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1.
Eur J Case Rep Intern Med ; 10(12): 004119, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38077712

RESUMEN

Drug-induced liver injury (DILI) is a liver condition caused by any drug or toxic substance. The spectrum of DILI manifestations can range from asymptomatic elevation of liver enzymes to acute liver failure. Antibiotics are one of the major causes of DILI. The authors report the case of a 37-year-old male with nausea, right hypochondrium pain and fever with history of bismuth subcitrate, metronidazole and tetracycline combination treatment in the previous five days. DILI was suspected and other aetiologies of acute hepatitis were excluded such as viral, autoimmune or even haemochromatosis and Wilson's disease. Liver biopsy was performed, being compatible with the diagnosis of DILI; DILI is a diagnosis of exclusion. Bismuth subcitrate, metronidazole and tetracycline combination treatment is a rare cause of DILI. LEARNING POINTS: Bismuth subcitrate, metronidazole and tetracycline in combination is a rare cause of drug-induced liver injury (DILI).DILI is an exclusion diagnosis.Liver biopsy has an important role in the diagnosis of DILI.

2.
Eur J Case Rep Intern Med ; 10(9): 003848, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37680782

RESUMEN

Overall gastric cancer incidence is decreasing, but incidence of gastric signet ring cell carcinoma has been rising. The diagnosis can be challenging. It has a poorer prognosis because it tends to be diagnosed at advanced stages. Lymphedema is a rare presentation. We report a rare presentation of signet ring cell carcinoma in a 49-year old male, with no underlying medical condition. The patient presented with lymphedema of lower limbs, scrotum and abdominal wall. LEARNING POINTS: Signet ring cell carcinoma tends to have an infiltrative behavior. Endoscopic analysis may not lead to any macroscopic finding.In highly suspicious cases, endoscopic exploration should be complemented with an endoscopic ultrasound or blind random biopsies.

3.
R Soc Open Sci ; 10(9): 230392, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37771965

RESUMEN

The ecological state of the Persian or Arabian Gulf (hereafter 'Gulf') is in sharp decline. Calls for comprehensive ecosystem-based management approaches and transboundary conservation have gone largely unanswered, despite mounting marine threats made worse by climate change. The region's long-standing political tensions add additional complexity, especially now as some Gulf countries will soon adopt ambitious goals to protect their marine environments as part of new global environmental commitments. The recent interest in global commitments comes at a time when diplomatic relations among all Gulf countries are improving. There is a window of opportunity for Gulf countries to meet global marine biodiversity conservation commitments, but only if scientists engage in peer-to-peer diplomacy to build trust, share knowledge and strategize marine conservation options across boundaries. The Gulf region needs more ocean diplomacy and coordination; just as critically, it needs actors at its science-policy interface to find better ways of adapting cooperative models to fit its unique marine environment, political context and culture. We propose a practical agenda for scientist-led diplomacy in the short term and lines of research from which to draw (e.g. co-production, knowledge exchange) to better design future science diplomacy practices and processes suited to the Gulf's setting.

4.
Mar Pollut Bull ; 188: 114655, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36764146

RESUMEN

Levels of organic contaminants (TPHs, PAHs) were simultaneously determined in both abiotic (sediments, seawater) and biotic (Pinctada radiata oysters) samples at four sites along the coastline of Qatar (Arabian Gulf) in 2017-2018. TPHs and PAHs were more frequently detected in oyster tissues than sediment and seawater samples collected from the same areas. While levels of TPHs and PAHs in seawater and sediments were lower than previous local studies and worldwide studies, PAHs levels observed in pearl oyster tissue (25.9-2240 µg/kg) were relatively higher than in previous studies in Qatar. In general, eight PAHs compounds were detected in oyster tissue, with benzo(a)pyrene displaying the highest concentration. The coast of Qatar could be affected by seasonal patterns of pollutants, where TPHs and PAHs levels increased in winter compared to summer. These results provide key information on the use of the pearl oyster as a bioindicator species and Qatar's marine environment.


Asunto(s)
Ostreidae , Petróleo , Hidrocarburos Policíclicos Aromáticos , Contaminantes Químicos del Agua , Animales , Monitoreo del Ambiente/métodos , Sedimentos Geológicos , Qatar , Contaminantes Químicos del Agua/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Hidrocarburos
5.
Artículo en Inglés | MEDLINE | ID: mdl-36429383

RESUMEN

As society tries to tackle climate change around the globe, communities need to reduce its impact on human health. The purpose of this review is to identify key stakeholders involved in mitigating and adapting to climate change, as well as the type and characteristics of community empowerment actions implemented so far to address the problem. Published and unpublished studies from January 2005 to March 2022 in English and Portuguese were included in this review. The search, conducted on PubMed, CINAHL, Scopus, MEDLINE, Scopus, Web of Science, SciELO, and RCAAP (Repositório Científico de Acesso Aberto de Portugal), followed a three-step search strategy. Data extraction was performed by two independent reviewers, using an extraction tool specifically designed for the review questions. Twenty-seven studies were eligible for inclusion: six used interviews as a qualitative method, three were systematic reviews, three were case study analyses, three used surveys and questionnaires as quantitative methods, two used integrative baseline reviews, and three utilized a process model design. Six studies targeted local, public and private stakeholders. Community settings were the context target of fifteen studies, whereas twelve specifically referred to urban settings. Seven types of community actions were acknowledged across the globe, characterised as hybrid interventions and referring to the leading stakeholders: local governments, non-governmental organizations, civil society, universities, public health, and private sectors.


Asunto(s)
Cambio Climático , Salud Pública , Humanos , Salud Pública/métodos , Gobierno Local , Participación de la Comunidad , Portugal
6.
Animals (Basel) ; 12(18)2022 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-36139303

RESUMEN

Streptococcosis, particularly that caused by S. iniae and S. agalactiae, is a major re-emerging bacterial disease seriously affecting the global sustainability of aquaculture development. Despite a wide spread of the disease in aquaculture, few studies have been directed at assessing the in vitro antagonistic activity and in vivo efficacy of medicinal herbs and other plants against streptococcal agents. Most in vitro studies of plant extractives against S. iniae and S. agalactiae have found antibacterial activity, but essential oils, especially those containing eugenol, carvacrol or thymol, are more effective. Although essential oils have shown better anti-streptococcal activity in in vitro assays, in vivo bioassays require more attention. The extracts examined under in vivo conditions show moderate efficacy, increasing the survival rate of infected fish, probably through the enhancement of immunity before challenge bioassays. The available data, however, lack dosage optimization, toxicity and bioavailability assays of a specific plant or its bioactive compound in fish organs; hence, it is difficult to judge the validation of clinical efficacy for the prevention or treatment of fish streptococcosis. Despite the known bioactive compounds of many tested plants, few data are available on their mode of action towards streptococcal agents. This review addresses the efficacy of medicinal plants to fish streptococcosis and discusses the current gaps.

7.
Sci Total Environ ; 774: 145043, 2021 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-33609843

RESUMEN

In recent years, high resolution mass spectrometry (HRMS) combined with separation techniques has allowed comprehensive analysis of contaminants of emerging concern (CECs) as well as their metabolites and transformation products in various environmental samples via retrospective screening. However, to date, only a few suspect or non-targeted studies on the occurrence of CECs in marine aquatic system are reported. In this study, two methods, based on direct injection for seawater, or ultrasound-assisted extraction for sediments, followed by LC-Q-TOF-MS analysis were developed and applied for the simultaneous targeted and screening of contaminants in coastal samples (seawater, particulates and sediment) from Qatar collected in 2017-2018. Among the twenty-one target analytes (pesticides, PPCPs and a plasticizer), two compounds only were detected in seawater. Caffeine was detected in seawater samples at all sampling sites, and cotinine was detected in seawater samples collected in Umm Bab in 2018 and seawaters receiving stormwater. Traces of trimethoprim and carbamazepine were detected in sediment samples collected at four sites in 2017. These results suggest some inputs of domestic wastewater in the coastal waters in Qatar. In total, twelve molecular features were tentatively identified from suspect screening at concentration levels significantly higher than that in procedure blanks. The presence of four plasticizers and one pesticide were further confirmed using reference standards: diethyl phthalate (DEP), dibutyl phthalate (DBP), and tributyl phosphate (TBP) in seawater samples; bis(2-ethylhexyl) phthalate (DEHP) in sediment and particulate samples; and dinoterb in seawater after storm event and particulate samples. Overall, this study demonstrated the potential of high resolution LC-Q-TOF-MS/MS for combined targeted and non-targeted analyses of trace contaminants in marine systems over a broad range of log P values.


Asunto(s)
Monitoreo del Ambiente , Contaminantes Químicos del Agua , Qatar , Estudios Retrospectivos , Agua de Mar , Espectrometría de Masas en Tándem , Agua , Contaminantes Químicos del Agua/análisis
8.
PLoS One ; 15(5): e0232205, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32401792

RESUMEN

This study presents the taxonomic description of two new sponge species that are intimately associated with the hyperarid mangrove ecosystem of Qatar. The study includes a preliminary evaluation of the sponges' potential bioactivity against pathogens. Chalinula qatari sp. nov. is a fragile thinly encrusting sponge with a vivid maroon colour in life, often with oscular chimneys and commonly recorded on pneumatophores in the intertidal and shallow subtidal zone. Suberites luna sp. nov. is a massive globular-lobate sponge with a greenish-black colour externally and a yellowish orange colour internally, recorded on pneumatophores in the shallow subtidal zone, with large specimens near the seagrass ecosystem that surrounds the mangrove. For both species, a drug extraction protocol and an antibacterial experiment was performed. The extract of Suberites luna sp. nov. was found to be bioactive against recognized pathogens such as Staphylococcus epidermidis, Staphylococcus aureus and Enterococcus faecalis, but no bioactive activity was recorded for Chalinula qatari sp. nov. This study highlights the importance of increasing bioprospecting effort in hyperarid conditions and the importance of combining bioprospecting with taxonomic studies for the identification of novel marine drugs.


Asunto(s)
Antibacterianos , Ecosistema , Poríferos/clasificación , Animales , Sequías , Qatar
9.
Mar Genomics ; 51: 100734, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31818705

RESUMEN

The pearl oyster Pinctada imbricata radiata is an iconic species in Qatar, representing an integral part of the nation's cultural heritage and one of the main economic foundations upon which the nation developed. During the early part of the 20th century, nearly half the Qatar population was involved in the pearl oyster industry. However, the fishery has undergone steady decline since the 1930s, and the species is now under threat due to multiple confounding pressures. This manuscript presents the first de novo transcriptome of the Qatari pearl oyster assembled into 30,739 non-redundant coding sequences and with a BUSCO completeness score of 98.4%. Analysis of the transcriptome reveals the close evolutionary distance to the conspecific animal Pinctada imbricata fucata but also highlights differences in immune genes and the presence of distinctive transposon families, suggesting recent adaptive divergence. This data is made available for all to utilise in future studies on the species.


Asunto(s)
Pinctada/genética , Transcriptoma , Animales , Qatar
10.
Environ Pollut ; 253: 841-849, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31349193

RESUMEN

A rapid method based on solvent extraction followed by direct injection in liquid chromatography-quadrupole-time-of-flight-mass spectrometry (LC-Q-TOF-MS) was developed for the targeted and suspect screening of contaminants in the soft tissues of the pearl oyster Pinctada imbricata radiata. The quantification method was first validated for the targeted analysis of 21 contaminants including some pharmaceutically active compounds, with the relative recoveries ranging from 88 to 123%, and method detection limits generally below 1 ng g-1 on the wet weight (ww) basis. This targeted analysis method was then applied to oyster samples collected around the Qatari coast between 2017/2018, and none of the 21 compounds were detected in these samples. The post-acquisition data treatment based on the accurate mass measurement in both full MS scan and All Ions MS/MS was further used for mining other contaminants in oyster extracts, as well as 21 targeted compounds spiked in oyster extracts (suspect screening). The 21 spiked compounds were identified successfully and the estimated limit of identification for the individual 21 compounds ranged from 0.5 to 117 ng g-1 ww of oyster tissues. A phthalate, di(2-ethylhexyl) phthalate (DEHP) was identified to be present in oyster extracts from 2018 batches, at a concentration level significantly higher than that in procedure blanks. These results confirmed that high resolution MS data obtained using the targeted method can be exploited through suspect screening workflows to identify contaminants in the tissues of bioindicator mollusks. However, a number of false identifications could be obtained and future work will be on improving the success rate of the correct identifications using this workflow.


Asunto(s)
Monitoreo del Ambiente/métodos , Pinctada/metabolismo , Contaminantes Químicos del Agua/metabolismo , Animales , Cromatografía Liquida/métodos , Moluscos , Espectrometría de Masas en Tándem/métodos
11.
PLoS One ; 14(5): e0215865, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31042736

RESUMEN

A number of molluscs within the Class Bivalvia are defined by their ability to secrete fine silk like threads known as byssus which are used to anchor themselves to solid substrates. With relatively few exceptions the majority of these species remain in a sedentary state throughout their life attached via their byssal threads. However, observations of adult Pinctada imbricata radiata pearl oysters made during this study revealed this species' ability to implement active movement. Byssal threads were secreted in a sequence of attachment and detachment phases, which resulted in the active displacement of the oyster. The oyster was observed, in the laboratory over a 9 day period, travelling a distance of 28cm in a horizontal path. After horizontal displacement, a vertical climbing phase was observed until the oyster reached the water surface at which point the byssus was discarded and the animal dropped, drifting in accordance with water current intensity. It is possible that these adaptations of byssal use are a result of environmentally induced evolutionary change within P. i. radiata.


Asunto(s)
Pinctada/fisiología , Seda/fisiología , Animales , Océano Índico , Locomoción
12.
Eur J Case Rep Intern Med ; 6(3): 001063, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30931281

RESUMEN

Bilateral deep vein thrombosis (DVT) should prompt investigation for pro-thrombotic conditions and the exclusion of vascular compromise due to intrinsic and extrinsic factors. The authors present the case of a 47-year-old man admitted with bilateral DVT and diagnosed with inferior vena cava (IVC) infra-renal segment agenesis, and discuss the management of this rare condition. LEARNING POINTS: Bilateral deep vein thrombosis in young and otherwise healthy individuals should prompt investigation of the aetiology and risk factors in case life-long treatment and anticoagulation therapy is required.Although rare, anatomical variations and congenital malformations should be considered even in adult patients.Rare medical cases should prompt a multidisciplinary approach to investigation and treatment, as prognosis will depend on both therapeutic procedures and anticipation of complications.

13.
Eur J Case Rep Intern Med ; 5(10): 000944, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30755979

RESUMEN

Boerhaave syndrome is rare, has an non-specific clinical presentation and most commonly develops after persistent vomiting. Septic shock dominates the clinical picture as a result of extensive infection of the mediastinum and pleural and abdominal cavities. The current management of Boerhaave syndrome includes conservative, endoscopic and surgical treatments. The authors present the case of a 94-year-old man admitted to hospital with community-acquired pneumonia with mild respiratory insufficiency complicated by oesophageal perforation after an episode of vomiting and the development of a large left pleural effusion. An endoscopic approach with the placement of an oesophageal prosthesis was chosen given the advanced age of the patient. The hospital stay was complicated by pleural effusion infection requiring broad-spectrum antibiotics and prosthesis substitution. The patient was discharged after 60 days of hospitalization, without the need for oxygen supplementation, and scoring 80% on the Karnofsky Performance Status Scale. The increase in average life expectancy requires a case-by-case approach, where the benefits of invasive manoeuvres and likelihood of discharge are weighed against an acceptable quality of life, aiming to prevent futile medical treatment. LEARNING POINTS: Boerhaave syndrome is a complete rupture of the oesophageal wall secondary to a sudden increase in intraluminal oesophageal pressure, often in the lower third and left lateral position of the oesophagus.The management of Boerhaave syndrome depends on the time of diagnosis and clinical presentation and includes conservative, endoscopic and surgical approaches.Curative, aggressive approaches focused on the treatment of disease are often not appropriate for an aging population, hence the need for a case-by-case approach, where the benefits of invasive manoeuvres and likelihood of discharge are weighed against an acceptable quality of life, aiming to prevent futile medical treatment.

14.
Intern Emerg Med ; 12(1): 63-68, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27497950

RESUMEN

Predictors of short-term readmission after ischemic stroke have been previously identified, but few studies analyzed predictors of long-term readmission, namely early imaging findings and treatment with intravenous thrombolysis (IVT). To characterize predictors of hospital readmission during the first year after hospitalization for ischemic stroke. The study consists of a retrospective cohort of consecutive ischemic stroke patients admitted in a Portuguese university hospital during 2013, who survived index hospitalization. We collected clinical and imaging information using the electronical clinical record. Information concerning 1-year unplanned hospital readmissions was assessed using the Portuguese electronic Health Data Platform. Descriptive and univariate analyses, Kaplan-Meier survival curve and multivariate survival analysis with Cox regression model were used. We included 480 patients, 50.6 % women, median age 79 years (interquartile range = 68-85). One-year hospital readmissions occurred in 165 patients [34.4 %, 95 % confidence interval (95 % CI) 30.2-38.7]. The main causes for readmission were infectious diseases (43.8 %), ischemic stroke or transient ischemic attack recurrence (13.2 %) and cardiac diseases (6.4 %). In-hospital mortality associated with readmission was 23.0 %. The independent predictors of 1-year hospital readmission after ischemic stroke were admission mini-National Institute of Health Stoke Scale [hazards ratio (HR) 1.05, 95 % CI 1.02-1.08, p = 0.002], and mild or absent early signs of ischemia on admission computed tomography (CT) (HR 0.54, 95 % CI 0.32-0.91, p = 0.021) and IVT (HR 0.11, 95 % CI 0.01-0.80, p = 0.029). Hospital readmission during the first year after ischemic stroke occurs in 1/3 of patients and is associated with high in-hospital mortality. Clinical stroke severity, early signs of ischemia on admission CT, and treatment with IVT are independent predictors of 1-year hospital readmission.


Asunto(s)
Isquemia Encefálica/complicaciones , Readmisión del Paciente/estadística & datos numéricos , Accidente Cerebrovascular/etiología , Factores de Tiempo , Anciano , Anciano de 80 o más Años , Femenino , Hospitalización/estadística & datos numéricos , Humanos , Masculino , Pronóstico , Estudios Retrospectivos , Factores de Riesgo , Índice de Severidad de la Enfermedad
15.
PLoS One ; 9(12): e113925, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25470487

RESUMEN

The production of Venerupis decussata relies on wild seed collection, which has been recently compromised due to recruitment failure and severe mortalities. To address this issue and provide an alternative source of seed, artificial spawning and larval rearing programs were developed. However, hatchery-based seed production is a relatively new industry and it is still underdeveloped. A major hurdle in the European clam seed production is the control of spawning and reproduction, which is further hindered by the impossibility of obtaining fertile gametes by gonadal "stripping", as meiosis re-initiation is constrained to a maturation process along the genital ducts. In the present study, oocytes were collected from 15 females and microarray analyses was performed to investigate gene expression profiles characterizing released and stripped ovarian oocytes. A total of 198 differentially expressed transcripts between stripped and spawned oocytes were detected. Functional analysis carried out on these transcripts highlighted the importance of a few biological processes, which are most probably implicated in the control of oocyte competence. Significant differences were observed for transcripts encoding proteins involved in meiosis progression (e.g. dual specificity phosphatase CDC25), WNT signalling (e.g. frizzled class receptor 8, wingless-type MMTV integration site family member 4), steroid synthesis (e.g. progestin and adipoQ receptor family member 3, cytochrome P450-C17), mRNA processing (e.g. zinc finger protein XlCOF28), calcium regulation (e.g. regucalcin, calmodulin) and ceramide metabolism (ceramidase B, sphingomyelinase). This study provides new information on transcriptional profiles putatively associated with ovarian egg infertility, and suggests potential mechanisms regulating early oocyte development in clams. Genes which were differentially expressed between stripped and spawned oocytes might have a pivotal role during maturation process in the gonadal duct and could be interesting targets for further functional studies aiming to make ovarian oocytes fertilizable.


Asunto(s)
Bivalvos/metabolismo , Perfilación de la Expresión Génica , Regulación del Desarrollo de la Expresión Génica , Oocitos/metabolismo , Animales , Bivalvos/citología , Bivalvos/crecimiento & desarrollo , Femenino , Ontología de Genes , Análisis de Secuencia por Matrices de Oligonucleótidos , Oocitos/citología , Oocitos/crecimiento & desarrollo , Análisis de Componente Principal , Vía de Señalización Wnt/genética
16.
PLoS One ; 9(3): e92202, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24643002

RESUMEN

The European clam, Ruditapes decussatus is a species with a high commercial importance in Portugal and other Southern European countries. Its production is almost exclusively based on natural recruitment, which is subject to high annual fluctuations. Increased knowledge of the natural reproductive cycle of R. decussatus and its molecular mechanisms would be particularly important in providing new highly valuable genomic information for better understanding the regulation of reproduction in this economically important aquaculture species. In this study, the transcriptomic bases of R. decussatus reproduction have been analysed using a custom oligonucleotide microarray representing 51,678 assembled contigs. Microarray analyses were performed in four gonadal maturation stages from two different Portuguese wild populations, characterized by different responses to spawning induction when used as progenitors in hatchery. A comparison between the two populations elucidated a specific pathway involved in the recognition signals and binding between the oocyte and components of the sperm plasma membrane. We suggest that this pathway can explain part of the differences in terms of spawning induction success between the two populations. In addition, sexes and reproductive stages were compared and a correlation between mRNA levels and gonadal area was investigated. The lists of differentially expressed genes revealed that sex explains most of the variance in gonadal gene expression. Additionally, genes like Foxl2, vitellogenin, condensing 2, mitotic apparatus protein p62, Cep57, sperm associated antigens 6, 16 and 17, motile sperm domain containing protein 2, sperm surface protein Sp17, sperm flagellar proteins 1 and 2 and dpy-30, were identified as being correlated with the gonad area and therefore supposedly with the number and/or the size of the gametes produced.


Asunto(s)
Bivalvos/genética , Gametogénesis/genética , Regulación del Desarrollo de la Expresión Génica , Aptitud Genética , ARN Mensajero/genética , Animales , Bivalvos/clasificación , Femenino , Células Germinativas/metabolismo , Gónadas/crecimiento & desarrollo , Gónadas/metabolismo , Masculino , Análisis por Micromatrices , Análisis de Secuencia por Matrices de Oligonucleótidos , Filogeografía , Portugal , Reproducción/genética , Factores Sexuales
17.
Int J Mol Sci ; 12(11): 8086-95, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22174651

RESUMEN

The selection of a DNA extraction method is a critical step when subsequent analysis depends on the DNA quality and quantity. Unlike mammals, for which several capable DNA extraction methods have been developed, for molluscs the availability of optimized genomic DNA extraction protocols is clearly insufficient. Several aspects such as animal physiology, the type (e.g., adductor muscle or gills) or quantity of tissue, can explain the lack of efficiency (quality and yield) in molluscs genomic DNA extraction procedure. In an attempt to overcome these aspects, this work describes an efficient method for molluscs genomic DNA extraction that was tested in several species from different orders: Veneridae, Ostreidae, Anomiidae, Cardiidae (Bivalvia) and Muricidae (Gastropoda), with different weight sample tissues. The isolated DNA was of high molecular weight with high yield and purity, even with reduced quantities of tissue. Moreover, the genomic DNA isolated, demonstrated to be suitable for several downstream molecular techniques, such as PCR sequencing among others.


Asunto(s)
ADN/aislamiento & purificación , Genoma , Genómica/métodos , Moluscos/clasificación , Animales , Electroforesis en Gel de Agar , Análisis de Secuencia de ADN
18.
Genetica ; 139(6): 823-31, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21670988

RESUMEN

We describe the chromosomal location of GC-rich regions, 28S and 5S rDNA, core histone genes, and telomeric sequences in the veneroid bivalve species Venerupis aurea and Tapes (Venerupis) rhomboides, using fluorochrome staining with propidium iodide, DAPI and chromomycin A3 (CMA) and fluorescent in situ hybridization (FISH). DAPI dull/CMA bright bands were coincident with the chromosomal location of 28S rDNA in both species. The major rDNA was interstitially clustered at a single locus on the short arms of the metacentric chromosome pair 5 in V. aurea, whereas in T. rhomboides it was subtelomerically clustered on the long arms of the subtelocentric chromosome pair 17. 5S rDNA also was a single subtelomeric cluster on the long arms of subtelocentric pair 17 in V. aurea and on the short arms of the metacentric pair 9 in T. rhomboides. Furthermore, V. aurea showed four telomeric histone gene clusters on three metacentric pairs, at both ends of chromosome 2 and on the long arms of chromosomes 3 and 8, whereas histone genes in T. rhomboides clustered interstitially on the long arms of the metacentric pair 5 and proximally on the long arms of the subtelocentric pair 12. Double and triple FISH experiments demonstrated that rDNA and H3 histone genes localized on different chromosome pairs in the two clam species. Telomeric signals were found at both ends of every single chromosome in both species. Chromosomal location of these three gene families in two species of Veneridae provides a clue to karyotype evolution in this commercially important bivalve family.


Asunto(s)
Bivalvos/genética , Análisis Citogenético , ADN Ribosómico/genética , Histonas/genética , Telómero/genética , Animales , Composición de Base/genética , Mapeo Cromosómico , Femenino , Masculino
19.
Genome ; 48(1): 177-80, 2005 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15729410

RESUMEN

Aneuploidy has previously been observed in the Pacific oyster, Crassostrea gigas, and shown to be negatively correlated with growth. Moreover, a significant impact of atrazine exposure has been described in C. gigas, and persistence of that effect has been observed between generations. Evidence of differential chromosome loss has been demonstrated in aneuploid karyotypes of C. gigas using the G-banding technique. Pairs 1, 5, 9, and 10 are characterized by the loss of 1 chromosome. As restriction enzyme (RE) digestion chromosome banding allows a better identification of chromosome pairs, we used this technique to identify which chromosomes are affected when aneuploidy is increased by exposure to atrazine. The progeny of oysters contaminated by atrazine were analysed using the restriction enzyme HaeIII. The study of 26 RE-banded aneuploid karyotypes showed that the same chromosome pairs (1, 5, 9, and 10) were affected by the loss of 1 chromosome (61%, 15%, 42%, and 42%, respectively). Further investigation is required to enable a better understanding of aneuploidy in oysters, especially with respect to why some chromosomes are more easily lost than others, and why cells tolerate the loss of these chromosomes.


Asunto(s)
Aneuploidia , Atrazina/toxicidad , Cromosomas/efectos de los fármacos , Ostreidae/efectos de los fármacos , Ostreidae/genética , Animales , Cromosomas/química , Desoxirribonucleasas de Localización Especificada Tipo II/química , Cariotipificación
20.
Environ Toxicol Chem ; 22(1): 219-23, 2003 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12503768

RESUMEN

Aneuploidy has previously been described and studied in the Pacific oyster, Crassostrea gigas, and has been shown to be negatively correlated with growth. The present study investigated the effect of atrazine on the level of aneuploidy in this species. Crassostrea gigas adults and juveniles were subjected to different concentrations of atrazine representing a peak value found in a polluted environment (46.5 nM) and a value 10 times higher (465 nM). Although atrazine did not show any effect on the oyster mortality, significant differences in aneuploidy level were observed between the different treatments (9% for the control, 16% for 46.5 nM and 20% for 465 nM atrazine). Moreover, the same levels of aneuploidy were observed at adult and juvenile stages. This is the first reported evidence for an environmental effect on aneuploidy in C. gigas. These results will be useful for the oyster aquaculture industry and management of resources. The lowest atrazine level in the current study represents realistic potential exposure, and the results suggest that studies should be made on other aquatic species at risk of exposure to atrazine in the wild. This widely used compound may be an important factor causing damage to genetic material.


Asunto(s)
Aneuploidia , Atrazina/efectos adversos , Exposición a Riesgos Ambientales , Herbicidas/efectos adversos , Ostreidae/fisiología , Contaminantes Químicos del Agua/efectos adversos , Factores de Edad , Animales , Medición de Riesgo
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