Papers by Florence Okafor
African histoplasmosis caused by Histoplasma capsulatum var. duboisii is an important deep mycosi... more African histoplasmosis caused by Histoplasma capsulatum var. duboisii is an important deep mycosis endemic in Central and West Africa and in the island of Madagascar. The disease is characterized by presence of granulomatous lesions in the skin, subcutaneous tissues and bones. Lungs and other internal organs are rarely involved. The natural reservoir of the etiological agent has only been recently discovered in a bat cave in Nigeria. The status of asymptomatic infection is not certain. Investigations on skin and serum reactivity have sugges-ted frequent prevalence of asymptomatic infections due to H. capsulatum var. duboisii among the residents in the vicinity of the cave microfocus of the fungus. The exact portal of entry into the body is not known, but inhalation into the lungs and direct inoculation in the skin have been incriminated. Laboratory diagnosis is confirmed by in vitro conversion into large yeast forms (8-15 µm in diameter) and by the demonstration of these forms withi...
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Mycopathologia, 1993
Lecythophora mutabilis was isolated from the lungs of 3 and from the liver of 2 bats,Eidolon helv... more Lecythophora mutabilis was isolated from the lungs of 3 and from the liver of 2 bats,Eidolon helvum a fruit eating species.Wangiella dermatitidis was recovered from the liver of 2 bats of the same species. The isolates were pathogenic for laboratory mice when injected by subcutaneous, intraperitoneal and intravenous routes.W. dermatitidis was neurotropic in the mice injected intravenously.
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New Visions in Biological Science Vol. 3
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Experimental Parasitology, Nov 1, 2003
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British Microbiology Research Journal, 2014
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Proceedings of Spie the International Society For Optical Engineering, 2006
ABSTRACT Optical trapping and transportation of microorganisms by the moving interference pattern... more ABSTRACT Optical trapping and transportation of microorganisms by the moving interference pattern was demonstrated with low-power (~50mW) HeNe-laser. Novel type of short-pulsed (ns) electrophoresis induced by photogalvanic effect is suggested and tested. We propose to use novel synergetic approach, based on synchronous application of optical trapping and pulsed electrical field for transportation and selective separation of solution components.
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Twelve fungal isolates recovered from oil-contaminated soils were screened for crude oil biodegra... more Twelve fungal isolates recovered from oil-contaminated soils were screened for crude oil biodegradation activity in a shake-flask culture. Among the twelve fungal isolates, only eight showed potentials for biodegradation. Of these eight isolates, two of them identified as Aspergillus versicolor and Aspergillus niger which exhibited the fastest onset and highest extent of biodegradation were selected for further study on specific polycyclic aromatic hydrocarbon (PAH) biodegradation. Both isolates exhibited above 98% degradation efficiency for polycyclic aromatic hydrocarbon moieties when grown in a culture medium incorporated with 1% crude oil (hydrocarbon) and 0.1 %Tween 80 for 7 days.
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Mycoses, 2000
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International Journal of Environmental Research and Public Health, 2013
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International Journal of Biological Macromolecules, 2012
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Current Medicinal Chemistry, 2013
In this review we discuss the role of ATP synthase as a molecular drug target for natural and syn... more In this review we discuss the role of ATP synthase as a molecular drug target for natural and synthetic antimicrobial/ antitumor peptides. We start with an introduction of the universal nature of the ATP synthase enzyme and its role as a biological nanomotor. Significant structural features required for catalytic activity and motor functions of ATP synthase are described. Relevant details regarding the presence of ATP synthase on the surface of several animal cell types, where it is associated with multiple cellular processes making it a potential drug target with respect to antimicrobial peptides and other inhibitors such as dietary polyphenols, is also reviewed. ATP synthase is known to have about twelve discrete inhibitor binding sites including peptides and other inhibitors located at the interface of α/β subunits on the F(1) sector of the enzyme. Molecular interaction of peptides at the β DEELSEED site on ATP synthase is discussed with specific examples. An inhibitory effect of other natural/synthetic inhibitors on ATP is highlighted to explore the therapeutic roles played by peptides and other inhibitors. Lastly, the effect of peptides on the inhibition of the Escherichia coli model system through their action on ATP synthase is presented.
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Applied Organometallic Chemistry, 2006
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Nanoscale systems have peculiar optical properties, deriving from confinement in one or more dime... more Nanoscale systems have peculiar optical properties, deriving from confinement in one or more dimensions to the nanometer scale, efficient energy and charge transfer over nanoscale distances, and.
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Journal of Agriculture & Life Sciences
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Mycopathologia, 1996
The epidemiology of histoplasmosis duboisii (African histoplasmosis) is not well understood. The ... more The epidemiology of histoplasmosis duboisii (African histoplasmosis) is not well understood. The present study was carried out to investigate the prevalence of skin sensitivity and to determine by immunodiffusion the presence of antibodies among humans to histoplasmin around a recently discovered natural focus of Histoplasma capsulatum var. duboisii in a bat cave in Ogbunike in the Anambra State of Nigeria. Out of the 40 subjects, all young adults aged 18–30 years, comprising cave guides, traders and farmers examined in the immediate vicinity of the cave, 14 (35.0%) gave a positive skin test. In another population of the same age group, comprising 620 persons, viz. traders, farmers, palm oil workers and some patients attending rural clinics, examined in other nearby areas in Anambra State, 55 (8.8%) reacted positively to histoplasmin. In the immunodiffusion tests, 2 (2.08%) of the 96 school children and 17 (9.4%) of the 181 young adults, including farmers, palm oil workers and traders tested amongst the population around the cave, demonstrated precipitating antibodies to histoplasmin in their sera. Only 5 (0.79%) of the 630 adults of the same age group with similar occupations examined from other areas in Anambra State had precipitating antibodies. Out of another 50 subjects examined, viz.; wood workers, traders, farmers, and school teachers in Nsukka in the Enugu State, two (4.0%) demonstrated antibodies. It is suggested that asymptomatic infections due to the duboisii variety of H. capsulatum may be common in the human population around the cave. A diligent search with the help of local hospitals and public health officials may reveal clinical cases of histoplasmosis duboisii with cutaneous and systemic lesions.
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Mycoses, 1997
Summary. Histoplasma capsulatum var. duboisii has only recently been shown to occur naturally in ... more Summary. Histoplasma capsulatum var. duboisii has only recently been shown to occur naturally in soil admixed with bat guano in a bat cave. We report our observations on the in vitro interaction of Histoplasma capsulatum var. duboisii with other fungi recovered from the same habitat or other sources by employing co-culture technique and by investigating antibiosis between H. capsulatum var. duboisii and other fungi. The range of interactions varied from total overgrowth of Histoplasma by Aspergillus fumigatus and Microsporum gypseum, through partial antagonism by Lecythophora mutabilis, to mutual inhibition by Wangiella dermattidis. Those fungi that exhibited a competitive advantage in terms of growth did not affect the viability of Histoplasma. Lysis and mycoparasitic structures were not observed in the co-cultures. However, the cultural filtrate of Chrysosporium indicum inhibited the growth of the Histoplasma strains. The results suggest the ability of H. capsulatum var. duboisii to co-exist with a variety of other potentially pathogenic and non-pathogenic fungi in an ecological niche.Zusammenfassung. Es wird über Beobachtungen der Wechselwirkungen zwischen Histoplasma capsulatum var. duboisii und anderen Pilzen mittels Kokulturtechnik in vitro berichtet. Das Spektrum der Wechselwirkungen reichte von totaler Überwucherung durch Aspergillus fumigatus und Microsporum gypseumüber partiellen Antagonismus mit Lecythophora mutabilis bis zu gegenseitiger Hemmung durch Wangiella dermatitidis. Die Pilze, die einen kompetitiven Wachstumsvorteil zeigten, beeinflußten jedoch nicht die Lebensfähigkeit von Histoplasma. Lyse und Mycoparasitismus wurden in den Kokulturen nicht beobachtet. Jedoch hemmte das Kulturfiltrat von Chrysosporium indicum das Wachstum der Histoplasma-Stämme. Die Ergebnisse sprechen für die Fähigkeit von H. capsulatum var. duboisii, mit einer Vielzahl anderer pathogener und nicht-pathogener Pilze in einer ökologischen Nische zu überleben.
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Abstract Twelve fungal isolates recovered from oil-contaminated soils were screened for crude oil... more Abstract Twelve fungal isolates recovered from oil-contaminated soils were screened for crude oil biodegradation activity in a shake-flask culture. Among the twelve fungal isolates, only eight showed potentials for biodegradation. Of these eight isolates, two of them ...
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Mycopathologia, 1996
Histoplasma capsulatum var.duboisii is the etiological agent of African histoplasmosis, an import... more Histoplasma capsulatum var.duboisii is the etiological agent of African histoplasmosis, an important deep mycosis in West Africa. Not much is known about the physiological properties of this fungus. This communication reports on the extracellular proteolytic enzyme activity of this fungus. Five isolates of this fungus tested hydrolyzed azocasein and bovine serum albumin at pH 6.8 and 8.0. Assay of the crude enzyme showed that proteolytic activity increased with age and peaked on the 10th day and then again on the 13th day for the yeast form, and on the 11th day of growth for the mycelial form. The optimum temperature and pH for maximum enzyme activity were 35 °C and 6.8 respectively. The proteinase activity was more pronounced with the yeast form than with the mycelial form. The action of enzyme inhibitors suggested the presence of an aspartyl proteinase.
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Mycopathologia, 1993
Lecythophora mutabilis was isolated from the lungs of 3 and from the liver of 2 bats,Eidolon helv... more Lecythophora mutabilis was isolated from the lungs of 3 and from the liver of 2 bats,Eidolon helvum a fruit eating species.Wangiella dermatitidis was recovered from the liver of 2 bats of the same species. The isolates were pathogenic for laboratory mice when injected by subcutaneous, intraperitoneal and intravenous routes.W. dermatitidis was neurotropic in the mice injected intravenously.
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Papers by Florence Okafor