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1.
Nature ; 619(7969): 311-316, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37438592

RESUMO

Coral reefs are losing the capacity to sustain their biological functions1. In addition to other well-known stressors, such as climatic change and overfishing1, plastic pollution is an emerging threat to coral reefs, spreading throughout reef food webs2, and increasing disease transmission and structural damage to reef organisms3. Although recognized as a global concern4, the distribution and quantity of plastics trapped in the world's coral reefs remains uncertain3. Here we survey 84 shallow and deep coral ecosystems at 25 locations across the Pacific, Atlantic and Indian ocean basins for anthropogenic macrodebris (pollution by human-generated objects larger than 5 centimetres, including plastics), performing 1,231 transects. Our results show anthropogenic debris in 77 out of the 84 reefs surveyed, including in some of Earth's most remote and near-pristine reefs, such as in uninhabited central Pacific atolls. Macroplastics represent 88% of the anthropogenic debris, and, like other debris types, peak in deeper reefs (mesophotic zones at 30-150 metres depth), with fishing activities as the main source of plastics in most areas. These findings contrast with the global pattern observed in other nearshore marine ecosystems, where macroplastic densities decrease with depth and are dominated by consumer items5. As the world moves towards a global treaty to tackle plastic pollution6, understanding its distribution and drivers provides key information to help to design the strategies needed to address this ubiquitous threat.


Assuntos
Recifes de Corais , Plásticos , Plásticos/efeitos adversos , Plásticos/análise , Cadeia Alimentar , Oceano Pacífico , Oceano Atlântico , Oceano Índico , Tamanho da Partícula , Atividades Humanas , Caça
2.
Glob Chang Biol ; 30(9): e17513, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39319475

RESUMO

Human activities and climate change have accelerated species losses and degradation of ecosystems to unprecedented levels. Both theoretical and empirical evidence suggest that extinction cascades contribute substantially to global species loss. The effects of extinction cascades can ripple across levels of ecological organization, causing not only the secondary loss of taxonomic diversity but also functional diversity erosion. Here, we take a step forward in coextinction analysis by estimating the functional robustness of reef fish communities to species loss. We built a tripartite network with nodes and links based on a model output predicting reef fish occupancy (113 species) as a function of coral and turf algae cover in Southwestern Atlantic reefs. This network comprised coral species, coral-associated fish (site occupancy directly related to coral cover), and co-occurring fish (occupancy indirectly related to coral cover). We used attack-tolerance curves and estimated network robustness (R) to quantify the cascading loss of reef fish taxonomic and functional diversity along three scenarios of coral species loss: degree centrality (removing first corals with more coral-associated fish), bleaching vulnerability and post-bleaching mortality (most vulnerable removed first), and random removal. Degree centrality produced the greatest losses (lowest R) in comparison with other scenarios. In this scenario, while functional diversity was robust to the direct loss of coral-associated fish (R = 0.85), the taxonomic diversity was not robust to coral loss (R = 0.54). Both taxonomic and functional diversity showed low robustness to indirect fish extinctions (R = 0.31 and R = 0.57, respectively). Projections of 100% coral species loss caused a reduction of 69% of the regional trait space area. The effects of coral loss in Southwestern Atlantic reefs went beyond the direct coral-fish relationships. Ever-growing human impacts on reef ecosystems can cause extinction cascades with detrimental consequences for fish assemblages that benefit from corals.


Assuntos
Biodiversidade , Mudança Climática , Recifes de Corais , Extinção Biológica , Peixes , Animais , Peixes/fisiologia , Antozoários/fisiologia
4.
Environ Manage ; 73(3): 634-645, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38006452

RESUMO

Ecosystem services (ES) embrace contributions of nature to human livelihood and well-being. Reef environments provide a range of ES with direct and indirect contributions to people. However, the health of reef environments is declining globally due to local and large-scale threats, affecting ES delivery in different ways. Mapping scientific knowledge and identifying research gaps on reefs' ES is critical to guide their management and conservation. We conducted a systematic assessment of peer-reviewed articles published between 2007 and 2022 to build an overview of ES research on reef environments. We analyzed the geographical distribution, reef types, approaches used to assess ES, and the potential drivers of change in ES delivery reported across these studies. Based on 115 articles, our results revealed that coral and oyster reefs are the most studied reef ecosystems. Cultural ES (e.g., subcategories recreation and tourism) was the most studied ES in high-income countries, while regulating and maintenance ES (e.g., subcategory life cycle maintenance) prevailed in low and middle-income countries. Research efforts on reef ES are biased toward the Global North, mainly North America and Oceania. Studies predominantly used observational approaches to assess ES, with a marked increase in the number of studies using statistical modeling during 2021 and 2022. The scale of studies was mostly local and regional, and the studies addressed mainly one or two subcategories of reefs' ES. Overexploitation, reef degradation, and pollution were the most commonly cited drivers affecting the delivery of provisioning, regulating and maintenance, and cultural ES. With increasing threats to reef environments, the growing demand for assessing the contributions to humans provided by reefs will benefit the projections on how these ES will be impacted by anthropogenic pressures. The incorporation of multiple and synergistic ecosystem mechanisms is paramount to providing a comprehensive ES assessment, and improving the understanding of functions, services, and benefits.


Assuntos
Antozoários , Ecossistema , Animais , Humanos , Recifes de Corais , Conservação dos Recursos Naturais/métodos , Antozoários/fisiologia , Modelos Estatísticos
5.
Nature ; 549(7670): 82-85, 2017 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-28854164

RESUMO

Studies on the distribution and evolution of organisms on oceanic islands have advanced towards a dynamic perspective, where terrestrial endemicity results from island geographical aspects and geological history intertwined with sea-level fluctuations. Diversification on these islands may follow neutral models, decreasing over time as niches are filled, or disequilibrium states and progression rules, where richness and endemism rise with the age of the archipelago owing to the splitting of ancestral lineages (cladogenesis). However, marine organisms have received comparatively little scientific attention. Therefore, island and seamount evolutionary processes in the aquatic environment remain unclear. Here we analyse the evolutionary history of reef fishes that are endemic to a volcanic ridge of seamounts and islands to understand their relations to island evolution and sea-level fluctuations. We also test how this evolutionary history fits island biogeography theory. We found that most endemic species have evolved recently (Pleistocene epoch), during a period of recurrent sea-level changes and intermittent connectivity caused by repeated aerial exposure of seamounts, a finding that is consistent with an ephemeral ecological speciation process. Similar to findings for terrestrial biodiversity, our data suggest that the marine speciation rate on islands is negatively correlated with immigration rate. However, because marine species disperse better than terrestrial species, most niches are filled by immigration: speciation increases with the random accumulation of species with low dispersal ability, with few opportunities for in situ cladogenesis and adaptive radiation. Moreover, we confirm that sea-level fluctuations and seamount location play a critical role in marine evolution, mainly by intermittently providing stepping stones for island colonization.


Assuntos
Organismos Aquáticos/isolamento & purificação , Biodiversidade , Peixes/fisiologia , Ilhas , Filogeografia , Animais , Organismos Aquáticos/fisiologia , Oceano Atlântico , Evolução Biológica , Brasil , Recifes de Corais
6.
J Fish Biol ; 103(2): 324-335, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37169731

RESUMO

Density-dependent mechanisms and habitat use are important drivers of marine spatial distribution in complex ecosystems such as coral or rocky reefs. In the last decade, a few studies have assessed habitat use by reef fishes in nearshore and coastal environments along the Brazilian coast. Serranidae (groupers and sea basses) are regarded as excellent models for understanding habitat use patterns due to their diversity, long lifespan, wide distribution, morphological and functional diversity, and behavioural complexity. Their trophic position in the food web, from meso- to top-predators, grants them critical roles as top-down population controllers. Herein, we present the first assessment of habitat use by five sympatric Serranidae in a Brazilian oceanic island, Trindade. The model species selected for this assessment were the coney (Cephalopholis fulva), the rock hind (Epinephelus adscensionis), the greater soapfish (Rypticus saponaceus), the Creole-fish (Paranthias furcifer) and the hybrid between C. fulva and P. furcifer. Our findings revealed that the species showed specific associations with topographic characteristics related to shelter from predation, reproduction and feeding. Habitat use in Trindade was similar to that observed in nearshore coastal environments (where the hybrid is absent). The present work contributes to the knowledge of habitat use and niche partitioning among key species, which is a valuable tool to subsidize effective conservation initiatives such as designing marine protected areas focusing on the behaviour and habitat use of key ecological players.


Assuntos
Antozoários , Bass , Animais , Ecossistema , Comportamento Predatório , Peixes , Cadeia Alimentar , Recifes de Corais
7.
J Fish Biol ; 101(1): 179-189, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35538668

RESUMO

The red porgy (Pagrus pagrus) is a carnivore bottom dweller sparid, inhabiting flat sandy bottoms, rhodolith and seagrass beds of the Mediterranean Sea, the Western Atlantic (from Florida to Argentina) and the Eastern Atlantic (from Britain to Gabon). Along its native range, the red porgy is highly targeted by commercial and artisanal fisheries. In the past 40 years, the population decline of the species has been widely reported. In many locations, such as the Brazilian coast, stocks have collapsed. The central portion of the Brazilian coast harbours the largest rhodolith beds in the world and the highest levels of nektonic and benthic biodiversity. Along the rhodolith megahabitat, P. pagrus density is disproportionately higher (by 480%) than that of conspicuous benthic fishes inhabiting the same environment. Despite the ecological and economic importance of such an important species along its native range, little is known regarding its habitat use, niche availability and population responses to global warming. Here we present habitat affinities based on data sampled using baited remote stereo-video systems, and modelled niche availability and global warming populational responses. Our findings reveal that the red porgy is a species highly associated with rhodolith beds along the central portion of the Brazilian coast. The presence of a disproportional density and biomass of the red porgy, compared to other marine fish species, indicates that the species plays a key ecological role as a carnivore, mesoconsumer and prey/predator tolerant species, maintaining essential ecological functions in the habitat. In a global warming scenario, the model predicted populational niche shifts poleward and a severe niche erosion at lower latitudes as expected. Conservation initiatives (implementation of Maine Protected Areas, trawling exclusion zones, mining exclusion zones, fisheries management policies) are urgent to secure future stocks of the red porgy and also preserve the fragile rhodolith beds they inhabit.


Assuntos
Ecossistema , Perciformes , Animais , Biodiversidade , Peixes , Mar Mediterrâneo
8.
J Environ Manage ; 311: 114838, 2022 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-35279488

RESUMO

Marine Protected Areas (MPAs) are a widely used tool for coral reefs conservation, but massive tourism activities inside MPAs worldwide can challenge their effectiveness. This study investigated the role of different levels of protection strictness (no-entry, low and high tourism-allowed zones) set for a marine sanctuary in shaping benthic cover and reef fish community structure in the richest and largest coral reef system of the Southwestern Atlantic. Reef fish community structure and benthic cover differed between protection levels. No-entry zones showed significant higher coral coverage and biomass of piscivores and herbivores than tourism-allowed zones. Highest differences were found between no-entry and high tourism intensity zones. Despite the fact that protection from fishing by itself can ensure conservation benefits, we show here that the establishment of no-entry zones improve MPAs effectiveness.

9.
Clin Radiol ; 76(8): 571-575, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34092363

RESUMO

AIM: To establish if detailed review of trauma reports with reference to coding manual improved accuracy of ISS and to establish if demonstrated changes in coding affected performance and tariff payment. MATERIALS AND METHODS: A study was undertaken which gathered data from 6 months across the five trusts with information on imaging undertaken, mechanism of injury (MOI), Injury Severity Score (ISS), and injury descriptors was included. Patients with ISS near to a best practice tariff boundary of 9 and 16 (5-8 and 11-15) then had their imaging reviewed by the Radiology Department with direct reference to the ISS coding manual. Injuries were then re-coded and ISS recalculated. RESULTS: Over the 6-month period, 1,693 patients were admitted to the database from the five hospitals. One hundred and sixty-nine (9.9%) patients met the inclusion criteria for review. Thirty-five (20.7%) had a change in abbreviated (region specific) injury code, with 30 a change in the resultant ISS. Three had a decrease in ISS and 27 increased ISS with all 27 moving across an ISS best practice tariff and three moving across two payment tariff boundaries. With re-coding, there was a potential £15,000 of lost revenue from the major trauma centre (MTC) alone. CONCLUSION: Reporting with reference to ISS description improves the accuracy of ISS significantly. Radiologists improving the descriptions of specific injury patterns and adopting 'Trauma Audit and Research Network friendly' reporting strategies may improve data accuracy, performance, and payment of best practice tariffs to hospitals.


Assuntos
Escala de Gravidade do Ferimento , Radiologistas/normas , Ferimentos e Lesões/diagnóstico por imagem , Bases de Dados Factuais/estatística & dados numéricos , Humanos , Radiologistas/economia , Reprodutibilidade dos Testes , Tomografia Computadorizada por Raios X/métodos , Reino Unido , Ferimentos e Lesões/economia
10.
J Fish Biol ; 97(4): 1143-1153, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32743800

RESUMO

Saint Peter and Saint Paul's Archipelago (SPSPA), one of the smallest and most isolated island groups in the world, is situated on the Mid-Atlantic Ridge, between Brazil and the African continent. SPSPA has low species richness and high endemism; nonetheless, the diversity of fishes from deep habitats (>30 m depth) had not been previously studied in detail. Several expeditions conducted between 2009 and 2018 explored the shallow and deep reefs of SPSPA using scuba, closed-circuit rebreathers, manned submersibles, baited remote underwater stereo-videos (stereo-BRUV) and fishing between 0 and 1050 m depth. These expeditions yielded 41 new records of fishes for SPSPA: 9 in open waters, 9 in shallow waters (0-30 m), 8 in mesophotic ecosystems (30-150 m) and 15 in deeper reefs (>150 m). Combined with literature records of adult pelagic, shallow and deep-reef species, as well as larvae, the database of the fish biodiversity for SPSPA currently comprises 225 species (169 recorded as adult fishes and 79 as larvae, with 23 species found in both stages). Most of them (112) are pelagic, 86 are reef-associated species and 27 are deep-water specialists. Species accumulation curves show that the number of fish species has not yet reached an asymptote. Whereas the number of species recorded in SPSPA is similar to that in other oceanic islands in the Atlantic Ocean, the proportion of shorefishes is relatively lower, and the endemism level is the third highest in the Atlantic. Twenty-nine species are listed as threatened with extinction. Observations confirm the paucity of top predators on shallow rocky reefs of the island, despite the presence of several pelagic shark species around SPSPA. Because all of the endemic species are reef associated, it is argued that the new marine-protected areas created by the Brazilian government do not ensure the protection and recovery of SPSPA's biodiversity because they allow exploitation of the most vulnerable species around the archipelago itself. This study suggests a ban on reef fish exploitation inside an area delimited by the 1000 m isobath around the islands (where all known endemics are concentrated) as the main conservation strategy to be included in the SPSPA management plan being prepared by the Brazilian government.


Assuntos
Biodiversidade , Bases de Dados Factuais , Peixes/classificação , Animais , Oceano Atlântico , Brasil , Recifes de Corais , Ecossistema , Ilhas , Tubarões
11.
Prostate ; 75(13): 1376-83, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26047130

RESUMO

BACKGROUND: African-American (AA) men experience higher rates of prostate cancer (PCa) and vitamin D (vitD) deficiency than white men. VitD is promoted for PCa prevention, but there is conflicting data on the association between vitD and PCa. We examined the association between serum vitD and dietary quercetin and their interaction with PCa risk in AA men. METHODS: Participants included 90 AA men with PCa undergoing treatment at Howard University Hospital (HUH) and 62 controls participating in HUH's free PCa screening program. We measured serum 25-hydroxy vitD [25(OH)D] and used the 98.2 item Block Brief 2000 Food Frequency Questionnaires to measure dietary intake of quercetin and other nutrients. Case and control groups were compared using a two-sample t-test for continuous risk factors and a Fisher exact test for categorical factors. Associations between risk factors and PCa risk were examined via age-adjusted logistic regression models. RESULTS: Interaction effects of dietary quercetin and serum vitD on PCa status were observed. AA men (age 40-70) with normal levels of serum vitD (>30 ng/ml) had a 71% lower risk of PCa compared to AA men with vitD deficiency (OR = 0.29, 95%CI: 0.08-1.03; P = 0.055). In individuals with vitD deficiency, increased dietary quercetin showed a tendency toward lower risk of PCa (OR = 0.91, 95%CI: 0.82-1.00; P = 0.054, age-adjusted) while men with normal vitD were at elevated risk (OR = 1.23, 95%CI: 1.04-1.45). CONCLUSION: These findings suggest that AA men who are at a higher risk of PCa may benefit more from vitD intake, and supplementation with dietary quercetin may increase the risk of PCa in AA men with normal vitD levels. Further studies with larger populations are needed to better understand the impact of the interaction between sera vitD levels and supplementation with quercetin on PCa in AA men.


Assuntos
Negro ou Afro-Americano , Dieta , Neoplasias da Próstata/etnologia , Quercetina/administração & dosagem , Vitamina D/sangue , Adulto , Idoso , Suplementos Nutricionais , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias da Próstata/sangue , Neoplasias da Próstata/prevenção & controle , Risco
12.
J Occup Environ Med ; 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38913827

RESUMO

OBJECTIVE: This paper aims to review the risks associated with using lentiviral and retroviral vectors in research and clinical settings and to propose an update to an effective treatment plan. METHODS: Risks of exposure were evaluated based on vector design, safety features, viral tropism, transgene, and means and modes of transmission. These risks were weighed against the potential risks and benefits of current HIV medications. RESULTS: We recommend the following post-exposure prophylactic treatment for significant lentiviral vector exposures: 1) dolutegravir 50 mg. taken once a day for 7 days; and 2) tenofovir disoproxil fumarate 300 mg. taken once a day for 7 days (28 days of both medications for replication-competent vectors). CONCLUSIONS: Due to the highly efficient delivery of transgenes by modern lentiviral and retroviral vectors, post-exposure prophylaxis is indicated to prevent vector integration and oncogenic risks.

13.
Poult Sci ; 103(6): 103753, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38652947

RESUMO

The formation of Campylobacter jeuni biofilms on processing surfaces is a significant concern in poultry processing, contributing to food safety risks. This study focused on assessing the biofilm forming capabilities of 12 field isolates of C. jejuni of different aerotolerance categories on stainless steel surfaces, a prevalent material in poultry processing environments. Working cultures of each isolate were prepared to approximately 6 log CFU/mL and incubated on stainless steel coupons under microaerobic or aerobic conditions at room temperature or 42°C for 72 h. Biofilm attached cells were enumerated using direct plating and biofilm density was measured using a crystal violet assay by measuring the optical density (OD600) a. Data analysis was conducted using the PROC GLIMMIX procedure in SAS 9.4 with a significance level of 0.05. The study revealed a notable interaction between aerotolerance categories and temperature (P < 0.039) impacting the number of biofilms attached C. jejuni cells on stainless steel coupons. All isolates had significantly higher counts when incubated at 42°C compared to room temperature, regardless of oxygen level (P < 0.001). Furthermore, stronger biofilm density was observed at 42°C compared to room temperature, regardless of oxygen level. These findings underscore the influence of temperature on the biofilm forming ability of C. jejuni. The ability of these field isolates to form biofilms under various environmental conditions suggests a heightened potential for surface colonization and increased infection risk in poultry processing facilities.


Assuntos
Biofilmes , Campylobacter jejuni , Aço Inoxidável , Temperatura , Campylobacter jejuni/fisiologia , Aerobiose , Animais , Microbiologia de Alimentos
14.
Cancer Discov ; 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39109936

RESUMO

Oncogene amplification on extrachromosomal DNA (ecDNA) is a pervasive driver event in cancer, yet our understanding of how ecDNA forms is limited. Here, we couple a CRISPR-based method for ecDNA induction with extensive characterization of newly formed ecDNA to examine their biogenesis. We find that DNA circularization is efficient, irrespective of 3D genome context, with formation of 800kb, 1 Mb, and 1.8 Mb ecDNAs reaching or exceeding 15%. We show non-homologous end joining and microhomology-mediated end joining both contribute to ecDNA formation, while inhibition of DNA-PKcs and ATM have opposing impacts on ecDNA formation. EcDNA and the corresponding chromosomal excision scar can form at significantly different rates and respond differently to DNA-PKcs and ATM inhibition. Taken together, our results support a model of ecDNA formation in which double strand break ends dissociate from their legitimate ligation partners prior to joining of illegitimate ends to form the ecDNA and excision scar.

15.
J Intern Med ; 274(5): 440-50, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23751076

RESUMO

Genomic variation, through effects on gene structure and expression, plays an important role in understanding disease predisposition, biology and clinical response to therapy. Transforming this knowledge into clinically relevant information that tailors interventions to an individual's specific genetic, physical, social and environmental profile is challenging. To illustrate how research initiatives at preclinical phases of development are attempting to address clinically important issues in oncology, six clinical problems related to cancers of the colon, prostate, breast, pancreas and brain (medulloblastoma) as well as metastatic disease of different origins are described. A unifying theme across applications is that healthy individuals previously indistinguishable in regards to cancer risk and patients with cancer previously categorized as similar with regard to prognosis or drug response are being stratified into more refined subgroups with different clinical profiles. Effective matching of a broad range of tests with more tailored strategies for prevention and/or treatment will require well-designed clinical studies to evaluate benefits and costs.


Assuntos
Variação Genética/genética , Neoplasias/genética , Medicina de Precisão/métodos , Neoplasias Cerebelares/genética , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/genética , Detecção Precoce de Câncer , Predisposição Genética para Doença/genética , Humanos , Masculino , Meduloblastoma/genética , Metástase Neoplásica/genética , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/mortalidade , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/genética , Sobreviventes
16.
Spinal Cord ; 51(2): 156-60, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22824860

RESUMO

STUDY DESIGN: Retrospective study. OBJECTIVES: The purpose of this investigation was to review the outcomes and safety of retrograde ureteroscopic laser lithotripsy (URS) for the treatment of urolithiasis in the spinal cord injury (SCI) population. SETTING: Virginia, USA. METHODS: All patients with SCI who underwent URS with holmium:YAG laser lithotripsy for urolithiasis over a 15-year period were identified. Stone size, location and number at presentation were recorded. Information regarding patient characteristics, intra-operative complications, surgical efficacy, stone clearance, peri-operative complications, and follow-up stone events was collected and analyzed. RESULTS: A total of 67 URS procedures were performed on 29 SCI patients during the study period with an average follow-up of 3.4 years. Patients had an average of 2.3 ipsilateral ureteroscopies. The majority (85.1%) used indwelling catheters for long-term bladder management, and complete stone clearance after the first procedure was 34.3%. Of the 44 cases with residual stones >4 mm, 20 (45.5%) were secondary to technical or procedural limitations. The intra-operative complication rate was comparable to non-SCI studies at 1.5%, but peri-operative complications were significantly higher at 29.9% with the majority due to urosepsis. Factors associated with peri-operative complications include chronic obstructive pulmonary disease, motor incomplete injuries and lack of a pre-operative ureteral stent. CONCLUSION: URS in the SCI population is an effective treatment for ureteral or renal stones but may be associated with greater risks and reduced efficacy.


Assuntos
Traumatismos da Medula Espinal/complicações , Urolitíase/complicações , Urolitíase/terapia , Adulto , Humanos , Lasers de Estado Sólido , Litotripsia a Laser/efeitos adversos , Litotripsia a Laser/métodos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento , Ureteroscopia/efeitos adversos , Ureteroscopia/métodos
17.
Nat Genet ; 4(2): 135-9, 1993 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8348150

RESUMO

Expansion of trinucleotide repeats can give rise to genetic disease. We have developed a technique, repeat expansion detection (RED), that can identify potentially pathological repeat expansion without prior knowledge of chromosomal location. Human genomic DNA is used as a template for a two-step cycling process that generates oligonucleotide multimers when expanded trinucleotide sequences are present at the level found in myotonic dystrophy and fragile-X patients. We have identified at least one new locus exhibiting trinucleotide expansion. Analysis of three families transmitting a long CTG repeat shows that the allele in these families corresponds to a locus on chromosome 18. RED constitutes a powerful tool to identify other diseases caused by this mechanism, particularly diseases associated with anticipation.


Assuntos
Cromossomos Humanos Par 18 , Análise Mutacional de DNA/métodos , Amplificação de Genes , Genoma Humano , Oligonucleotídeos , Sequências Repetitivas de Ácido Nucleico , DNA Ligases , Síndrome do Cromossomo X Frágil/genética , Testes Genéticos , Humanos , Escore Lod , Distrofia Miotônica/genética , Desnaturação de Ácido Nucleico , Hibridização de Ácido Nucleico , Linhagem , Moldes Genéticos
18.
Nat Genet ; 29(2): 229-32, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11586305

RESUMO

Linkage disequilibrium (LD) analysis is traditionally based on individual genetic markers and often yields an erratic, non-monotonic picture, because the power to detect allelic associations depends on specific properties of each marker, such as frequency and population history. Ideally, LD analysis should be based directly on the underlying haplotype structure of the human genome, but this structure has remained poorly understood. Here we report a high-resolution analysis of the haplotype structure across 500 kilobases on chromosome 5q31 using 103 single-nucleotide polymorphisms (SNPs) in a European-derived population. The results show a picture of discrete haplotype blocks (of tens to hundreds of kilobases), each with limited diversity punctuated by apparent sites of recombination. In addition, we develop an analytical model for LD mapping based on such haplotype blocks. If our observed structure is general (and published data suggest that it may be), it offers a coherent framework for creating a haplotype map of the human genome.


Assuntos
Genoma Humano , Haplótipos , Sequência de Bases , Cromossomos Humanos Par 5 , DNA , Humanos , Desequilíbrio de Ligação , Cadeias de Markov , Dados de Sequência Molecular , Polimorfismo de Nucleotídeo Único
19.
Nat Genet ; 22(4): 384-7, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10431245

RESUMO

Radiation hybrid (RH) maps are a useful tool for genome analysis, providing a direct method for localizing genes and anchoring physical maps and genomic sequence along chromosomes. The construction of a comprehensive RH map for the human genome has resulted in gene maps reflecting the location of more than 30,000 human genes. Here we report the first comprehensive RH map of the mouse genome. The map contains 2,486 loci screened against an RH panel of 93 cell lines. Most loci (93%) are simple sequence length polymorphisms (SSLPs) taken from the mouse genetic map, thereby providing direct integration between these two key maps. We performed RH mapping by a new and efficient approach in which we replaced traditional gel- or hybridization-based assays by a homogeneous 5'-nuclease assays involving a single common probe for all genetic markers. The map provides essentially complete connectivity and coverage across the genome, and good resolution for ordering loci, with 1 centiRay (cR) corresponding to an average of approximately 100 kb. The RH map, together with an accompanying World-Wide Web server, makes it possible for any investigator to rapidly localize sequences in the mouse genome. Together with the previously constructed genetic map and a YAC-based physical map reported in a companion paper, the fundamental maps required for mouse genomics are now available.


Assuntos
Técnicas Genéticas , Genoma , Camundongos/genética , Mapeamento Físico do Cromossomo , Animais , Escore Lod , Modelos Genéticos , Modelos Estatísticos , Polimorfismo Genético
20.
Nat Genet ; 28(1): 87-91, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11326283

RESUMO

The genetics of asthma and atopy have been difficult to determine because these diseases are genetically heterogeneous and modified by environment. The pedigrees in our study (n=86) originate in eastern central Finland (Kainuu province). According to census records, this region had only 200 households (2,000 inhabitants) in the mid sixteenth to mid seventeenth centuries. The current population of 100,000 represents the expansion of these founders within the past 400 years. Because this population is relatively homogeneous, we hypothesized that the molecular genetic mechanisms underlying asthma might also have reduced heterogeneity and therefore be easier to dissect than in mixed populations. A recent twin family study supported a strong genetic component for asthma in Finland. We carried out a genome-wide scan for susceptibility loci in asthma in the Kainuu subpopulation. We identified two regions of suggestive linkage and studied them further with higher-density mapping. We obtained evidence for linkage in a 20-cM region of chromosome 7p14-p15 for three phenotypes: asthma, a high level of immunoglobulin E (IgE; atopy) and the combination of the phenotypes. The strongest linkage was seen for high serum IgE (non-parametric linkage (NPL) score 3.9, P=0.0001), exceeding the threshold for genome-wide significance based on simulations. We also observed linkage between this locus and asthma or atopy in two independent data sets.


Assuntos
Asma/genética , Cromossomos Humanos Par 7/genética , Efeito Fundador , Hipersensibilidade Imediata/genética , Asma/epidemiologia , Mapeamento Cromossômico , Feminino , Finlândia/epidemiologia , Ligação Genética , Marcadores Genéticos , Predisposição Genética para Doença , Genoma Humano , Humanos , Hipersensibilidade Imediata/epidemiologia , Imunoglobulina E , Masculino , Linhagem
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