Smith RJ et al. (1988) Trop Med Parasitol "Vascular perfusion of Onchocerca volvulus nodules."

Williams JF, Smith RJ, Guderian RH, Cotter TP

[Trop Med Parasitol, 1988]

Perfusion of the vascular bed was achieved in 24 freshly excised nodules of Onchocerca volvulus varying from 0.5 to 2 cm in diameter. India Ink, Microfil polymer, or acrylate perfusates were passed through the vascular supply via cannulation of superficial capsular vessels. After clearing in glycerol or methyl salicylate, or KOH corrosion in the case of the acrylate, nodules were examined microscopically. Small nodules had an extensive blood supply, diffusely distributed throughout the nodule matrix, and in close association with the coils of the worms. In bigger nodules the central area appeared more dense, and intense vascularization appeared to be more peripheral; in the largest nodules the central core was not well vascularized, but a band of heavy vascularization was seen at the margin of the core, fed by superficial vessels and in close contact with worm coils. Very fine branches of the vascular tree were perfused by all three contrast media, but histologically there was evidence of incomplete filling of the smallest vessels. However, there was no extravasation of per-fusates around parasites, even where the approximation between between vessels and parasite surfaces was close. The possibility is considered that O. volvulus may control blood vessel proliferation by release of angiogenesis factors, analogous to rapidly growing solid tumors.

Spasiano D et al. (2016) J Hazard Mater "Removal of benzoylecgonine from water matrices through UV254/H2O2 process: Reaction kinetic modeling, ecotoxicity and genotoxicity assessment."

Russo D, Andreozzi R, Vaccaro M, Li Puma G, Marotta R, Reis NM, Spasiano D, Guida M, Siciliano A

[J Hazard Mater, 2016]

Benzoylecgonine (BE), the main cocaine metabolite, has been detected in numerous surface water and treatment plants effluents in Europe and there is urgent need for effective treatment methods. In this study, the removal of BE by the UV254/H2O2 process from different water matrices was investigated. By means of competition kinetics method, the kinetic constant of reaction between BE and the photogenerated hydroxyl radicals (OH) was estimated resulting in kOH/BE=5.13x10(9)M(-1)s(-1). By-products and water matrices scavengers effects were estimated by numerical modeling of the reaction kinetics for the UV254/H2O2 process and validated in an innovative microcapillary film (MCF) array photoreactor and in a conventional batch photoreactor. The ecotoxicity of the water before and after treatment was evaluated with four organisms Raphidocelis subcapitata, Daphnia magna, Caenorhabditis elegans, and Vicia faba. The results provided evidence that BE and its transformation by-products do not have significant adverse effects on R. subcapitata, while D. magna underwent an increase of lipid droplets. C. elegans was the most sensitive to BE and its by-products. Furthermore, a genotoxicity assay, using V. faba, showed cytogenic damages during the cell mitosis of primary roots.

Junkum A et al. (2003) Mem Inst Oswaldo Cruz "Comparative studies on the biology and filarial susceptibility of selected blood-feeding and autogenous Aedes togoi sub-colonies."

Boonyatakorn C, Junkum A, Choochote W, Jitpakdi A, Komalamisra N, Leemingsawat S, Jariyapan N

[Mem Inst Oswaldo Cruz, 2003]

Blood-feeding and autogenous sub-colonies were selected from a laboratory, stock colony of Aedes togoi, which was originally collected from Koh Nom Sao, Chanthaburi province, Southeast Thailand. Comparative biology and filarial susceptibility between the two sub-colonies (blood-feeding: F11, F13; autogeny: F38, F40) were investigated to evaluate their viability and vectorial capacity. The results of comparison on biology revealed intraspecific differences, i.e., the average egg deposition/gravid female (F11/F38; F13/F40), embryonation rate (F13/F40), hatchability rate (F11/F38; F13/F40), egg width (F11/F38), wing length of females (F13/F40), and wing length and width of males (F11/F38) in the blood-feeding sub-colony were significantly greater than that in the autogenous sub-colony; and egg length (F11/F38) and width (F13/F40), and mean longevity of adult females (F11/F38) and males (F13/F40) in the blood-feeding sub-colony were significantly less than that in the autogenous sub-colony. The results of comparison on filarial susceptibility demonstrated that both sub-colonies yielded similar susceptibilities to Brugia malayi [blood-feeding/autogeny = 56.7% (F11)/53.3%(F38), 60%(F13)/83.3%(F40)] and Dirofilaria immitis [blood-feeding/autogeny = 85.7%(F11)/75%(F38), 45%(F13)/29.4%(F40)], suggesting autogenous Ae. togoi sub-colony was an efficient laboratory vector in study of filariasis.

Eto K et al. (1999) J Biol Chem "Ca(2+)/Calmodulin-dependent protein kinase cascade in Caenorhabditis elegans. Implication in transcriptional activation."

Kimura Y, Eto K, Tokumitsu H, Arai K, Takahashi N, Muramatsu M, Masuho Y

[J Biol Chem, 1999]

We have recently demonstrated that Caenorhabditis elegans Ca(2+)/calmodulin-dependent protein kinase kinase (CeCaM-KK) can activate mammalian CaM-kinase IV in vitro (Tokumitsu, H., Takahashi, N., Eto, K., Yano, S., Soderling, T.R., and Muramatsu, M. (1999) J. Biol. Chem. 274, 15803-15810). In the present study, we have identified and cloned a target CaM-kinase for CaM-KK in C. elegans, CeCaM-kinase I (CeCaM-KI), which has approximately 60% identity to mammalian CaM-KI. CeCaM-KI has 348 amino acid residues with an apparent molecular mass of 40 kDa, which is activated by CeCaM-KK through phosphorylation of Thr(179) in a Ca(2+)/CaM-dependent manner, resulting in a 30-fold decrease in the K(m) of CeCaM-KI for its peptide substrate. Unlike mammalian CaM-KI, CeCaM-KI is mainly localized in the nucleus of transfected cells because the NH(2)-terminal six residues ((2)PLFKRR(7)) contain a functional nuclear localization signal. We have also demonstrated that CeCaM-KK and CeCaM-KI reconstituted a signaling pathway that mediates Ca(2+)-dependent phosphorylation of cAMP response element-binding protein (CREB) and CRE-dependent transcriptional activation in transfected cells, consistent with nuclear localization of CeCaM-KI. These results suggest that the CaM-KK/CaM-KI cascade is conserved in C. elegans and is functionally operated both in vitro and in intact cells, and it may be involved in Ca(2+)-dependent nuclear events such as transcriptional activation through phosphorylation of CREB.

Hans S et al. (2019) J Glob Antimicrob Resist "Magnesium deprivation affects cellular circuitry involved in drug resistance and virulence in Candida albicans."

Hameed S, Fatima Z, Hans S

[J Glob Antimicrob Resist, 2019]

OBJECTIVES: Candida albicans has to struggle for the limited micronutrients present in the hostile niche. One such significant environmental factor that C. albicans must surmount is magnesium (Mg) limitation. Herein, we aimed to study the effect of Mg deprivation on drug resistance mechanisms and virulence traits of C. albicans. METHODS: Drug susceptibilities against C. albicans SC5314was measured by broth microdilution and spot assay. Drug efflux pump activity was measured by substrate R6G efflux. Membrane intactness was studied by propidium iodide influx and ergosterol levels by alcoholic KOH method. Metabolic flexibility was studied by enzymatic activities of glyoxylate cycle. Virulence factors were assessed by yeast to hyphae, biofilm formation and cell adherence. In-vivo study was performed by Caenorhabditis elegans infection model. RESULTS: We found that Mg chelation leads to potentiation of membrane targeting antifungals. We explored the role of Mg on membrane homeostasis and found significant differences in ergosterol levels. Interestingly we also explored that Mg deprivation impedes metabolic flexibility of C. albicans SC5314 by inhibiting glyoxylate cycle enzymes. Furthermore, Mg deprivation inhibited potential virulence traits including morphological transition, biofilm formation and buccal epithelial cell adherence. All the disrupted targets were validated by RT-PCR which corroborates our findings. Lastly, we demonstrated the enhanced survival of C. albicans SC5314 infected Caenorhabditis elegans model under Mg deprivation. CONCLUSION: In view of the restricted growth of C. albicans in Mg deficient environment, approaches could be utilized to boost the effectiveness of existing antifungals thereby improving the management of fungal infections.