PCDD, PCDF, dl-PCB and organochlorine pesticides monitoring in São Paulo City using passive air sampler as part of the Global Monitoring Plan

The persistent organic pollutants (POPs), such as organochlorine pesticides and PCBs, are ordinarily monitored in the aquatic environment or in soil in the environmental quality monitoring programs in São Paulo, Brazil. One of the core matrices proposed in the POPs Global Monitoring Plan (GMP) from the Stockholm Convention list is the ambient air, which is not a usual matrix for POPs monitoring in the country. In this study POP levels were evaluated in the air samples from an urban site in São Paulo City over five years, starting in 2010 as a capacity building project for Latin America and the Caribbean region for POP monitoring in ambient air using passive samplers. Furthermore, after the end of the Project in 2012, the monitoring continued in the same sampling site as means to improving the analytical capacity building and contribute to the GMP data. The POPs monitored were 17 congeners of 2,3,7,8 chloro-substituted PCDDs and PCDFs, dioxin-like PCBs, indicator PCBs, organochlorine pesticides and toxaphene. The results show a slight decrease in PCDD/F, dl-PCBs and indicator PCBs levels along the five years. The organochlorine pesticide endosulfan was present at its highest concentration at the beginning of the monitoring period, but it was below detection level in the last year of the monitoring. Some other organochlorine pesticides were detected close to or below quantitation limits. The compounds identified were dieldrin, chlordane, α-HCH, γ-HCH, heptachlor, heptachlor epoxide, hexachlorobenzene and DDTs. Toxaphene congeners were not detected. These results have confirmed the efficacy of passive sampling for POP monitoring and the capacity building for POP analysis and monitoring was established. However more needs to be done, including expansion of sampling sites, new POPs and studies on sampling rates to be considered in calculating the concentration of POPs in ambient air using a passive sampler.

Genetic structure of natural populations of Theobroma in the Juruena National Park, Mato Grosso State, Brazil

Several species within the genus Theobroma have particularly high economic value, including T. cacao and T. grandiflorum. Other species in this genus, such as T. speciosum and T. subincanum, have potential value for use in the conservation of genetic diversity in breeding programs. These latter species could also be domesticated or improved to produce commercial products. Using 13 simple sequence repeat loci, the population structure and genetic diversity of T. speciosum and T. subincanum natural populations in the Juruena National Park, Mato Grosso State, Brazil, was studied. We sampled all individuals of each species (N = 25) present inside a designated research area established by the Program for Research on Biodiversity. The average number of alleles per locus was 5 for T. speciosum and 6.69 for T. subincanum, with average PIC values above 0.5 in both species. All evaluated individuals varied genetically. Seeds from the individuals analyzed will be useful for the development of germplasm banks and for establishment of breeding programs.

An innovative biocatalyst for production of ethanol from xylose in a continuous bioreactor

The use of the hemicellulose fraction of biomass may be important for the feasibility of the production of second generation bioethanol. Wild strains of Saccharomyces cerevisiae are widely used in industry for production of 1st generation ethanol, and the robustness of this yeast is an important advantage in large scale applications. Isomerization of xylose to xylulose is an essential step in this process. This reaction is catalyzed by glucose isomerase (GI). A new biocatalyst is presented here for the simultaneous isomerization and fermentation (SIF) of xylose. GI from Streptomyces rubiginosus was immobilized in chitosan, through crosslinking with glutaraldehyde, and the support containing the immobilized GI (IGI-Ch) was co-immobilized with S. cerevisiae, in calcium alginate gel. The immobilization experiments led to high immobilized protein loads (30-68 mg × g(support)(-1)), high yields (circa of 100%) and high recovered enzyme activity (>90%). The IGI-Ch derivative with maximum activity presented 1700 IU × g(catalyst)(-1), almost twice the activity of a commercial immobilized GI, GENSWEET(®) IGI-HF. At typical operational conditions for xylose SIF operation (pH 5, 30-35 °C, presence of nutrients and ethanol concentrations in the medium up to 70 L(-1)), both derivatives, IGI-Ch and GENSWEET(®) IGI-HF retained app. 90% of the initial activity after 120 h, while soluble GI was almost completely inactive at pH 5, 30 °C. The isomerization xylose/xylulose, catalyzed by IGI-Ch, reached the equilibrium in batch experiments after 4h, with 12,000 IU × L(-1) (7 g(der) × L(-1)), at pH 5 and 30 °C, in the presence of fermentation nutrients. After co-immobilization of IGI-Ch with yeast in alginate gel, this biocatalyst succeeded in producing 12 g × L(-1) of ethanol, 9.5 g × L(-1) of xylitol, 2.5 g × L(-1) of glycerol and 1.9 g × L(-1) of acetate after consumption of 50 g × L(-1) of xylose, in 48 h, using 32.5 × 10(3) IU × L(-1) and 20 g(yeast) × L(-1), at 35 °C and initial pH 5.3.

Topical anti-inflammatory potential of Physalin E from Physalis angulata on experimental dermatitis in mice

The anti-inflammatory effect of physalin E, a seco-steroid isolated from Physalis angulata L. was evaluated on acute and chronic models of dermatitis induced by 12-O-tetradecanoyl-phorbol-13-acetate (TPA) and oxazolone, respectively, in mouse ear. The changes in ear edema/thickness, production of pro-inflammatory cytokines (TNF-alpha and IFN-gamma), myeloperoxidase (MPO) activity, and histological and immunohistochemical findings were analysed, as indicators of dermal inflammation. Similar to dexamethasone, topically applied Physalin E (0.125; 0.25 and 0.5 mg/ear) potently inhibited the TPA and oxazolone-induced dermatitis, leading to substantial reductions in ear edema/thickness, pro-inflammatory cytokines, and MPO activity. These effects were reversed by mifepristone, a steroid antagonist and confirmed by immunohistochemical and histopathological analysis. The data suggest that physalin E may be a potent and topically effective anti-inflammatory agent useful to treat the acute and chronic skin inflammatory conditions.

Assessment of antimutagenic and genotoxic potential of senna (Cassia angustifolia Vahl.) aqueous extract using in vitro assays

Senna (Cassia angustifolia Vahl.) is widely used as a laxative, although potential side effects, such as toxicity and genotoxicity, have been reported. This study evaluated genotoxic and mutagenic effects of senna aqueous extract (SAE) by means of four experimental assays: inactivation of Escherichia coli cultures; bacterial growth inhibition; reverse mutation test (Mutoxitest) and DNA strand break analysis in plasmid DNA. Our results demonstrated that SAE produces single and double strand breaks in plasmid DNA in a cell free system. On the other hand, SAE was not cytotoxic or mutagenic to Escherichia coli strains tested. In effect, SAE was able to avoid H(2)O(2)-induced mutagenesis and toxicity in Escherichia coli IC203 (uvrA oxyR) and IC205 (uvrA mutM) strains, pointing to a new antioxidant/antimutagenic action of SAE.

Bradykinin into amygdala induces thermal hyperalgesia in rats

Bradykinin is one of the most potent endogenous algesic substances and its role in pain transmission has been intensively studied in the periphery. However, the action of this peptide in central structures involved in pain transmission remains unclear. Administration of bradykinin (0.25 nmol/site) into the right amygdala of adult male Wistar rats induced thermal hyperalgesia, evaluated in the paw-flick test. Bradykinin-induced hyperalgesia was abolished by co-administration with the B(2) receptor antagonist Hoe 140 (5 pmol/site), the NMDA antagonist MK-801 (5 nmol/site), the cyclooxygenase inhibitor indomethacin (10 nmol/site) and the glial metabolic inhibitor fluorocitrate (1 nmol/site). Since the intra-amygdala administration of bradykinin did not alter spontaneous locomotion in the open-field test, it is unlikely that the current described hyperalgesic effect of bradykinin is due to an unspecific action on motor activity. These findings provide evidence that bradykinin, through activation of amygdalar B(2) receptors induces hyperalgesia and that glutamatergic- and prostanoid-mediated mechanisms are involved in such effect.

Genotoxic potentiality of aqueous extract prepared from Chrysobalanus icaco L. leaves

Plants have been related to our lives, being used as medicine, regardless of scientific evidence of side effects. This work analyses the toxicological effects of Chrysobalanus icaco L. aqueous extract, used in different pathologies. It was studied through: (i) alteration of plasmid pUC 9.1 topology; (ii) survival of bacterial strains submitted, or not, to previous treatment with SnCl2; (iii) transformation efficiency of E. coli strain by the treatment with the plasmid pUC 9.1. In (i), the treatment of the plasmid resulted in DNA single-strand breaks (SSB). A decrease of the lethal effect induced by SnCl2 in presence of the extract was found, while no C. icaco bacterial survival reduction was observed. The transformation efficiency of the plasmid was also reduced. Results suggest that the extract could present a potential genotoxic effect, as demonstrated either by the induction of SSB in plasmid or in transformation efficiency experiments. Finally, it presents an antioxidant action.

Biological effects of stannous chloride, a substance that can produce stimulation or depression of the central nervous system

It was demonstrated that tin, as stannous chloride (SnCl(2)), can facilitate the neuromuscular transmission by accelerating the transmitter release from the nerve terminals in the mouse. When this salt is injected into laboratory animals, it can produce stimulation or depression of the central nervous system. Because calcium (Ca(2+)) influx into the cytoplasm is indispensable to release the transmitter, it would be possible that SnCl(2) increases the Ca(2+) influx at the nerve terminals but not by blocking the K(+) channels. SnCl(2) is known to inhibit the immune response in rodents and to induce tumor generation in thyroid gland. There is no general agreement regarding its genotoxicity and it was discussed that the effects of this salt might depend on the physicochemical conditions and the route of its administration. SnCl(2) has been used in many sectors of human interest, such as food industry and nuclear medicine. This salt is directly administered to human beings endovenously, when it is used as a reducing agent to prepare 99mTc-radiopharmaceuticals which are also used for cerebral studies. SnCl(2) is capable to promote the generation of reactive oxygen species (ROS) that are responsible for the oxidative stress. Oxidative stress has been related with aging and other neurological diseases. So, it is relevant to evaluate other biological effects of SnCl(2). We decided to study these effects using Escherichia coli mutant strains, deficient in DNA repair genes, and supercoiled plasmid DNA. We evaluated the influence of medicinal plants, metal chelating agents, and ROS scavengers against the SnCl(2) deleterious effects. Our results show that SnCl(2) produced lesions in vitro as well as in vivo. This inactivation may be due to the production of ROS. We observed that the genotoxic effect of SnCl(2) was partly inhibited or disappeared, when the treatments were done in the presence of medicinal plants, metal chelating agents, and ROS scavengers. In conclusion, these findings suggest that the SnCl(2) biological effects may be associated with the generation of ROS. Moreover, we can speculate that ROS could be associated with the detrimental effects in the brain due to exogenous or endogenous metals.

Evaluation of the cytotoxic and mutagenic potentiality of technetium-99m in Escherichi coli

Since technetium-99m (99mTc) was introduced in medical research it has become one of the most employed radionuclides in nuclear medicine. 99mTc is ideal for routine use on the labeling of different radiopharmaceuticals due to its favorable characteristics. However, some biological effects have been described. These effects may be related to internal conversion electron and/or Auger electron emissions from 99mTc decay that present high linear energy transfer and can generate reactive oxygen species (ROS) in the medium. We evaluated in Escherichia coli K12S and Salmonella typhimurium TA102, both proficient in DNA repair, contribution of those decay emissions on the cytotoxicity induced by 99mTc, both either by generating lesions on DNA or by inducing alterations at membrane. We also studied the genotoxic and/or mutagenic potentiality of 99mTc, in Salmonella typhimurium, using the Ames test. The results showed that: i/ 99mTc is cytotoxic to the Escherichia coli K12S strains; ii/ this effect is related to the electrons (Auger and internal conversion) emissions, and iii/ the 99mTc is not mutagenic and/or genotoxic, when measured by Ames test.

Antioxidant action of bixin against cisplatin-induced chromosome aberrations and lipid peroxidation in rats

Cisplatin is one of the most active cytotoxic agents in the treatment of cancer, but has serious side effects, inducing nephrotoxicity and chromosome aberrations. In this study we evaluated the role of the carotenoid bixin on cisplatin-induced oxidative stress in Wistar rats through three markers of oxidative damage: chromosome aberrations, glutathione depletion and lipid peroxidation. The animals were divided into six treatment groups with six rats in each (n= 6). The dose of cisplatin (5.0 mg kg(-1)body wt.) was injected i.p. and bixin (2.5 or 5.0 mg kg(-1)body wt.) was given by gavage at 48, 24 h and 10 min before the cisplatin injection. The treatment with the highest dose of bixin resulted in a statistically significant reduction, by about 33%, in cisplatin-induced abnormal metaphases (P< 0.05). A single dose of cisplatin enhanced the formation of lipid peroxides in 29% and resulted in a 29% depletion in renal glutathione 24 h after cisplatin administration (P< 0.05). The pretreatment with bixin reduced the total number of chromosome aberrations, inhibited the increase in lipid peroxidation, and inhibited renal glutathione depletion induced by cisplatin. Since the pretreatment with bixin alone was safe, under the present experimental conditions, the results suggest that bixin may have future clinical application after further studies.

[Mortality rate associated to traffic accidents and registered motor vehicles]

OBJECTIVE

The mortality rate due to traffic accidents is an information often used while making public health policies. In order to measure traffic violence, a study was carried to analyze the number of death by traffic accidents per registered motor vehicle.

METHODS

Based on the number of registered vehicles, population and traffic accident deaths, obtained from the Statistical Yearbook (1999), Demographic Yearbook (1997), Denatran (1999), Ministério da Saúde (2000) and Fundação IBGE (2000) 61 countries and 51 areas in Brazil were studied. Traffic accident mortality rate was broken down into registered motor vehicles per capita and the number of deaths per motor vehicle. To assess this relationship, the samples (international and Brazilian) were subdivided into three groups according to the number of vehicles per capita. To test the statistical significance of this relationship, log-linear regression was used.

RESULTS

The number of deaths per motor vehicles is associated to the number of registered motor vehicles per capita. The statistical relationship is -1.067 for international data and -0.515 for the Brazilian data.

CONCLUSIONS

To prevent traffic accidents, there is a need of further studies to explain the high numbers of deaths due to motor vehicles associated with the low rate of registered motor vehicles per capita.

Development of new urea-functionalized silica stationary phases

New urea-functionalized silica stationary phases were prepared by a single-step surface modification through reaction of LiChrosorb Si100 (5 microm particle size) with a homologous series of alkoxysilanes, synthesized in our laboratory, with the general formula (CH3CH2O)3Si(CH2)3NHC(O)NH(CH2)nCH3, where n=4, 6 and 11. The modified silicas were characterized by elemental analysis of carbon and nitrogen, solid-state 29Si- and 13C-cross polarization magic angle spinning nuclear magnetic resonance and nitrogen adsorption isotherms at 77 K. Chromatographic evaluation of the three urea-functionalized silicas in 150x3.9 mm I.D. HPLC columns was carried out by the separation of a test mixture composed of uracil, acetophenone, benzene, toluene and naphthalene, using acetonitrile-water as mobile phase. These new stationary phases, with embedded polar urea groups, are very promising when compared with amide phases prepared by the conventional two-step modification process. A single-step reaction process silica modification is better for obtaining a well-characterized and homogeneous modified surface.

The effect of drugs on the labeling of blood elements with technetium-99m

The influence of drugs on the labeling of red blood cells and plasma proteins with 99mTc has been reported. Any drug, which alters the labeling of the tracer, could be expected to modify the disposition of the radiopharmaceuticals. Red blood cells (RBC) labeled with technetium-99m (99mTc) are used for several evaluations in nuclear medicine. We have evaluated the effect of Thuya occidentalis, Peumus boldus and Nicotiana tabacum (tobacco) extracts on the labeling of RBC and plasma and cellular proteins with 99mTc. Blood was incubated with the drugs. Stannous chloride (SnCl2) solutions and 99mTc were added. Plasma (P) and blood cells (BC) were separated. The percentage of radioactivity (%ATI) bound to P and BC was determined. The %ATI on the plasma and cellular proteins was also evaluated by precipitation of P and BC samples with trichloroacetic acid (TCA) and isolation of soluble (SF) and insoluble (IF) fractions. The analysis of the results shows that there is a decrease in %ATI (from 97.64 to 75.89 percent) in BC with Thuya occidentalis extract. The labeling of RBC and plasma proteins can be decreased in presence of tobacco. This can be due either a direct or indirect effect (reactive oxygen species) of tobacco. The analysis of radioactivity in samples of P and BC isolated from samples of whole blood treated with Peumus boldus showed a rapid uptake of the radioactivity by blood cells in the presence of the Peumus boldus, whereas there was a slight decrease in the amount of 99mTc radioactivity in the TCA-insoluble fraction of plasma. This study shows that extracts of some medicinal plants can affect the radiolabeling of red blood cells with 99mTc using an in vitro technique.

[Accuracy of the oscillometric method to measure blood pressure in children]

OBJECTIVE: The aim of this study is to analyze the substitution of the standard auscultatory method by the oscillometric blood pressure monitor, independently of the validity of the intraarterial blood pressure measurement. The accuracy of the automatic oscillometric monitor was compared to the auscultatory mercury manometer blood pressure measurement in apparently healthy school age children. METHODS: A device able to perform 3 simultaneous readings are used: one reading by the monitor and the others by two "blind" observers. We studied 72 school age children with the following characteristics: mean age 9.5 (6.1-16.1) and 39 males (54.2%). RESULTS: The difference for the systolic and diastolic blood pressure obtained by the monitor was in average + 6.2 mmHg and + 10.0 mmHg, respectively, when compared to the observer's readings. There was neither a good correlation nor a good agreement between the two observers and the monitor in the blood pressure determination. CONCLUSIONS: We concluded that the substitution of the standard auscultatory method for the non-invasive oscillometric method to measure blood pressure in school age children can not be generally recommended.

[Evolutive aspects of post-transfusion hepatitis C. Review of 175 cases]

Hepatitis C virus is the main agent responsible for post-transfusion hepatitis. Progression to chronic hepatitis, cirrhosis and hepatocellular carcinoma is very common. The aim of this study was to evaluate the frequency, timing and factors related to progression of hepatitis C. One hundred seventy five patients with chronic post-transfusion hepatitis C were grouped in a cirrhosis group (n = 92) and a non-cirrhosis group (n = 83). The medium time of development to cirrhosis was 11 +/- 6 years. Patients with cirrhosis were older at the time they received transfusion, used more alcohol and had longer times of evolution. The prognosis was worse in the cirrhosis group with a mortality rate of 28.4% and 9.1% of evolution towards hepatocellular carcinoma, comparing with 5.5% and 0% in the non-cirrhosis group respectively. It is shown that post-transfusion hepatitis C is slowly developing progressive disease which progress is much more rapidly in elderly patients and patients with others factors of liver damage.

Evaluation of technetium-99m decay on Escherichia coli inactivation: effects of physical or chemical agents

Technetium-99m (99mTc) has been used in nuclear medicine and in biomedical research to label molecular and cellular structures employed as radiotracers. Here, we have evaluated, on a DNA repair proficient Escherichia coli strain, the 99mTc decay inactivation and the influence of the (i) pre-treatment with metal ion chelators or of the (ii) treatment with a free radical scavenger on the protection of the cells against the lethal effect of the 99mTc. As SnCl2 is frequently used as a reducing agent in the 99mTc-labeling process, we have also studied the capability of SnCl2 to alter the biological effects induced by the 99mTc decay. As we are exposed to either chemical or physical agents in the nature, we have decided to study a possible influence of the ultraviolet solar radiation in the biological phenomena induced by the 99mTc decay. Our data point out (i) a very important role of the Auger and/or conversion electrons in the cytotoxicity induced by the 99mTc decay; (ii) SnCl2, the metal ion chelators and the free radical scavenger protect the cells against the lethal effect of the 99mTc; and (iii) near-UV does not alter the lethal effect of the 99mTc decay.

Acid and Base Catalysts in the Hybrid Silica Sol-Gel Process

Sol-gel silicas were synthesized from the hydrolysis of tetraethoxysilane and N-beta-aminoethyl-gamma-aminopropyltrimethoxysilane in the presence of water and ethanol by using ammonium hydroxide or hydrochloric acid as base or acid catalysts, respectively. The influence of the type of the catalyst employed was studied by comparing the surface areas and pore sizes and volumes for both sol-gel silicas. Nitrogen elemental analysis and 13C and 29Si NMR spectra showed that both silicas present similar chemical compositions and structures. The electron-microscope results demonstrated that the particles are uniformly spherical and well shaped in both cases. The sol-gel silica obtained via basic catalysis presented relatively small spherical particles in comparison to those synthesized by acidic catalysis. The results obtained suggest that acidic catalysis is a better procedure for the synthesis of these organofunctionalized hybrid sol-gel silicas. Copyright 1997 Academic Press. Copyright 1997Academic Press