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1.
Int J Mol Sci ; 23(11)2022 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-35682757

RESUMO

Antibodies play a crucial role in the immune response, in fighting off pathogens as well as helping create strong immunological memory. Antibody-dependent enhancement (ADE) occurs when non-neutralising antibodies recognise and bind to a pathogen, but are unable to prevent infection, and is widely known and is reported as occurring in infection caused by several viruses. This narrative review explores the ADE phenomenon, its occurrence in viral infections and evaluates its role in infection by SARS-CoV-2 virus, which causes coronavirus disease 2019 (COVID-19). As of yet, there is no clear evidence of ADE in SARS-CoV-2, though this area is still subject to further study.


Assuntos
COVID-19 , SARS-CoV-2 , Anticorpos Neutralizantes , Anticorpos Antivirais/uso terapêutico , Anticorpos Facilitadores , Humanos
2.
Int J Mol Sci ; 23(9)2022 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-35563221

RESUMO

Staphylococcus protein A (SpA) is found in the cell wall of Staphylococcus aureus bacteria. Its ability to bind to the constant Fc regions of antibodies means it is useful for antibody extraction, and further integration with inorganic materials can lead to the development of diagnostics and therapeutics. We have investigated the adsorption of SpA on inorganic surface models such as experimentally relevant negatively charged silica, as well as positively charged and neutral surfaces, by use of fully atomistic molecular dynamics simulations. We have found that SpA, which is itself negatively charged at pH7, is able to adsorb on all our surface models. However, adsorption on charged surfaces is more specific in terms of protein orientation compared to a neutral Au (111) surface, while the protein structure is generally well maintained in all cases. The results indicate that SpA adsorption is optimal on the siloxide-rich silica surface, which is negative at pH7 since this keeps the Fc binding regions free to interact with other species in solution. Due to the dominant role of electrostatics, the results are transferable to other inorganic materials and pave the way for new diagnostic and therapeutic designs where SpA might be used to conjugate antibodies to nanoparticles.


Assuntos
Simulação de Dinâmica Molecular , Proteína Estafilocócica A , Adsorção , Anticorpos , Dióxido de Silício/química , Staphylococcus , Propriedades de Superfície
3.
Curr Opin Colloid Interface Sci ; 54: 101461, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33907504

RESUMO

Nanoparticles are small particles sized 1-100 nm, which have a large surface-to-volume ratio, allowing efficient adsorption of drugs, proteins, and other chemical compounds. Consequently, functionalized nanoparticles have potential diagnostic and therapeutic applications. A variety of nanoparticles have been studied, including those constructed from inorganic materials, biopolymers, and lipids. In this review, we focus on recent work targeting the severe acute respiratory syndrome coronavirus 2 virus that causes coronavirus disease (COVID-19). Understanding the interactions between coronavirus-specific proteins (such as the spike protein and its host cell receptor angiotensin-converting enzyme 2) with different nanoparticles paves the way to the development of new therapeutics and diagnostics that are urgently needed for the fight against COVID-19, and indeed for related future viral threats that may emerge.

4.
Pak J Med Sci ; 36(3): 327-332, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32292428

RESUMO

OBJECTIVE: To explore the impact of Blackboard (Bb) formative assessment on the final score in the endocrine module and determine the medical students' perception of the impact and effectiveness of Bb. METHODS: This exploratory case study was carried out at the King Abdulaziz University (KAU), Jeddah, Saudi Arabia (SA). Blackboard was used in the course management and formative assessment of third-year medical students and three years of data was collected (2016, 2017, 2019). In the last week of the module before the final exam, a formative assessment test that comprised of 50 Multiple Choice Questions (MCQs) was posted on Bb each year. All the students filled a questionnaire regarding their perception about the impact and effectiveness of Bb. RESULTS: Overall, summative exam scores were significantly higher than the scores in formative assessment (p <0.001). A substantial positive correlation was observed between students' marks in the online (Bb) MCQ exam and their final exam marks (p <0.001). Regarding the features of Bb, most often used by the students' were course resources uploaded on the Bb, assignments, online quizzes, and others. Majority of the students were satisfied with the use of Bb in this module. CONCLUSIONS: The majority of the students liked this blended learning (BL) method and conceded the impact and effectiveness of Bb. The formative online assessment on Bb improved the students' performance in the final exam and a positive correlation was noted between students' marks in online (Bb) exams with their final exam marks.

5.
Med Teach ; 40(sup1): S104-S113, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29909725

RESUMO

BACKGROUND: Medical education has a longstanding tradition of using logbooks to record activities. The portfolio is an alternative tool to document competence and promote reflective practice. This study assessed the acceptance of portfolio use among Saudi undergraduate medical students. METHODS: Portfolios were introduced in the 2nd through 5th years at King Abdulaziz University over a two-year period (2013-2015). At the end of each academic year, students completed a mixed questionnaire that included a self-assessment of skills learned through the use of portfolio. RESULTS: The results showed a difference in focus between basic and clinical years: in basic years students' focus was on acquiring practical skills, but in clinical years they focused more on acquiring complex skills, including identifying and managing problems. The questionnaire responses nonetheless revealed a positive trend in acceptance (belief in the educational value) of portfolios among students and their mentors, across the years of the program. CONCLUSIONS: Using portfolios as a developmental learning and formative assessment tool in the early undergraduate years was found to contribute to students' ability to create their own clinical skills guidelines in later years, as well as to engage in and appreciate reflective learning.


Assuntos
Atitude do Pessoal de Saúde , Competência Clínica/normas , Educação de Graduação em Medicina/métodos , Avaliação Educacional/métodos , Estudantes de Medicina/estatística & dados numéricos , Humanos , Faculdades de Medicina , Autoavaliação (Psicologia) , Inquéritos e Questionários
6.
Med Teach ; 39(sup1): S37-S44, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28281375

RESUMO

AIM: This study aimed to evaluate fifth-year medical students' perception of their learning experience during pediatric rotation at the medical college of King Abdulaziz University (KAU), Jeddah, Saudi Arabia. METHOD: This cross-sectional study was conducted by distributing a questionnaire to fifth-year students who attended the pediatric rotation at KAU, during 2013-2014. RESULTS: Three hundred fifty-six out of 360 students agreed to participate, representing a response rate of 99%. More than 90% were satisfied with the module, and 80% reported the usefulness of the orientation session. The mean scores for the usefulness of morning experience and afternoon activities were 7.20 ± 2.40 and 6.40 ± 2.70, respectively. A significant difference in the mean scores for supervision was observed between the clerkship sites (p = .0001), with the highest score for consultants' supervision (7.01 ± 2.90) and lowest for interns' supervision (4.81 ± 3.30). CONCLUSIONS: Overall, although the program was satisfactory to the majority of participants, areas of concern were identified. Students reported more effective learning and development of clinical skills , during the morning rounds, when supervised by consultants and senior specialists, and in activities that involved examining patients, presenting cases, and participating in discussions.


Assuntos
Educação de Graduação em Medicina/métodos , Aprendizagem , Pediatria/educação , Estudantes de Medicina , Estudos Transversais , Humanos , Percepção , Arábia Saudita , Faculdades de Medicina , Estudantes de Medicina/psicologia
7.
Pediatr Nephrol ; 18(6): 506-10, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12720080

RESUMO

Familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC) is a rare autosomal recessive tubular disorder that is frequently associated with progressive renal failure. The primary defect is related to impaired tubular reabsorption of magnesium (Mg) and calcium (Ca) in the thick ascending limb of Henle's loop. We have studied seven Arab patients with this syndrome who belong to four different families. The mean age at first presentation was 1.5+/-1.3 years (range 0.1-3 years) and at diagnosis 5.9+/-4.3 years (range 0.5-12 years). The presenting features were convulsions and carpopedal spasms (5 patients), polydipsia and polyuria (2 patients), rickets (2 patients), and recurrent urinary tract infections (1 patient). Bilateral nephrocalcinosis was observed in all patients. All patients had hypomagnesemia with a mean serum Mg of 0.45+/-0.09 mmol/l, an inappropriately high urine Mg of 2.07+/-0.73 mmol/24 h or fractional excretion of 15.3+/-7.1%, high urine Ca excretion of 4.1+/-1.2 mmol/24 h or urine Ca to creatinine ratio of 2.6+/-1.6, and normal serum potassium level of 4.4+/-0.34 mmol/l. All patients received Mg supplements and thiazide but exhibited slow worsening of their kidney function. After a mean follow-up of 4.4+/-3.9 years, one patient progressed to end-stage renal failure (ESRF). In conclusion, we report seven Arab patients with FHHNC syndrome. The clinical and biochemical data were similar to previous reports. However, they tend to show a slower rate of progression to ESRF.


Assuntos
Cálcio/urina , Deficiência de Magnésio/diagnóstico , Deficiência de Magnésio/genética , Nefrocalcinose/genética , Árabes , Criança , Pré-Escolar , Progressão da Doença , Saúde da Família , Feminino , Seguimentos , Genes Recessivos , Humanos , Lactente , Falência Renal Crônica/sangue , Falência Renal Crônica/genética , Falência Renal Crônica/urina , Deficiência de Magnésio/urina , Masculino , Nefrocalcinose/sangue , Nefrocalcinose/urina , Irmãos
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