Acanthamoeba castellanii trophozoites that survive multipurpose solutions are able to adhere to cosmetic contact lenses, increasing the risk of infection.

Amoebae of the genus Acanthamoeba are etiological agents of amoebic keratitis, for which up to now there is no treatment of choice and one of its main risk factors is the use of contact lenses, including cosmetic contact lenses. Recently there has been an increase in amoebic keratitis cases due to the use of cosmetic contact lenses. Therefore, having a solution for the care of lenses with an efficient disinfectant effect that prevents the adhesion of trophozoites to lenses becomes essential. This study was carried out to determine the effect of 8 multipurpose contact lenses care solutions on Acanthamoeba castellanii trophozoites viability, and the efficiency of two of them to prevent the trophozoites adherence onto two cosmetic contact lenses (Acuvue 2, approved by the US Food and Drug Administration, and Magic Eye CCL, not approved). After 3 h of interaction, only AO Sept Plus, OPTI FREE Replenish, Renu Plus, Bio True and Multiplus significantly reduced the number of viable trophozoites with respect to the control; at 6 h Renu Plus, and at 12 h Conta Soft Plus and Multiplus, maintained the inhibitory effect. Only Opti Free Pure Moist did not significantly reduce the number of viable trophozoites. Multiplus and Opti Free Pure Moist (selected for their greater and lesser antiamibic effect) significantly reduced trophozoite adherence to both lenses; however, Opti Free Pure Moist was more efficient, despite the fact that A. castellanii adhered similarly to both lenses. Our results show that in all the multipurpose solutions evaluated, hundreds of viable A. castellanii trophozoites remain after several hours of incubation. Therefore, storage of the lenses in their case with MPS maintains the potential risk of amoebic keratitis in, cosmetic contact lenses wearers. Moreover, the use of CCL, not approved by the FDA, can increase the risk factor for AK since its poor manufacture can favor the permanence of amoebae, in addition to being a risk for corneal integrity.

Zearalenone Does Not Show Genotoxic Effects in the Drosophila melanogaster Wing Spot Test, but It Induces Oxidative Imbalance, Development, and Fecundity Alterations.

Zearalenone (ZEN) is a non-steroidal mycoestrogen produced by the Fusarium genus. ZEN and its metabolites compete with 17-beta estradiol for cytosolic estrogen receptors, causing reproductive alterations in vertebrates. ZEN has also been associated with toxic and genotoxic effects, as well as an increased risk for endometrial adenocarcinomas or hyperplasia, breast cancer, and oxidative damage, although the underlying mechanisms remain unclear. Previous studies have monitored cellular processes through levels of transcripts associated with Phase I Xenobiotic Metabolism (Cyp6g1 and Cyp6a2), oxidative stress (hsp60 and hsp70), apoptosis (hid, grim, and reaper), and DNA damage genes (Dmp53). In this study, we evaluated the survival and genotoxicity of ZEN, as well as its effects on emergence rate and fecundity in Drosophila melanogaster. Additionally, we determined levels of reactive oxygen species (ROS) using the D. melanogaster flare and Oregon R(R)-flare strains, which differ in levels of Cyp450 gene expression. Our results showed that ZEN toxicity did not increase mortality by more than 30%. We tested three ZEN concentrations (100, 200, and 400 µM) and found that none of the concentrations were genotoxic but were cytotoxic. Taking into account that it has previously been demonstrated that ZEN administration increased hsp60 expression levels and apoptosis gene transcripts in both strains, the data agree with an increase in ROS and development and fecundity alterations. Since Drosophila lacks homologous genes for mammalian estrogen receptors alpha and beta, the effects of this mycotoxin can be explained by a mechanism different from estrogenic activity.

External pH Variations Modify Proliferation, Erythrophagocytosis, Cytoskeleton Remodeling, and Cell Morphology of Entamoeba histolytica Trophozoites.

To infect the human host, Entamoeba histolytica carries out processes requiring cytoskeleton remodeling, which involves reorganizing the actin fibers. However, little is known about the external influence factors, e.g., the pH, on the parasite's cytoskeleton remodeling or cell morphology. Such influence becomes relevant given the pH gradient that the amoeba cope with when going through the human colonic mucus during infection. Therefore, we analyzed the proliferation, the reorganization of the actin fibers, and other actin structures and cell shape during adhesion to fibronectin and erythrophagocytosis in trophozoites at different external pH conditions (6.0, 6.5, 6.8, 7.5, 8.0). We found that the best condition of external pH to perform such functions was 6.8. At acid pH, the trophozoites presented better-defined actin fibers that formed a more compact network, while at alkaline pH, the fibers reorganized, forming a looser and less defined network. Similarly, the number of actin dots also changed from acid to alkaline pH. In conclusion, the external pH alters the proliferation of the amoebas and promotes the dynamic restructuration of their cytoskeleton, allowing them to carry out their functions.

Genotoxicity and cytotoxicity evaluation of two thallium compounds using the Drosophila wing somatic mutation and recombination test.

Thallium (Tl) is a heavy and toxic metal and a byproduct of several human activities, such as cement production, mining, and coal combustion. Thallium is found in fruits, vegetables, and animal fodder with high Tl contamination; therefore, it is an environmental pollution issue and a toxicological contamination problem for human beings and other organisms when exposed to it. The mutagenic potential of Tl and its compounds is controversial, and there are few in vivo studies on its effects. We conducted the animal bioassay Drosophila wing somatic mutation and recombination test (SMART) to test for genotoxicity and assessed the genotoxic effects of Tl acetate (TlCH3COO) and Tl sulfate (Tl2SO4) on Drosophila melanogaster. Third instar larvae from the SMART standard cross (ST) were fed Tl acetate [0.2, 2, 20, 200, 600 and 1200 µM] and Tl sulfate [0.2, 2, 20, 200, and 600 µM]. Hexavalent chromium [CrO3, 500 µM] served as the positive control, and Milli-Q water served as the negative control. Only the high Tl2SO4 [600 µM] concentration resulted in genotoxicity with 87.6% somatic recombination, and both salts disrupted cell division of wing imaginal disc cells, showing the expected cytotoxic effects. Genotoxic risks due to high metal levels by bioaccumulation of Tl+1 or its compounds require further evaluation with other in vivo and in vitro assays.

Genotoxicity assessment of four novel quinazoline-derived trypanocidal agents in the Drosophila wing somatic mutation and recombination test.

Chagas disease, caused by the protozoan Trypanosoma cruzi, has increased in the world due to migration, travelling and climate change; at present, the principal problem is that common trypanocidal agents have resulted in toxic or inconvenient side effects. We tested for genotoxicity in the standard (ST) and high bioactivation (HB) crosses of Drosophila wing somatic mutation and recombination test, four novel trypanocidal agents derived from 2, 4, 6-triaminquinazoline (TAQ): 2,4-diamino-6 nitro-1,3 diazonaftalene (S-1QN2-1), 2,4-diacetamino-6-amino 1,3 diazonaftalene (D-1), N6-(4,methoxybenzyl)quinazoline-2,4,6-triamine (GHPM) and N6-[4-(trifluoromethoxy)benzyl]quinazoline-2,4,6-triamine (GHPMF) at 1.9, 3.9, 7.9 and 15 µM, respectively. Also, high-pressure liquid chromatography (HPLC) analysis was run to determine the remanence of either drug in flare, and Oregon R(R)-flare flies emerged from treated larvae. S-1QN2-1 showed genotoxicity only in the ST cross, increasing the small, large and total spot frequencies at all concentrations and twin spots only at 1.9 µM; D-1 and GHPM showed significant increments of large spots only at 15 µM in the ST cross; GHPMF was not genotoxic at any concentration or either cross. In the mwh clones accumulated distribution frequencies analysis, associated with disrupted cell division, S-1QN2-1 caused alterations in the ST cross at all concentrations but only at 15 µM in the HB cross; D-1 caused alterations at 3.9, 7.9 and 15 µM in the ST cross and at 1.9 and 15 µM in the HB cross; GHPM caused alterations at 7.9 and 15 µM in the ST cross and also at 1.9, 3.9 and 7.9 µM in the HB cross; GHPMF caused those alterations at all concentrations in the ST cross and at 1.9, 3.9 and 7.9 µM in the HB cross. The HPLC results indicated no traces of either agent in the flare and Oregon R(R)-flare flies. We conclude that S-1QN2-1 is clearly genotoxic, D-1 and GHPM have an unclear genotoxicity and GHPMF was not genotoxic; all quinazoline derivatives disrupted cell division. GHPMF is a good candidate to be tested in other genotoxicity and cytotoxic bioassays. The differences in the genotoxic activity of these trypanocidal agents are correlated with differences in their chemical structure.

Evaluation of the medicinal properties of Cyrtocarpa procera Kunth fruit extracts.

BACKGROUND: The fruit of Cyrtocarpa procera is used to treat stomach diseases by people living in San Rafael, Coxcatlan, Puebla. This work investigated the antibacterial, antioxidant, cytotoxic and anti-inflammatory activities of the fruit produced by this species. METHODS: Methanol extract was obtained by maceration. After obtaining the methanol extract (MeOH1), methanol subextract (MeOH2) and hexane (H) were obtained. The antibacterial activities of MeOH1, MeOH2 and H were evaluated through disc-diffusion. The quenching of free radicals was evaluated by decolorizing a methanolic DPPH solution. The cytotoxic activity of MeOH2 was evaluated by in vitro assay system of growth inhibition of human cervical carcinoma cell line (CasKi). The IL-1ß and TNF-α were determined through ELISA in the supernatants of the macrophage cell line (RAW 264.7). The MeOH2 subextract was separated by column chromatography, seventy-three fractions were collected. RESULTS: The Gram-positive and -negative bacteria examined were sensitive to MeOH1 and MeOH2; the MeOH2 was bactericidal toward Staphyloccocus aureus (MIC = 4 mg/mL) and Vibrio cholera (MIC = 4 mg/mL). The MeOH2 inhibited the DPPH radical (SC50 = 69.7 µg/mL), but a cytotoxicity assay revealed that the extract is not toxic according to the National Cancer Institute (LD50 = 22.03 µg/mL). The production of proinflammatory cytokines (IL- 1ß and TNF- α) by LPS- stimulated macrophages was reduced after the treatments. The methanol extract contained various organic acids, such as citric acid, palmitic acid and α- linoleic acid. CONCLUSIONS: The fruits of Cyrtocarpa procera are employed to treat ailments such as diarrhea, in this study were demonstrated some biological activities involved in a bacterial infection. This is the first research about of the medicinal properties of C. procera fruit.

Erythrophagocytosis in Entamoeba histolytica and Entamoeba dispar: a comparative study.

Entamoeba histolytica is the causative agent of human intestinal and liver amebiasis. The extraordinary phagocytic activity of E. histolytica trophozoites has been accepted as one of the virulence mechanisms responsible for their invasive capacity. The recognition of the noninvasive Entamoeba dispar as a different species has raised the question as to whether the lack of pathogenic potential of this ameba correlates with a limited phagocytic capacity. We have therefore compared the process of erythrophagocytosis in both species by means of light and video microscopy, hemoglobin measurement, and the estimation of reactive oxygen species (ROS). In the present study, we confirmed that E. dispar has lower erythrophagocytic capacity. We also observed by video microscopy a new event of erythrocyte opsonization-like in both species, being more characteristic in E. histolytica. Moreover, E. dispar showed a lower capacity to produce ROS compared with the invasive species and also showed a large population of amoebae that did not engulf any erythrocyte over time. Our results demonstrate that E. histolytica has a higher phagocytic capacity than E. dispar, including a higher rate of production of ROS in the course of ingesting red blood cells.

Silicone hydrogel contact lenses surface promote Acanthamoeba castellanii trophozoites adherence: qualitative and quantitative analysis.

PURPOSE: To describe the adhesion properties of Acanthamoeba castellanii trophozoites to silicone hydrogel contact lenses of first generation (lotrafilcon A), second generation (galyfilcon A), and third generation (comfilcon A) and correlate the results with their specific surface characteristics, time of interaction, and suspension media. METHODS: Qualitative and quantitative assessments of the adhesion of 200 trophozoites of A. castellanii on contact lenses in culture medium (Bacto Casitone) and isotonic saline (IS) at different time points (15 minutes and 6 hours) were determined. RESULTS: By scanning electron microscopy, A. castellanii trophozoites were observed firmly adhered to the surface of hydrogel lenses after 15 minutes of interaction. The surface of lotrafilcon A lenses on which amoebae adhere better (16.4±10.2 amoebae/lens section) is rough and folded, which increases the contact surface with trophozoites, allowing acanthopodia to attach firmly. Contrarily, galyfilcon A lenses have a smoother surface, and lower numbers of amoebae were observed adhered to these lenses (4.7±2.9 amoebae/lens section). Even fewer amoebae adhered to the smoother surface of the comfilcon A lens (2.2±1.7 amoebae/lens section). Trophozoites showed similar behavior in both Bacto Casitone medium and IS. CONCLUSION: A rough surface may contribute to better adhesion of amoebae to silicone hydrogel lenses. Although a reduced numbers of trophozoites adhered to smooth lenses, trophozoites are a risk factor for amoebic keratitis. Isotonic saline facilitated trophozoite survival, suggesting that homemade saline solutions may contribute to the persistence of trophozoites, especially when there is no proper hygiene regimen used with the contact lens cases.

Verbascoside is not genotoxic in the ST and HB crosses of the Drosophila wing spot test, and its constituent, caffeic acid, decreases the spontaneous mutation rate in the ST cross.

Verbascoside (VB) is a phenylpropanoid isolated from Buddleja species, some of which originate in Mexico, and was first described in the sixteenth century in the codices of Mexican traditional medicine. VB is present in alcohol extracts and is widely used in the north of Mexico as a sunscreen. VB absorbs UV-A and UV-B radiation and has high antioxidant and anti-inflammatory capacities. VB and its constituent caffeic acid (CA) were screened to determine their genotoxic activity using the Drosophila wing spot test. Third instar larvae (72±4 h) of the standard (ST) and high bioactivation (HB) crosses, with regulated and high levels of cytochrome P450s (Cyp450s), respectively, were exposed to VB or CA (0, 27, 57, 81, 135, and 173 mM). VB was not genotoxic at any of the concentrations tested in both crosses. The amount of VB residue as determined by HPLC in the adult flies that were fed with VB indicated a low metabolism of this compound, which explains the absence of genotoxicity. CA decreased the spontaneous frequencies of small and total spots and showed putative toxicity in the ST cross.

Temporal variation of phytoplankton from the tropical reservoir Valle de Bravo, Mexico.

Valle de Bravo reservoir is used for aquatic, fishing and as a source of drinking water to Mexico City. Annual data on composition, abundances, species richness and diversity of the phytoplankton surface community and some physical-chemical parameters variations were discussed. Results showed a spatial homogeneity for environmental descriptors and phytoplankton samples but a temporal significant difference between months. Pulses of high algal densities corresponded to late stratification (October, 103 x 10(3) cell ml(-1)), early stratification (April, 107 x 10(3) cell ml(-1)) and plenty stratification (June, 69 x 10(3) cell ml(-1)). Taxa that reached higher densities were: Microcystis spp., Snowella septentrionalis, Anabaena spp., Aphanizomenon yezoense and Fragilaria crotonensis. Contribution of each taxon to the total phytoplankton density showed that majorities were rare (41%) or dominants (40%). Frequent alternation between pulses and low densities and diversity of phytoplankton as well as a relative high number of taxa found (68), could be explained by daily strong winds, unstable epilimnion thickness and incorporation and extraction of substantial volumes of water occurred in the reservoir. Dominances of cyanobacteria and some chlorococcal species and a high temporal fluctuated Shannon-Wiener diversity index (0.45- 2.35 bits) pointing to eutrophic and perturbed conditions.

Lead acetate does not inhibit dimethylnitrosamine activation and interacts with phenobarbital which is genotoxic in the ST cross of the Drosophila wing spot test.

Lead acetate (PbAc) is known to inhibit the synthesis of the heme group, needed for hemeproteins like Cytochromes P450 (CYP450s). Dimethylnitrosamine (DMN) requires metabolic activation by CYP450s. The Drosophila wing spot test was performed to establish whether PbAc inhibits DMN activation in the standard (ST) and high bioactivation (HB) crosses, with different levels of CYP450s. Phenobarbital (PH) was used as an antagonist for its ability to induce CYP450s synthesis. PbAc (0.01, 0.1, 1.0mM) produced significant small spots frequencies in the ST cross, indicating a possible genotoxic activity, however, the total spots frequency was negative at all concentrations. DMN (0.076 mM) was genotoxic in both crosses; surprisingly, PH (12 mM) was genotoxic and the PH-DMN treatment resulted synergic in the ST cross. Interestingly, the PbAc-PH pre-co-treatments showed a possible interaction in the ST cross. The GC-MS analysis showed a drop in the PH content as the PbAc concentration increased. PbAc also seemed to inhibit the genotoxic activity of PH, except at 0.01 mM. It is concluded that PbAc does not inhibit DMN activation by CYP450s in both crosses since it exerted a clear genotoxicity and that PH is genotoxic and interacts with PbAc in the ST but not the HB cross.

Genotoxicity studies of organically grown broccoli (Brassica oleracea var. italica) and its interactions with urethane, methyl methanesulfonate and 4-nitroquinoline-1-oxide genotoxicity in the wing spot test of Drosophila melanogaster.

Broccoli (Brassica oleracea var. italica) has been defined as a cancer preventive food. Nevertheless, broccoli contains potentially genotoxic compounds as well. We performed the wing spot test of Drosophila melanogaster in treatments with organically grown broccoli (OGB) and co-treatments with the promutagen urethane (URE), the direct alkylating agent methyl methanesulfonate (MMS) and the carcinogen 4-nitroquinoline-1-oxide (4-NQO) in the standard (ST) and high bioactivation (HB) crosses with inducible and high levels of cytochrome P450s (CYPs), respectively. Larvae of both crosses were chronically fed with OGB or fresh market broccoli (FMB) as a non-organically grown control, added with solvents or mutagens solutions. In both crosses, the OGB added with Tween-ethanol yielded the expected reduction in the genotoxicity spontaneous rate. OGB co-treatments did not affect the URE effect, MMS showed synergy and 4-NQO damage was modulated in both crosses. In contrast, FMB controls produced damage increase; co-treatments modulated URE genotoxicity, diminished MMS damage, and did not change the 4-NQO damage. The high dietary consumption of both types of broccoli and its protective effects in D. melanogaster are discussed.

Genotoxicity of triasulfuron in the wing spot test of Drosophila melanogaster is modulated by winter wheat seedlings.

Triasulfuron (TS) is a widely used sulfonylurea herbicide which inhibits the acetolactate synthase in broad-leaf weeds and in some wheat crop grasses (Triticum aestivum L.). Residues can be found in soil and superficial water with high toxicity to primary producers. In cereals, TS metabolism depends on cytochromes P450 (CYPs), the age of seedlings and the interaction with compounds. The genotoxicity of TS was demonstrated in the wing spot test of Drosophila melanogaster, an in vivo assay based on the loss of heterozygosity of the mwh and flr markers in the wing imaginal disk cells of larvae fed with chemical agents. Chronic treatments with analytical grade TS, commercial formulation TS (Amber) 75WG) (0.5mg/mL) and commercial formulation bentazon (Basagran) 480) (0.24mg/mL) were performed with three-day-old larvae of the standard (ST) and the high bioactivation (HB) crosses with regulated and high constitutive levels of CYPs, respectively. To demonstrate the effect of winter wheat metabolism on TS genotoxicity, T. aestivum L. seedlings were immersed for 4h in these herbicides, and aqueous extracts (AEs) of the roots were prepared to expose the larvae. TS and Amber 75WG produced similar genotoxic effects in both crosses. Wheat metabolism modulated the genotoxicity because the AEs yielded statistically significant lower spot frequencies in the HB cross than in the ST cross. Differences between the two crosses of the wing spot test in D. melanogaster must be related to CYPs levels. Basagran 480 was genotoxic only in the HB cross, and wheat metabolism did not modulate its genotoxicity.

Genotoxicity of tamoxifen citrate and 4-nitroquinoline-1-oxide in the wing spot test of Drosophila melanogaster.

Tamoxifen (TAM) is an anti-oestrogen used for treatment and prevention of human breast cancer, but it is also related to human endometrial and uterine cancer. The wing spot test in Drosophila melanogaster was employed to determine the genotoxic effects of TAM and 4-nitroquinoline-1-oxide (4-NQO), a carcinogen that produces adducts similar to TAM-DNA adducts detected in rodent liver and human liver microsomes. As Drosophila spp. have no oestrogen receptor, no effects can result in binding of TAM to a receptor. Chronic treatments with TAM citrate were performed with 3-day-old larvae of the standard (ST) and high bioactivation (HB) crosses of the wing spot test at concentrations of 0.66, 1.66 and 3.33 mM. In addition, the carcinogen 4-NQO was administered at 2.5 and 5.0 mM. Somatic spots on normal wings from marker-heterozygous flies and on serrate wings from balancer-heterozygous flies were scored to determine mutation and recombination events in somatic cells for each compound. The results showed genotoxic effects of TAM at 1.66 and 3.33 mM in the ST cross only and without a clear dose-response effect. This suggests a weak genotoxicity of this anti-oestrogen. The negative results obtained with TAM in the HB cross may indicate efficient detoxification of the compound by the increased xenobiotic metabolism present in this cross. As reported before, 4-NQO showed genotoxic effects in the ST cross with a clear dose-response effect. For the first time, we report enhanced effects of this compound in the HB cross. It is concluded that the genotoxicity of TAM in the Drosophila wing spot test is different from that of 4-NQO.

Efectos de la administración central de agonistas GABAérgicos sobre la microestructura de la conducta alimenticia. Estudio experimental en ratas / Response to central administration of GABAergic agents on the microestructure of feeding behaviour. Experimental trial in rats

Debido a la administración de muscimol en el HVM (hipotálamo ventromedial) la ingesta de carbohidratos y la ingesta total se incrementaron; conductualmente este aumento de la ingesta de alimento se caracterizó por el aumento del tiempo total, asociado a un incremento en la duración de los episodios alimentarios. La administración de baclofén en el HVM incrementó la ingesta de carbohidratos y la ingesta total, este aumento se caracterizó por episodios alimentarios menos frecuentes pero más largos. Se confirma que la estimulación de los receptores GABAA y GABAB en el HVM inducen la alimentación y se concluye que el sistema GABAérgico está involucrado en el control de la conducta alimenticia.

Cáncer cervicouterino: Factores de riesgo y alteraciones asociadas en mujeres del estado de Guerrero / Uterine cervical cancer: Risk factors and associated alterations in women of the Guerrero state

El cáncer cervicouterino es la primera causa de muerte en la mujer mexicana. El conocimiento sobre su epidemiología es controversial, por lo que se realizó un estudio prospectivo en una comunidad guerrerence entre 1995 y 1996. A 281 mujeres con vida sexual se les interrogó sobre sus antecedentes ginecoobstétricos, nivel educativo y ocupación de su pareja sexual (factor masculino). A todas se les realizó citología cervicovaginal. La frecuencia de alteraciones evidenciadas mediante la citología exfoliativa fue del 7.4 por ciento (21 casos). Este porcentaje lo constituyeron 17 casos con displasias (6.04 por ciento) y cuatro con cáncer epidermoide (1.42 por ciento). La frecuencia de los factores de riesgo fue: Inicio temprano de vida sexual (76.1 por ciento), multigestas (76.1 por ciento), factor masculino (76.1 por ciento), multiparidad (66.6 por ciento), embarazo temprano (61.9 por ciento), tabaquismo (23.8 por ciento), más de tres compañeros sexuales (14.2 por ciento), virus del papiloma humano (9.5 por ciento) y herpes virus (4.7 por ciento)