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1.
J Environ Sci Health B ; 59(6): 341-349, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38709203

RESUMO

The increased consumption of pesticides can have a negative environmental impact by increasing the essential metals to toxic levels. Bordasul® is a commonly used fungicide in Brazil and it is composed of 20% Cu, 10% sulfur, and 3.0% calcium. The study of fungicides in vivo in non-target model organisms can predict their environmental impact more broadly. The Drosophila melanogaster is a unique model due to its ease of handling and maintenance. Here, the potential toxicity of Bordasul® was investigated by assessing the development, survival, and behavior of exposed flies. Exposure to Bordasul® impaired the development (p < 0.01) and caused a significant reduction in memory retention (p < 0.05) and locomotor ability (p < 0.001). Fungicides are needed to assure the world's food demand; however, Bordasul® was highly toxic to D. melanogaster. Therefore, Bordasul® may be potentially toxic to non-target invertebrates and new environmentally-safe biofertilizers have to be developed to preserve the biota.


Assuntos
Cobre , Drosophila melanogaster , Fungicidas Industriais , Animais , Drosophila melanogaster/efeitos dos fármacos , Fungicidas Industriais/toxicidade , Fungicidas Industriais/farmacologia , Cobre/toxicidade , Brasil , Feminino , Masculino , Comportamento Animal/efeitos dos fármacos
2.
Dis Esophagus ; 35(11)2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-35641160

RESUMO

The present study aims to compare the effectiveness of surgical and medical therapy in reducing the risk of cancer in Barrett's esophagus in a long-term evaluation. A prospective cohort was designed that compared Barrett's esophagus patients submitted to medical treatment with omeprazole or laparoscopic Nissen fundoplication. The groups were compared using propensity score matching paired by Barrett's esophagus length. A total of 398 patients met inclusion criteria. There were 207 patients in the omeprazole group (Group A) and 191 in the total fundoplication group (Group B). After applying the propensity score matching paired by Barrett's esophagus length, the groups were 180 (Group A) and 190 (Group B). Median follow-up was 80 months. Group B was significantly superior for controlling GERD symptoms. Group B was more efficient than Group A in promoting Barrett's esophagus regression or blocking its progression. Group B was more efficient than Group A in preventing the development of dysplasia and cancer. Logistic regression was performed for the outcomes of adenocarcinoma and dysplasia. Age and body mass index were used as covariates in the logistic regression models. Even after regression analysis, Group B was still superior to Group A to prevent esophageal adenocarcinoma or dysplasia transformation (odds ratio [OR]: 0.51; 95% confidence interval [CI]: 0.27-0.97, for adenocarcinoma or any dysplasia; and OR: 0.26; 95% CI: 0.08-0.81, for adenocarcinoma or high-grade dysplasia). Surgical treatment is superior to medical management, allowing for better symptom control, less need for reflux medication use, higher regression rate of the columnar epithelium and intestinal metaplasia, and lower risk for progression to dysplasia and cancer.


Assuntos
Adenocarcinoma , Esôfago de Barrett , Neoplasias Esofágicas , Laparoscopia , Humanos , Esôfago de Barrett/complicações , Esôfago de Barrett/tratamento farmacológico , Esôfago de Barrett/cirurgia , Fundoplicatura , Estudos Prospectivos , Neoplasias Esofágicas/etiologia , Neoplasias Esofágicas/prevenção & controle , Neoplasias Esofágicas/diagnóstico , Adenocarcinoma/etiologia , Adenocarcinoma/prevenção & controle , Adenocarcinoma/cirurgia , Omeprazol
3.
Phys Rev Lett ; 125(24): 241803, 2020 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-33412014

RESUMO

We present constraints on the existence of weakly interacting massive particles (WIMPs) from an 11 kg d target exposure of the DAMIC experiment at the SNOLAB underground laboratory. The observed energy spectrum and spatial distribution of ionization events with electron-equivalent energies >200 eV_{ee} in the DAMIC CCDs are consistent with backgrounds from natural radioactivity. An excess of ionization events is observed above the analysis threshold of 50 eV_{ee}. While the origin of this low-energy excess requires further investigation, our data exclude spin-independent WIMP-nucleon scattering cross sections σ_{χ-n} as low as 3×10^{-41} cm^{2} for WIMPs with masses m_{χ} from 7 to 10 GeV c^{-2}. These results are the strongest constraints from a silicon target on the existence of WIMPs with m_{χ}<9 GeV c^{-2} and are directly relevant to any dark matter interpretation of the excess of nuclear-recoil events observed by the CDMS silicon experiment in 2013.

4.
Phys Rev Lett ; 123(18): 181802, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31763884

RESUMO

We report direct-detection constraints on light dark matter particles interacting with electrons. The results are based on a method that exploits the extremely low levels of leakage current of the DAMIC detector at SNOLAB of 2-6×10^{-22} A cm^{-2}. We evaluate the charge distribution of pixels that collect <10e^{-} for contributions beyond the leakage current that may be attributed to dark matter interactions. Constraints are placed on so-far unexplored parameter space for dark matter masses between 0.6 and 100 MeV c^{-2}. We also present new constraints on hidden-photon dark matter with masses in the range 1.2-30 eV c^{-2}.

5.
Dis Esophagus ; 31(9)2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30169645

RESUMO

Achalasia is a relatively rare primary motor esophageal disorder, characterized by absence of relaxations of the lower esophageal sphincter and of peristalsis along the esophageal body. As a result, patients typically present with dysphagia, regurgitation and occasionally chest pain, pulmonary complication and malnutrition. New diagnostic methodologies and therapeutic techniques have been recently added to the armamentarium for treating achalasia. With the aim to offer clinicians and patients an up-to-date framework for making informed decisions on the management of this disease, the International Society for Diseases of the Esophagus Guidelines proposed and endorsed the Esophageal Achalasia Guidelines (I-GOAL). The guidelines were prepared according the Appraisal of Guidelines for Research and Evaluation (AGREE-REX) tool, accredited for guideline production by NICE UK. A systematic literature search was performed and the quality of evidence and the strength of recommendations were graded according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE). Given the relative rarity of this disease and the paucity of high-level evidence in the literature, this process was integrated with a three-step process of anonymous voting on each statement (DELPHI). Only statements with an approval rate >80% were accepted in the guidelines. Fifty-one experts from 11 countries and 3 representatives from patient support associations participated to the preparations of the guidelines. These guidelines deal specifically with the following achalasia issues: Diagnostic workup, Definition of the disease, Severity of presentation, Medical treatment, Botulinum Toxin injection, Pneumatic dilatation, POEM, Other endoscopic treatments, Laparoscopic myotomy, Definition of recurrence, Follow up and risk of cancer, Management of end stage achalasia, Treatment options for failure, Achalasia in children, Achalasia secondary to Chagas' disease.


Assuntos
Acalasia Esofágica/diagnóstico , Acalasia Esofágica/terapia , Adulto , Toxinas Botulínicas/uso terapêutico , Criança , Dilatação/métodos , Dilatação/normas , Gerenciamento Clínico , Acalasia Esofágica/fisiopatologia , Esofagoscopia/métodos , Esofagoscopia/normas , Medicina Baseada em Evidências , Feminino , Humanos , Masculino , Miotomia/métodos , Miotomia/normas , Fatores de Risco , Índice de Gravidade de Doença , Avaliação de Sintomas/métodos , Avaliação de Sintomas/normas
6.
Dis Esophagus ; 30(10): 1-8, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-28859394

RESUMO

Achalasia of the cardia is associated with an increased risk of esophageal carcinoma. The real burden of achalasia at the malignancy genesis is still a controversial issue. Therefore, there are no generally accepted recommendations on follow-up evaluation for achalasia patients. This study aims to estimate the risk of esophageal adenocarcinoma and squamous cell carcinoma in achalasia patients. We searched for association between carcinoma and esophageal achalasia in databases up to January 2017 to perform a systematic review and meta-analysis. A total of 1,046 studies were identified from search strategy, of which 40 were selected for meta-analysis. A cumulative number of 11,978 esophageal achalasia patients were evaluated. The incidence of squamous cell carcinoma was 312.4 (StDev 429.16) cases per 100,000 patient-years at risk. The incidence of adenocarcinoma was 21.23 (StDev 31.6) cases per 100,000 patient-years at risk. The prevalence for esophageal carcinoma was 28 carcinoma cases in 1,000 esophageal achalasia patients (CI 95% 2, 39). The prevalence for squamous cell carcinoma was 26 cases in 1,000 achalasia patients (CI 95% 18, 39) and for adenocarcinoma was 4 cases in 1,000 achalasia patients (CI 95% 3, 6).The absolute risk increase for squamous cell carcinoma was 308.1 and for adenocarcinoma was 18.03 cases per 100,000 patients per year. To the best of our knowledge, this is the first meta-analysis estimating the burden of achalasia as an esophageal cancer risk factor. The high increased risk rate for cancer in achalasia patients points to a strict endoscopic surveillance for these patients. Also, the increased risk for developing adenocarcinoma in achalasia patients suggests fundoplication after myotomy, to avoid esophageal reflux and Barret esophagus, a known risk factor for adenocarcinoma.


Assuntos
Adenocarcinoma/epidemiologia , Carcinoma de Células Escamosas/epidemiologia , Acalasia Esofágica/epidemiologia , Neoplasias Esofágicas/epidemiologia , Humanos , Incidência , Prevalência , Medição de Risco , Fatores de Risco , Taxa de Sobrevida
7.
Genet Mol Res ; 16(1)2017 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-28340275

RESUMO

The mini tomato production has expanded, becoming an amazing alternative for enterprise. Despite all commercial potential, the cultivation has the occurrence of pests as main obstacle during the crop development. Nowadays, there are no researches that aimed obtaining genotypes with high acylsugar content, capable of providing a broad-spectrum resistance to pests. This study aimed the selection of mini tomato genotypes, with high acylsugar content, and checking the resistance level to the silverleaf whitefly [Bemisia tabaci (Gennadius)] and to the two-spotted spider mites (Tetranychus urticae Koch). Sixteen genotypes were evaluated, from which 12 were on the generation F2BC1, originated from the interespecific cross between Solanum pennellii versus Solanum lycopersicum L. and 4 were check treatments, being three of cultivated tomatos (cv. Santa Clara, UFU-02, and UFU-73) and the wild accession LA-716 (S. pennellii). The variables analyzed were acylsugar content, repellency to the silverleaf whitefly, repellence to the two-spotted spider mites, and density of glandular trichomes. The genotypes UFU-22-F2BC1#9 and UFU-73-F2BC1#11 have high acylsugar content and both are resistant to the pests that were evaluated. New studies must be conducted seeking for inbred lines, obtained from the selected genotypes, aiming to get commercial hybrids with high acylsugar content.


Assuntos
Doenças das Plantas/prevenção & controle , Solanum lycopersicum/genética , Animais , Cruzamentos Genéticos , Resistência à Doença/genética , Genótipo , Hemípteros , Controle Biológico de Vetores , Feromônios/genética , Feromônios/metabolismo , Melhoramento Vegetal/métodos , Doenças das Plantas/parasitologia , Tetranychidae
9.
Artigo em Inglês | MEDLINE | ID: mdl-38518983

RESUMO

Copper (Cu2+) is a biologically essential element that participates in numerous physiological processes. However, elevated concentrations of copper have been associated with cellular oxidative stress and neurodegenerative diseases. Organo­selenium compounds such as diphenyl diselenide (DPDS) have in vitro and in vivo antioxidant properties. Hence, we hypothesized that DPDS may modulate the toxicity of Cu2+ in Drosophila melanogaster. The acute effects (4 days of exposure) caused by a high concentration of Cu2+ (3 mM) were studied using endpoints of toxicity such as survival and behavior in D. melanogaster. The potential protective effect of low concentration of DPDS (20 µM) against Cu2+ was also investigated. Adult flies aged 1-5 days post-eclosion (both sexes) were divided into four groups: Control, DPDS (20 µM), CuSO4 (3 mM), and the combined exposure of DPDS (20 µM) and CuSO4 (3 mM). Survival, biochemical, and behavioral parameters were determined. Co-exposure of DPDS and CuSO4 increased acetylcholinesterase (AChE) activity and the generation of reactive oxygen species (ROS as determined by DFCH oxidation). Contrary to our expectation, the co-exposure reduced survival, body weight, locomotion, catalase activity, and cell viability in relation to control group. Taken together, DPDS potentiated the Cu2+ toxicity.


Assuntos
Comportamento Animal , Derivados de Benzeno , Drosophila melanogaster , Compostos Organosselênicos , Estresse Oxidativo , Espécies Reativas de Oxigênio , Animais , Derivados de Benzeno/toxicidade , Derivados de Benzeno/farmacologia , Drosophila melanogaster/efeitos dos fármacos , Compostos Organosselênicos/farmacologia , Compostos Organosselênicos/toxicidade , Masculino , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Comportamento Animal/efeitos dos fármacos , Feminino , Cobre/toxicidade , Acetilcolinesterase/metabolismo , Antioxidantes/metabolismo , Catalase/metabolismo , Sulfato de Cobre/toxicidade , Locomoção/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos
10.
J Periodontal Res ; 48(1): 126-33, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22835005

RESUMO

BACKGROUND AND OBJECTIVE: A low-grade systemic inflammatory status originating from periodontal infection has been proposed to explain the association between periodontal disease and systemic conditions, including adverse obstetric outcomes. The aim of this study was to evaluate the effect of periodontal therapy during pregnancy on the gingival crevicular fluid and serum levels of six cytokines associated with periodontal disease and preterm birth. MATERIAL AND METHODS: A subsample of 60 women (18-35 years of age) up to 20 gestational weeks, previously enrolled in a larger randomized clinical trial, was recruited for the present study. Participants were randomly allocated to receive either comprehensive nonsurgical periodontal therapy before 24 gestational weeks (n = 30, test group) or only one appointment for supragingival calculus removal (n = 30, control group). Clinical data, and samples of blood and gingival crevicular fluid, were collected at baseline, at 26-28 gestational weeks and 30 d after delivery. The levels of interleukin (IL)-1ß, IL-6, IL-8, IL-10, IL-12p70 and tumor necrosis factor-α were analyzed by flow cytometry. RESULTS: After treatment, a major reduction in periodontal inflammation was observed in the test group, with bleeding on probing decreasing from 49.62% of sites to 11.66% of sites (p < 0.001). Periodontal therapy significantly reduced the levels of IL-1ß and IL-8 in gingival crevicular fluid (p < 0.001). However, no significant effect of therapy was observed on serum cytokine levels. After delivery, the levels of IL-1ß in the gingival crevicular fluid of the test group were significantly lower than were those in the control group (p < 0.001), but there were no significant differences between test and control groups regarding serum cytokine levels. CONCLUSION: Although periodontal therapy during pregnancy successfully reduced periodontal inflammation and gingival crevicular fluid cytokine levels, it did not have a significant impact on serum biomarkers.


Assuntos
Citocinas/sangue , Líquido do Sulco Gengival/química , Doenças Periodontais/terapia , Período Pós-Parto/sangue , Complicações Infecciosas na Gravidez/terapia , Adolescente , Adulto , Biomarcadores/análise , Biomarcadores/sangue , Citocinas/análise , Cálculos Dentários/terapia , Placa Dentária/terapia , Raspagem Dentária/métodos , Feminino , Humanos , Interleucina-10/análise , Interleucina-10/sangue , Interleucina-12/análise , Interleucina-12/sangue , Interleucina-1beta/análise , Interleucina-1beta/sangue , Interleucina-6/análise , Interleucina-6/sangue , Interleucina-8/análise , Interleucina-8/sangue , Higiene Bucal , Perda da Inserção Periodontal/terapia , Doenças Periodontais/complicações , Índice Periodontal , Bolsa Periodontal/terapia , Período Pós-Parto/metabolismo , Gravidez , Resultado da Gravidez , Segundo Trimestre da Gravidez/sangue , Segundo Trimestre da Gravidez/metabolismo , Nascimento Prematuro/sangue , Nascimento Prematuro/metabolismo , Aplainamento Radicular/métodos , Fator de Necrose Tumoral alfa/análise , Fator de Necrose Tumoral alfa/sangue , Adulto Jovem
11.
Sci Total Environ ; 873: 162150, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36773916

RESUMO

The demand for food to feed the growing world population has been promoting the indiscriminate use of chemical fertilizers, which can be detrimental to the environment. In order to maintain high crop productivity without damaging the ecosystem, biofertilizers have emerged as alternative to reduce the use of chemical fertilizers. So, environmentally safer biofertilizer can replace the exploitation of more toxic chemical fertilizer. Here, the fly Drosophila melanogaster was used to study the potential toxicity of the biofertilizer Beifort®. Flies were exposed to high concentrations of Beifort® in the diet (1.8 mL/L, 9.0 mL/L and 18 mL/L), and morphological and behavioral endpoints of toxicity were analyzed (development from egg to adult age, flies longevity, climbing performance, memory and learning of an associative learning, larvae digestive tract damage and plasmid DNA break). Beifort® did not modify flies development, survival, digestive track cell damage, locomotor activity or memory. Beifort® did not induce DNA breakage in vitro and had no toxicity to the non-target D. melanogaster after in vivo exposure. Thus, in addition of promoting the sustainable use of agricultural wastes, the exploitation of Beifort® can contribute to decrease the use of chemical fertilizers.


Assuntos
Drosophila melanogaster , Ecossistema , Animais , Fertilizantes/toxicidade , Fertilizantes/análise , Agricultura , Produção Agrícola
12.
Sci Total Environ ; 710: 135306, 2020 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-31926406

RESUMO

Copper is an essential element to all living organisms. Repeated use of metal-enriched chemicals, fertilizers, and organic substances may cause contamination at a large scale. Altered levels of Cu2+ may result in harmful effects and can be associated with memory and cognitive dysfunction. Studying simple, genetically tractable organisms such as Drosophila melanogaster, can reveal important data on the neural basis of conditioning. D. melanogaster is an important alternative experimental model to assess the toxic response to metals. In the present study, the effects of copper on flies' development and in learning and memory retention in male and female adult flies were investigated. We paired an odorant to pain perception and observed the aversion behavior over time. Exposure of D. melanogaster eggs to Cu2+ increased mortality of larvae, pupae, and adults and decreased memory retention in adults. Moreover, male flies demonstrated to be more susceptible to Cu2+ toxicity than females. The results therefore, reinforce the importance of controlling the anthropogenic heavy-metals soil contamination given their hazardous effects to living organisms.


Assuntos
Drosophila melanogaster , Animais , Cobre , Feminino , Larva , Aprendizagem , Masculino
13.
Dis Esophagus ; 22(7): 606-10, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19302218

RESUMO

Achalasia surgical treatment alters the esophagogastric junction anatomy (cardiomyotomy plus fundoplication or esophagectomy and gastric pull-up), thus favoring a certain degree of gastroesophageal reflux. Gastric secretory and hormonal functioning is not completely known in chagasic patients. The aim of this study was to evaluate the gastric secretory and hormonal response in patients with end-stage chagasic achalasia compared with normal subjects. Gastric secretion and hormonal response were assessed by estimation of gastric acid secretion (GAS) in basal condition and after pentagastrin stimulation, basal serum gastrin, and serum pepsinogen (SP) in basal condition and after betazole hydrochloride (Histalog; Eli Lilly and Company, Indianapolis, IN, USA) stimulation in 27 patients with chagasic achalasia. The results were then compared with those of 24 normal subjects. In the chagasic group, the mean basal and stimulated GAS were significantly lower than in the control group (basal: 1.277 vs. 3.13, P = 0.002; stimulated: 15.9 vs. 35.8, P = 0.0001). Chagasic patients' SG levels showed a significantly higher basal value than the control group (83.3 vs. 36.8, P = 0.0001). There was a significant increase of SP after stimulation compared with the basal levels in both chagasic and control groups. Although the chagasic patients' SP values were higher than the controls, this difference was not statistically significant, either in basal and stimulated conditions (basal: 122.0 vs. 108.9, stimulated 120 min: 177.1 vs. 158.9). In patients with chronic Chagas' disease (ChD), although autonomic denervation does not suppress the strength of the gastric mucosal cells' secretory response to stimulation, it reduces GAS (parietal cell) without, however, affecting SP production (chief cells). On the other hand, the gastrin-producing cells have continuously been stimulated by low GAS.


Assuntos
Doença de Chagas/fisiopatologia , Acalasia Esofágica/fisiopatologia , Ácido Gástrico/metabolismo , Adulto , Idoso , Betazol/farmacologia , Doença Crônica , Acalasia Esofágica/parasitologia , Acalasia Esofágica/cirurgia , Feminino , Determinação da Acidez Gástrica , Agonistas dos Receptores Histamínicos/farmacologia , Humanos , Masculino , Pessoa de Meia-Idade , Pepsinogênio A/sangue , Adulto Jovem
14.
DNA Repair (Amst) ; 73: 78-90, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30470509

RESUMO

Genomes are affected by a wide range of damage, which has resulted in the evolution of a number of widely conserved DNA repair pathways. Most of these repair reactions have been described in the African trypanosome Trypanosoma brucei, which is a genetically tractable eukaryotic microbe and important human and animal parasite, but little work has considered how the DNA damage response operates throughout the T. brucei life cycle. Using quantitative PCR we have assessed damage induction and repair in both the nuclear and mitochondrial genomes of the parasite. We show differing kinetics of repair for three forms of DNA damage, and dramatic differences in repair between replicative life cycle forms found in the testse fly midgut and the mammal. We find that mammal-infective T. brucei cells repair oxidative and crosslink-induced DNA damage more efficiently than tsetse-infective cells and, moreover, very distinct patterns of induction and repair of DNA alkylating damage in the two life cycle forms. We also reveal robust repair of DNA lesions in the highly unusual T. brucei mitochondrial genome (the kinetoplast). By examining mutants we show that nuclear alkylation damage is repaired by the concerted action of two repair pathways, and that Rad51 acts in kinetoplast repair. Finally, we correlate repair with cell cycle arrest and cell growth, revealing that induced DNA damage has strikingly differing effects on the two life cycle stages, with distinct timing of alkylation-induced cell cycle arrest and higher levels of damage induced death in mammal-infective cells. Our data reveal that T. brucei regulates the DNA damage response during its life cycle, a capacity that may be shared by many microbial pathogens that exist in variant environments during growth and transmission.


Assuntos
Dano ao DNA , Trypanosoma brucei brucei/crescimento & desenvolvimento , Trypanosoma brucei brucei/genética , Alquilação , Pontos de Checagem do Ciclo Celular/genética , Adutos de DNA/metabolismo , Reparo do DNA , DNA de Protozoário/genética , DNA de Protozoário/metabolismo , Estresse Oxidativo/genética , Rad51 Recombinase/metabolismo , Trypanosoma brucei brucei/citologia , Trypanosoma brucei brucei/metabolismo
15.
Chemosphere ; 69(1): 170-5, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17560625

RESUMO

The aim of the present study was to assess the effect of the exposure of Leporinus obtusidens (Piava) to zinc and copper on catalase activity in the liver, delta-aminolevulinate dehidratase (delta-ALA-D) activity in liver, muscle, brain and kidney, and thiobarbituric reactive species (TBARS) in brain, muscle and liver. In addition, hematological parameters were measured in blood. The fish were exposed to 10% and 20% of the derived LC(50) values, 2.3 and 4.6 mg Zn l(-1) and 0.02 and 0.04 mg Cu l(-1), and sampled on days 30 and 45. Exposure to Zn(II) and Cu(II) decreased hematological parameters and also delta-ALA-D activity mainly in liver and kidney at all concentrations tested. Liver catalase activity increased after zinc or copper exposure at all concentrations and exposure times tested. Thiobarbituric reactive substances (TBARS) increased in the brain and liver of the fish exposed to zinc(II) for 45 days at both metal concentrations. In muscle, zinc(II) increased TBARS production at both exposure times and concentrations tested. Copper(II) exposure reduced the TBARS levels in liver at both concentrations and times tested. In brain, there was a decrease in TBARS levels only after 45 days of exposure. In muscle, this decrease was observed after 30 days of exposure at both concentrations. Although zinc and copper are required as microelements in the cells, our results showed that the sublethal concentrations of these metals can change biochemical parameters which may alter normal cellular function. These results pointed out the differential sensitivity of fish tissues to essential, but also toxic and environmentally relevant metals. The alterations of distinct biochemical parameters in fish tissues certainly contribute to the toxicity of Zn and Cu, and are of importance for an area that has been growing and has still been poorly explored in the literature.


Assuntos
Cobre/toxicidade , Peixes/metabolismo , Poluentes Químicos da Água/toxicidade , Zinco/toxicidade , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Catalase/metabolismo , Contagem de Eritrócitos , Feminino , Hematócrito , Hemoglobinas/metabolismo , Rim/efeitos dos fármacos , Rim/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Músculos/efeitos dos fármacos , Músculos/metabolismo , Sintase do Porfobilinogênio/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
16.
Brain Res ; 906(1-2): 157-63, 2001 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-11430873

RESUMO

The aim of this study was to investigate the possible involvement of the glutamatergic system in the toxicity of organochalcogens, since this is an important neurotransmitter system for signal transduction and neural function. The results indicated that 100 microM diphenyl diselenide (PhSe)(2) and diphenyl ditelluride (PhTe)(2) inhibit by 50 and 70% (P<0.05), respectively, [(3)H]glutamate binding in vitro. Acute administration of 25 micromol/kg (PhSe)(2) or 3 micromol/kg (PhTe)(2) caused a significant reduction in [(3)H]glutamate (30%, P<0.05) or [(3)H]MK-801 binding (30%, P<0.05) to rat synaptic membranes. These results suggest that (PhSe)(2) and (PhTe)(2) affect, in a rather complex way, the glutamatergic system after acute in vivo exposure in rats. In vitro, total [(3)H]GMP-PNP binding was inhibited about 40% at 100 microM (PhSe)(2) and (PhTe)(2). Acute exposure in vivo to (PhSe)(2) decreased the stable [(3)H]GMP-PNP binding to 25% and (PhTe)(2) to 68% of the control value (P<0.05, for both compounds). Simultaneously, the unstable binding of [(3)H]GMP-PNP was decreased about 30 and 50% (P<0.05, for both compounds) after exposure to (PhSe)(2) and (PhTe)(2), respectively. GMP-PNP stimulated adenylate cyclase (AC) activity significantly in control animals. (PhSe)(2)- and (PhTe)(2)-treated animals increased the basal activity of this enzyme, but GMP-PNP stimulation was totally abolished. These results suggest that the toxic effects of organochalcogens could result from action at different levels of neural signal transduction pathways, possibly involving other neurotransmitters besides the glutamatergic system.


Assuntos
Derivados de Benzeno/toxicidade , Encéfalo/efeitos dos fármacos , Ácido Glutâmico/metabolismo , Compostos Organometálicos/toxicidade , Compostos Organosselênicos/toxicidade , Terminações Pré-Sinápticas/efeitos dos fármacos , Membranas Sinápticas/efeitos dos fármacos , Transmissão Sináptica/efeitos dos fármacos , Telúrio/toxicidade , Animais , Ligação Competitiva/efeitos dos fármacos , Ligação Competitiva/fisiologia , Encéfalo/metabolismo , Ditiotreitol/farmacocinética , Maleato de Dizocilpina/farmacocinética , Relação Dose-Resposta a Droga , Antagonistas de Aminoácidos Excitatórios/farmacocinética , Ácido Glutâmico/farmacocinética , Guanilil Imidodifosfato/farmacocinética , Masculino , Neurotoxinas/farmacologia , Terminações Pré-Sinápticas/metabolismo , Ratos , Ratos Wistar , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/metabolismo , Membranas Sinápticas/metabolismo , Transmissão Sináptica/fisiologia , Trítio/farmacocinética
17.
Hepatogastroenterology ; 38(6): 470-3, 1991 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1778572

RESUMO

One hundred and twenty-two patients with advanced mega-esophagus managed by esophagectomy without thoracotomy and cervical gastroplasty were evaluated. Sixty-nine patients were followed up for periods of 6 months to 16 years. Clinical assessment included X-ray studies and endoscopy of the cervical esophagus and mobilized stomach. The most common postoperative complications were pleural effusion (22.1%) and cervical fistula (8.2%). Mortality was 4.18%. Regurgitation was the most frequent complaint in the late follow-up, followed by heartburn. Both symptoms were related to esophagitis and diffuse gastritis. Diarrhea and dumping also occurred due to vagotomy and pyloromyotomy performed at the same time as esophagectomy. The endoscopic study demonstrated esophagitis in 25.5% of the patients, and diffuse erosive gastritis in 12.7%. The symptoms and late complications were handled by clinical measures and careful endoscopic follow-up. Gastroplasty was considered a good procedure for replacing the esophagus, solving the serious problem of dysphagia and for providing nutritional improvement for the patient.


Assuntos
Acalasia Esofágica/cirurgia , Acalasia Esofágica/epidemiologia , Fístula Esofágica/epidemiologia , Esofagectomia , Esofagite Péptica/epidemiologia , Feminino , Seguimentos , Refluxo Gastroesofágico/epidemiologia , Gastroplastia , Azia/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Derrame Pleural/epidemiologia , Complicações Pós-Operatórias/epidemiologia , Fatores de Tempo
18.
Artigo em Inglês | MEDLINE | ID: mdl-18244329

RESUMO

In this paper, we report experimental results on the frequency control of an optical oscillator based on a single-cavity DFB-MQW laser and a fiber loop reflector. Self-pulsation frequency can be controlled by changing the step amplitude of the laser bias current.

19.
Arq Neuropsiquiatr ; 53(1): 126-30, 1995 Mar.
Artigo em Português | MEDLINE | ID: mdl-7575197

RESUMO

Spinal subdural empyema is a very unusual condition. About 40 cases have been previously reported. The authors describe another case, mentioning the difficulties in diagnosis particularly when no primary infection is known. In these circumstances, the neurological signs and MRI are important; MRI demonstrates the level of the lesion and its subdural localization. Surgical treatment and antibiotics are clearly indicated and the earliest it is done, the better the results.


Assuntos
Empiema Subdural/diagnóstico , Imageamento por Ressonância Magnética , Doenças da Medula Espinal/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/uso terapêutico , Diagnóstico Diferencial , Empiema Subdural/cirurgia , Humanos , Masculino , Doenças da Medula Espinal/cirurgia , Punção Espinal , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/terapia , Espaço Subdural/patologia , Espaço Subdural/cirurgia
20.
Arq Gastroenterol ; 35(1): 45-8, 1998.
Artigo em Português | MEDLINE | ID: mdl-9711313

RESUMO

Laparoscopic cardiomyotomy has recently became a popular alternative to traditional laparotomy in the management of patients with nonadvanced achalasia. The laparoscopic approach for this disease is encouraging due to the low rate of complications associated with a shorter recovery period and reduced postoperative pain. This article describes an alternative technique in the laparoscopic treatment of achalasia with introduction of a supplementary 5 mm port in order to facilitate the cardiomyotomy and the construction of the valvuloplasty.


Assuntos
Acalasia Esofágica/cirurgia , Laparoscopia/métodos , Humanos , Laparoscópios
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