The Cryptococcus gattii species complex:Unique pathogenic yeasts with understudied virulence mechanisms

Members of Cryptococcus gattii/neoformans species complex are the etiological agents of the potentially fatal human fungal infection cryptococcosis. C. gattii and its sister species cause disease in both immunocompetent and immunocompromised hosts, while the closely related species C. neoformans and C. deneoformans predominantly infect immunocompromised hosts. To date, most studies have focused on similarities in pathogenesis between these two groups, but over recent years, important differences have become apparent. In this review paper, we highlight some of the major phenotypic differences between the C. gattii and neoformans species complexes and justify the need to study the virulence and pathogenicity of the C. gattii species complex as a distinct cryptococcal group.</p

The Drought-Migration Nexus: Implications for Socio-Ecological Conflicts in Nigeria

In Nigeria, the droughts in 1972 – 1975 and floods since 1988 marked the incidence of climate change. This study evaluates the linkages between drought-desertification causative climatic variables over time, the consequent migration caused by the climatic variations and socio-ecological conflicts in Nigeria. Climate data was obtained from the Nigeria Meteorological Agency and analyzed with the correlation and regression models. The data on conflicts was obtained from the National Emergency Management Agency and the public media The results of correlation analysis are; between cumulative number of conflicts and temperature (0.974), moisture balance (-0.838), time (0.735), and annual total rainfall(-0.918). The regression results also indicated from the direction and sizes of the coefficients that the reversal and rejuvenation of the damaged ecosystem if left to occur naturally will take a very long time. The ethical dimension of socio-ecological conflicts was appraised. Finally, suggestions for mitigating socio-ecological conflicts such as the need for advocacy and attitude re-orientation of the largely uneducated, poor and ignorant rural dwellers were made. DOI: 10.5901/mjss.2015.v6n2s1p47

Evaluation of binder and disintegrant properties of starch derived from Xanthosoma sagittifolium in metronidazole tablets

The aim of the study was to formulate metronidazole tablets using starch from Xanthosoma sagittifolium as binder and disintegrant in metronidazole tablets. Metronidazole tablets were produced by wet granulation method using X. sagittifolium starch as binder at concentrations of 5, 10, 15 and 20% w/w, and as disintegrant (5% w/w). The micromeritic properties of the granules were determined using the direct and indirect methods. The necessary official and non official tests were performed on the tablets to include uniformity of tablets weight, content of active ingredient, disintegration test, hardness, friability tests and in vitro drug release. Also, the phytochemical constituents of the starch were determined. The results show that the granules had a good flow and values obtained were within the specified limits for the production of good quality tablets. Deviations obtained from the tablet weight uniformity test were significantly (p&lt; 0.05) below 5%. Tablets disintegration time ranged from 3.00 ± 0.08 min to 14.00 ± 0.10 min for M1 and M4 tablets formulated with 5 and 20% of X. sagittifolium starch respectively. The tablets hardness ranged from 7.20 ± 1.25 to 8.55 ± 1.17 kgf. In vitro release showed that M1 tablets had T25, T50 and T90 % at 5, 13 and 23 min respectively, while M4 tablets had T25, T50 and T90 % at 8, 18 min and were unable to release 90% of metronidazole at 30 min. Phytochemical analysis showed that the starch contained alkaloids, glycosides, carbohydrate and steroids. Therefore, starch from X. sagittifolium could be used to formulate metronidazole tablets for improved oral bioavailability of metronidazole.Keywords: Xanthosoma sagittifolium starch, tablets binder and disintegrant, metronidazoleAfrican Journal of Biotechnology Vol. 12(20), pp. 3064-307

IN VITRO PROPERTIES OF SOLID LIPID MICROPARTICLES (SLMS) LOADED WITH METHANOLIC EXTRACT OF GARCINIA KOLA (HECKEL) SEED

Objective: The decline in the use of herbal medicine especially in the Western world may be due to lack of readily available market brand formulations and the fact that most herbal remedies are taken as tea, decoctions and infusions. The taste of some of these herbal drugs is not palatable, and some have unpleasant odour and colour hence, the need to formulate these drugs in form of encapsulated dosage forms. The objective of the work was to formulate solid lipid microparticles (SLMs) loaded with the methanolic extract of Garcinia kola seed. Methods: The SLMs containing 1 and 3 % of Garcinia kola seed extract were formulated using fat from Capra hircus and Phospholipon® 90H (3:1). The particle morphology and size, encapsulation efficiency (EE%), pH, in vitro release and the inhibition zone diameter (IZD) of the SLMs were determined. Results: The results showed that the extract was very bitter while, the encapsulated G. kola had slight bitter taste. The pH remained in the acidic region from 1 to 30 days. Particle size of 28.65 ± 1.13 and 29.49 ± 1.24 µm were obtained for SLMs loaded with 1 and 3 % of the extract respectively. SLMs had high EE% of 94 % and also exhibited good release of the extract in simulated intestinal fluid (SIF, pH 7.2). Garcinia kola-loaded SLMs had good activity against Staphylococcus aureus and no action against Escherichia coli. Conclusion: Therefore, Garcinia kola seed extract could be formulated as SLMs in order to mask its bitter taste and improve compliance. Â

FORMULATION AND EVALUATION OF ETHANOLIC EXTRACT OF CRYPTOLEPIS SANGUINOLENTA ROOT TABLETS

Objectives: To study were to formulate the ethanolic extract of Cryptolepis sanguinolenta root into tablets and to evaluate the effect of different binders and binder concentration on the properties of tablets. Materials and method: The phytochemistry of ethanolic extract of Cryptolepis sanguinolenta was evaluated. The tablets were formulated by wet granulation using gelatin and sodium carboxymethyl cellulose (SCMC) as binders at concentrations of 2 %, 4 %, 6 % and 8 %w/w. The tablets were evaluated using the necessary official and unofficial tests. Results: Phytochemical analysis revealed the presence of alkaloids, terpenoids, steroids, proteins, carbohydrate, resins, reducing sugars and glycosides. Tannins, saponins, flavonoids and acidic compounds were absent.  The tablets passed the uniformity of weight test and deviations obtained complied with BP specifications. Tablets disintegration time ranged from 8.00 ± 0.10 to 13.50 ± 0.21 min for tablets formulated with 2 and 4 % gelatin and 10.00 ± 0.17 to 31.00 ± 0.27 min for tablets formulated with 2 and 8 % SCMC. C. sanguinolenta tablets formulated gelatin significantly showed higher hardness values than SCMC (p &lt; 0.05). Tablets showed friability of approximately ≤ 1 %. Conclusion: Therefore, gelatin showed good properties for formulating Cryptolepis sanguinolenta normal release tablets than SCMC.Â

Loss of the scavenger receptor MARCO results in uncontrolled vomocytosis of fungi from macrophages

Vomocytosis, also known as nonlytic exocytosis, is a process whereby fully phagocytosed microbes are expelled from phagocytes without discernible damage to either the phagocyte or microbe. Although this phenomenon was first described in the opportunistic fungal pathogen Cryptococcus neoformans in 2006, to date, mechanistic studies have been hampered by an inability to reliably stimulate or inhibit vomocytosis. Here we present the fortuitous discovery that macrophages lacking the scavenger receptor MAcrophage Receptor with COllagenous domain (MARCO), exhibit near-total vomocytosis of internalised cryptococci within a few hours of infection. Our findings suggest that MARCO’s role in modulating vomocytosis is independent of its role as a phagocytic receptor and instead may be driven by variation in cytoskeletal arrangement between wildtype and MARCO-deficient macrophages

SUSTAINED RELEASE ARTEMETHER-LOADED SOLID LIPID MICROPARTICLES, BASED ON SOLIDIFIED REVERSE MICELLAR SOLUTION (SRMS)

Objectives: To prepare and evaluate sustained release artemether-loaded SLMs based on SRMS Material and methods: SRMS, consisting of mixtures of Phospholipon® 90H (P90H) and Softisan® 154 (1:1, 2:1 and 1:2) were formulated and characterized using differential scanning calorimetry (DSC). The SRMS were used to formulate artemether-loaded SLMs by melt homogenization. The SLMs were characterized based on particle size and morphology, pH stability, encapsulation efficiency (EE%) and loading capacity. In vitro release was carried out in simulated intestinal fluid (SIF, pH 7.5). Results: Thermograms of the SRMS (1:1, 2:1 and 1:2) showed sharp endothermic peaks at 65.5, 64.4 and 62.3 oC respectively. Maximum EE% of 70.00 ± 1.50 % was obtained for SLMs formulated with SRMS 1:1 and 1 % artemether. Loading capacity ranged from 5.67 to 17.90 g drug/100 g lipid. In vitro release showed about 80 to 84 % drug release at 7 h. Particle size of artemether-loaded SLMs ranged from 18.60 ± 0.09 to 34.80 ± 0.30 µm. The pH decreased significantly at 60 days from 6 to 4.8 for batch A2 formulated with SRMS 2:1 and 3 % artemether (p &lt; 0.05). Conclusion: artemether-loaded SLMs based on SRMS had good sustained release properties and could be used once daily in order to enhance patient's compliance.   Key words: Malaria, artemether, SRMS, lipids, sustained release SLMs Â

Loss of the scavenger receptor MARCO results in uncontrolled vomocytosis of fungi from macrophages

Vomocytosis, also known as nonlytic exocytosis, is a process whereby fully phagocytosed microbes are expelled from phagocytes without discernible damage to either the phagocyte or microbe. Although this phenomenon was first described in the opportunistic fungal pathogen Cryptococcus neoformans in 2006, to date, mechanistic studies have been hampered by an inability to reliably stimulate or inhibit vomocytosis. Here we present the fortuitous discovery that macrophages lacking the scavenger receptor MAcrophage Receptor with COllagenous domain (MARCO), exhibit near‐total vomocytosis of internalised cryptococci within a few hours of infection. Marco−/− macrophages also showed elevated vomocytosis of a yeast‐locked C. albicans strain, suggesting this to be a broadly relevant observation. We go on to show that MARCO's role in modulating vomocytosis is independent of its role as a phagocytic receptor, suggesting that this protein may play an important and hitherto unrecognised role in modulating macrophage behaviour

In vivo studies on the biochemical indices of Plasmodium berghei infected mice treated with Alstonia boonei leaf and root extracts

Background: A study on the biochemical indices of albino mice infected with Plasmodium berghei and treated with Alstonia boonei aqueous and ethanolic extracts was undertaken. Methods: 216 males mice were randomly assigned to six treatment groups each containing six mice for both aqueous and ethanolic extracts experiments. P. berghei NK-65 was inoculated into the mice intraperitoneally and establishment of infection confirmed. Administration of extracts of was done after phytochemical and acute toxicity tests at varying concentrations, for both suppressive and curative tests. Blood samples collected by ocular puncturing were examined for the biochemical indices; ALT, AST, ALP, creatinine and total protein using the standard procedures. Results: A. boonei extracts suppression of P. berghei in mice was comparable to the standard drug. Significantly higher (p&lt;0.05) recovery of mice treated with A. boonei extracts was observed. The biochemical indices examined all had significantly (p&lt;0.05) increased concentration after 7 days post-infection, except for total protein concentration which had no significant increase or decrease due to A. boonei extracts administration. Conclusion: The antiplasmodial potentials of A. boonei leaf and root extracts were dosage and duration-dependent, and have demonstrated satisfactory normalization of altered biochemical indices due to malaria

Evaluation Of Vitamin Composition and Anti-Inflammatory Properties of Cucumber (Cucumis Sativus) Peels

Inadequate vitamins in humans can cause significant impairment in cellular and immune functions, as well as trigger inflammatory responses. Boosting immunity with vitamins helps in prevention and treatment of many diseases. There is a need to search for diets rich in vitamins which can boost immunity. This study explored vitamin composition and anti-inflammatory properties of cucumber peels using standard methods. The in-vitro anti-inflammatory effects were measured on the ability of the ethanol extract of cucumber peels to inhibit proteinase activities, albumin denaturation, and stabilize erythrocyte membrane, using blood samples from laboratory rat, while Aspirin and Diclophenac Sodium served as reference drugs. Vitamins found in cucumber peels were A (0.35 ± 0.03 mg/g), β-carotene (0.86±0.04mg/g), B₁ (1.14±0.38mg/g), B₂ (0.24±0.02mg/g), B₃ (0.71±0.03mg/g), B₆ (1.04±0.06mg/g), B₉ (0.66±0.01mg/g), C (1.58±0.01mg/g), D (1.11±0.01mg/g), E (0.54±0.01mg/g), and K (0.78±0.01mg/g). The extracts inhibited proteinase activity, albumin denaturation, and stabilization of erythrocyte membrane in a concentration-dependent manner, and recorded maximum activities of 19.14% anti-proteinase, 26.78% inhibition of albumin denaturation, 12.92% inhibition of heat-induced haemolysis, and 26.90% inhibition of hypotonicity-induced haemolysis at the highest concentration of 500µg/ml. These results indicated that cucumber peels are good sources of vitamins and possess anti-inflammatory properties.