2-carboxylate in good yields and investigated their antioxidant and antimicrobial activities. Among all the synthesized compounds, C1 (IC50: 16.43 ± 0.57 μM) and C12 (IC50:15.98 ± 0.72 μM) have registered good antioxidant activity as compared to the standard drug Trolox. Compound-C1, C3, and C6 have registered very good inhibition against all gram-positive and gram-negative bacterial strains with MIC values ranging from 9.375 to 37.5 (μg mL-1). Compound-C7, C8, C9, C10, and C11 have registered good inhibition against B. subtilis and S. aureus with MIC values ranging from 18.75 to 37.5 (μg mL-1). Compound-C10 and C11 against P. aero-ginosa have shown prominent activity than the standard drug Penicillin (MIC: 12.5 μg mL-1) with MIC 9.375 μg mL-1 (~ 1.33 fold potent than Penicillin). Compound-C7, C8, and C9 have registered good to moderate antifungal activity against four tested fungal strains with MIC values ranging from 18.75 and 37.5 μg mL-

Design, synthesis, and biological evaluation of novel substituted imidazo[2,1-<i>a</i>]isoindole derivatives as antibacterial agents

<p>An efficient protocol has been developed for the synthesis of fused imidazo[2,1-<i>a</i>]isoindol-5-ones (<b>2a–d</b>) from 2-iodo benzoic acids and <i>N</i>,<i>N</i>-carbonyldiimidazole (CDI) using one-pot Pd-catalyzed C‒C bond coupling. The reaction of imidazo[2,1-<i>a</i>]isoindol-5-one (<b>2a–d</b>) with substituted α-bromo ketones in toluene afforded corresponding imidazo[2,1-<i>a</i>]isoindolium derivatives (<b>3a–i</b>) in good yields. The structures of the title compounds were well established on the basis of infrared (IR), ¹H NMR, carbon-13 nuclear magnetic resonance (¹³C NMR), mass spectral data, and elemental analysis (C, H, and N). <i>In vitro</i> antibacterial results revealed that, the compounds <b>3b</b> and <b>3i</b> were found to possess an excellent broad spectrum of inhibiting potency against all the tested bacterial strains with minimum inhibitory concentration values ranging from 3.125 to 25 µg mL⁻¹.</p

Synthesis and antimicrobial evaluation of some novel thiomorpholine derived 1,4-disubstituted 1,2,3-triazoles

A convenient synthesis of novel1,4-disubstituted 1,2,3-triazoles (4a-j & 5a-j) is reported via copper (I) - catalyzed one pot [3+2] cycloaddition of various alkyl halides, sodium azide with (prop-2-yn-1-yl)thiomorpholine and 4-(prop-2-yn-1-yl)thiomorpholine 1,1-dioxide. All the synthesized compounds were investigated for their antimicrobial activity. Compounds 4a, 4b, 4c, 4g, 5a and 5j against S.epidermidis, 4a, 5a and 5d against P. aeroginosa, 4a, 4b and 4g against K.pneumoniae, 4b, 5a and 5d against S.aureus and 5b, 5e and 5j against B.Subtilis have shown excellent antibacterial activity compared to the standard drugs Penicillin and Streptomycin. Compounds 4c, 4e, 4f, 4j, 5c, 5d, 5g and 5j have registered moderate antifungal activity as compared with standard drug Ampothericin-B