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1.
Heliyon ; 9(11): e22270, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38045152

RESUMEN

Objective: The main aim of this study is to develop a valid and reliable instrument to assess levels of knowledge and perceptions of predatory journals. Methods: The current study employed successive methods framework including (1) item generation through a literature review and theoretical framework development, (2) validity testing in terms of face, content, and construct validity for perceptions construct as well as item analysis for knowledge scale, and (3) reliability testing in terms of Cronbach's alpha, Kuder-Richardson (KR-20), item-to-total correlations, corrected item-to-total correlations, Cronbach's alpha if item deleted, and test-retest reliability. A total of 304 participants were recruited from King Fahad Medical City (KFMC) in Riyadh, Saudi Arabia to evaluate its construct validity and reliability. This was established using exploratory factor analysis (EFA) with principal axis factoring (PFA) and varimax rotation as well as confirmatory factor analysis (CFA) for perception construct. Results: An instrument was developed from this study called the "Predatory Journals KP Assessment Questionnaire". The results of EFA and CFA confirmed the construct validity of the perception construct. Item analysis confirmed the construct validity of the knowledge scale. The internal consistency and test-retest reliability were achieved for the knowledge scale items, consisting of 13 items. The results of EFA confirmed the measured constructs of perceptions toward predatory journals. The results of EFA and CFA for perception construct resulted in only one factor with 9 items. Conclusion: This study has successfully developed a valid and reliable questionnaire to measure knowledge and perceptions of predatory journals among researchers in the clinical and health disciplines. This instrument serves as a valuable guide for future studies that aim to assess researcher's knowledge and perceptions about predatory journals and examine the differences in these measured constructs according to their demographic and professional characteristics.

2.
Biomedicine (Taipei) ; 12(3): 12-19, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36381187

RESUMEN

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzyme deficiency disorder affecting over 400 million individuals worldwide. G6PD protects red blood cells (RBC) from the harmful effects of oxidative substances. There are more than 400 G6PD mutations, of which 186 variants have shown to be linked to G6PD deficiency by decreasing the activity or stability of the enzyme. Different variants manifest different clinical phenotypes which complicate comprehending the mechanism of the disease. In order to carry out computational approaches to elucidate the structural changes of different G6PD variants that are common to the Asian population, a complete G6PD monomer-ligand complex was constructed using AutoDock 4.2, and the molecular dynamics simulation package GROMACS 4.6.7 was used to study the protein dynamics. The G410D and V291M variants were chosen to represent classes I and II respectively and were created by in silico site-directed mutagenesis. Results from the Root mean square deviation (RMSD), Root mean square fluctuation (RMSF) and Radius of gyration (Rg) analyses provided insights on the structure - function relationship for the variants. G410D indicated impaired dimerization and structural NADP binding while the impaired catalytic activity for V291M was indicated by a conformational change at its mutation site.

3.
J Empir Res Hum Res Ethics ; 17(5): 536-544, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36154532

RESUMEN

Contract cheating and ghostwriting are forms of misconduct that are unethical and a serious academic issue, especially among healthcare professionals, as they directly impact patient health. To date, research on this area in the Middle East has been limited. Therefore, we used a validated self-administered questionnaire to investigate the awareness, perceptions, and reasons for these behaviors among 682 students in health specialties at five universities in Riyadh, Saudi Arabia. The majority of the students (60.1%) were unaware of the terms "contract cheating" and "ghostwriting," and 69.5% had not received any prior training on integrity. However, having prior training had a positive effect on awareness levels, and respondents attending private universities were significantly more aware than those attending public universities. The factors that contributed to contract cheating behavior included poor time management, English language difficulties, and a lack of writing skills. These findings emphasize the need for integrity training at the national level to raise awareness.


Asunto(s)
Decepción , Plagio , Humanos , Universidades , Encuestas y Cuestionarios , Estudiantes
4.
Int J Immunopathol Pharmacol ; 36: 3946320221090330, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35404688

RESUMEN

INTRODUCTION: Type 1 diabetes mellitus (T1DM) is characterized by autoimmune destruction of insulin-producing pancreatic beta (ß-) cells. Previous studies suggested an imbalance between and pro- and anti-inflammatory cytokines exacerbates T1DM development. OBJECTIVES: We aimed to test the hypothesis that patients with T1DM carry a higher frequency of regulatory genes associated with low levels of the anti-inflammatory cytokines interleukin-4 (IL-4), its receptor (IL-4R), and interleukin-10 (IL-10). METHODS: Accordingly, we compared frequencies of five different single nucleotide polymorphisms (SNPs) in T1DM patients and healthy controls who had been typed for HLA-DRB1, HLA-DQA1, and HLA-DQB1 genes. RESULTS: The frequencies of rs2070874 (IL-4) alleles C and T differed between T1DM patients and controls (cp = 0.0065), as did their codominant (cp = 0.026) and recessive (cp = 0.015) models. Increased frequencies were observed in T1DM patients for HLA alleles: DRB1*03 (pc < 0.0013), DRB1*04 (cp = 0.0169), DQA1*03 (cp = 0.0222), DQA1*05 (cp < 0.0006), DQB1*02 (cp = 0.0005), and DQB1*06 (cp < 0.0005). And lower frequencies were observed for: DRB1*07 (cp = 0.0078), DRB1*11 (cp = 0.0013), DRB1*13 (cp < 0.0364), DRB1*15 (cp < 0.0013), DQA1*01 (cp < 0.0006), and DQA1*02 (cp = 0.0348). Certain DRB1: DQA1: DQB1 haplotypes showed greater frequencies, including, 03:05:02 (p < 0.0001) and 04:03:03 (p = 0.0017), whereas others showed lower frequencies, including, 07:02:02 (p = 0.0032), 11:05:03 (p = 0.0007), and 15:01:06 (p = 0.0002). Stratification for the above HLA haplotypes with rs2070874 C/C exhibited no significant differences between T1DM patients overall and controls. However, when stratified for the vulnerable HLA haplotype (03:05:02/04:03:03), young patients in whom T1DM began at ≤13 years had a higher frequency of the SNP (rs2070874 C/C); a gene associated with low IL-4 production (p < 0.024). CONCLUSION: This study suggests that possession of the rs2070874 C/C genotype, which is associated with low production of IL-4, increases the risk of T1DM in young individuals carrying vulnerable HLA alleles/haplotypes.


Asunto(s)
Diabetes Mellitus Tipo 1 , Predisposición Genética a la Enfermedad , Interleucina-4 , Polimorfismo de Nucleótido Simple , Diabetes Mellitus Tipo 1/genética , Frecuencia de los Genes , Antígenos HLA-DQ/genética , Cadenas beta de HLA-DQ/genética , Cadenas HLA-DRB1/genética , Haplotipos , Humanos , Interleucina-4/genética
5.
Artículo en Inglés | MEDLINE | ID: mdl-35356236

RESUMEN

Materials and Methods: G. kola methanolic extract was fractionated using increasingly polar solvents. Fractions were administered to streptozotocin (STZ)-induced diabetic mice until marked motor signs developed in diabetic controls. Fine motor skills indicators were measured in the horizontal grid test (HGT) to confirm the prevention of motor disorders in treated animals. Column chromatography was used to separate the most active fraction, and subfractions were tested in turn in the HGT. Gas chromatography-mass spectrometry (GC-MS) technique was used to assess the components of the most active subfraction. Results: Treatment with ethyl acetate fraction and its fifth eluate (F5) preserved fine motor skills and improved the body weight and blood glucose level. At dose 1.71 mg/kg, F5 kept most parameters comparable to the nondiabetic vehicle group values. GC-MS chromatographic analysis of F5 revealed 36 compounds, the most abundantly expressed (41.8%) being the ß-lactam molecules N-ethyl-2-carbethoxyazetidine (17.8%), N,N-dimethylethanolamine (15%), and isoniacinamide (9%). Conclusions: Our results suggest that subfraction F5 of G. kola extract prevented the development of motor signs and improved disease profile in an STZ-induced mouse model of diabetic encephalopathy. Antidiabetic activity of ß-lactam molecules accounted at least partly for these effects.

6.
Pediatr Res ; 91(3): 539-544, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-33824452

RESUMEN

BACKGROUND: This study aimed to assess the telomere length and plasma telomere repeat-binding factor 2 (TRF2) levels in addition to other inflammatory markers in children with sickle cell disease (SCD). METHODS: We enrolled 106 children (90 SCD and 26 controls) aged 1-15 years from the Hematology unit of King Fahad Medical City (KFMC), Saudi Arabia. Genomic DNA extracted from blood and leukocyte TL was determined using quantitative reverse transcription PCR, whereas TRF2, C-reactive protein, interleukin-6, and DNA oxidative damage were determined by using respective commercially available assays. RESULTS: Leukocyte TL was inversely correlated with age in the SCD patients (r = -0.24, P = 0.02) and the controls (r = -0.68, P < 0.0001). In addition, SCD patients had significantly shorter TL (7.74 ± 0.81 kb) (P = 0.003) than controls (8.28 ± 0.73 kb). In contrast, no significant difference in TL among the SCD genotypes (HbSS and HbSß0) has been observed. A modest, positive correlation was seen between TL and reticulocyte % (r = 0.21; P = 0.06). There were no significant differences in the TL and TRF2 concentrations between subjects with HbSS and HbSß0 genotypes. CONCLUSIONS: Short leukocyte TL was significantly associated with SCD. An inverse association was observed between TL and hemoglobin. Hydroxyurea treatment revealed no impact on TL. IMPACT: This study explored the TL and plasma TRF2 in Saudi children with SCD. This is the first documentation that SCD children have shorter TL than their healthy counterparts, and no association between TL and TRF2 has been observed. Hydroxyurea treatment showed no impact on TL in children with SCD. This study is the first of its kind in children with SCD. It will pave the way for another study with a larger sample size in a diverse population to scrutinize these findings better.


Asunto(s)
Anemia de Células Falciformes , Hidroxiurea , Anemia de Células Falciformes/tratamiento farmacológico , Anemia de Células Falciformes/genética , Biomarcadores , Niño , Humanos , Hidroxiurea/uso terapéutico , Leucocitos , Proteínas de Unión a Telómeros
7.
Saudi J Biol Sci ; 27(12): 3641-3646, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33304175

RESUMEN

Garcinia kola (G. kola), is a plant characterized by its hypoglycemic properties. We recently reported our findings on the extracts of G. kola, in which we found that it prevented the loss of inflammation-sensible neuronal populations in streptozotocin (STZ)-induced rat models of type 1 diabetes mellitus (T1DM). In the present study we assessed the effect of G. kola bioactive compounds extracted successively with water, hexane, methylene chloride, ethyl acetate, and butanol. through analyzing biochemical markers of oxidative stress, inflammation, and metabolic function in STZ-induced diabetic animals. Animals made diabetic by a single injection with STZ (60 mg/kg, i.p.), were treated daily with either vehicle solution, insulin, or G. kola extracts and its fractions from the first to the 6th-week post-injection. Biochemical markers; glucose, insulin, C-peptide, neuron-specific enolase (NSE), creatinine kinase, glutathione peroxidase, malondialdehyde (MDA), resistin, soluble E-selectin (SE-Selectin), and C-reactive proteins (CRP) levels in the sera were determined in the study groups. A marked increase in blood glucose (209.26% of baseline value), and a decrease in body weight (-12.37%) were observed in diabetic control animals but not in animals treated with either insulin or G. kola extracts and its fractions. The sub-fraction F5, G. kola ethyl acetate had the highest bioactive activities, with a maintenance of blood sugar, malondialdehyde, C-peptide, E-selectin, C-reactive protein (CRP) and neuron-specific enolase (NSE) to levels and responses comparable to healthy non-diabetic vehicle group and the positive control diabetic insulin-treated group. Our findings suggest that G. kola may have a strong therapeutic potential against T1DM and its microvascular complications.

8.
Adv Physiol Educ ; 42(4): 541-546, 2018 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-30192187

RESUMEN

The aim of the study was to explore the factors associated with the recall of basic medical physiology knowledge among medical interns and to determine the level of retained basic science knowledge. Two hundred and four interns, 114 women and 90 men, working in two major tertiary medical care centers, King Fahad Medical City (KFMC; 29 students) and King Khalid University Hospital (KKUH; 117 students), in Riyadh city, participated in the study. An anonymous knowledge test with 10 validated multiple-choice questions was developed specifically for this purpose. One hundred and forty-six interns (117 working at KKUH and 29 at KFMC) had graduated from medical schools adopting a conventional instructional system, whereas 58 (3 from KKUH and 55 from KFMC had graduated from schools adopting an integrated system (hybrid problem-based learning). Fifty-two students (26%) gained a score ≥60%, whereas 152 students (74%) obtained <60% of the score. Higher scores were associated with younger age ( P < 0.01), traditional curriculum ( P < 0.001), interns from KKUH ( P < 0.001), and candidates for postgraduate studies ( P < 0.02). There was no significant association between recall of physiology knowledge and all other variables studied, including sex. Multivariate analyses show that age and traditional curriculum are the only significant predictors of knowledge retention. Almost three-fourths of the interns scored <60%, and higher scores were significantly associated with younger interns, traditional curriculum, working in KKUH, and interns preparing for graduate studies. However, the difference between the two curricula disappears when the influence of hospital training is considered.


Asunto(s)
Conocimientos, Actitudes y Práctica en Salud , Internado y Residencia , Recuerdo Mental/fisiología , Fisiología/educación , Adulto , Estudios Transversales , Femenino , Humanos , Internado y Residencia/tendencias , Masculino , Fisiología/tendencias , Arabia Saudita , Adulto Joven
9.
J Complement Integr Med ; 14(3)2017 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-28889733

RESUMEN

Background We reported recently that extracts of seeds of Garcinia kola, a plant with established hypoglycemic properties, prevented the loss of inflammation-sensible neuronal populations like Purkinje cells in a rat model of type 1 diabetes mellitus (T1DM). Here, we assessed G. kola extract ability to prevent the early cognitive and motor dysfunctions observed in this model. Methods Rats made diabetic by single injection of streptozotocin were treated daily with either vehicle solution (diabetic control group), insulin, or G. kola extract from the first to the 6th week post-injection. Then, cognitive and motor functions were assessed using holeboard and vertical pole behavioral tests, and animals were sacrificed. Brains were dissected out, cut, and processed for Nissl staining and immunohistochemistry. Results Hyperglycemia (209.26 %), body weight loss (-12.37 %), and T1DM-like cognitive and motor dysfunctions revealed behavioral tests in diabetic control animals were not observed in insulin and extract-treated animals. Similar, expressions of inflammation markers tumor necrosis factor (TNF), iba1 (CD68), and Glial fibrillary acidic protein (GFAP), as well as decreases of neuronal density in regions involved in cognitive and motor functions (-49.56 % motor cortex, -33.24 % medial septal nucleus, -41.8 % /-37.34 % cerebellar Purkinje /granular cell layers) were observed in diabetic controls but not in animals treated with insulin or G. kola. Conclusions Our results indicate that T1DM-like functional alterations are mediated, at least partly, by neuroinflammation and neuronal loss in this model. The prevention of the development of such alterations by early treatment with G. kola confirms the neuroprotective properties of the plant and warrant further mechanistic studies, considering the potential for human disease.


Asunto(s)
Antiinflamatorios/farmacología , Cognición/efectos de los fármacos , Diabetes Mellitus Experimental/tratamiento farmacológico , Garcinia kola , Destreza Motora/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Fitoterapia , Administración Oral , Animales , Antiinflamatorios/uso terapéutico , Diabetes Mellitus Experimental/inducido químicamente , Diabetes Mellitus Experimental/fisiopatología , Diabetes Mellitus Experimental/psicología , Diabetes Mellitus Tipo 1/inducido químicamente , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Diabetes Mellitus Tipo 1/fisiopatología , Diabetes Mellitus Tipo 1/psicología , Masculino , Fármacos Neuroprotectores/uso terapéutico , Extractos Vegetales/farmacología , Extractos Vegetales/uso terapéutico , Ratas , Ratas Wistar , Semillas , Estreptozocina , Resultado del Tratamiento
10.
Hum Immunol ; 77(1): 110-114, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26542066

RESUMEN

Genetic and environmental factors play important roles in predisposing an individual to the development of type 1 diabetes (T1D). Several studies have investigated the role of killer cell immunoglobulin-like receptors (KIRs) and their HLA-class I ligands in susceptibility to T1D development, but only some of these studies have demonstrated an association. KIRs and their corresponding HLA class I ligands were investigated in Saudi patients with T1D compared with healthy controls. No significant differences in KIR gene distribution were observed between T1D patients and healthy controls. However, the homozygous C1/C1 ligand was considered a risk factor in predisposing individuals to T1D, whereas C2/C2 and HLA-Bw4 were considered protective factors against T1D. KIR2DL2/2DS2-C1C1 and KIR2DL3-C1C1 were significantly associated with T1D, and KIR2DS1-C2C2 and KIR2DL1-C2C2 were significantly less frequent in T1D patients. Stratification of KIR-HLA class I ligands in terms of the absence/presence of specific genotypes has different indications for susceptibility to T1D.


Asunto(s)
Diabetes Mellitus Tipo 1/inmunología , Células Asesinas Naturales/inmunología , Receptores KIR/genética , Adolescente , Niño , Preescolar , Diabetes Mellitus Tipo 1/genética , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Genotipo , Antígenos HLA-B/genética , Humanos , Desequilibrio de Ligamiento , Polimorfismo Genético , Arabia Saudita
11.
Artículo en Inglés | MEDLINE | ID: mdl-20445250

RESUMEN

Glutamate dehydrogenase (EC 1.4.1.2-4) from Peptoniphilus asaccharolyticus has been expressed as a selenomethionine-derivatized recombinant protein and diffraction-quality crystals have been grown that are suitable for structure determination. Preliminary structural analyses indicate that the protein assembles as a homohexameric enzyme complex in solution, similar to other bacterial and mammalian enzymes to which its sequence identity varies between 25 and 40%. The structure will provide insight into its preference for the cofactor NADH (over NADPH) by comparisons with the known structures of mammalian and bacterial enzymes.


Asunto(s)
Glutamato Deshidrogenasa/química , Peptostreptococcus/enzimología , Cristalografía por Rayos X , Expresión Génica , Glutamato Deshidrogenasa/genética
12.
FEBS Lett ; 582(13): 1816-20, 2008 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-18472008

RESUMEN

Clostridial glutamate dehydrogenase mutants with the 5 Trp residues in turn replaced by Phe showed the importance of Trp 64 and 449 in cooperativity with glutamate at pH 9. These mutants are examined here for their behaviour with NAD+ at pH 7.0 and 9.0. The wild-type enzyme displays negative NAD+ cooperativity at both pH values. At pH 7.0 W243F gives Michaelis-Menten kinetics, and the same behaviour is shown by W243F and also W310F at pH 9.0, but not by W64F or W449F. W243 and W310 are apparently much more important than W64 and W449 for the coenzyme negative cooperativity, implying that different conformational transitions are involved in cooperativity with the coenzyme and with glutamate.


Asunto(s)
Proteínas Bacterianas/metabolismo , Clostridium symbiosum/enzimología , Glutamato Deshidrogenasa/metabolismo , Glutamatos/metabolismo , NAD/metabolismo , Regulación Alostérica , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Glutamato Deshidrogenasa/química , Glutamato Deshidrogenasa/genética , Glutamatos/química , Mutación , NAD/química , Fenilalanina/química , Fenilalanina/genética , Triptófano/química , Triptófano/genética
13.
FEBS J ; 274(16): 4126-34, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17645547

RESUMEN

The hexameric glutamate dehydrogenase of Clostridium symbiosum has previously been shown to undergo a pH-dependent inactivating conformational change that perturbs the environment of one or more Trp residues and is reversed by glutamate in a highly cooperative fashion with a Hill coefficient of almost 6. Five single mutants have now been made in which each of the Trp residues in turn has been replaced by Phe. All five were successfully over-produced as soluble proteins and purified. Far-UV CD showed that none of the mutations significantly affected secondary structure. All five proteins were active, ranging from 13 U.mg(-1) (W64F) to 20.8 U.mg(-1) (W393F), compared to 20 U.mg(-1) for wild-type, and the kinetic parameters at pH 7 were little changed, except for a five- to six-fold increase in Km for glutamate in W243F. Thermostability was also relatively little changed, although W310F and W393F were somewhat more stable and W64F less stable than the unmutated enzyme. All still showed the characteristic reversible, time-dependent high-pH inactivation. Near-UV CD spectra, reflecting the environment of aromatic residues, were recorded at both pH 7 and 8.8, and four of the mutants showed essentially the same perturbation in the 280 nm region as the wild-type enzyme. W64F, however, showed essentially no change. W64 is thus clearly a passive reporter of the pH-dependent conformational change, and not actually required for the transition to occur. The CD comparisons also suggest that the aromatic CD spectrum is contributed almost entirely by W64 and W449. Consistent with the pH-dependent change, all five mutant proteins also showed a positively cooperative response to glutamate at pH 9, reversing the inactivation. However, the Hill coefficient decreased from > 5 for wild-type to approximately 3 for the active site cleft mutation W243F and to approximately 2 for the interfacial mutants W64F and W449F in which the trimer-trimer interaction may be directly interrupted. W64 of each subunit is in contact with W449 in its dimer partner at the trimer-trimer interface. It seems that, although neither of these two residues is required for the pH-dependent change, together, they are essential in mediating the total cooperativity of the hexameric enzyme's response to glutamate and are presumably directly involved in transmitting conformational information between the two trimers.


Asunto(s)
Proteínas Bacterianas/química , Clostridium symbiosum/enzimología , Glutamato Deshidrogenasa/química , Triptófano/química , Sustitución de Aminoácidos , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Sitios de Unión/genética , Dicroismo Circular , Estabilidad de Enzimas , Glutamato Deshidrogenasa/genética , Glutamato Deshidrogenasa/metabolismo , Ácido Glutámico/metabolismo , Ácido Glutámico/farmacología , Concentración de Iones de Hidrógeno , Cinética , Mutación , Fenilalanina/química , Fenilalanina/genética , Fenilalanina/metabolismo , Conformación Proteica/efectos de los fármacos , Estructura Terciaria de Proteína , Temperatura , Triptófano/genética , Triptófano/metabolismo
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