40 resultados para Organonitrogen compounds -- Environmental aspects
Resumo:
A study was carried out in the area of influence of the Porto Primavera Hydroelectric Power Station, in western São Paulo State, to investigate ecological and epidemiological aspects of malaria in the area and monitor the profile of the anopheline populations following the environmental changes brought about by the construction of the lake. Mosquitoes captured were analyzed by standardized indicator species analysis (ISA) before and during different flooding phases (253 m and 257 m elevations). The local human population was studied by means of parasitological (thin/thick blood smears), molecular (PCR) and serological tests. Serological tests consisted of Enzyme Linked Immunosorbent Assay (ELISA) with synthetic peptides of the circumsporozoite protein (CSP) from classic Plasmodium vivax, P. vivax variants (VK247 and "vivax-like"), P. malariae and P. falciparum and Indirect Immunofluorescence Assay (IFA) with asexual forms of P. vivax, P. malariae and P. falciparum. The results of the entomological survey indicated that, although the Anopheles darlingi population increased after the flooding, the population density remained very low. No malaria, parasite infection or DNA was detected in the inhabitants of the study area. However, there was a low frequency of antibodies against asexual forms and a significant prevalence of antibodies against P. vivax, P. vivax variants, P. falciparum and P. malariae; the presence of these antibodies may result from recent or less recent contact with human or simian Plasmodium (a parallel study in the same area revealed the existence of a sylvatic cycle). Nevertheless, these results suggest that, as in other places where malaria is present and potential vectors circulate, the local epidemiological conditions observed could potentially support the transmission of malaria in Porto Primavera Lake if infected individuals are introduced in sufficient numbers. Further studies are required to elucidate the phenomena described in this paper.
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American cutaneous leishmaniasis (ACL) occurs in epidemic outbreaks and in sporadic cases with small annual variation in the Pontal of Paranapanema, SP. There is little research on the sandfly fauna of this region. The last outbreaks were related to the Movement of the Landless Workers (MST) and with the ecological tourism in preserved forest of the Parque Estadual do Morro do Diabo (PEMD). AIM: identification of the sandfly fauna within the PEMD, mainly anthropophilic species already incriminated as vectors of ACL, as well as their seasonality, hourly frequency and data of the behavior. M&M: The captures were undertaken with CDC light and Shannon traps from 6:00 pm to 10:00 pm, monthly from May 2000 to December 2001. The temperature and relative humidity data were registered at hourly intervals. RESULTS: The captured species were: Brumptomyia brumpti, Nyssomyia neivai, Nyssomyia whitmani, Pintomyia fischeri and Pintomyia pessoai. The P. pessoai predominated (34.39%) and N. neivai was less found (0.74%), only being captured in CDC traps. Shannon trap captured more sandflies (63.01%) than the CDC traps (36.99%). Despite the environmental degradation anthropophilic species, indicates favorable bioecological conditions for persistence of vectors and potential transmission of leishmaniasis.
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From 1977 (index case) to 2006, 87 cases of visceral leishmaniasis were confirmed in the municipality of Rio de Janeiro, Brazil, in periurban areas on the continental and coastal slopes of the Pedra Branca massif and the continental slopes of the Gericinó massif. The majority (65.5%) of the patients were more than five years old, predominantly males (61.5%), but without any difference between the sexes below the age of 14 years. The overall fatality rate was 10.4%. Two cases of visceral leishmaniasis/human immunodeficiency virus coinfection were detected. Leishmania chagasi was isolated from human and canine cases. The associations between the presence of phlebotomines and human and canine migrations, disorderly occupation involving degradation of environmental preservation areas and poor socioeconomic conditions may have created a favorable setting for the establishment and propagation of the disease. Close epidemiological surveillance associated with traditional control measures and others (active case researches, land clearing and health education), reduced the incidence of human cases from 2.8 per 100,000 inhabitants in 1981 to less than 0.01 per 100,000 since 1997. The canine infection rates decreased from 4.6% in 1984 to 1.6% in 2008. Lutzomyia longipalpis was not detected in some locations where human and canine cases occurred. In the years 2007 and 2008, no new human cases were reported, but there is a persistent and worrisome residual canine seroprevalence.
Resumo:
Introduction: This work was carried out on the purpose of identifying the species of phlebotomine sandflies in the municipality of Monte Negro, state of Rondonia, Brazil, that may have been transmitting the American cutaneous leishmaniasis (ACL), and concisely describe epidemiological aspects of disease. METHODS: The epidemiologic and socioeconomical indicators were obtained from government institutions and the local Municipal Secretary of Health. Phlebotomine sandflies were captured using CDC light traps between July 2006 to July 2008. The total of 1,240 of female sandflies were examined by PCR method directed to k-DNA. RESULTS: There has been a significant decrease in the incidence of ACL of about 50% over the last ten years in the municipality. A total of 1,935 specimens of 53 sandfly species were captured, three of the genus Brumptomyia genus and 50 of the genus Lutzomyia. The predominant species was Lutzomyia acanthopharynx, Lutzomyia whitmani, Lutzomyia geniculata and Lutzomyia davisi. None were positive for Leishmania sp. CONCLUSIONS: Four sandflies species were found in the State of Rondonia for the first time: Brumptomyia brumpti, Lutzomyia tarapacaensis, Lutzomyia melloi and Lutzomyia lenti. The presence of Lutzomyia longipalpis, was also captured. Socioeconomical improvement of Brazilian economy and the increase of environmental surveillance in the last 15 years collaborated in the decrease of people exposed to vectors, reducing the incidence of ACL.
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Introduction The diverse and complex environmental conditions of the Amazon Basin favor the breeding and development of Anopheles species. This study aimed to describe the composition, abundance and temporal frequency of Anopheles species and to correlate these factors with precipitation, temperature and relative humidity. Methods The study was conducted in the District of Coração, State of Amapá, Brazil. Samples were collected monthly during three consecutive nights, from 6:00 PM to 10:00 PM, from December 2010 to November 2011. In addition, four 12-hour collections (i.e., 6:00 PM to 6:00 AM) were performed during this period. Results A total of 1,230 Anopheles specimens were collected. In the monthly collections, Anopheles darlingi was the predominant species, followed by An. braziliensis and An. albitarsis s.l., whereas An. darlingi, An. peryassui and An. braziliensis were the most frequent species collected in the 12-hour collections. The greatest number of anophelines was collected in September (the dry season). The highest frequency of anophelines was observed for An. darlingi during September, when there were the least rainfalls of the year, along with lower relative humidity and higher temperatures. There was little variation in the abundance of this species in other months, with the exception of slight increases in February, July and August. Conclusions The major malaria vectors, An. darlingi and An. albitarsis s.l. (likely An. marajoara), were the most abundant species collected in the study area. Consequently, prevention and control measures should be taken to prevent malaria outbreaks in the District of Coração.
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OBJECTIVE: The present study aims to evaluate the environmental role in the distribution of hypertension, obesity, and smoking and spousal concordance for the presence/absence of these 3 cardiovascular risk factors. METHODS: A cross-sectional study was conducted in a community in Rio de Janeiro, Brazil. The households were randomly selected. Odds ratios were estimated to measure spousal concordance, across socioeconomic levels.. RESULTS: Overall a significant aggregation of all 3 risk factors was present. The crude odds ratio for hypertension was 1.78 (95%CI=1.02-3.08); for obesity, it was 1.80 (95%CI=1.09-2.96); and for smoking, it was 3.40 (95% CI=2.07-5.61). The spousal concordance for hypertension decreased significantly (p<0.001) from the lower to the higher educational level. In the case of obesity and smoking, the opposite was observed, although p-values for the linear trend were 0.10 and 0.08, respectively. CONCLUSION: In lower socioeconomic levels, couples are more concordant for hypertension and discordant for smoking. For hypertension and smoking, education seems to be a discriminant stronger than income, but for obesity the 2 socioeconomic indicators seem to represent different aspects of the environmental determinants of risk factor distribution.
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The occurrence of cell reabsorption in the ovaries of queens in several rates of laying eggs, artificially impeded of laying, and in nurse workers, of Apis mellifera (Linnaeus, 1758), was studied with light (LM) and transmission electron microscopy (TEM). Two types of structures were described and named by analogy with vertebrates ovarian structures, as corpus luteus, when resulting from the reabsorption of the follicular cells after ovulation, and corpus atresicus when resulting from total follicular reabsorption at any oocyte developmental stage. These structures have the same morphological characteristics and physiological signification in both castes. The corpus luteus occurrence indicates ovulation and its number is correspondent to the queen's rates of oviposition. The presence of this structure in nurse workers ovarioles shows that this caste may lay eggs. The incidence of corpus atresicus in queens decay with the increasing of the oviposition indicating that the inhibition of the normal sequence of oocyte maturation in the ovaries is deleterious. Both, corpus luteus and corpus atresicus incidence may be influenced by environmental factors.
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A series of studies have been undertaken to find cases in which heterokaryons show adaptative response to environmental change. Comparisons have also been made between the phenotypes of heterokaryons and corresponding heterozygotes. Unsuccessful attempts were made to produce heterokaryons, on complete medium, balanced by one previously-existing mutant and one newly-obtained slow-growing mutant. Adaptation was achieved in heterokaryons carrying different mutant alleles conferring resistance to: (a) acriflavine, (b) actidione and (c) p-fluorophenylalanine. Comparison with the heterozygote in case (a) suggested a highly localised action of the allele determining resistance. A similar comparison for (b) suggested a non-localised action. In cases (b) and (c) dosage effects were observed in the degree of resistance that the heterokaryons, compared with the corresponding heterozygotes, could achieve. In case (c) interaction of the resistance marker with a nutritional marker (nic8) has been investigated further and a new unteraction between nic8 and Act1 detected. During this work a new conidial colour mutant, fawn, was isolated and characterised. It is likely to be a valuable visual marker, especially in view of its interaction with other colour mutants.
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Triatoma rubrovaria has become the most frequently captured triatomine species since the control of T. infestans in the state of Rio Grande do Sul (RS), Brazil. The aim of this study was to evaluate aspects of the vectorial competence of T. rubrovaria using nymphs raised in laboratory under environmental conditions of temperature and humidity and fed on mice. The average developmental period of T. rubrovaria was 180.1 days. The percentage of defecation shortly after feeding was still higher than previous studies in which samples of T. rubrovaria subjected to a slight starvation period before the blood meal were used. The obtained results support former indication that T. rubrovaria presents bionomic characteristics propitious to be a good vector of Trypanosoma cruzi to man. Therefore its domiciliary invasion process must be continuously monitored.
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The objective of this study was to determine the effects of rainfall, temperature, sunlight and relative humidity, as well as predators and parasitoids, leaf chemical composition and levels of leaf nitrogen and potassium on the intensity of Scirtothrips manihoti (Thysanoptera: Thripidae) attack on cassava Manihot esculenta Crantz var. Cacau. The leaf compounds (E)-farnesene/trans-farnesol and D-friedoolean-14-en-3-one correlated significantly with the population of S. manihoti. Insect population decreased in the dry and cold season probably due to leaf senescence. Significative correlation was observed between Syrphidae with S. manihoti populations.
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The chelating agent EDTA (ethylenediaminetetraacetic acid) is a compound of massive use world wide with household and industrial applications, being one of the anthropogenic compounds with highest concentrations in inland European waters. In this review, the applications of EDTA and its behavior once it has been released into the environment are described. At a laboratory scale, degradation of EDTA has been achieved; however, in natural environments studies detect poor biodegradability. It is concluded that EDTA behaves as a persistent substance in the environment and that its contribution to heavy metals bioavailability and remobilization processes in the environment is a major concern.
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Polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofuranes (PCDF) and polychlorinated biphenyls (PCB) are types of persistent and bioaccumulating organic pollutants with enhanced chronic toxicity and carcinogenic properties and can be considered as environmental indicators of anthropogenic activities since their occurrence in the environment can always be linked to anthropogenic activities. The present paper reviews the main sources and behaviour of these compounds in the environment as well as the risks they represent to man and biota.
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Efforts presented by the scientific community in recent years towards the development of numerous green chemical processes and wastewater treatment technologies are presented and discussed. In the light of these approaches, environmentally friendly technologies, as well as the key role played by the well-known advanced oxidation processes, are discussed, giving special attention to the ones comprising ozone applications. Fundamentals and applied aspects dealing with ozone technology and its application are also presented.
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Natural and synthetic estrogens have been detected in rivers, lakes and estuaries in several parts of the world. The primary sources of these compounds are the industrial and household effluents, which are not eliminated by the received treatment. This paper presents a brief description of the problem as well as the physical and chemical characteristics of the main compounds, the environmental behavior, methods of determination, ecotoxicological aspects and a discussion about its relevance in terms of ecology and public health.
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Anatoxin-a and its analogues are azabicyclic alkaloids that represent one of the most powerful nicotinic agonists known for the nicotinic acetylcholine receptor (nAChR). Because of this potent mechanism of action, anatoxin-a and its derivatives represent a target for the discovery of novel drugs. Their syntheses are useful for environmental monitoring and also for pharmacokinetic/pharmacodynamic and toxicological studies. Some strategies for the synthesis of anatoxin-a and analogous compounds are described herein, covering the period from 1996 to the present date. In this review, emphasis is given to the chemical and toxicological aspects of some variants of anatoxin-a, including homoanatoxin-a and anatoxin-a(s).