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1.
BMC Nurs ; 21(1): 316, 2022 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-36384544

RESUMO

BACKGROUND: Flipped learning excessively boosts the conceptual understanding of students through the reversed arrangement of pre-learning and in classroom learning events and challenges students to independently achieve learning objectives. Using a gamification method in flipped classrooms can help students stay motivated and achieve their goals.  METHODS: This study adopted a randomized controlled study design with a pre-test and post-test and involved 128 nursing students at Mansoura University. This study randomly divided the students into the study and control groups. Data were collected at three time points using six tools. In the intervention group, Moodle was gamified for 6 weeks.  RESULTS: A significant difference in the students' self-confidence (p = 0.021), skills knowledge (p < 0.001), intensity of preparation (p < 0.001), and motivation (p < 0.001) was observed between the two groups; however, no difference in the students' skills performance (p = 0.163) was observed between the two groups after using gamified flipped classrooms. CONCLUSIONS: Compared with the traditional flipped classrooms, gamified flipped classrooms improved nursing students' motivation, intensity of preparation, skills knowledge, and self-confidence during laboratory clinical practice. Thus, gamification is a learning approach that can be implemented in conjunction with the flipped classroom model to motivate students to participate in the learning process. TRIAL REGISTRATION: Prospectively registered with ClinicalTrials.gov on 26/04/2021; registration number NCT04859192.

2.
Genes (Basel) ; 13(10)2022 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-36292572

RESUMO

The use of next-generation sequencing (NGS) has helped in identifying many genes that cause congenital anomalies of the kidney and urinary tract (CAKUT). Bilateral renal agenesis (BRA) is the most severe presentation of CAKUT, and its association with autosomal recessively inherited genes is expanding. Highly consanguineous populations can impact the detection of recessively inherited genes. Here, we report two families harboring homozygous missense variants in recently described genes, NPNT and GFRA1. Two consanguineous families with neonatal death due to CAKUT were investigated. Fetal ultrasound of probands identified BRA in the first family and severe renal cystic dysplasia in the second family. Exome sequencing coupled with homozygosity mapping was performed, and Sanger sequencing was used to confirm segregation of alleles in both families. In the first family with BRA, we identified a homozygous missense variant in GFRA1: c.362A>G; p.(Tyr121Cys), which is predicted to damage the protein structure. In the second family with renal cystic dysplasia, we identified a homozygous missense variant in NPNT: c.56C>G; p.(Ala19Gly), which is predicted to disrupt the signal peptide site. We report two Saudi Arabian consanguineous families with CAKUT phenotypes that included renal agenesis caused by missense variants in GFRA1 and NPNT, confirming the role of these two genes in human kidney development.


Assuntos
Sistema Urinário , Humanos , Recém-Nascido , Receptores de Fator Neurotrófico Derivado de Linhagem de Célula Glial/genética , Rim , Mutação , Sinais Direcionadores de Proteínas/genética , Arábia Saudita , Sistema Urinário/anormalidades
3.
Hum Mutat ; 43(12): e24-e37, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36177613

RESUMO

The use of genetic testing within nephrology is increasing and its diagnostic yield depends on the methods utilized, patient selection criteria, and population characteristics. We performed exome sequencing (ES) analysis on 102 chronic kidney disease (CKD) patients with likely genetic kidney disease. Patients had diverse CKD subtypes with/without consanguinity, positive family history, and possible hereditary renal syndrome with extra-renal abnormalities or progressive kidney disease of unknown etiology. The identified genetic variants associated with the observed kidney phenotypes were then confirmed and reported. End-stage kidney disease was reported in 51% of the cohort and a family history of kidney disease in 59%, while known consanguinity was reported in 54%. Pathogenic/likely pathogenic variants were identified in 43 patients with a diagnostic yield of 42%, and clinically associated variants of unknown significance (VUS) were identified in further 21 CKD patients (21%). A total of eight novel predicted pathogenic variants and eight VUS were detected. The clinical utility of ES within the nephrology clinic was demonstrated allowing patient management to be disease-specific. In this cohort, ES detected a diagnostic molecular abnormality in 42% of patients with CKD phenotypes. Positive family history and high rates of consanguinity likely contributed to this high diagnostic yield.


Assuntos
Testes Genéticos , Insuficiência Renal Crônica , Humanos , Arábia Saudita/epidemiologia , Sequenciamento do Exoma , Consanguinidade , Testes Genéticos/métodos , Insuficiência Renal Crônica/diagnóstico , Insuficiência Renal Crônica/epidemiologia , Insuficiência Renal Crônica/genética
4.
Clin Genet ; 102(1): 61-65, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35246978

RESUMO

Congenital anomalies of the kidney and urinary tract (CAKUT) are a spectrum of abnormalities affecting morphogenesis of the kidneys and other structures of the urinary tract. Bilateral renal agenesis (BRA) is the most severe presentation of CAKUT. Loss of either nephronectin (NPNT) or its receptor ITGA8 leads to failure of metanephric kidney development with resulting renal agenesis in murine models. Very recently, a single family with renal agenesis and a homozygous truncating variant in NPNT was reported. We report two families in whom genome-wide linkage analysis showed an autozygous locus linked to BRA (at least one member has unilateral renal agenesis) at 4q24, with an LOD score of ~3. Exome sequencing detected a nonsense variant in NPNT in both families within the linkage interval. The pathogenicity of this variant was supported by reverse transcription polymerase chain reaction data showing complete nonsense-mediated decay of the NPNT transcript. Our report confirms the candidacy of NPNT in renal agenesis in humans and shows that even complete loss of function can be compatible with the formation of a single kidney.


Assuntos
Rim Único , Animais , Anormalidades Congênitas , Proteínas da Matriz Extracelular , Humanos , Rim/anormalidades , Nefropatias/congênito , Camundongos , Anormalidades Urogenitais , Refluxo Vesicoureteral
5.
Hum Genet ; 141(1): 101-126, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34853893

RESUMO

Fetal abnormalities are detected in 3% of all pregnancies and are responsible for approximately 20% of all perinatal deaths. Chromosomal microarray analysis (CMA) and exome sequencing (ES) are widely used in prenatal settings for molecular genetic diagnostics with variable diagnostic yields. In this study, we aimed to determine the diagnostic yield of trio-ES in detecting the cause of fetal abnormalities within a highly consanguineous population. In families with a history of congenital anomalies, a total of 119 fetuses with structural anomalies were recruited and DNA from invasive samples were used together with parental DNA samples for trio-ES and CMA. Data were analysed to determine possible underlying genetic disorders associated with observed fetal phenotypes. The cohort had a known consanguinity of 81%. Trio-ES led to diagnostic molecular genetic findings in 59 fetuses (with pathogenic/likely pathogenic variants) most with multisystem or renal abnormalities. CMA detected chromosomal abnormalities compatible with the fetal phenotype in another 7 cases. Monogenic ciliopathy disorders with an autosomal recessive inheritance were the predominant cause of multisystem fetal anomalies (24/59 cases, 40.7%) with loss of function variants representing the vast majority of molecular genetic abnormalities. Heterozygous de novo pathogenic variants were found in four fetuses. A total of 23 novel variants predicted to be associated with the phenotype were detected. Prenatal trio-ES and CMA detected likely causative molecular genetic defects in a total of 55% of families with fetal anomalies confirming the diagnostic utility of trio-ES and CMA as first-line genetic test in the prenatal diagnosis of multisystem fetal anomalies including ciliopathy syndromes.


Assuntos
Aberrações Cromossômicas , Ciliopatias/genética , Feto/anormalidades , Feto/fisiopatologia , Variação Genética , Estudos de Coortes , Consanguinidade , Feminino , Predisposição Genética para Doença , Testes Genéticos/métodos , Humanos , Análise em Microsséries , Fenótipo , Gravidez , Diagnóstico Pré-Natal/métodos , Sequenciamento do Exoma
6.
BMC Public Health ; 21(1): 2043, 2021 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-34749683

RESUMO

BACKGROUND: Rural Latino children and adults are less active than urban and non-Latino counterparts. We examined physical activity (PA) patterns of rural Latino children and their parents, and explored parental beliefs about and reported barriers of Latino family physical activity. Latino families in a rural area in eastern Washington state, with children in grades 3-5 were included. METHODS: We used mixed methods. Children (n = 27) and parents (n = 25) wore an accelerometer for 5 days; parents (n = 31) participated in a semi-structured interview and completed a demographic survey. Parent and child activity levels were compared using paired t-tests; interviews were analyzed with qualitative content analysis. RESULTS: Although 100% children and 46% parents met physical activity guidelines, parents and children spent most of the day in sedentary behaviors. Parent-reported PA barriers included their long work hours, lack of transportation, and their child's screen-time. CONCLUSION: Addressing barriers and reducing sedentary time could increase PA of rural Latino families.


Assuntos
Exercício Físico , Pais , Adulto , Criança , Hispânico ou Latino , Humanos , Tempo de Tela , Comportamento Sedentário
7.
J Clin Nurs ; 30(21-22): 3163-3170, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33896066

RESUMO

AIMS: To determine the effect of adding structured simulation to a traditional classroom lecture format on students' knowledge acquisition and their evaluation of faculty teaching effectiveness, compared to traditional classroom lectures alone. BACKGROUND: There is a critical lack of high-quality clinical placements/experiences in nursing education, particularly in clinical specialty populations, such as paediatrics. Simulation has been shown to help students practice in a safe environment. However, less is known about the outcomes of embedding simulation in didactic class sessions or classroom lectures. Additionally, data on the impact of simulation as a teaching pedagogy on faculty teaching effectiveness is limited. DESIGN: Post-test, nonequivalent control group quasi-experimental study. METHODS: Students in two prelicensure nursing programs participated in a 10-week term paediatric nursing course taught by the same faculty member on two different campuses. The students at one campus, designated as the control group (n = 43), received four hours of traditional, lecture-only, instructions. The group at a second campus, the intervention group (n = 44), received the same lectures with added structured simulations. Students' knowledge acquisition and their evaluation of faculty teaching effectiveness were measured in both groups using the same standardised assessment measures. The CONSORT checklist was followed. RESULTS: Students' knowledge acquisition scores and their evaluation scores of faculty teaching effectiveness were significantly higher in the intervention (simulation) group compared to the control group. A significantly higher number of students in the simulation group scored above the national average Nursing Care of Children score as compared to students in the control group. CONCLUSIONS: Integrating simulation with didactic instruction enhanced students' knowledge acquisition and improved their opinion of faculty teaching effectiveness. RELEVANCE TO CLINICAL PRACTICE: Augmenting lecture with simulation may provide students with learning experiences that they may not have during clinical rotation due to a lack of paediatric clinical placement sites and differences between sites.


Assuntos
Educação em Enfermagem , Estudantes de Enfermagem , Criança , Humanos , Aprendizagem , Enfermagem Pediátrica , Percepção , Ensino
8.
J Nephrol ; 34(3): 893-900, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-32643034

RESUMO

INTRODUCTION: Congenital anomalies of the kidney and urinary tract (CAKUT) are a group of abnormalities that affect structure of the kidneys or other structures of the urinary tract. The majority of CAKUT are asymptomatic and are diagnosed prenatally by ultrasound scanning or found incidentally in postnatal life. CAKUT varies in severity and may lead to life-threatening kidney failure and end-stage kidney disease. Renal agenesis, a severe form of CAKUT, is a congenital absence of one or both kidneys. Bilateral renal agenesis belongs to a group of prenatally lethal renal diseases and is often detected on fetal ultrasound scanning during the investigation of oligohydramnios. Approximately 40% of fetuses with bilateral renal agenesis are stillborn or die a few hours postnatally. Mutations in many renal development genes have been shown to be associated with renal agenesis. METHODS: Six consanguineous Saudi Arabian families were recruited to study the molecular genetic causes of recurrent miscarriages and lost fetuses due to oligohydramnios, renal agenesis and other congenital anomalies. Whole exome sequencing was employed to underlying detect genetic defects. RESULTS: Novel loss of function variants were detected in FRAS1 and FREM2. In FRAS1, a homozygous splice site variant c.9780+2T>C was found in an affected fetus, segregating form each parent. In addition, in three other families both parents were heterozygous for a frameshift variant (c.8981dupT; p.His2995Profs*3) and splice site variants (c.5217+1G>C and c.8098+2T>A), respectively. In FREM2, a homozygous nonsense variant (c.2303C>G; p.Ser768*) was found in an affected fetus, segregating from both parents. In another family, both parents carried a FREM2 heterozygous frameshift variant (c.3969delC; p.Asn1323Lysfs*5). CONCLUSION: We describe consanguineous families with clinical features of antenatal oligohydramnios and bilateral renal agenesis, in whom we have identified novel pathogenic variants in FRAS1 and FREM2. These finding highlights the association between mutations in FRAS1 and FREM2 and antenatal/perinatal death.


Assuntos
Anormalidades Congênitas , Proteínas da Matriz Extracelular , Nefropatias/congênito , Rim/anormalidades , Consanguinidade , Proteínas da Matriz Extracelular/genética , Feminino , Humanos , Gravidez , Splicing de RNA/genética , Arábia Saudita
9.
Genes (Basel) ; 11(9)2020 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-32825426

RESUMO

BACKGROUND: Intellectual developmental disorder with cardiac defects and dysmorphic facies (IDDCDF, MIM 618316) is a newly described disorder. It is characterized by global developmental delay, intellectual disability and speech delay, congenital cardiac malformations, and dysmorphic facial features. Biallelic pathogenic variants of TMEM94 are associated with IDDCDF. METHODS AND RESULTS: In a prenatal setting, where fetal abnormalities were detected using antenatal sonography, we used trio-exome sequencing (trio-ES) in conjunction with chromosomal microarray analysis (CMA) to identify two novel homozygous loss of function variants in the TMEM94 gene (c.606dupG and c.2729-2A>G) in two unrelated Saudi Arabian families. CONCLUSIONS: This study provides confirmation that TMEM94 variants may cause IDDCDF. For the first time we describe the pathogenicity of TMEM94 defects detected during the prenatal period.


Assuntos
Face/anormalidades , Feto/anormalidades , Cardiopatias Congênitas/diagnóstico , Deficiência Intelectual/diagnóstico , Proteínas de Membrana/genética , Mutação , Anormalidades Múltiplas , Família , Feminino , Testes Genéticos , Cardiopatias Congênitas/genética , Humanos , Deficiência Intelectual/genética , Fenótipo , Gravidez
10.
Oncol Nurs Forum ; 47(1): 56-69, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31845920

RESUMO

OBJECTIVES: To understand breast cancer survivors' and providers' attitudes and beliefs regarding exercise counseling and structured exercise programs within cancer care. SAMPLE & SETTING: 61 female breast cancer survivors and 11 breast cancer providers from a university cancer center in the Pacific Northwest. METHODS & VARIABLES: Survivors completed anonymous self-report surveys, and providers participated in semistructured interviews. Survey data were analyzed using descriptive statistics, and interview transcripts were analyzed using qualitative content analysis. RESULTS: Breast cancer survivors and providers believed that including exercise counseling within cancer care was important. More than half of the survivors reported that they would attend structured exercise classes; a majority of providers thought cancer centers should offer exercise programs. IMPLICATIONS FOR NURSING: Nurses could facilitate exercise counseling within cancer care and advocate for clinic-based exercise programs.


Assuntos
Atitude Frente a Saúde , Neoplasias da Mama/psicologia , Neoplasias da Mama/terapia , Sobreviventes de Câncer/psicologia , Terapia por Exercício/psicologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Pessoa de Meia-Idade , Noroeste dos Estados Unidos , Inquéritos e Questionários
11.
Electron Physician ; 9(12): 5902-5907, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29560140

RESUMO

BACKGROUND: With more than 500,000 new cases annually, human brucellosis is the commonest zoonotic disease worldwide. In some endemic countries, its prevalence is more than 10 per 100,000 population. OBJECTIVE: The aim of this study was to determine the magnitude of the problem and the clinical features, laboratory findings, treatment given and complications seen in children with brucellosis in Najran City, Kingdom of Saudi Arabia. METHODS: This is a case-series study by analysis of data of children known or diagnosed to have brucellosis for the last 4 years in Najran City. Data was obtained by reviewing the hospital records of the Maternity and Children Hospital and Najran Armed Forces Hospital in Najran during the period from 2013 to 2017. The statistical analysis was carried out using SPSS version 16.0. Since it was the first report of brucellosis on the study population, we used descriptive statistics (frequency, proportion, mean, and standard deviation) for presenting the findings. RESULTS: We studied 57 diagnosed cases of child brucellosis throughout the past 4 years in Najran, south Saudi Arabia with an average number of about 12 cases per year. Of the cases, 15.8% reported a history of ingestion of raw milk and dairy product and only 1.8% of them reported a history of animal contact while 82.4% confirmed unknown mode of transmission. Fever was the only finding in 36.8%, fever and arthralgia 21.1%, and fever and myalgia 19.3%. Two thirds of the cases were diagnosed by standard agglutination test (SAT). Hepatosplenomegaly was found in 10.5%. Rifampicin was the antibiotic of choice and 70.2% of cases have been cured but 3.5% relapsed and 1.8% died from complications. CONCLUSIONS: Results suggest brucellosis be considered in every child living in an endemic area, showing symptoms of fever and having a history of ingestion of raw milk and dairy product and/or animal contact.Prevention should rely on health education of the public about different issues of the disease including boiling raw milk.

12.
Electron Physician ; 9(11): 5740-5745, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29403613

RESUMO

BACKGROUND: Peptic ulcer disease is a multifactorial health problem, and its prevalence and risk factors have changed considerably within the past century. OBJECTIVE: To determine the prevalence of peptic ulcer among the population of Arar city and to identify risk factors for peptic ulcer and to estimate their relative impact on ulcer incidence. METHODS: A cross-sectional study was carried out on the population of Arar city, Northern Saudi Arabia from November 01, 2016 to April 30, 2017. Data were analyzed by SPSS version 16, using descriptive statistics, prevalence, and Chi-square test. RESULTS: Total prevalence of peptic ulcer among the studied respondents was thus: 21.9% had peptic ulcer; 16.2% gastric ulcer and 5.6% duodenal ulcer. In 19.7% of the cases, the pain was severe, 92.4% reported that pain was precipitated by certain food. In addition to heartburn, 78.8% reported loss of appetite, 71.2% indigestion, 66.7% regurgitation, 59.1% nausea and vomiting and 42.4% with chest pain. Regarding the risk factors, coffee drinking came in first place (81.8%) followed by physical stress in 77.3%, spicy food in 57.6%, prolonged use of Non-steroidal anti-inflammatory drugs (NSAIDs) in 33.3% and Helicobacter pylori (H. pylori) infection in 24.2%. A further 22.7% reported melena as a complication while only 10.6% reported hematemesis. CONCLUSION: This is the first population-based study in Arar, Northern Saudi Arabia reporting point prevalence of peptic ulcer disease. The rate of 16.2% for gastric ulcer and 5.6% for duodenal ulcers are substantially high. Coffee drinking, physical stress, spicy food, prolonged use of NSAID and H. pylori infection were the reported risk factors. Population-based endoscopic studies are recommended.

13.
Electron Physician ; 9(11): 5754-5759, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29403615

RESUMO

BACKGROUND: Deep venous thrombosis (DVT) is a condition that occurs frequently among surgical, as well as acutely ill hospitalized medical patients, and is responsible for significant morbidity and mortality in hospitalized patients. Risk factors include older age, surgery and immobilization (as with bed rest, orthopedic casts, and sitting on long flights. OBJECTIVE: This study was conducted to identify the frequency and factors associated with occurrence of DVT among elderly patients referred to King Abdulaziz University (KAU) Hospital, Jeddah, Kingdom of Saudi Arabia. METHODS: The current study is a hospital based cross sectional study. The emergency, inpatients and outpatients' departments at KAU hospital were reviewed. We studied all the referred elderly subjects during the study period. All elderly patients (540) referred to or admitted to the hospital departments and who were clinically suspected to have DVT and subjected to Doppler examination were included in the study. Data were analyzed using descriptive statistics and Chi square test. RESULTS: Based on the results of Doppler examination, DVT was detected in 97 (18.0%) of the studied elderly population. There were no significant differences in gender between patients who developed DVT and those who were negative by Doppler examination (p=0.018). Other comorbidities as diabetes, IHD and hypertension were significantly associated with the occurrence of DVT among the participants (p=0.05, 0.05 and 0.04 respectively). Furthermore, the other investigated factors such as being bed ridden, cancer, orthopedic cast and previous DVT were not significantly associated with the development of DVT among the studied elderly patients (p=0.42, 0.16, 0.45 and 0.75 respectively). CONCLUSION: DVT has high prevalence in Jeddah; KSA. Thrombophilia screening should be regular for elderly patients with diabetes, hypertension and bed-ridden patients with recurrent DVT or patients with other risk factors. Knowing the most common risk factors and their significance in developing DVT is essential for early detection of DVT to prevent unwanted complications for elderlies.

14.
Electron Physician ; 8(12): 3318-3324, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28163843

RESUMO

INTRODUCTION: Guillain-Barré syndrome is the most common cause of acute flaccid paralysis in children, and defined as an acute inflammatory polyneuropathy. The objective of this study was to assess the clinico-laboratory profile, and outcome of Guillain-Barré syndrome in children at Sohag University Hospital. METHODS: This prospective cohort observational study was conducted in 2014-2015. The included children were subjected to through medical history and detailed systemic and neurological examination. Nerve conduction studies and cerebrospinal fluid analysis were done for all patients. Follow up was done at three and six months both clinically and by nerve conduction studies. RESULTS: This study included 50 patients (27 males/23 females) with median age of 2.92 years. Upper respiratory tract infections were the most common antecedent infections (50%) and the neurological findings were weakness of both lower limbs and pain in all patients (100%) followed by sphincteric dysfunction (26%) while cranial neuropathies were found in 4%. Nerve conduction study revealed that acute inflammatory demyelinating polyradiculoneuropathy was found in 52% of cases, acute motor axonal neuropathy in 36% of cases, whereas acute motor-sensory axonal neuropathy was found in 6% of cases. The outcome was good in about 78% of cases, Hughes motor scale revealed that 58% were healthy, 18% had minor signs or symptoms, 12% walked without support, 6% walked with support, and 6% were bed ridden. CONCLUSION: The outcome was favorable, although a minority of patients suffered neurological deficit. Immediate administration of intravenous immunoglobulin reduced mortality and disability.

15.
Arch Environ Contam Toxicol ; 52(4): 489-95, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17380237

RESUMO

During the present study, microcystin (MCYST) concentrations in the Nile River and irrigation canal sediments, Egypt, were investigated during the period January-December 2001. Batch experiments were also conducted to confirm the adsorption of MCYSTs on these sediments. The results of field study showed that MCYST concentrations in the sediments were correlated with total count of cyanobacteria, particularly Microcystis aeruginosa, and MCYST within phytoplankton cells in most sites. No detectable levels of MCYSTs were found in the cell-free water of all studied sites in the Nile River and irrigation canals during the entire study period. The data obtained from batch adsorption experiments confirmed the capability of the Nile River and irrigation canal sediments for MCYST adsorption; and that adsorption was sediment weight-dependent and thus fitted the Freundlich adsorption isotherm. The results also revealed that both adsorption capacity (K(f)) and intensity (1/n) varied significantly with clay and organic matter contents of these sediments. The results of present study have two implications. First, the presence of cyanobacterial toxins in freshwater sediments can affect benthic organisms inhabiting these sediments, and thus it should be considered during biological monitoring of rivers and streams. Second, the ability of freshwater sediments to adsorb cyanobacterial toxins suggests that bank filtration could be used in developing countries (e.g., Egypt), which require an inexpensive and low-maintenance method for removing these toxins from drinking water.


Assuntos
Sedimentos Geológicos/análise , Microcistinas/análise , Poluentes da Água/análise , Adsorção , Contagem de Colônia Microbiana , Cianobactérias/isolamento & purificação , Cianobactérias/metabolismo , Egito , Monitoramento Ambiental , Sedimentos Geológicos/química , Microcistinas/química , Rios/química , Estações do Ano , Poluentes da Água/química
16.
Toxicon ; 47(5): 584-90, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16564062

RESUMO

The present study describes for the first time the species composition and toxicity of benthic cyanobacteria forming mats on the Nile River and irrigation canal sediments in Egypt. A total of 19 species of cyanobacteria were isolated from these mats during this study. The toxicity of the extracts of these species was investigated using Artemia salina assay, mouse bioassay and enzyme linked immunosorbent assay (ELISA). The results showed that all the 19 benthic species isolated from cyanobacterial mats, were toxic to A. salina. Two of these species, namely Calothrix parietina and Phormidium tenue, caused toxicity to mice with neurotoxic signs appeared within 12 h after injection. Whereas, five species showed hepatotoxic effects to mice within 6 h after injection. The results of ELISA showed that all the extracts which had hepatotoxic effects to mice, contained high levels of microcystins with concentrations ranging from 1.6 to 4.1 mg g(-1) dry weight. HPLC analysis for heptotoxic extracts revealed that these extracts contained two peaks corresponding to microcystin-YR and -LR with different proportions. This study suggests that benthic species should be considered along with planktonic species during monitoring of toxic cyanobacteria in water sources, particularly the Nile river which is the main source of drinking water in Egypt.


Assuntos
Agricultura , Cianobactérias/crescimento & desenvolvimento , Cianobactérias/metabolismo , Peptídeos Cíclicos/biossíntese , Rios/microbiologia , Microbiologia da Água , Abastecimento de Água , Animais , Artemia/metabolismo , Bioensaio , Cromatografia Líquida de Alta Pressão , Cianobactérias/classificação , Egito , Ensaio de Imunoadsorção Enzimática , Sedimentos Geológicos , Larva , Masculino , Camundongos , Microcistinas
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