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1.
Arch Gynecol Obstet ; 2023 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-37401942

RESUMO

PURPOSE: This is the first study that aimed to determine antigen levels in plasma and genotypes of PAI-2 in pregnant and non-pregnant homozygous sickle cell anemia (SCA) patients. METHODS: The study subjects were all Bahraini females in the reproductive age group. The study population included 31 pregnant homozygous SS (SCA) patients. Three control groups were also studied to evaluate the effect of pregnancy and SCA on PAI-2 levels and fibrinolysis: (1) 31 healthy non-pregnant volunteers; (2) 31 cases of normal pregnancy; and (3) 20 non-pregnant SCA patients. Pregnancies were screened in the second (TM2) and third (TM3) trimesters. Global coagulation, fibrinolysis rate (euglobulin clot lysis time, ECLT), PAI-2 antigen (ELISA), and PAI-2 Ser(413)/Cys polymorphism (restriction fragment length polymorphism analysis) were determined. RESULTS: Feto-maternal complications were documented in both pregnancy groups. PAI-2 antigen levels were undetectable in the non-pregnant groups, but was quantifiable in both pregnant groups. Impaired fibrinolysis rate and rising PAI-2 levels with progression of pregnancy were observed in both healthy and SCA subjects. These changes were more prominent in SCA, although the rise in ECLT was less steep and PAI-2 antigen levels were not significantly different compared to normal pregnancy in the third trimester. No correlation was observed between PAI-2 genotypes and plasma antigen levels. Also, no significant difference in feto-maternal complications was found in normal (n = 25) versus SCA pregnant patients (n = 30). CONCLUSIONS: These observations suggest that with progression of pregnancy, increasing PAI-2 levels contribute to the hypercoagulable state, particularly in SCA patients.

2.
Biomarkers ; 22(3-4): 268-278, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27321479

RESUMO

Circulating microRNAs (miRNAs) have been shown as promising biomarkers for various diseases. We investigated the predictive potential of circulating endothelium-enriched miR-126 in type 2 diabetes patients (T2D) without chronic complications and T2D patients with coronary artery diseases (CAD). The expression levels of circulating miR-126, determined by quantitative real time PCR, were decrease in peripheral blood of T2D patients and T2D with CAD compared with healthy controls. MiR-126 strongly associated with T2D and CAD, negatively correlated with LDL in CAD patients and differentiated between T2D patients, T2D patients with CAD and healthy subjects. Circulating miR-126 may serve as a biomarker for predicting patients with T2D and diabetic CAD.


Assuntos
Doença da Artéria Coronariana/complicações , Diabetes Mellitus Tipo 2/complicações , MicroRNAs/sangue , Biomarcadores/sangue , Estudos de Casos e Controles , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/diagnóstico , Complicações do Diabetes/sangue , Complicações do Diabetes/diagnóstico , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/diagnóstico , Endotélio , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
3.
Ann Hum Biol ; 41(1): 61-6, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24028143

RESUMO

BACKGROUND: The geographical location of Egypt at the crossroads of several major cultural areas between North Africa and the Middle East has contributed to its population history. AIM: To analyse the genetic structure of the population living in two geographical parts of Egypt. SUBJECTS AND METHODS: A sample of 112 Egyptians from the North African part of Egypt (Ismailia sample) and a sample of 52 Egyptians from the Asian part Sinai, have been analysed using 10 Alu insertion polymorphisms. RESULTS: The results of the present study showed a significant genetic difference between the Sinai and Ismailia samples. The latter showed an evident genetic affinity with North African populations; whereas the Sinai sample was found to be genetically closer to the Middle East populations. The Sinai sample showed a low average heterozygosity, unlike that found in the Ismailia sample. CONCLUSION: This study provides new insights into the genetic structure of the Egyptian population living in a land bridge between Africa and Asia. Results suggest a genetic discontinuity between the Sinai population and that of the North African part of Egypt. This discontinuity would have been maintained thanks to geo-climatic and social factors.


Assuntos
Elementos Alu , Mutagênese Insercional , Polimorfismo Genético , Árabes , Egito , Marcadores Genéticos , Humanos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Análise de Sequência de DNA
4.
J Mol Histol ; 55(4): 415-426, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38713244

RESUMO

Antipsychotic drugs (APDs) are used to treat many psychiatric illnesses as schizophrenia. Typical antipsychotic drugs (TAPDs) are being used; however, they have many side effects. Atypical antipsychotic drugs (AAPDs) are newer medications with known fewer side effects. Aripiprazole (ARI) is an AAPD, recommended by healthcare providers, even during pregnancy. It can cross the placental barrier and enter fetal circulation, so it might be possible that ARI can adversely impair normal placental development and growth, if it is given prenatally. ARI was applied orally to pregnant female rats in two doses (3& 6 mg/kg body weight). On gestation day 20, the mothers were sacrificed, and the placentas were removed and processed for general histological and electron microscopic evaluations. Immunohistochemistry was done using anti-PCNA (proliferating cell nuclear antigen), anti-Bax (for apoptosis) and anti-vascular endothelial growth factor alpha (VEGFA). Morphological evaluation revealed degenerative changes in the placenta as dark nuclei, vacuolization, and cyst formation. Ultra-structurally, there was degeneration of cellular components including organelles and nuclei. These changes were found in different cells of the basal and labyrinth zones and were dose dependent. Immunohistochemistry revealed upregulation of Bax and VEGFA and downregulation of PCNA. Prenatal administration of the AAPD, ARI to pregnant female rats resulted in histological changes in the placenta. Additionally, there was a decrease in cellular proliferation and increase in apoptosis, and vascular impairment. This indicates placental atrophy and dysgenesis and might suggest possible teratogenic effects to ARI, which needs further evaluation.


Assuntos
Aripiprazol , Imuno-Histoquímica , Placenta , Animais , Feminino , Gravidez , Aripiprazol/efeitos adversos , Aripiprazol/farmacologia , Placenta/efeitos dos fármacos , Placenta/metabolismo , Placenta/ultraestrutura , Placenta/patologia , Ratos , Antipsicóticos/toxicidade , Antipsicóticos/efeitos adversos , Fator A de Crescimento do Endotélio Vascular/metabolismo , Proteína X Associada a bcl-2/metabolismo , Antígeno Nuclear de Célula em Proliferação/metabolismo , Apoptose/efeitos dos fármacos
5.
Clin Anat ; 26(5): 572-7, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23339087

RESUMO

The palmaris longus (PL) is one of the most variable muscles in the human body. Racial differences in its variation have been documented. Several studies have attempted to correlate PL absence with other anatomical variations. This study was conducted to determine the prevalence of absence of PL, correlate it with gender and body side and to determine its association with other anatomical variations in the Egyptian population. The presence of PL was clinically determined in 386 Egyptians using the standard technique. All subjects were examined for the presence of the flexor digitorum superficialis (FDS) to the fifth finger. Allen's test was done to assess the completeness of the superficial palmar arch (SPA). The overall prevalence of absence of the PL in Egyptian subjects was 50.8%. There was no significant difference in PL absence with regard to the body side but a significant difference was seen as regards gender and when bilateral absence of PL was compared to its unilateral absence. Absence of FDS tendon to the fifth finger was seen in 1.3% subjects. There was no association between the absence of the FDS tendon to the fifth finger and either presence or absence of PL and also between the absence of PL and the incompleteness of SPA in both genders. In conclusion, the prevalence of absence of PL in the Egyptian population represents one of the highest rates of absence to be reported for this muscle, which is significantly different from that in other ethnic groups.


Assuntos
Variação Anatômica , Antebraço/anatomia & histologia , Músculo Esquelético/anatomia & histologia , Adulto , Idoso , Egito , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
6.
Genome Res ; 19(9): 1516-26, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19439515

RESUMO

Structural variants (SVs) are common in the human genome. Because approximately half of the human genome consists of repetitive, transposable DNA sequences, it is plausible that these elements play an important role in generating SVs in humans. Sequencing of the diploid genome of one individual human (HuRef) affords us the opportunity to assess, for the first time, the impact of mobile elements on SVs in an individual in a thorough and unbiased fashion. In this study, we systematically evaluated more than 8000 SVs to identify mobile element-associated SVs as small as 100 bp and specific to the HuRef genome. Combining computational and experimental analyses, we identified and validated 706 mobile element insertion events (including Alu, L1, SVA elements, and nonclassical insertions), which added more than 305 kb of new DNA sequence to the HuRef genome compared with the Human Genome Project (HGP) reference sequence (hg18). We also identified 140 mobile element-associated deletions, which removed approximately 126 kb of sequence from the HuRef genome. Overall, approximately 10% of the HuRef-specific indels larger than 100 bp are caused by mobile element-associated events. More than one-third of the insertion/deletion events occurred in genic regions, and new Alu insertions occurred in exons of three human genes. Based on the number of insertions and the estimated time to the most recent common ancestor of HuRef and the HGP reference genome, we estimated the Alu, L1, and SVA retrotransposition rates to be one in 21 births, 212 births, and 916 births, respectively. This study presents the first comprehensive analysis of mobile element-related structural variants in the complete DNA sequence of an individual and demonstrates that mobile elements play an important role in generating inter-individual structural variation.


Assuntos
Biologia Computacional/métodos , Elementos de DNA Transponíveis/genética , Variação Genética , Genoma Humano , Elementos Alu , Deleção de Genes , Humanos , Dados de Sequência Molecular , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA
7.
Sci Rep ; 12(1): 11099, 2022 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-35773337

RESUMO

Several mitochondrial DNA (mtDNA) mutations of Leber's hereditary optic neuropathy (LHON) have been reported in patients with multiple sclerosis (MS) from different ethnicities. To further study the involvement of LHON mtDNA mutations in MS in the Arab population, we analyzed sequencing data of the entire mitochondrial genome from 47 unrelated Saudi individuals, 23 patients with relapse-remitting MS (RRMS) and 24 healthy controls. Ten LHON mutations/variants were detected in the patients but were absent in the controls. Of them, the common primary pathogenic mutation m.14484T>C and the rare mutation m.10237T>C were found in one patient, whereas the rare mutation m.9101T>C was found in another patient. The remaining were secondary single nucleotide variants (SNVs) found either in synergy with the primary/rare mutations or individually in other patients. Patients carrying LHON variants also exhibited distinct mtDNA variants throughout the mitochondrial genome, eight were previously reported in patients with LHON. Moreover, five other LHON-related SNVs differed significantly in their prevalence among patients and controls (P < 0.05). This study, the first to investigate LHON mtDNA mutations/variants in a Saudi cohort may suggest a role of these mutations/variants in the pathogenesis or genetic predisposition to MS, a possibility which needs to be explored further in a large-scale.


Assuntos
Genoma Mitocondrial , Esclerose Múltipla , Atrofia Óptica Hereditária de Leber , Árabes/genética , DNA Mitocondrial/genética , Humanos , Esclerose Múltipla/genética , Mutação , Recidiva Local de Neoplasia/genética , Atrofia Óptica Hereditária de Leber/genética , Atrofia Óptica Hereditária de Leber/patologia
8.
Biomed Rep ; 14(3): 33, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33585035

RESUMO

Pre-diabetes represents an intermediate state of altered glucose metabolism between normal glucose levels and type 2 diabetes mellitus (T2D), and is considered a significant risk factor for the development of T2D and related complications. Early detection of pre-diabetes may allow for the use of timely and effective treatment strategies to prevent its progression. Circulating microRNAs (miRNAs/miRs) that reflect changes in diabetes-related tissues, including the pancreas, liver, skeletal and heart muscle, and adipose tissue are promising biomarkers of disease progression. In our previous study, it was demonstrated that the cardiac and skeletal muscle specific miR-1 and miR-133 are upregulated in the blood of patients with T2D and cardiovascular disease. Since both miRNAs have been shown to be implicated in insulin resistance, an important feature of pre-diabetes, we hypothesised that their expression may be increased prior to clinical diagnosis of T2D, and may thus serve as biomarkers for pre-diabetes. The expression levels of circulating miRNAs were evaluated by reverse transcription-quantitative PCR in whole blood samples from 55 subjects, including 28 pre-diabetes individuals with impaired fasting glucose (FG) and impaired glucose tolerance, and 27 healthy controls. The individuals with pre-diabetes exhibited significantly higher expression levels of miR-1 and miR-133 compared with the controls (P<0.05). Target prediction search revealed that both miR-1 and miR-133 target several pathways involved in the pathophysiology of diabetes. Pearson's correlation analysis revealed that the two miRNAs were positively correlated with blood glucose parameters, including FG, 2-h oral glucose tolerance test and glycated haemoglobin A1c levels, as well as with insulin resistance (P<0.05). Multivariate logistic regression analysis revealed that the two miRNAs were significantly and directly associated with pre-diabetes, and this association remained significant after adjustment for several confounding variables (P<0.05). Moreover, linear regression analysis showed that the Homeostatic Model Assessment-Insulin Resistance was the only significant predictor to be significantly associated with both miRNAs (P<0.05). In discriminating pre-diabetes individuals from healthy controls, the area under the curves (AUCs) of the receiver operating characteristic curves (ROCs) were 0.813 and 0.810 for miR-1 and miR-133 respectively (P<0.05). Despite the relatively small number of participants, the present study showed for the first time that circulating levels of miR-1 and miR-133 were increased in individuals with pre-diabetes, and they were associated with important features of pre-diabetes. Thus, they may serve as clinical biomarkers for the early-stages of T2D.

9.
Adv Med Educ Pract ; 12: 755-768, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34285628

RESUMO

BACKGROUND: While online education is by no means a new concept, it was recently thrust into the spotlight after school campuses all over the world were forced to close because of the COVID-19 pandemic. The sudden need to shift revealed emerging challenges to online teaching, both logistic and personal. One important challenge is the ability to assess the readiness of educators for online teaching, so that appropriate and specific feedback/training can be offered to those in need. This study aims at developing, validating, and implementing a tool to measure the teachers' readiness for online teaching in three medical schools from three different countries. METHODS: This was a multi-center, cross-sectional study that involved developing a survey through review of literature and previous studies, item development and revision, and pilot testing. The survey was then distributed electronically to a convenient sample of 217 teaching faculty members of different academic ranks from three medical schools in Egypt, Saudi Arabia, and Bahrain. Exploratory factor analysis and reliability study were performed. Descriptive statistics were applied, and the statistical significance level was set at 0.05. RESULTS: Factor analysis produced the following five factors: "Online Teaching and Course Design Skills", "Digital Communication", "Basic Computer Skills", "Advanced Computer Skills" and "Using Learning Management Systems". The tool showed high reliability (alpha = 0.94). Survey results showed highest mean scores for Basic Computer Skills with lower scores for Online Teaching and Course Design Skills and Using Learning Management Systems. ANOVA revealed statistically significant differences between the three studied schools regarding Digital Communication (F=5.13; p=0.007) and Basic Computer Skills (F=4.47; p=0.012) factors. CONCLUSION: The tool proved to be reliable and valid. Results indicated an overall acceptable readiness in the three involved schools, with a need for improvement in "Online Teaching and Course Design" and Using Learning Management Systems.

10.
J Cardiovasc Transl Res ; 12(4): 347-357, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30610670

RESUMO

Circulating miRNAs are increasingly suggested as clinical biomarker for diseases. We evaluated the expression of circulating cardiomyocyte-enriched miR-1 and miR-133 by real-time PCR in blood from patients with type 2 diabetes (T2D) without and with coronary artery disease (CAD) and healthy controls, investigated their association with the risk of CAD risk and their potential as biomarkers. The two miRNAs were upregulated in patients with T2D and CAD compared with controls, associated with CAD risk and remained significant after adjustment for multiple confounders. LDL-C was a positive predictor for miR-1 and miR-133, and mean blood pressure was also a positive predictor for miR-133. Both miRNAs strongly distinguished CAD from controls. miR-1 significantly distinguished CAD from T2D with higher diagnostic ability than miR-133, whereas the miR-1/miR-133 combination improved the diagnostic value. Upregulation of circulating miR-1 and miR-133 associate with the risk of CAD in T2D patients and may serve as diagnostic biomarkers.


Assuntos
Doença da Artéria Coronariana/sangue , Diabetes Mellitus Tipo 2/sangue , Angiopatias Diabéticas/sangue , MicroRNAs/sangue , Idoso , Biomarcadores/sangue , Estudos de Casos e Controles , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/etiologia , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/diagnóstico , Angiopatias Diabéticas/diagnóstico , Angiopatias Diabéticas/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Medição de Risco , Fatores de Risco , Regulação para Cima
11.
Adv Med Educ Pract ; 9: 881-886, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30555266

RESUMO

CONSTRUCT: We assessed the validity of the modified System for Evaluation of Teaching Qualities (mSETQ) in evaluating clinical teachers in Bahrain. BACKGROUND: Clinical teacher assessment tools are essential for improving teaching quality. The mSETQ is a teaching quality measurement tool, and demonstrating the validity of this tool could provide a stronger evidence base for the utilization of this questionnaire for assessing medical teachers in Bahrain. APPROACH: This study assessed the construct validity of this questionnaire in medical schools across Bahrain using 400 medical students and 149 clinical teachers. Data were analyzed using confirmatory factor analysis (CFA). The goodness-of-fit index (GFI), comparative fit index (CFI), root mean square residual, and standardized root mean square error of approximation (RMSEA) indices were used to evaluate the model fit. The internal consistency reliability was assessed using Cronbach's alpha. RESULTS: The results of the CFA revealed an acceptable fit. All criteria for a good model fit were met except for the RMSEA fit index and the standardized root mean square residual (SRMR) value, which was very close to an acceptable value. Good overall reliability was found in the study (α=0.94). CONCLUSION: The overall findings of this study provided some evidence supporting the reliability and validity of the mSETQ instrument.

12.
Biomed Rep ; 9(6): 531-539, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30546882

RESUMO

Multiple sclerosis (MS) has become prevalent in the Arabian Gulf area with high incidence in Bahrain due to environmental influences and genetic susceptibilities, but there is a lack of study into human leukocyte antigen (HLA) types in patients with MS in Bahrain. The present study aimed to study the HLA types expressed in MS patients compared with in control subjects. Blood samples from 50 Bahraini patients with MS and 50 Bahraini control subjects' were subjected to HLA tissue typing by polymerase chain reaction using sequence-specific primers. In comparison with those in control subjects, the allele frequencies of HLA class-I antigens A2, A9, A19, B5, B35 and B40 were higher in MS patients. For class II antigens, the allele frequencies of DR3, DR4 and DR16 were higher in MS patients. The allele frequency of DR15 was lower in MS patients than in control subjects but the difference was not statistically significant (P=0.138). The higher prevalence of the HLA-ABDR allele was common among the female patients with MS, in relapse remission stage, in cases with higher expanded disability status scale scores and with disease duration between 4 and 9 years. Haplotype HLA-A2-B40-DR2 exhibited significantly higher frequency in MS patients compared with in control subjects (P=0.03). In conclusion, the results indicated different alleles associated with MS compared with previous reviews. The present study supports the importance of identifying genetic susceptibilities and targets for therapies in specific populations and individuals, to personalize disease management in terms of prediction, protective measures and treatment.

13.
Mutat Res ; 616(1-2): 175-80, 2007 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-17166523

RESUMO

A mutant allele of the beta-chemokine receptor gene CCR5 bearing a 32-basepair (bp) deletion that prevents cell invasion by the primary transmitting strain of HIV-1 has recently been characterized. Individuals homozygous for the mutation are resistant to infection, even after repeated high-risk exposure, but this resistance appears not absolute, as isolated cases of HIV-positive deletion homozygotes are emerging. The consequence of the heterozygous state is not clear, but it may delay the progression to AIDS in infected individuals. In order to evaluate the frequency distribution of CCR5-Delta32 polymorphism among Egyptians, a total of 200 individuals (154 from Ismailia and 46 from Sinai) were tested. Only two heterozygous individuals from Ismailia carried the CCR5-Delta32 allele (0.6%), and no homozygous (Delta32/Delta32) individuals were detected among the tested samples. The presence of the CCR5-Delta32 allele among Egyptians may be attributed to the admixture with people of European descent. Thus we conclude that the protective deletion CCR5-Delta32 is largely absent in the Egyptian population.


Assuntos
Infecções por HIV/genética , Infecções por HIV/imunologia , Imunidade Inata/genética , Receptores CCR5/genética , Deleção de Sequência , Alelos , Egito , Frequência do Gene , Genótipo , Humanos , Reação em Cadeia da Polimerase , Síria
14.
Adv Med ; 2016: 9182863, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27847860

RESUMO

Background. The morphology and function of anterolateral ligament (ALL) of the knee are not clearly understood even today with all the sophisticated techniques available. There have been differing descriptions of the ALL of the knee in literature, and not all of them have been named or described clearly. Aim. The present study was undertaken to provide a clear structure/relationship description on ALL. Materials and Methods. We used 24 formalin-fixed cadaveric limbs. Knee regions of the all the limbs were neatly dissected and the ALL was exposed. Its proximal and distal attachments were traced carefully. Middle portion of ALL was removed and processed for histological analysis. Results. ALL was found in one right knee (4.16%). It extended distally from the lateral femoral condyle to the lateral tibial plateau margin. Its attachment on the tibial plateau was located between head of the fibula and Gerdy's tubercle. A strong connection was identified between the ALL and the periphery of the middle third of the lateral meniscus. Histological analysis of ALL confirmed the presence of true ligamentous structure in it with dense connective tissue and plenty of fibroblasts. Conclusion. The prevalence of ALL in different populations along with its clinical significance has been discussed in detail in this paper.

15.
BMC Evol Biol ; 5: 18, 2005 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-15725352

RESUMO

BACKGROUND: Alu elements are short (approximately 300 bp) interspersed elements that amplify in primate genomes through a process termed retroposition. The expansion of these elements has had a significant impact on the structure and function of primate genomes. Approximately 10 % of the mass of the human genome is comprised of Alu elements, making them the most abundant short interspersed element (SINE) in our genome. The majority of Alu amplification occurred early in primate evolution, and the current rate of Alu retroposition is at least 100 fold slower than the peak of amplification that occurred 30-50 million years ago. Alu elements are therefore a rich source of inter- and intra-species primate genomic variation. RESULTS: A total of 153 Alu elements from the Ye subfamily were extracted from the draft sequence of the human genome. Analysis of these elements resulted in the discovery of two new Alu subfamilies, Ye4 and Ye6, complementing the previously described Ye5 subfamily. DNA sequence analysis of each of the Alu Ye subfamilies yielded average age estimates of approximately 14, approximately 13 and approximately 9.5 million years old for the Alu Ye4, Ye5 and Ye6 subfamilies, respectively. In addition, 120 Alu Ye4, Ye5 and Ye6 loci were screened using polymerase chain reaction (PCR) assays to determine their phylogenetic origin and levels of human genomic diversity. CONCLUSION: The Alu Ye lineage appears to have started amplifying relatively early in primate evolution and continued propagating at a low level as many of its members are found in a variety of hominoid (humans, greater and lesser ape) genomes. Detailed sequence analysis of several Alu pre-integration sites indicated that multiple types of events had occurred, including gene conversions, near-parallel independent insertions of different Alu elements and Alu-mediated genomic deletions. A potential hotspot for Alu insertion in the Fer1L3 gene on chromosome 10 was also identified.


Assuntos
Elementos Alu , Animais , Evolução Biológica , Mapeamento Cromossômico , Evolução Molecular , Deleção de Genes , Variação Genética , Genoma , Genoma Humano , Hominidae , Humanos , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Software
16.
J Mol Biol ; 326(4): 1127-46, 2003 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-12589758

RESUMO

The preTa subfamily of long interspersed elements (LINEs) is characterized by a three base-pair "ACG" sequence in the 3' untranslated region, contains approximately 400 members in the human genome, and has low level of nucleotide divergence with an estimated average age of 2.34 million years old suggesting that expansion of the L1 preTa subfamily occurred just after the divergence of humans and African apes. We have identified 362 preTa L1 elements from the draft human genomic sequence, investigated the genomic characteristics of preTa L1 insertions, and screened individual elements across diverse human populations and various non-human primate species using polymerase chain reaction (PCR) assays to determine the phylogenetic origin and levels of human genomic diversity associated with the L1 elements. All of the preTa L1 elements analyzed by PCR were absent from the orthologous positions in non-human primate genomes with 33 (14%) of the L1 elements being polymorphic with respect to insertion presence or absence in the human genome. The newly identified L1 insertion polymorphisms will prove useful as identical by descent genetic markers for the study of human population genetics. We provide evidence that preTa L1 elements show an integration site preference for genomic regions with low GC content. Computational analysis of the preTa L1 elements revealed that 29% of the elements amenable to complete sequence analysis have apparently escaped 5' truncation and are essentially full-length (approximately 6kb). In all, 29 have two intact open reading frames and may be capable of retrotransposition.


Assuntos
Evolução Molecular , Genoma Humano , Elementos Nucleotídeos Longos e Dispersos/genética , Análise de Sequência de DNA , Animais , Sequência de Bases , Linhagem Celular , Humanos , Reação em Cadeia da Polimerase , Polimorfismo Genético , Primatas/genética , Alinhamento de Sequência
17.
J Mol Biol ; 316(5): 1033-40, 2002 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-11884141

RESUMO

Alu elements belonging to the previously identified "young" subfamilies are thought to have inserted in the human genome after the divergence of humans from non-human primates and therefore should not be present in non-human primate genomes. Polymerase chain reaction (PCR) based screening of over 500 Alu insertion loci resulted in the recovery of a few "young" Alu elements that also resided at orthologous positions in non-human primate genomes. Sequence analysis demonstrated these "young" Alu insertions represented gene conversion events of pre-existing ancient Alu elements or independent parallel insertions of older Alu elements in the same genomic region. The level of gene conversion between Alu elements suggests that it may have a significant influence on the single nucleotide diversity within the genome. All the instances of multiple independent Alu insertions within the same small genomic regions were recovered from the owl monkey genome, indicating a higher Alu amplification rate in owl monkeys relative to many other primates. This study suggests that the majority of Alu insertions in primate genomes are the products of unique evolutionary events.


Assuntos
Elementos Alu/genética , Evolução Molecular , Conversão Gênica/genética , Genoma , Mutação/genética , Primatas/genética , Animais , Sequência de Bases , Amplificação de Genes/genética , Genoma Humano , Humanos , Cinética , Dados de Sequência Molecular , Mutagênese Insercional/genética , Alinhamento de Sequência , Análise de Sequência de DNA
18.
Adv Med Educ Pract ; 6: 27-34, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25610011

RESUMO

PURPOSE: This study examined the relationships between the different aspects of students' course experience, self-regulated learning, and academic achievement of medical students in a blended learning curriculum. METHODS: Perceptions of medical students (n=171) from the Royal College of Surgeons in Ireland, Medical University of Bahrain (RCSI Bahrain), on the blended learning experience were measured using the Student Course Experience Questionnaire (SCEQ), with an added e-Learning scale. In addition, self-regulated learning was measured using the Motivated Strategies for Learning Questionnaire (MSLQ). Academic achievement was measured by the scores of the students at the end of the course. A path analysis was created to test the relationships between the different study variables. RESULTS: Path analysis indicated that the perceived quality of the face-to-face component of the blended experience directly affected the motivation of students. The SCEQ scale "quality of teaching" directly affected two aspects of motivation: control of learning and intrinsic goal orientation. Furthermore, appropriate course workload directly affected the self-efficacy of students. Moreover, the e-Learning scale directly affected students' peer learning and critical thinking but indirectly affected metacognitive regulation. The resource management regulation strategies, time and study environment, and effort regulation directly affected students' examination scores (17% of the variance explained). However, there were no significant direct relationships between the SCEQ scales and cognitive learning strategies or examination scores. CONCLUSION: The results of this study will have important implications for designing blended learning courses in medical schools.

19.
Blood Coagul Fibrinolysis ; 26(8): 919-24, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26226255

RESUMO

Thrombomodulin is expressed on endothelial cells and monocytes (mTM) where it has an anticoagulant function. Enzymatic cleavage from the cell surface produces soluble thrombomodulin (sTM) in plasma. Abnormal levels of sTM and mutations in the thrombomodulin gene (THBD) are linked to cardiovascular disease. The aim of this study was to investigate THBD proximal promoter mutations and levels of sTM and mTM in men presenting with premature acute coronary syndrome (ACS). This prospective cross-sectional study included 100 adult men with premature ACS (age <55 years) and 60 healthy age-matched controls. Plasma sTM was assayed by ELISA. mTM expression was assessed by flow cytometry with CD141 antibody. The -33 G/A polymorphism was identified by PCR-restriction fragment length polymorphism analysis and the THBD proximal promoter region was sequenced. Significantly lower sTM (P < 0.001) and higher mTM (P < 0.001) were seen in ACS patients. Heterozygous THBD promoter polymorphisms -33 G/A and -9/-10 GG/AT were found in eight patients and five control individuals. In patients and control individuals, allele frequencies of A were 0.02 and 0.025, and that of AT were 0.025 and 0.017, respectively. There were no significant associations of these polymorphisms with ACS, sTM levels or mTM expression. THBD polymorphisms -33 G/A and -9/-10 GG/AT are present in low frequency in our patient population, and are more frequent in the South Asians as compared to the Arabs. The frequency of -33 G/A is lower, whereas that of -9/-10 GG/AT is higher than that reported in the Orientals. The presence of THBD proximal promoter polymorphisms do not explain variations in levels of sTM and mTM in this patient population.


Assuntos
Síndrome Coronariana Aguda/genética , Polimorfismo Genético , Regiões Promotoras Genéticas , Trombomodulina/genética , Síndrome Coronariana Aguda/sangue , Síndrome Coronariana Aguda/patologia , Adulto , Fatores Etários , Alelos , Barein , Estudos de Casos e Controles , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Expressão Gênica , Frequência do Gene , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Monócitos/metabolismo , Monócitos/patologia , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Trombomodulina/sangue
20.
Atherosclerosis ; 242(2): 521-8, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26302166

RESUMO

OBJECTIVE: The variant allele of rs3798220 in the apolipoprotein(a) gene (LPA) is used to assess the risk for coronary artery disease (CAD) in Europeans, where it is associated with short alleles of the Kringle IV-2 (KIV-2) copy number variation (CNV) and high lipoprotein(a) (Lp(a)) concentrations. No association of rs3798220 with CAD was detected in a GWAS of East Asians. Our study investigated the association of rs3798220 with Lp(a) concentrations and KIV-2 CNV size in non-European populations to explain the missing association of the variant with CAD in Asians. METHODS: We screened three populations from Africa and seven from Asia by TaqMan Assay for rs3798220 and determined KIV-2 CNV sizes of LPA alleles by pulsed-field gel electrophoresis (PFGE). Additionally, CAD cases from India were analysed. To investigate the phylogenetic origin of rs3798220, 40 LPA alleles from Chinese individuals were separated by PFGE and haplotyped for further SNPs. RESULTS: The variant was not found in Africans. Allele frequencies in East and Southeast Asians ranged from 2.9% to 11.6%, and were very low (0.15%) in CAD cases and controls from India. The variant was neither associated with short KIV-2 CNV alleles nor elevated Lp(a) concentrations in Asians. CONCLUSION: Our study shows that rs3798220 is no marker for short KIV-2 CNV alleles and high Lp(a) in East and Southeast Asians, although the haplotype background is shared with Europeans. It appears unlikely that this SNP confers atherogenic potential on its own. Furthermore, this SNP does not explain Lp(a) attributed risk for CAD in Asian Indians.


Assuntos
Apolipoproteínas A/genética , Variações do Número de Cópias de DNA , Polimorfismo de Nucleotídeo Único , África , Alelos , Ásia , Povo Asiático , China , Doença da Artéria Coronariana/etnologia , Doença da Artéria Coronariana/genética , Eletroforese em Gel de Campo Pulsado , Frequência do Gene , Marcadores Genéticos , Variação Genética , Estudo de Associação Genômica Ampla , Genótipo , Haplótipos , Humanos , Índia , Filogenia , Isoformas de Proteínas/genética
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