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1.
Sci Total Environ ; 923: 171390, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38438044

RESUMO

Marine microdebris (MDs, <5 mm) and mesodebris (MesDs, 5-25 mm), consist of various components, including microplastics (MPs), antifouling or anticorrosive paint particles (APPs), and metallic particles (Mmps), among others. The accumulation of these anthropogenic particles in macroalgae could have significant implications within coastal ecosystems because of the role of macroalgae as primary producers and their subsequent transfer within the trophic chain. Therefore, the objectives of this study were to determine the abundance of MDs and MesDs pollution in different species of macroalgae (P. morrowii, C. rubrum, Ulva spp., and B. minima) and in surface waters from the Southwest Atlantic coast of Argentina to evaluate the ecological damage. MDs and MesDs were chemically characterized using µ-FTIR and SEM/EDX to identify, and assess their environmental impact based on their composition and degree of pollution by MPs, calculating the Polymer Hazard Index (PHI). The prevalence of MDs was higher in foliose species, followed by filamentous and tubular ones, ranging from 0 to 1.22 items/g w.w. for MPs and 0 to 0.85 items/g w.w. for APPs. It was found that macroalgae accumulate a higher proportion of high-density polymers like PAN and PES, as well as APPs based on alkyd, PMMA, and PE resins, whereas a predominance of CE was observed in surrounding waters. Potentially toxic elements, such as Cr, Cu, and Ti, were detected in APPs and MPs, along with the presence of epiplastic communities on the surface of APPs. According to PHI, the presence of high hazard score polymers, such as PAN and PA, increased the overall risk of MP pollution in macroalgae compared to surrounding waters. This study provided a baseline for MDs and MesDs abundance in macroalgae as well as understanding the environmental impact of this debris and their bioaccumulation in the primary link of the coastal trophic chain.


Assuntos
Alga Marinha , Poluentes Químicos da Água , Plásticos , Monitoramento Ambiental , Ecossistema , Argentina , Poluentes Químicos da Água/análise , Microplásticos
2.
Sci Total Environ ; 914: 170026, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38218486

RESUMO

Estuarine coastal water and sediments collected from multiple locations within the middle Río de la Plata (RDLP) estuary were analyzed in order to identify the presence of microplastics (MPs, <5 mm) and mesoplastics (MePs, 5-25 mm) in one of the most significant estuaries in the Southwestern Atlantic. The present study represents one of the first researches to survey MPs and MePs contamination in key stations at RDLP estuary. Average concentrations of 14.17 ± 5.50 MPs/L and 10.00 MePs/L were detected in water samples, while 547.83 ± 620.06 MPs/kg (dry weight) and 74.23 ± 47.29 MePs/kg d.w. were recorded in sediments. The greatest abundances were observed in the more anthropized areas, near urban settlements. Fibers were the most conspicuous plastic items in water and sediments, followed by fragments. On the other hand, surface sediments, and 50 cm and 100 cm-depth sediments also presented MPs and MePs indicating they could serve as a stratigraphic indicator for recently formed sediments. The main polymer type identified were acrylic fibers, followed by polypropylene (PP) and polyethylene terephthalate (PET). Besides, SEM-EDX detected the presence of Si, Fe, Ti, Al and Cl onto the plastics' surface. These elements may serve as additives to enhance the plastics' properties, such as in the case of Ti, or they could originate from the environment, like biogenic Si or Fe, and Al possibly as a component of the suspended particles or sediments adhered to the micro or meso plastics. Finally, the results of the present study showed that MPs and MePs are commonly found in waters and also tend to be trapped in sediments of the RDLP estuary supporting the assertion that these areas play a substantial role in influencing the transport, dispersion, and buildup of MPs in estuarine regions.

3.
Sci Total Environ ; 913: 169677, 2024 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-38163594

RESUMO

Microplastics (MPs) and antifouling paint particles (APPs) are important components of marine microdebris (MDs), which constitute a potential environmental risk. This study analyzed baseline contamination levels of MDs and mesodebris (MesDs) in intertidal sediments at different depths, exploring the geomorphological influence in three Argentine coastal environments: Bahía Blanca Estuary (BBE), Los Pocitos (LP) and Puerto Madryn (PM). The MDs and MesDs samples were characterized by µ-FTIR, SEM/EDX and XRD. The abundance of MPs and APPs in sediments, range between 19.78 and 1087.19 and between 0 and 172.93 items/kg d.w., respectively. Despite variations in population and industrial developments in these areas, MPs abundance shows no significant differences in low and high intertidal zones. However, mean MPs concentrations were higher in the surface layer (0-5 cm) compared to the deeper sediments (5-10 cm), indicating recent MPs deposition. Chemical characterization evidenced the presence of cellulose (CE) and denser polymers as acrylonitrile butadiene styrene (ABS) and polyacrylics (PAN), APPs, metallic and black MDs. Surface degradation and heavy metals (Zn, Cr, and Ba) were also detected in APPs and other MDs, either as additives or adhered to their surfaces. Changes in crystallinity were also observed on the MesDs due to weathering. The calculated polymer hazard index (PHI) and the presence of hazardous polymers such as ABS and PAN indicated an increased risk of MPs pollution on the BBE and PM coasts. The pollution load index (PLI) values (from 4.63 to 5.34) suggested unpolluted to moderately polluted levels. These findings offer insights into potential risks associated with MDs in Argentine intertidal sediments, underscoring the critical need to comprehend the geomorphology and the influence of coastal dynamics. This is crucial for effectively addressing challenges linked to MDs pollution guiding the development of robust management and mitigation strategies.

4.
Mar Pollut Bull ; 191: 114997, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37148588

RESUMO

In this study, we surveyed the presence of personal protective equipment (PPE) waste on the streets of Bogotá-Colombia, Lima-Perú, and Mar del Plata-Argentina. Furthermore, this work is also focused on the release capacity of Ag, Cu, and Zn metals associated with nanoparticles, and microplastics (MPs) from textile face masks (TFMs) and disposable face masks. According to our results, an association between low-income areas and PPE waste was found, which may be related to the periodicity of waste collection and economic activity. Polymers, like polypropylene, cotton-polyester, and additives, such as CaCO3, MgO, and Ag/Cu as nanoparticles, were identified. TFMs released high levels of Cu (35,900-60,200 µg·L-1), Zn (2340-2380 µg·L-1), and MPs (4528-10,640 particles/piece). Metals associated with nanoparticles leached by face masks did not present any antimicrobial activity against P. aeruginosa. Our study suggests that TFMs may leach large amounts of polluting nano/micromaterials in aquatic environments with potential toxicological effects on organisms.


Assuntos
Metais Pesados , Nanopartículas , Microplásticos , Máscaras , Plásticos , Cidades , Metais Pesados/análise , Equipamento de Proteção Individual , América do Sul
5.
J Hazard Mater ; 440: 129737, 2022 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-35988489

RESUMO

In this study, the influence of the plastisphere on metals accumulation and weathering processes of polystyrene (PSMPs) and nylon microplastics (NyMPs) in polluted waters during a 129 day-assay were studied. MPs were characterized through scanning electron microscopy (SEM) with Energy dispersive X-ray (EDX), X-ray diffraction (XRD), attenuated total reflectance Fourier transformed infrared (ATR-FTIR) spectroscopy, contact angle, and thermogravimetric analysis (TGA). Also Cr, Mn, Zn, Cd, Pb, and Cu in the plastisphere on MPs were analyzed during the assay. Potentially pathogenic Vibrio, Escherichia coli, and Pseudomonas spp. were abundant in both MPs. Ascomycota fungi (Phona s.l., Alternaria sp., Penicillium sp., and Cladosporium sp.), and yeast, were also identified. NyMPs and PSMPs exhibited a decrease in the contact angle and increased their weights. SEM/EDX showed weathering signs, like surface cracks and pits, and leaching TiO2 pigments from NyMPs after 42 days. XRD displayed a notorious decrease in NyMPs crystallinity, which could alter its interaction with external contaminants. Heavy metal accumulation on the plastisphere formed on each type of MPs increased over the exposure time. After 129 days of immersion, metals concentrations in the plastisphere on MPs were in the following order Cr ˃ Mn ˃ Zn ˃ Cu ˃ Pb ˃ Cd, demonstrating how the biofilm facilitates metal mobilization. The results of this study lead to a better understanding of the impact of marine plastic debris as vectors of pathogens and heavy metals in coastal environments.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Cádmio/análise , Chumbo , Metais Pesados/análise , Microplásticos , Nylons , Plásticos/química , Poliestirenos/análise , Poluentes Químicos da Água/química
6.
Sci Total Environ ; 837: 155631, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35508238

RESUMO

Synthetic microdebris (particles of <5 mm) are a worldwide concern because they can affect the community structure of the aquatic ecosystems, organisms, and even food webs. For the biomonitoring of synthetic microdebris (especially microplastics, MPs), mainly benthic invertebrates are used, but crabs have been less studied in the literature. We studied the synthetic microdebris contamination in water, sediments, and three representative intertidal crabs (Neohelice granulata, Cyrtograpsus angulatus and Leptuca uruguayensis) with different lifestyles from the Bahía Blanca estuary, Argentina. The results obtained show the presence of cotton-polyamide (PA), polyethylene (PE), and polyethylene terephthalate (PET) in surface waters. In sediments, we identified cellulose modified (CE), polyester (PES), polyethylene (PE), and alkyd resin, while in crabs, cotton-PA and CE were the predominant ones. The MPs abundance ranged from 8 to 68 items L-1 in surface water, from 971 to 2840 items Kg-1 in sediments, and from 0 to 2.58 items g-1 ww for the three species of crabs. Besides, paint sheets ranged from 0 to 17 in the total samples, with Cr, Mo, Ti, Pb, Cu, Al, S, Ba and Fe on their surface. There were significant differences between the microdebris abundances in the abiotic matrices but not among crabs species. The ecological traits of the different crabs helped to understand the accumulation of synthetic microdebris, an important characteristic when determining the choice of a good biomonitor.


Assuntos
Braquiúros , Poluentes Químicos da Água , Animais , Ecossistema , Monitoramento Ambiental/métodos , Estuários , Sedimentos Geológicos , Plásticos , Polietilenos , Espécies Sentinelas , Água , Poluentes Químicos da Água/análise
7.
Mar Pollut Bull ; 174: 113276, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35090270

RESUMO

A wide range of contaminants of emerging concern such as micro/nanoplastics (MPs/PNPs) and metal-nanoparticles (Me-NPs) from anthropogenic activities have been identified in aquatic environments. The hazardous effects of these micro/nanomaterials as pollutants in organisms and the lack of knowledge about their behavior in aquatic environments have generated growing concern in the scientific community. The nanomaterials have a colloidal-type behavior due to their size range but with differences in their physicochemical properties. This review comprises the behavior of micro/nanomaterials pollutants and the physicochemical interactions between MPs/PNPs and Me-NPs in aquatic environments, and their potential toxicological effects in organisms. Moreover, this article describes the potential use of Me-NPs to remove MPs/PNPs present in the water column due to their photocatalytic and magnetic properties. It also discusses the challenge to determine harmful effects of micro/nanomaterials pollutants in organisms and provides future research directions to improve integrated management strategies to mitigate their environmental impact.


Assuntos
Poluentes Ambientais , Nanopartículas Metálicas , Nanoestruturas , Poluentes Químicos da Água , Efeitos Antropogênicos , Nanopartículas Metálicas/toxicidade , Nanoestruturas/toxicidade , Poluentes Químicos da Água/toxicidade
8.
Mar Pollut Bull ; 173(Pt B): 113023, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34695691

RESUMO

This study assesses for the first time the concentrations of microplastics (MPs) in sediments, water and two human-consumed mussels with different ecological traits (Amarilladesma mactroides and Brachidontes rodriguezii) in a touristic sandy beach of Argentina. MPs were characterized through FTIR and SEM/EDX techniques. All the samples presented MPs with similar concentrations as other human-impacted coastal areas of the world, being black and blue fibers of < 0.5 and 0.5-1 mm the most abundant. SEM images exhibited cracks and fractures with clay minerals and microorganisms adhered to MPs surface. EDX spectrums showed potentially toxic elements, such as Cr, Ti, and Mo. FTIR identified polymers such as cellulose, polyamides, and polyacrylates in most of the samples analyzed. Our study demonstrates that microplastic pollution is a common threat to sandy beaches in Argentina, worsened by plastic particles carrying metal ions with potential toxic effects to the biota, including A. mactroides, an endangered species.


Assuntos
Bivalves , Poluentes Químicos da Água , Animais , Argentina , Monitoramento Ambiental , Sedimentos Geológicos , Humanos , Microplásticos , Plásticos , Água , Poluentes Químicos da Água/análise
9.
Sci Total Environ ; 785: 147141, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33933772

RESUMO

Microplastics have been a global concern due to their potential and widespread risks to organisms and environments. In this study, we investigated the abundance, distribution, and characteristics of microplastics (MPs) in the surface waters of the Bahía Blanca Estuary (BBE), specifically in its inner and middle zone. The results showed the dominant shape of MPs were fibers, being black, transparent, and blue the main colors. The concentrations of MPs ranged from 182 to 33,373 items m-3 with a mean value of 6162 items m-3. The highest concentrations of MPs were detected in the middle zone of the estuary, a site that receives untreated sewage effluents from the city. The most abundant size ranges were from 0.5 to 1.5 mm (44.21%) and ˂0.5 mm (40.21%) and were predominant at all the sampling sites. The concentration of mesoplastics in the inner zone (16 items m-3) presented larger values than in the middle zone (5 items m-3). A wide variety of polymeric materials with predominance of microfibers such as cellulose-based, polyacrylonitrile, polyethylene terephthalate, and polypropylene were identified. Polyester/alkyd resins and poli(vinyl chloride) were also found. The analysis of MPs surface through SEM/EDX detected a variety of elements such as C, O, Si, Al, K, Ca, Cl, Ti, Fe, S, and P, indicating potential contaminant carriers in the water column. Some plastic particles presented a high degree of degradation on their surface morphology. Untreated sewage discharges appear to be a significant input of MPs. Therefore, the results provided in the present study should be considered by stakeholders interested in the management and conservation of this large coastal wetland with significant ecological and economic value.

10.
Mar Pollut Bull ; 165: 112093, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33611229

RESUMO

The contamination of estuaries by heavy metals from anthropogenic activities in the industrial, domestic, and agricultural sectors is a global concern. In this study, the Cr, Fe, and Mn levels in the suspended particulate matter (SPM) were analyzed in estuarine waters from Bahia Blanca Estuary, during 2014-2015. The values of particulate Cr ranged from 7.33 to 35.20 µg g-1, which could be associated to several anthropogenic sources. The positive correlations found between Cr and Chlorophyll-a, and Cr and particulate organic carbon (POC) suggest the strong influence of phytoplankton on the adsorption of this metal and on the increase of particulate Cr. Negative correlations were found between Cr and DO and between Cr and pH, which could indicate an increasing trend in the dissolved form of Cr. This study suggests that the physical-chemical characteristics of the water column as well as phytoplankton and POC dynamics influence the behavior of Cr in this estuary.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Argentina , Brasil , Cromo , Monitoramento Ambiental , Estuários , Sedimentos Geológicos , Metais Pesados/análise , Poluentes Químicos da Água/análise
11.
Sci Total Environ ; 763: 144365, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33360513

RESUMO

The propagation of the COVID-19 pandemic worldwide has been alarming in the last months. According to recommendations of the World Health Organization (WHO), the use of face masks is essential for slowing down the transmission rate of COVID-19 in human beings. This pandemic has generated a substantial increase in the use, as well as in the production, of face masks and other elements (gloves, face protectors, protective suits, safety shoes) manufactured with polymeric materials, including antiviral textiles most of which will end as microplastic pools. Focusing on South America, the use and mismanagement of this type of personal protective equipment (PPE) represents an environmental problem. Added to this issue are the increase in the use of single-use plastic, and the reduction of plastic recycling due to the curfew generated by the pandemic, further aggravating plastic pollution on coasts and beaches. Recently, researchers have developed antiviral polymeric textile technology composed of Ag and Cu nanoparticles for PPE to reduce the contagion and spread of COVID-19. Antiviral polymeric textile wastes could also have long-term negative repercussions on aquatic environments, as they are an important emerging class of contaminants. For this reason, this work provides reflections and perspectives on how the COVID-19 pandemic can aggravate plastic pollution on beaches and coastal environments, consequently increasing the damage to marine species in the coming years. In addition, the potential impact of the pandemic on waste management systems is discussed here, as well as future research directions to improve integrated coastal management strategies.


Assuntos
Antivirais , COVID-19 , Humanos , Pandemias , Plásticos , SARS-CoV-2 , América do Sul/epidemiologia , Têxteis
12.
Sci Total Environ ; 754: 142413, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33254940

RESUMO

The composition and the interaction of the suspended particulate matter (SPM) with metal ions, along with the presence and characteristics of microplastics, were analyzed for the first time in the water column of the inner zone of Bahía Blanca Estuary during winter (June, July, and August) 2019. Surface analysis techniques (Scanning Electron Microscopy combined with Energy Dispersive X-ray Spectroscopy, X-ray Photoelectron Spectroscopy, and X-ray Diffraction) were employed to obtain an in-depth characterization of the particulate matter, suggesting the presence of Fe in our samples, with a mixture of Fe3+/Fe2+ oxidation states. Microplastics ranged in concentrations between 3 and 11.5 items L-1, with an average of 6.50 items L-1 (S.E: ±4.01), being fibers the most abundant type. Infrared Spectroscopy suggests that these fibers correspond to semi-synthetic cellulose-based and poly(amide) remains. We concluded that the SPM is a significant vehicle for metals which might have adverse effects on marine organisms.

13.
Mar Pollut Bull ; 161(Pt A): 111700, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33022492

RESUMO

Microplastics (plastics <5 mm) contamination is of worldwide concern and represents a threat to the environment, biota, and humans. Also, they are potential carriers of other contaminants, increasing their adverse effects. In this study, it was analyzed for the first time the chemical composition and abundance of microplastics (MPs) in the commercial shrimp Pleoticus muelleri. Fibers were the predominant plastics (mean: 1.31 fibers g-1 wet weight) in the abdominal muscle of the shrimps being black, the dominant colour. µ-Raman showed that fibers were composed of polyethylene (PE), polypropylene (PP), and cellulose. Also, weathering and topography of the fibers were analyzed through wide-field confocal microscopy. C, O, Si, Al, K, as well as Fe, Zn, S, Ba, Br, and Ti on the plastic surface were detected with SEM/EDS, indicating potential carriers of contaminants. CAPSULE: The shrimp Pleoticusmuelleri ingests fibers with different chemical elements adsorbed on the plastic surface.


Assuntos
Plásticos , Poluentes Químicos da Água , Monitoramento Ambiental , Humanos , Microplásticos , Músculos/química , Poluentes Químicos da Água/análise
14.
Int J Tuberc Lung Dis ; 16(12): 1699-705, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23131272

RESUMO

BACKGROUND: Global studies of the long-term association between tobacco consumption and chronic obstructive pulmonary disease (COPD) have relied upon descriptions of trends. OBJECTIVES: To statistically analyse the relationship of tobacco consumption with data on mortality due to COPD over the past 100 years in Australia. METHODS: Tobacco consumption was reconstructed back to 1887. Log-linear Poisson regression models were used to analyse cumulative cohort and lagged time-specific smoking data and its relationship with COPD mortality. RESULTS: Age-standardised COPD mortality, although likely misclassified with other diseases, decreased for males and females from 1907 until the start of the Second World War in contrast to steadily rising tobacco consumption. Thereafter, COPD mortality rose sharply in line with trends in smoking, peaking in the early 1970s for males and over 20 years later for females, before falling again. Regression models revealed both cumulative and time-specific tobacco consumption to be strongly predictive of COPD mortality, with a time lag of 15 years for males and 20 years for females. CONCLUSIONS: Sharp falls in COPD mortality before the Second World War were unrelated to tobacco consumption. Smoking was the primary driver of post-War trends, and the success of anti-smoking campaigns has sharply reduced COPD mortality levels.


Assuntos
Nicotiana/efeitos adversos , Doença Pulmonar Obstrutiva Crônica/mortalidade , Fumar/efeitos adversos , Fumar/mortalidade , Adolescente , Adulto , Distribuição por Idade , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Austrália/epidemiologia , Distribuição de Qui-Quadrado , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Mortalidade/tendências , Fatores de Risco , Distribuição por Sexo , Fatores Sexuais , Fumar/tendências , Abandono do Hábito de Fumar , Prevenção do Hábito de Fumar , Fatores de Tempo , II Guerra Mundial , Adulto Jovem
15.
Int J Tuberc Lung Dis ; 16(6): 774-6, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22507759

RESUMO

Despite the availability of a Mycobacterium bovis bacille Calmette Guérin (BCG) vaccine, tuberculosis (TB) remains a global public health problem. In this study, we introduced the c-di-GMP phosphodiesterase gene Rv1357c, implicated in regulating mycobacterial replication within macrophages, into BCG Pasteur, and tested the resulting strain for its capacity to serve as a vaccine against TB in a murine model. Modified BCG was more phagocytosed than its parental strain, but halted bacterial replication, and protected against M. tuberculosis challenge similarly to unmodified BCG.


Assuntos
Aciltransferases/imunologia , Vacina BCG/imunologia , Mycobacterium tuberculosis/imunologia , Tuberculose Pulmonar/prevenção & controle , Vacinação , Aciltransferases/genética , Animais , Linhagem Celular , Modelos Animais de Doenças , Macrófagos/imunologia , Macrófagos/microbiologia , Camundongos , Camundongos Endogâmicos BALB C , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/crescimento & desenvolvimento , Fagocitose , Fatores de Tempo , Tuberculose Pulmonar/imunologia , Tuberculose Pulmonar/microbiologia , Vacinas Sintéticas/imunologia
16.
Int J Tuberc Lung Dis ; 15(12): 1608-14, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22118166

RESUMO

BACKGROUND: Indonesia bears the third highest tuberculosis (TB) burden in the world. Current mortality estimates are based on notification and case fatality rates derived from the National TB Control Programme. OBJECTIVE: To report TB mortality measures for 2007-2008 based on death registration systems in selected populations in five provinces of Indonesia. METHODS: Data were compiled from sites in Central Java, Lampung, Gorontalo, West Kalimantan and Papua in 2007-2008, covering 2.5 million people. Overall mortality levels and TB mortality indicators were computed. Data quality was assessed in terms of completeness of death registration and strength of evidence in verbal autopsy questionnaires. RESULTS: A total of 1547 TB deaths were diagnosed in the five provinces. There was direct or indirect evidence of incomplete death registration at all sites. More than 90% of TB diagnoses from verbal autopsies were based on strong evidence. The results demonstrate high TB death rates in Papua, and significant mortality differentials across provinces. CONCLUSIONS: The measurement of cause-specific mortality is feasible by strengthening death registration in Indonesia. Observed TB mortality rates from five sites are baseline evidence for monitoring TB control programmes. Sustained efforts are required to develop death registration as a routine annual source of mortality data for Indonesia.


Assuntos
Política de Saúde , Programas Nacionais de Saúde/organização & administração , Tuberculose/mortalidade , Autopsia , Atestado de Óbito , Estudos de Viabilidade , Humanos , Indonésia/epidemiologia , Tuberculose/epidemiologia
17.
Diabetologia ; 51(2): 285-97, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18094957

RESUMO

AIMS/HYPOTHESIS: An immunohistochemical and genomic analysis of human pancreatic development from 9-23 weeks of fetal age was undertaken to provide a comparative analysis of human and murine islet development. METHODS: Human fetal pancreases obtained at gestational ages 9-23 weeks were processed in parallel for immunohistochemistry and gene expression profiling by Affymetrix microarrays. RESULTS: By 9-11 weeks, the pancreas was made up principally of mesenchymal tissue infiltrated by branched epithelial structures containing scattered hormone-negative neurogenin3-positive endocrine cells. Protoacinar structures emerged by 15-19 weeks, along with clusters of endocrine cells producing either glucagon or insulin. By 20-23 weeks, vascularised islet-like structures appeared. More than 70% of endocrine cells produced a single hormone at any age. Analysis of Ki67 immunoreactivity showed that the replicative rate of endocrine cells was low and suggested that the endocrine expansion was derived from hormone-negative precursors. Insulin, glucagon, somatostatin, ghrelin and pancreatic polypeptide transcripts were present at 9-10 weeks and increased progressively, commensurate with the expansion of endocrine cell volume. The human equivalent of a mouse endocrine secondary transition was not evident, neither in terms of morphology nor in dramatic changes in endocrine-specific transcriptional regulators. By contrast, exocrine genes showed a marked transition at around 11 weeks, associated with a greater than sixfold increase in exocrine gene transcripts. CONCLUSIONS/INTERPRETATION: The observed extension of terminal differentiation of human endocrine tissue into late gestation is in contrast with findings in the mouse. It indicates that the human fetal pancreas could provide an abundant islet precursor cell population that could be expanded ex vivo for therapeutic transplantation.


Assuntos
Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica no Desenvolvimento , Antígeno Ki-67/análise , Pâncreas/metabolismo , Idade Gestacional , Humanos , Imuno-Histoquímica , Análise de Sequência com Séries de Oligonucleotídeos , Pâncreas/embriologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa
18.
Ann Trop Med Parasitol ; 100(5-6): 481-99, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16899150

RESUMO

Any planning process for health development ought to be based on a thorough understanding of the health needs of the population. This should be sufficiently comprehensive to include the causes of premature death and of disability, as well as the major risk factors that underlie disease and injury. To be truly useful to inform health-policy debates, such an assessment is needed across a large number of diseases, injuries and risk factors, in order to guide prioritization. The results of the original Global Burden of Disease Study and, particularly, those of its 2000-2002 update provide a conceptual and methodological framework to quantify and compare the health of populations using a summary measure of both mortality and disability: the disability-adjusted life-year (DALY). Globally, it appears that about 56 million deaths occur each year, 10.5 million (almost all in poor countries) in children. Of the child deaths, about one-fifth result from perinatal causes such as birth asphyxia and birth trauma, and only slightly less from lower respiratory infections. Annually, diarrhoeal diseases kill over 1.5 million children, and malaria, measles and HIV/AIDS each claim between 500,000 and 800,000 children. HIV/AIDS is the fourth leading cause of death world-wide (2.9 million deaths) and the leading cause in Africa. The top three causes of death globally are ischaemic heart disease (7.2 million deaths), stroke (5.5 million) and lower respiratory diseases (3.9 million). Chronic obstructive lung diseases (COPD) cause almost as many deaths as HIV/AIDS (2.7 million). The leading causes of DALY, on the other hand, include causes that are common at young ages [perinatal conditions (7.1% of global DALY), lower respiratory infections (6.7%), and diarrhoeal diseases (4.7%)] as well as depression (4.1%). Ischaemic heart disease and stroke rank sixth and seventh, retrospectively, as causes of global disease burden, followed by road traffic accidents, malaria and tuberculosis. Projections to 2030 indicate that, although these major vascular diseases will remain leading causes of global disease burden, with HIV/AIDS the leading cause, diarrhoeal diseases and lower respiratory infections will be outranked by COPD, in part reflecting the projected increases in death and disability from tobacco use.


Assuntos
Doenças Transmissíveis/epidemiologia , Saúde Global , Adolescente , Adulto , Causas de Morte , Criança , Pré-Escolar , Doença Crônica/epidemiologia , Humanos , Lactente , Recém-Nascido , Pessoa de Meia-Idade , Mortalidade , Anos de Vida Ajustados por Qualidade de Vida , Fatores de Risco
20.
Tob Control ; 13(4): 388-95, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15564623

RESUMO

BACKGROUND: Smoking has been causally associated with increased mortality from several diseases, and has increased considerably in many developing countries in the past few decades. Mortality attributable to smoking in the year 2000 was estimated for adult males and females, including estimates by age and for specific diseases in 14 epidemiological subregions of the world. METHODS: Lung cancer mortality was used as an indirect marker of the accumulated hazard of smoking. Never-smoker lung cancer mortality was estimated based on the household use of coal with poor ventilation. Estimates of mortality caused by smoking were made for lung cancer, upper aerodigestive cancer, all other cancers, chronic obstructive pulmonary disease (COPD), other respiratory diseases, cardiovascular diseases, and selected other medical causes. Estimates were limited to ages 30 years and above. RESULTS: In 2000, an estimated 4.83 million premature deaths in the world were attributable to smoking, 2.41 million in developing countries and 2.43 million in industrialised countries. There were 3.84 million male deaths and 1.00 million female deaths attributable to smoking. 2.69 million smoking attributable deaths were between the ages of 30-69 years, and 2.14 million were 70 years of age and above. The leading causes of death from smoking in industrialised regions were cardiovascular diseases (1.02 million deaths), lung cancer (0.52 million deaths), and COPD (0.31 million deaths), and in the developing world cardiovascular diseases (0.67 million deaths), COPD (0.65 million deaths), and lung cancer (0.33 million deaths). The share of male and female deaths and younger and older adult deaths, and of various diseases in total smoking attributable deaths exhibited large inter-regional heterogeneity, especially in the developing world. CONCLUSIONS: Smoking was an important cause of global mortality in 2000, affecting a large number of diseases. Age, sex, and disease patterns of smoking-caused mortality varied greatly across regions, due to both historical and current smoking patterns, and the presence of other risk factors that affect background mortality from specific diseases.


Assuntos
Doenças Cardiovasculares/mortalidade , Neoplasias/mortalidade , Doenças Respiratórias/mortalidade , Fumar/mortalidade , Adulto , Distribuição por Idade , Idoso , Causas de Morte , Efeitos Psicossociais da Doença , Países Desenvolvidos , Países em Desenvolvimento , Neoplasias do Sistema Digestório/mortalidade , Feminino , Humanos , Pneumopatias Obstrutivas/mortalidade , Neoplasias Pulmonares/mortalidade , Masculino , Pessoa de Meia-Idade , Neoplasias do Sistema Respiratório/mortalidade , Distribuição por Sexo , Fumar/efeitos adversos
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