Synthesis of N₄'-[¹⁸F]fluoroalkylated ciprofloxacin as a potential bacterial infection imaging agent for PET study

Syntheses and evaluation of fluoroalkylated ciprofloxacin analogues are described. Among these analogues, N?'-3-fluoropropylciprofloxacin (16) showed the most efficient antibacterial activity against E. coli strains (DH5α and TOP10) and a high binding affinity for DNA gyrase of bacteria. To develop bacteria-specific infection imaging agents for positron emission tomography (PET), no-carrier-added N?-3-[1?F]fluoropropylciprofloxacin ([1?F]16) was prepared in two steps from N?-3-methanesufonyloxypropylciprofloxacin, resulting in a 40% radiochemical yield (decay corrected for 100 min) via the tert-alcohol media radiofluorination protocol with high radiochemical purity (> 99%) as well as high specific activity (149 ± 75 GBq/μmol). The agent was stable (> 90%), as shown by an in vitro human serum stability assay. A bacterial uptake and blocking study of [1?F]16 using authentic compound 16 in TOP10 cells demonstrated its high specific bacterial uptake. The results suggest that this radiotracer holds promise as a useful bacterial infection radiopharmaceutical for PET imaging.     

Selection of an antiviral RNA aptamer against hemagglutinin of the subtype H5 avian influenza virus

Avian influenza is an acute viral respiratory disease caused by RNA viruses of the family Orthomyxoviridae. The influenza A virus subtype H5 can cause severe illness and results in almost 100% mortality rate among livestock. Hemagglutinin (HA) present in the virus envelope plays an essential role in the initiation of viral infection. In this study, we investigated the efficacy of using HA as a target for antiviral therapy through nucleic acid aptamers. After purification of the receptor binding domain (HA1) of HA protein, activity of recombinant HA1 was confirmed by using hemagglutination assay. We selected RNA aptamer candidates after 15 rounds of iterative Systematic Evolution of Ligands by EXponential enrichment (SELEX) targeting the biologically active HA protein. The selected RNA aptamer HAS15-5, which specifically binds to HA1, exhibited significant antiviral efficacy according to the results of a hemagglutination inhibition assay using egg allantoic fluids harboring the virus. Thus, the RNA aptamer HAS15-5, which acts by blocking and inhibiting the receptor-binding domain of viral HA, can be developed as a novel antiviral agent against type H5 avian influenza virus.     

Diesel and Kerosene Degradation by <Emphasis Type="Italic">Pseudomonas desmolyticum</Emphasis> NCIM 2112 and <Emphasis Type="Italic">Nocardia hydrocarbonoxydans</Emphasis> NCIM 2386

Pseudomonas desmolyticum NCIM 2112 (Pd 2112) and Nocardia hydrocarbonoxydans NCIM 2386 (Nh 2386) demonstrated an ability to degrade diesel and kerosene. Triton X-100 had enhanced the diesel degradation process by reducing the time required for the maximum utilization of total petroleum hydrocarbon. Fourier transform infrared spectroscopy spectrum of degraded diesel indicates the presence of aliphatic and aromatic aldehydes, C=C aromatic nuclei, and substituted benzenes. Surface tension reduction and stable emulsification was increased using consortium when compared to individual strains. Triton X-100 showed increase in microbial attachment to hydrocarbon among the various chemical surfactants tested. For generating a rapid assay to screen microorganisms capable of degrading kerosene, the acetaldehyde produced in the degradation process could be used as an indicator of degradation. These results indicate diesel and kerosene degradation ability of both of the strains.     

Metal accumulation in two contiguous eutrophic peri-urban lakes,Chivero and Manyame,Zimbabwe

Concentrations of aluminium, cadmium, chromium, cobalt, copper, iron, lead, nickel and zinc were determined in surface water, benthic sediments, and the gills, liver and stomach muscle tissues of Oreochromis niloticus and Clarias gariepinus in peri-urban lakes Chivero and Manyame, Zimbabwe. Five sites were sampled in each lake once per month in November 2015, February, May, August and November 2016. Pollution load index detected no metal contamination, whereas the geo-accumulation index reflected heavy to extreme sediment pollution, with Fe, Cd, Zn, Cr, Ni and Cu present in both lakes. Significant spatial temporal variations were detected for Al, Cr, Cu and Pb across sites within and between the two lakes. High Fe, Al and Cr concentrations in water and sediments in lakes Chivero and Manyame derive from geogenic background sources in addition to anthropogenic loads and intensity. Elevated concentrations of Al, Pb, Cu, Cd, Fe and Zn detected in gills, liver and stomach tissue of catfish corroborate concentrations in water and sediments, and pose the highest ecological and health risk for hydrobionts in lakes Chivero and Manyame. Contiguity of peri-urban lakes exposes them to similar threats, necessitating creative water management strategies, which ensure ecological continuity.     

The antidepressant-like effect of Ocimum basilicum in an animal model of depression

We investigated the efficacy of Ocimum basilicum (OB) essential oils for treating depression related behavioral, biochemical and histopathological changes caused by exposure to chronic unpredictable mild stress (CUMS) in mice and to explore the mechanism underlying the pathology. Male albino mice were divided into four groups: controls; CUMS; CUMS plus fluoxetine, the antidepressant administered for pharmacological validation of OB; and CUMS plus OB. Behavioral tests included the forced swim test (FST), elevated plus-maze (EPM) and the open ?eld test (OFT); these tests were performed at the end of the experiment. We assessed serum corticosterone level, protein, gene and immunoexpression of brain-derived neurotropic factor (BDNF) and glucocorticoid receptors (GRs) as well as immunoexpression of glial fibrillary acidic protein (GFAP), Ki67, caspase-3 in the hippocampus. CUMS caused depression in the mice as evidenced by prolonged immobility in the FST, prolonged time spent in the open arms during the EPM test and reduction of open field activity in the OFT. OB ameliorated the CUMS induced depressive status. OB significantly reduced the corticosterone level and up-regulated protein and gene expressions of BDNF and GR. OB reduced CUMS induced hippocampal neuron atrophy and apoptosis, and increased the number of the astrocytes and new nerve cells. OB significantly increased GFAP-positive cells as well as BDNF and GR immunoexpression in the hippocampus.     

Preparation of soybean seed samples for FT-IR microspectroscopy

Typical preparation of seed samples for infrared (IR) microspectroscopy involves imbibition of the seed for varying time periods followed by cryosectioning. Imbibition, however, may initiate germination even at 4° C with associated changes in the chemistry of the sample. We have found that it is possible to section seeds that are sufficiently hard, such as soybeans, on a standard laboratory microtome without imbibition. The use of dry sectioning of unimbibed seeds is reported here, as well as a comparison of different mounting media and modes of analysis. Glycerol, Tissue-Tek, and ethanol were used as mounting media, and the quality of the resulting spectra was assessed. Ethanol was the preferred mountant, because it dried quickly with no residue and thus did not interfere with the spectrum of interest. Analysis in transmission mode using barium fluoride windows to hold the samples was compared with transmission-reflection analysis with sections mounted on special infrared-reflecting slides. The two modes of analysis performed well in different regions of the spectrum. The mode of analysis (transmission vs. transmission-reflection) should be based on the components of greatest interest in the sample.