Maria Cristina Picinato Medeiros de Araújo

Determination of anthropogenic and biogenic compounds on atmospheric aerosol collected in urban, biomass burning and forest areas in São Paulo, Brazil

This study was conducted at three sites of different characteristics in São Paulo State: São Paulo (SPA), Piracicaba (PRB) and Mata Atlântica Forest (MAT). PM(10), n-alkanes, pristane and phytane, PAHs, water-soluble ions and biomass burning tracers like levoglucosan and retene, were determined in quartz fiber filters. Samplings occurred on May 8th to August 8th, 2007 at the MAT site; on August 15th to 29th in 2007 and November 10th to 29th in 2008 at the PRB site and, March 13th to April 4th in 2007 and August 7th to 29th in 2008 at the SPA site. Aliphatic compounds emitted biogenically were less abundant at the urban sites than at the forest site, and its distribution showed the influence of tropical vascular plants. Air mass transport from biomass burning regions is likely to impact the sites with specific molecular markers. The concentrations of all species were variable and dependent of seasonal changes. In the most dry and polluted seasons, n-alkane and cation total concentrations were similar between the megacity and the biomass burning site. PAHs and inorganic ion abundances were higher at São Paulo than Piracicaba, yet, the site influenced by biomass burning seems to be the most impacted by the organic anion abundance in the atmosphere. Pristane and phytane confirm the contamination by petroleum residues at urban sites; at the MAT site, biological activity and long range transport of pollutants might influence the levels of pristane.

Potentiation by turmeric and curcumin of γ-radiation-induced chromosome aberrations in Chinese hamster ovary cells

The effect of turmeric and curcumin, two natural antioxidants, on the frequencies of chromosome aberrations induced in Chinese hamster ovary (CHO) cells by gamma-radiation was investigated. Cells were treated with three concentrations of each drug, turmeric (100, 250, and 500 microg/ml) and curcumin (2.5, 5, and 10 microg/ml), and then irradiated (2.5 Gy) during different phases of the cell cycle. Turmeric was not clastogenic by itself, whereas curcumin at 10 microg/ml enhanced the chromosomal damage frequency. Neither of the two antioxidants showed protective effect against the clastogenicity of gamma-radiation. Instead, an obvious increase in the frequencies of chromosome aberrations was observed when turmeric at 500 microg/ml was associated with gamma-radiation during G2/S phase, and curcumin at 10 microg/ml plus gamma-radiation during S and G2/S phases of the cell cycle. The results clearly indicate the exacerbated effect of turmeric and curcumin on radiation-induced clastogenicity, suggesting that these antioxidants are also potentiating agents depending on the experimental conditions.

Mutagenic and cytotoxic activity of an isocoumarin (paepalantine) isolated from Paepalanthus vellozioides

A new isocoumarin with antimicrobial activity was isolated from Paepalanthus vellozioides (a native Brazilian plant) and called paepalantine. This study was carried out to assess the mutagenic activity of this new agent in assays with Salmonella typhimurium TA100, TA98, and TA102 and in Chinese hamster ovary (CHO) cell cultures, as well as cytotoxicity to McCoy cells. paepalantine caused a significant dose-dependent increase in the frequency of revertants in the three strains used in the assay, both with and without S9 mix, in concentrations varying from 2 to 128 micrograms/plate. The mutagenicity was confirmed in assays with CHO cells treated in the G1, S, and G2 phases of the cell cycle. There was an increase in the chromosomal aberration frequency, mainly in the G2 phase. Furthermore, the mitotic index of the treated cultures (40,80, and 160 micrograms/ml) was significantly lower, indicating cytotoxicity. The midpoint cytotoxicity values of McCoy cells by the neutral red (NR) and microculture tetrazolium (MTT) techniques resulted in a NR50 and MTT50 of 30 and 38 micrograms/ml, respectively. Alterations to the paepalantine structure are suggested to reduce its mutagenic and cytotoxic activity in investigations for its antineoplastic potential.

Protective effect of thiourea, a hydroxyl-radical scavenger, on curcumin-induced chromosomal aberrations in an in vitro mammalian cell system.

Natural dietary antioxidants are extensively studied for their ability to protect cells from damage to DNA, protein, and lipids induced by antitumor agents or radiation that leads to the generation of free radical in normal cells in vivo and in vitro. Curcumin is a natural antioxidant known to possess therapeutic properties and has been reported to scavenge free radicals and to inhibit clastogenesis in mammalian cells. However, curcumin has been reported to induce a significant increase in the frequency of chromosomal aberrations in Chinese hamster ovary (CHO) cells. To investigate whether the clastogenic activity of curcumin in CHO cells in culture can be ascribed to a pro-oxidant behavior, mediated by free radical generation, experiments were carried out with the combination of curcumin (15 microg/ml) and thiourea (10, 20, or 40 microg/ml), a potent hydroxyl radical scavenger. The results showed that the clastogenic action of curcumin was statistically decreased in a dose-dependent manner in the presence of thiourea. These data have shown that curcumin-induced chromosomal damage in CHO cells can be mediated by hydroxyl radical generation in the present experimental conditions. Teratogenesis Carcinog. Mutagen. 21:175-180, 2001.

Modulatory effects of curcumin on the chromosomal damage induced by doxorubicin in Chinese hamster ovary cells

Curcumin, a natural phenolic compound, is gaining importance as a free radical scavenger. This study was undertaken to investigate the modulatory effects of curcumin on the chromosomal damage induced by the antitumoral doxorubicin (DXR), a known free radical generator, in Chinese hamster ovary cells in culture. Cells were treated with three concentrations of curcumin (2.5, 5, or 10 microg/ml) and then treated with DXR (1.0 microg/ml) during different phases of the cell cycle. The results show that curcumin induces chromosomal damage in CHO at the highest concentration when compared to the untreated control. Neither treatment with curcumin shows a reduction in the clastogenicity of DXR. Instead, a statistically significant increase in the frequency of chromosomal damage was observed when the middle and the highest concentrations of curcumin were associated with DXR during the G1/S, S, and S/G2 phases of the cell cycle. The results clearly indicate the potentiating effect of curcumin on DXR-induced chromosomal damage.

Effects of turmeric and its active principle, curcumin, on bleomycin-induced chromosome aberrations in Chinese hamster ovary cells

Antioxidantes de ocorrencia natural tem sido exaustivamente estudados quanto a sua capacidade de proteger organimos e celulas contra danos oxidativos. Muitos constituintes das plantas, incluindo curcuma e curcumina, parecem ser potentes antimutagenos e antioxidantes. Os efeitos de curcuma e curcumina na frequencia de aberracoes cromossomicas induzidas pelo agente radiomimetico bleomicina (BLM) foram investigados em celulas do ovario de hamster chines (CHO). Tres concentracoes de cada droga, curcuma (100, 250 e 500 mg/ml) e curcumina (2,5, 5,0 e 10 mg/ml), foram combinadas com BLM (10 mg/ml) em celulas CHO tratadas durante as fases G1/S, S ou G2/S do ciclo celular. Nem curcuma nem curcumina evitaram o dano cromossomico induzido pela BLM em fase alguma do ciclo celular. Ao contrario, a potenciacao da clastogenicidade da BLM pelo curcumina foi nitidamente observada em celulas tratadas durante as fases S e G2/S. A curcumina tambem se mostrou clastogenica na dose de 10 mg/ml nos protocolos de tratamento de 9 e 13 h. Contudo, o mecanismo exato pelo qual a curcumina produziu efeitos potenciadores e clastogenicos permanece desconhecido.

Supplemented tissue culture medium 199 is a better medium for in vitro maturation of oocytes from women with polycystic ovary syndrome women than human tubal fluid

OBJECTIVE To compare oocyte maturation, fertilization and cleavage rates, and embryonic developmental quality after culture of human immature oocytes from polycystic ovary syndrome (PCOS) patients in human tubal fluid (HTF) or tissue culture medium (TCM) 199. DESIGN Prospective, randomized, controlled trial. SETTING University hospital. PATIENT(S) Thirteen women undergoing 23 in vitro maturation cycles, from whom 119 oocytes were retrieved. INTERVENTION(S) Cumulus-enclosed germinal vesicle-stage oocytes matured in TCM-199-supplemented or HTF-supplemented media. MAIN OUTCOME MEASURE(S) Oocyte maturation and fertilization rates, embryonic developmental quality. RESULT(S) Significant differences were observed between TCM 199 and HTF regarding maturation rate (82% vs. 56.9%), fertilization rate (70% vs. 39.4%), and embryo quality (81.3% vs. 41.7%). CONCLUSION(S) Human tubal fluid medium, although widely used for embryo fertilization and maintenance in IVF techniques, is not an appropriate medium for the maturation of oocytes obtained from PCOS patients in nonstimulated cycles.

Oocyte diameter as a predictor of fertilization and embryo quality in assisted reproduction cycles

OBJECTIVE To assess the impact of the mean oocyte diameter (MOD) on occurrence of fertilization and embryo quality in assisted reproduction cycles. DESIGN Prospective observational study. SETTING Sector of Human Reproduction of the University Hospital, Faculty of Medicine of Ribeirão Preto, University of São Paulo (HCFMRP-USP). PATIENT(S) Thirty-five women undergoing intracytoplasmic sperm injection (ICSI) at the University Hospital of Ribeirão Preto from May to October 2007. INTERVENTION(S) MOD assessment. MAIN OUTCOME MEASURE(S) Occurrence of fertilization and qualitative embryo classification on 2nd and 3rd day after ICSI. RESULT(S) We divided 160 metaphase II oocytes according to MOD into groups A (MOD below the 25th percentile), B (MOD between 25th and 75th percentile), and C (MOD above the 75th percentile). There was no statistically significant association between MOD and the occurrence of fertilization or the qualitative embryo classification on days 2 and 3. There was no statistically significant difference between groups regarding number of cells or the qualitative embryo classification on days 2 and 3. CONCLUSION(S) The MOD of mature oocytes does not seem to be related to the occurrence of fertilization or to the developmental quality of human embryos on days 2 and 3 after ICSI.

Noninvasive imaging of the meiotic spindle of in vivo matured oocytes from infertile women with endometriosis.

The objectives of this prospective study were to evaluate the nuclear maturation stage and the presence and location of meiotic spindles of in vivo matured oocytes from infertile women with and without endometriosis (male or tubal causes of infertility) undergoing stimulated cycles for intracytoplasmic sperm injection (ICSI). We also compared the ICSI outcomes among groups. We analyzed the meiotic spindles of oocytes from 36 patients with endometriosis I/II, 24 with endometriosis III/IV, and 60 without endometriosis (male or tubal causes of infertility). The oocytes were imaged using polarization microscopy. There were no differences in the number of oocytes in telophase I (mean [standard deviation]: 0.1 [0.5], 0.2 [0.4], and 0.2 [0.5], respectively, in the endometriosis I/II, endometriosis III/IV, and control groups), in metaphase II with visible spindles (4.2 [2.5], 3.1 [2.0], and 3.6 [2.2], respectively, in the endometriosis I/II, endometriosis III/IV, and control groups), and in spindle location among groups. We can conclude from this study that noninvasive analysis of spindles from in vivo matured oocytes of infertile patients with endometriosis did not demonstrate significant differences in terms of the nuclear maturation stage, the percentage of oocytes in metaphase II with visible spindles, and the spindle localization when compared to the control group. However, it is important to state that there are no studies evaluating the accuracy of polarization microscopy for the detection of meiotic anomalies in human oocytes, which would need to be better evaluated in future studies using an appropriate methodology.

Oócitos aparentemente maduros injetados em telófase I apresentam piores resultados de reprodução assistida

PURPOSE: To evaluate the nuclear maturation stage and the presence of meiotic spindles of in vivo matured oocytes from infertile women undergoing stimulated cycles for intracytoplasmic sperm injection (ICSI) and compare intracytoplasmic sperm injection outcomes between oocytes in telophase I (TI) and metaphase II (MII), and the ones with and without visible meiotic spindle. METHODS: A prospective and controlled study with 106 infertile patients who underwent ovarian stimulation for intracytoplasmic sperm injection purposes. Patients aged 38 years or less, with basal follicle stimulating hormone (FSH) less than 10 mIU/mL and body mass index (BMI) less than 30 kg/m². Were included patients presenting any systemic diseases, any active infection, smokers or patients who had been using hormonal medications and hormonal and nonhormonal anti-inflammatory drugs for the past two months prior to the assisted reproduction procedure were excluded. The oocytes with the first polar body extruded (in vivo matured oocytes) were imaged by polarization microscopy immediately before intracytoplasmic sperm injection and characterized according to nuclear maturation stage (telophase I and metaphase II) and to the presence of a meiotic spindle. We analyzed the fertilization rates, cleavage, number of good quality embryos on the second day (D2) from oocytes on telophase I versus those in metaphase II, and metaphase II visible spindle versus non-visible ones. Data were analyzed comparatively by Fishers exact test. The level of significance was set at 5% in all analyses (p<0.05). RESULTS: The meiotic spindles of 516 oocytes were imaged using polarization microscopy. From the 516 oocytes analyzed, seventeen were in telophase I (3.3%) and 499 (96.7%) in metaphase II. The oocytes injected in telophase I had significantly lower fertilization rates than those injected in metaphase II (53 and 78%, respectively) and produced no good quality embryos on day 2. When the oocytes with and without a visible meiotic spindle were compared, there was no significant difference in the intracytoplasmic sperm injection results. CONCLUSIONS: Oocytes injected in telophase I showed lower fertilization rates when compared to those in metaphase II. It is possible that the analysis of oocyte nuclear maturation by polarization microscopy can be used as a predictor of fertilization after intracytoplasmic sperm injection.