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2.
Braz J Med Biol Res ; 52(7): e8303, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31291382

RESUMO

Reinforcement omission effects (ROEs) are characterized by higher response rates after reinforcement omission than after reinforcement delivery. This pattern of behavior is interpreted in terms of motivational and attentional processes. Recent studies from our laboratory have shown that the amygdala, nucleus accumbens, and medial prefrontal cortex are involved in ROE modulation. Also, the literature has demonstrated a role of other areas such as substantia nigra pars compacta (SNc) and the ventral tegmental area (VTA) in processes related to surprising events, such as prediction error and presentation or omission of an event (exteroceptive stimulus and reinforcement). Since these structures send projections to areas related to ROE modulation such as the amygdala, nucleus accumbens, and prefrontal cortex, the objective of the present study was to determine whether the SNc and VTA also integrate the circuit involved in ROE modulation. Rats were trained on a fixed-interval 12 s with limited-hold 6 s signaled schedule of reinforcement (Pre-lesion training). After acquisition of stable performance, the rats received bilateral neurotoxic lesions of the SNc (Experiment 1) and VTA (Experiment 2). Following postoperative recovery, the rats were submitted to two refresher sessions (Post-lesion training). Subsequently, the training was changed from a 100 to a 50% schedule of reinforcement (Post-lesion testing). In both experiments, the results showed that there was no difference in performance between sham rats and rats with bilateral lesions of the SNc or the VTA.


Assuntos
Comportamento Animal/fisiologia , Condicionamento Operante/fisiologia , Parte Compacta da Substância Negra/lesões , Substância Negra/lesões , Área Tegmentar Ventral/lesões , Animais , Aprendizagem/fisiologia , Masculino , Parte Compacta da Substância Negra/fisiopatologia , Ratos , Ratos Wistar , Substância Negra/fisiopatologia , Área Tegmentar Ventral/fisiopatologia
3.
Braz. j. med. biol. res ; 52(7): e8303, 2019. graf
Artigo em Inglês | LILACS-Express | ID: biblio-1011594

RESUMO

Reinforcement omission effects (ROEs) are characterized by higher response rates after reinforcement omission than after reinforcement delivery. This pattern of behavior is interpreted in terms of motivational and attentional processes. Recent studies from our laboratory have shown that the amygdala, nucleus accumbens, and medial prefrontal cortex are involved in ROE modulation. Also, the literature has demonstrated a role of other areas such as substantia nigra pars compacta (SNc) and the ventral tegmental area (VTA) in processes related to surprising events, such as prediction error and presentation or omission of an event (exteroceptive stimulus and reinforcement). Since these structures send projections to areas related to ROE modulation such as the amygdala, nucleus accumbens, and prefrontal cortex, the objective of the present study was to determine whether the SNc and VTA also integrate the circuit involved in ROE modulation. Rats were trained on a fixed-interval 12 s with limited-hold 6 s signaled schedule of reinforcement (Pre-lesion training). After acquisition of stable performance, the rats received bilateral neurotoxic lesions of the SNc (Experiment 1) and VTA (Experiment 2). Following postoperative recovery, the rats were submitted to two refresher sessions (Post-lesion training). Subsequently, the training was changed from a 100 to a 50% schedule of reinforcement (Post-lesion testing). In both experiments, the results showed that there was no difference in performance between sham rats and rats with bilateral lesions of the SNc or the VTA.

4.
Arq. bras. med. vet. zootec ; 66(5): 1427-1434, Sep-Oct/2014. tab, graf
Artigo em Português | LILACS | ID: lil-729743

RESUMO

Na cirurgia de ovariossalpingo-histerectomia (OSH), há várias técnicas para realização da hemostasia e da secção do pedículo ovariano, sendo mais comum a técnica das três pinças. O eletrobisturi bipolar pode ser utilizado com eficácia para hemostasia e corte de tecidos. Objetivou-se nesta pesquisa comparar, em gatas, a hemostasia e a secção do pedículo ovariano mediante o uso do eletrobisturi bipolar com a técnica das três pinças, ambas via celiotomia mediana, em relação ao tempo cirúrgico e à eficiência hemostática (hematócrito). Quarenta gatas, com idade de seis meses a sete anos, peso entre 1,68 e 4,14kg, foram submetidas à hemostasia e à secção desse pedículo, sendo 20 pela técnica convencional e 20 por meio do eletrobisturi bipolar. Na análise estatística, observou-se que o uso do eletrobisturi bipolar gera uma diminuição média significativa na duração da cirurgia, quando comparado com o outro método, sem diferenças quanto à comparação de hematócritos pré e pós-cirúrgicos. Por meio do modelo de regressão múltiplo, verificou-se que as variáveis: idade, peso, número de gestações, número de partos e número de cios não influenciaram significativamente no tempo. Concluiu-se, portanto, que o eletrobisturi bipolar oferece eficiência e maior rapidez na realização da hemostasia e da diérese do pedículo ovariano de gatas submetidas à OSH eletiva...


In ovariosalpingohisterectomy (OSH) surgery, there are several techniques for hemostasis and resection of ovarian pedicle, the most common being the three tweezers technique. The bipolar eletrobisturi can be used effectively for hemostasis and cutting tissue. The aim of this research was to compare, in cats, hemostasis and resection of ovarian pedicle eletrobisturi with bipolar forceps and the three techniques, both via median celiotomy, in relation to time and surgical hemostatic efficiency (hematocrit). Forty cats aged six months to seven years, weighing between 1.68 and 4.14kg, underwent hemostasis and pedicle of this section, 20 with the conventional technique and 20 with eletrobisturi bipolar. Statistical analysis showed that the use of bipolar eletrobisturi generates a significant decrease in the mean duration of surgery when compared with a method without differences in hematocrit comparing pre-and post-surgery. Through the multiple regression model we found that the variables age, weight, number of pregnancies, number of births and number of cycles did not significantly influence the time. We conclude, therefore, that the bipolar eletrobisturi is efficient and fast for hemostasis and dieresis ovarian pedicle of cats undergoing elective ovariohysterectomy...


Assuntos
Animais , Gatos , Gatos , Hemostasia Cirúrgica/veterinária , Histerectomia/veterinária , Procedimentos Cirúrgicos Eletivos/veterinária , Instrumentos Cirúrgicos/veterinária , Técnicas Hemostáticas/veterinária
5.
Transplant Proc ; 46(6): 1723-6, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25131021

RESUMO

Kidney transplantation in children has shown steady improvement in graft survival outcome over the last decades. Using data obtained from the transplantation registry of our center between 1984 and 2012, we assessed the independent determinants of graft failure using the Cox proportional hazards regression. Altogether, 128 recipients younger than 18 years of age at the time of kidney transplantation and who had >3 months graft survival were studied. During 9.95 years of medium follow-up, 27 censored graft failures occurred. Censored graft survival rates at 5, 10, 15, and 20 years post-transplantation were 93%, 82%, 70%, and 63%, respectively. Studied factors included recipient and donor age, recipient gender, dialysis vintage, donor/recipient cytomegalovirus (CMV) serology, panel-reactive antibody percentage, human leukocyte antigen mismatching, previous transplantation number, donor type (deceased vs living donation), cold ischemia time, induction therapy with antithymocyte globulin, occurrence of acute tubular necrosis, and development of acute rejection. Using univariate analysis, the significant predictors for graft-censored failure were adult donor (P < .001), recipient age (P = .035), human leukocyte antigen mismatching (P = .025), antithymocyte globulin induction (P = .03), and development of acute rejection (P < .001). Two factors independently predicted graft-censored failure in multivariate analysis. The odds ratios for graft failure in patients with acute rejection and in children who received an organ of an adult were 3.744 and 4.962, respectively. Pediatric recipients should receive the first priority for allografts from pediatric donors and acute rejection should be meticulously prevented.


Assuntos
Rejeição de Enxerto , Transplante de Rim , Adolescente , Fatores Etários , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Análise Multivariada , Sistema de Registros , Doadores de Tecidos , Adulto Jovem
6.
Environ Sci Pollut Res Int ; 20(10): 7348-54, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23640390

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) are significant environmental contaminants as they are present naturally as well as anthropogenically in soil, air and water. In spite of their low solubility, PAHs are spread to the environment, and they are present in surface water, industrial effluent or groundwater. Amongst all remediation technologies for treating groundwater contaminated with PAHs, the use of a permeable reactive biobarrier (PRBB) appears to be the most cost-effective, energy efficient, and environmentally sound approach. In this technology, the microorganisms are used as reactive medium to degrade or stabilize the contaminants. The main limits of this approach are that the microorganisms or consortium used for forming the PRBB should show adequate characteristics. They must be retained in the barrier-forming biofilm, and they should also have degradative ability for the target pollutants. The aim of the present work is to evaluate the viability of Arthrobacter viscosus as bioreactive medium for forming PRBB. Initially, the ability of A. viscosus to remove PAHs, benzo[a]anthracene 100 µM and phenanthrene 100 µM was evaluated operating in a batch bench-scale bioreactor. In both cases, total benzo[a]anthracene and phenanthrene removals were obtained after 7 and 3 days, respectively. Furthermore, the viability of the microorganisms was evaluated in the presence of chromium in a continuous mode. As a final point, the adhesion of A. viscosus to sepiolite forming a bioreactive material to build PRBB was demonstrated. In view of the attained results, it can be concluded that A. viscosus could be a suitable microorganism to form a bioreactive medium for PAHs remediation.


Assuntos
Arthrobacter/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Biodegradação Ambiental , Reatores Biológicos , Modelos Biológicos , Modelos Químicos , Hidrocarbonetos Policíclicos Aromáticos/análise , Solubilidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/metabolismo
7.
Chemosphere ; 91(5): 711-6, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23402919

RESUMO

In this work, the formation of permeable reactive biobarriers (PRBBs) using Trichoderma longibrachiatum over nylon sponge as bioreactive medium for removal of polycyclic aromatic hydrocarbons (PAHs) was studied. Colony formation was pretested without PAH presence by inoculation of fungus into nylon sponge. The fungus formed a large quantity of strongly adhesive biofilm among nylon sponge. Afterwards, the ability of the developed bioreactive medium was tested to remediate phenanthrene in aqueous medium and in soil. In aqueous medium, a 90% of phenanthrene concentration reduction was observed after 14 d. However, the pollutant removal in soil requires previous fungus colonization and the attained level was around 70% after 28 d. Subsequently, the formed bioreactive material was used in a glass column reactor to evaluate its application as PRBBs. Mixtures of phenanthrene, benzo[a]anthracene and pyrene at several concentrations, from 100 to 400 µM, were treated. In all cases, the performance of the PRBB was satisfactory and total PAH removals were achieved. These results suggest that PRBBs of T. longibrachiatum supported on nylon sponge can be an effective method for the treatment of PAHs.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Trichoderma/metabolismo , Poluentes Químicos da Água/metabolismo , Biodegradação Ambiental , Filtração/instrumentação , Nylons , Hidrocarbonetos Policíclicos Aromáticos/análise , Trichoderma/fisiologia , Poluentes Químicos da Água/análise
8.
Environ Sci Pollut Res Int ; 19(5): 1800-8, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22203400

RESUMO

PURPOSE: In this study, a novel and ecological alternative have been developed to treat soils contaminated with hexavalent chromium coupling two well-known systems: electrokinetic remediation and permeable reactive biobarriers. The electric field promotes the electromigration of the hexavalent chromium oxyanions towards the anode. The biobarriers were placed before the anode electrode, in order to promote the reduction and retention of the chromium migrating in its direction. Thus, this technology provided a global treatment to soil removal without subsequent treatments of the contaminated effluents. METHODS: The electrokinetic system was coupled with two different permeable reactive biobarriers composed by Arthrobacter viscosus bacteria, supported either in activated carbon or zeolite. An electric field of 10 V was applied and two different treatment times of 9 and 18 days were tested. RESULTS: Removal values of 60% and 79% were obtained when electrokinetic treatment was coupled with zeolite and activated carbon biobarriers, respectively, for a test period of 18 day. The reduction of hexavalent chromium to trivalent chromium was around 45% for both systems. CONCLUSIONS: In this work, two types of biobarriers were efficiently coupled to electrokinetic treatment to decontaminate soil with Cr(VI). Furthermore, the viability of the new coupling technology developed (electrokinetic + biobarriers) to treat low-permeability polluted soils was demonstrated.


Assuntos
Cromo/isolamento & purificação , Eletroquímica/métodos , Poluentes do Solo/isolamento & purificação , Arthrobacter , Cromo/química , Recuperação e Remediação Ambiental , Concentração de Íons de Hidrogênio , Poluentes do Solo/química , Zeolitas
9.
J Hazard Mater ; 192(2): 545-53, 2011 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-21684081

RESUMO

This work aims at the reutilization of a Cr-loaded NaY zeolite obtained by biorecovery of chromium from water as catalyst in the oxidation of volatile organic compounds (VOC). Cr-NaY catalysts were obtained after biosorption of Cr(VI) using a bacterium, Arthrobacter viscosus, supported on the zeolite. The biosorption experiments were conducted at different pH values in the range 1-4. The catalysts were characterized by several techniques, namely ICP-AES, SEM-EDS, XRD, XPS, Raman, H(2)-TPR and N(2) adsorption. The zeolite obtained at pH 4 has the highest content of chromium, 0.9%, and was selected as the best catalyst for the oxidation of different VOC, namely ethyl acetate, ethanol and toluene. For all VOC tested, the catalyst with chromium showed higher activity and selectivity to CO(2), in comparison with the starting zeolite NaY. The presence of chromium shifted also the reaction pathways. In terms of selectivity to CO(2), the following sequence was observed: ethyl acetate>toluene>ethanol.


Assuntos
Cromo/química , Compostos Orgânicos Voláteis/química , Ítrio/química , Zeolitas/química , Catálise , Microscopia Eletrônica de Varredura , Oxirredução , Análise Espectral
10.
J Dairy Sci ; 93(2): 437-55, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20105516

RESUMO

Processing of whey proteins yields several bioactive peptides that can trigger physiological effects in the human body: on the nervous system via their opiate and ileum-contracting activities; on the cardiovascular system via their antithrombotic and antihypertensive activities; on the immune system via their antimicrobial and antiviral activities; and on the nutrition system via their digestibility and hypocholesterolemic effects. The specific physiological effects, as well the mechanisms by which they are achieved and the stabilities of the peptides obtained from various whey fractions during their gastrointestinal route, are specifically discussed in this review.


Assuntos
Proteínas do Leite/metabolismo , Fenômenos Fisiológicos da Nutrição/fisiologia , Peptídeos/fisiologia , Humanos , Peptídeos/química , Peptídeos/metabolismo , Estabilidade Proteica , Proteínas do Soro do Leite
11.
J Hazard Mater ; 167(1-3): 756-62, 2009 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-19216027

RESUMO

Adsorption of hexavalent chromium [Cr(VI)] onto a loamy sand soil was studied using batch and steady flow tests with contaminant solutions at pH 2, 5 and 7. In all the cases the adsorption of Cr(VI) decreased with increasing pH. The hexavalent chromium speciation and its presence as different oxyanions, according to the solution pH, were the main variables affecting the adsorption process. The influence of the ratio soil/solution concentration was also studied in flow systems at pH 2. Chromium retention increased with the increasing of its concentration in the influent solution. A two-site adsorption model was fitted to the breakthrough curves of hexavalent chromium solutions in order to estimate the Freundlich (k(F)) and Langmuir (S(max)) adsorption parameters, using CXTFIT code. These values were compared to those determined by batch tests and it was concluded that batch tests tended to underestimate these parameters. Nevertheless, they followed the same trend as the parameters determined in opened system, even when the pH of the initial solution was modified.


Assuntos
Cromo/isolamento & purificação , Solo , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Concentração de Íons de Hidrogênio , Portugal , Soluções , Purificação da Água/métodos
12.
Bioresour Technol ; 100(1): 220-6, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18565747

RESUMO

The aim of this work is to evaluate the applicability of a biofilm to the removal of chromium in solution, at a pilot scale. The effect of the initial concentration of metal on the biosorption behavior of an Arthrobacter viscosus biofilm supported on granular activated carbon, in batch and column essays was also analyzed. Six isotherm equations have been tested in the present study. The best fit was obtained with the Freundlich model. It was observed that as the initial chromium concentration increases, the uptake increases too, but the removal percentage decreases, with values between 95.20% (C(0)=5mg/l) and 38.28% (C(0)=1000 mg/l). The batch adsorption studies were used to develop a pilot bioreactor able to remove chromium from aqueous solutions. Data obtained in a pilot-scale reactor showed an average removal percentage of 99.9%, during the first 30 days, for the initial concentration of 10mg/l and an average removal percentage of 72%, for the same period and for the initial concentration of 100mg/l. Uptake values of 11.35 mg/g and 14.55 mg/g were obtained, respectively, for the initial concentration of 10 and 100mg/l. The results obtained are very promising and encourage the utilization of this biofilm in environmental applications.


Assuntos
Arthrobacter/metabolismo , Reatores Biológicos/microbiologia , Cromo/metabolismo , Resíduos Industriais/prevenção & controle , Poluentes Químicos da Água/farmacocinética , Purificação da Água/métodos , Biofilmes/crescimento & desenvolvimento , Cromo/isolamento & purificação , Membranas Artificiais , Projetos Piloto , Soluções , Poluentes Químicos da Água/isolamento & purificação
13.
J Hazard Mater ; 153(1-2): 799-809, 2008 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-17933461

RESUMO

The ability of three different bacterial species supported on granular activated carbon (GAC) to remove hexavalent chromium from low concentration liquid solutions was investigated, in batch and column studies. The microorganisms tested were Cr(VI) reducing types: Streptococcus equisimilis (CECT 926), Bacillus coagulans (CECT 12) and Escherichia coli (CECT 515). The results showed metal uptake values of 5.82, 5.35 and 4.12 mg/g(bios.), respectively, for S. equisimilis, B. coagulans and E. coli, for an initial metal concentration of 100 mg/l. In the same order and for the initial concentration of 50 mg/l, metal uptake values were 2.33, 1.98 and 3.60 mg/g(bios.). Finally, for the initial metal concentration of 10 mg/l, those values were, respectively, 0.66, 1.51 and 1.12 mg/g(bios.). Studies made with an industrial effluent, with the aim of testing these biofilms in a real situation, showed values of Cr uptake of 0.083, 0.090 and 0.110 mg/g(bios.), respectively, for S. equisimilis, B. coagulans and E. coli, for an initial concentration of 4.2 mg/l of total Cr. The quantification of polysaccharides, playing a key role in the whole process, was made and it was concluded that the production of polysaccharides is higher for B. coagulans followed by S. equisimilis and E. coli (9.19, 7.24 and 4.77 mg/g(bios.)). The batch studies data were described using the Freundlich, Langmuir, Redlich-Peterson, Dubinin-Radushkevich, Sips and Toth model isotherms. The best fit was obtained with Sips and Toth model isotherms, respectively, for the S. equisimilis and for the B. coagulans biofilms. For the E. coli biofilm the Freundlich, Redlich-Peterson, Sips and Toth models fitted very well to the experimental data. The Adams-Bohart, Wolborska and Yoon and Nelson models were applied to column studies data. Those models were found suitable for describing the dynamic behaviour of the columns with respect to the inlet chromium concentration. Obtained results showed that the biofilms tested are very promising for the removal of Cr(VI) in diluted industrial wastewater. Despite differences in the cell wall structure and composition, the three bacteria exhibit comparable sorption affinities towards chromium, in the open systems studies. The Gram-positive bacteria tested (B. coagulans and S. equisimilis) presented best metal removal percentages in batch studies.


Assuntos
Bacillus/química , Carbono/química , Cromo/química , Escherichia coli/química , Streptococcus/química , Poluentes Químicos da Água/química , Adsorção , Bacillus/metabolismo , Biofilmes , Biopolímeros/metabolismo , Escherichia coli/metabolismo , Resíduos Industriais , Modelos Químicos , Polissacarídeos/metabolismo , Streptococcus/metabolismo , Eliminação de Resíduos Líquidos/métodos
14.
Protein Pept Lett ; 9(2): 159-66, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12141914

RESUMO

A lectin from the red marine alga Hypnea musciformis (HML) was purified by extraction with 20 mM PBS, precipitation with 70% saturated ammonium sulphate, ion-exchange DEAE-Cellulose chromatography and RP-HPLC. The 9.3 kDa polypeptide agglutinates erythrocytes from various sources and shows oligomerization tendencies under certain MALDI-TOF/MS conditions. Preliminary N-terminal sequencing and biological assays strongly suggest that the HML may belong to a new class of algae lectins.


Assuntos
Lectinas/química , Lectinas/isolamento & purificação , Rodófitas/metabolismo , Animais , Cromatografia Líquida de Alta Pressão , Cromatografia por Troca Iônica , Dimerização , Humanos , Estrutura Terciária de Proteína , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
15.
Lepr Rev ; 71(1): 77-80, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10820991

RESUMO

A leprosy elimination campaign (LEC) was carried out in 15 endemic areas of Amazonas State, Brazil, in 1997. The LEC concentrated effort to detect leprosy cases during a multi-vaccination national campaign for serious public health problems other than leprosy, such as polio, diphtheria, hepatitis, measles, etc. The national campaign involved intensive population mobilization, giving a valuable opportunity to examine people for leprosy. The LEC personnel included 2964 individuals (municipal and state health workers and community volunteers), distributed in 688 health units and 53 reference health centres. As a result of the LEC, 74,814 person-to-person communications in the community were given; 10,297 clinical skin examinations were conducted, and 40 new leprosy cases were detected on the day of the campaign in urban areas of the municipalities. This total was low, compared to results in other states of Brazil, possibly due to the development of health education activities and regular community services in the state of Amazonas since 1987 and to the early implementation of WHO multiple drug therapy (MDT) from 1982 onwards. Despite the fact that the LEC was carried out only in the urban areas of the municipalities, the finding of no cases of leprosy in 7 out of 15 of them was surprising and may indicate that the prevalence of hidden cases of leprosy is not all that high, at least in these areas of the Amazonas State.


Assuntos
Surtos de Doenças/prevenção & controle , Doenças Endêmicas/prevenção & controle , Promoção da Saúde/organização & administração , Programas de Rastreamento , Brasil/epidemiologia , Doenças Endêmicas/estatística & dados numéricos , Feminino , Humanos , Hanseníase/epidemiologia , Masculino
17.
J Pediatr (Rio J) ; 72(5): 295-8, 1996.
Artigo em Português | MEDLINE | ID: mdl-14688915

RESUMO

A cross-sectional epidemiological study has investigated lead poisoning among all the 101 children aged 1 to 5 years, living at less then 500 m from a lead smelter which has been operating since 1960 in Santo Amaro da Purificação, State of Bahia, Brazil. Lead poisoning was evaluated by determining the concentrations of zinc protoporphyrin (ZPP) in whole blood. Results were compared with those obtained from 98 children of the same age range, in a nursery from Salvador, capital of the State of Bahia. In Santo Amaro, ZPP geometric mean was 65.5 mg/dl (geometric S.D. = 1.7), much higher, therefore, than the normal threshold of 30 microg/dl recommended by the CDC-USA. A child was excluded from statistical analyses because of very high ZPP level: 789 mg/dl. In Salvador, ZPP geometric mean was 31.0 mg/dl (geometric SD = 1.6). "Extremely elevated" ZPP levels (above 156 mg/dl) were observed in 8% of the children from Santo Amaro and in none (0%) of the children from Salvador, this statistical difference being highly significant. Anaemia was present among 35.0% of the children from Santo Amaro and among 25.5% of those from Salvador. One year-old children showed the highest levels of ZPP and anaemia. No marked statistical association was found between ZPP levels and anaemia. Lead contamination of this children population remained in a permanently high level during, at least, the period from 1980 to 1992. In December, 1993 the lead smelter has definitively ceased its industrial activities in Santo Amaro da Purificação.

18.
Bull Pan Am Health Organ ; 30(1): 51-62, 1996 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8919726

RESUMO

A cross-sectional epidemiologic survey conducted at the beginning of 1992 evaluated the status of lead intoxication among children from 1 to 5 years of age living within 500 meters of a primary lead smelter in the Brazilian city of Santo Amaro, Bahia. A total of 103 children in this age group were initially enrolled in the study; however, 2 were later excluded because they could not be located, and 1 was excluded from the statistical analyses for reasons noted below. The results were compared with those from similar surveys made in 1980 and 1985 in the same area with children of the same age. A blood sample was obtained from each child, the child's hematocrit and zinc protoporphyrin (ZPP) level were determined, and an interview questionnaire was used to collect information of clinical or epidemiologic interest from the child's mother or guardian. The geometric average ZPP was 65.5 micrograms/100 mL (geometric standard deviation = 1.7), a level far exceeding the upper limit of normality established by the U.S. Centers for Disease Control and Prevention of 30 micrograms/100 mL. One child was excluded from the statistical analyses because it exhibited an extremely high ZPP level (789 micrograms/100 mL). Higher average ZPP levels were found for girls, children with darker-skinned racial backgrounds, children from homes where smelter slag was commonly used around the house, children presenting pica, and children of smelter workers. Of the symptoms of lead poisoning investigated, only nervousness and easy irritability exhibited high frequencies among the children studied. However, the prevalence of above-normal ZPP levels suggestive of lead poisoning was 92.2% in 1980, 98.4% in 1985, and 97.0% in 1992. Hence, the apparent prevalence of lead poisoning continued very high in 1992, indicating that the control measures adopted were ineffective or that other unidentified and uncontrolled risk factors were playing an important role. Overall, however, the proportion of children with very high ZPP levels fell sharply, and that of children with moderately high levels also declined notably, indicating that the severity of the problem had been reduced even though new cases of intoxication continued to occur. The Santo Amaro smelter closed its doors in December 1993.


Assuntos
Exposição Ambiental , Intoxicação por Chumbo/epidemiologia , Metalurgia , Brasil/epidemiologia , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Lactente , Intoxicação por Chumbo/sangue , Intoxicação por Chumbo/etiologia , Estudos Longitudinais , Masculino , Vigilância da População , Prevalência , Fatores de Risco , Inquéritos e Questionários , Saúde da População Urbana
19.
Environ Res ; 71(1): 11-5, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8757233

RESUMO

The dose-response relationship between erythrocyte protoporphyrin (EP) and blood lead (PbB) was investigated among children with different subgroups of iron status. The data bank from Santo Amaro City, Brazil, was taken to study 490 children aged 1-9 years who lived at less than 900 m from a primary lead smelter. Mean PbB was 58.9 +/- 25.3 micrograms/dl and mean EP was 87.1 +/- 68.1 micrograms/dl. At PbB levels lower than 60 micrograms/dl, the dose-response curve for EP versus PbB followed the classical pattern; children with low iron status showing greater EP "response" than those with typical iron status and those with high iron status, after controlling for the effects of age and racial group. Among children with PbB > or = 60 micrograms/dl, EP response increased according to the following order: typical < low < high iron status.


Assuntos
Exposição Ambiental , Eritrócitos/metabolismo , Ferro/sangue , Intoxicação por Chumbo/sangue , Chumbo/sangue , Protoporfirinas/sangue , Brasil/epidemiologia , Criança , Pré-Escolar , Poluentes Ambientais/toxicidade , Humanos , Lactente , Intoxicação por Chumbo/epidemiologia
20.
Endod Dent Traumatol ; 10(4): 174-8, 1994 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7995248

RESUMO

The present work studied the reaction caused in the connective tissue of rats by implantation of two brands of gutta-percha cones, and thermoplasticized gutta-percha cylinders. Thirty-six rats were used, in groups of 12, for periods of 15, 30, and 60 days. Each animal received one test implant of each material, and one implant of Teflon as control. The cylinders, and one of the brands of gutta-percha cones, were well tolerated by the connective tissue. The cones of the other brand elicited different reactions, of which the possible causes are herein discussed.


Assuntos
Guta-Percha/toxicidade , Animais , Tecido Conjuntivo/efeitos dos fármacos , Reação a Corpo Estranho/etiologia , Granuloma de Células Gigantes/etiologia , Próteses e Implantes , Ratos
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