Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
1.
J Adolesc Health ; 73(6S): S73-S80, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37953012

RESUMO

PURPOSE: Poor mental health is associated with sexual and reproductive health (SRH) risks, including human immunodeficiency virus (HIV) and pre-exposure prophylaxis discontinuation. Adolescents and young people (AYP) are vulnerable to HIV and depression. This paper describes the prevalence and severity of depression and associated factors in AYP accessing SRH services in South Africa. METHODS: A cross-sectional analysis of enrollment data (January 2019 to December 2021) from a cohort of individuals receiving pre-exposure prophylaxis services at eight clinics in three provinces in South Africa was conducted. Females (n = 1,074) and males (n = 231) aged 15-24 years were included. Interviewer-administered questionnaires were conducted, and the prevalence and severity of depression assessed using the Patient Health Questionnaire-9. Multivariate analysis was used to identify factors associated with depression. RESULTS: Over 40% of participants had experienced any depression symptoms (43.7% of females, 38.5% of males). For males, experiencing intimate partner violence was the only predictor of depression symptoms (adjusted odds ratio (AOR) 8.81, 95% confidence intervals (CI) 1.03-75.44). For females, living with both parents (AOR 1.70, 95% CI 1.15-2.51), having transactional sex (AOR 1.63, 95% CI 1.00-2.65), experiencing any intimate partner violence (AOR 1.96, 95% CI 1.34-2.89), and using drugs (AOR 1.78, 95% CI 1.03-3.11) were all positively associated with depression symptoms. Resilience was a protective factor against depression symptoms for both sexes (males: AOR 0.96, 95% CI 0.93-0.98; females: AOR 0.96, 95% CI 0.95-0.97). DISCUSSION: There is a high burden of depression among AYP accessing SRH services in South Africa. Mental health screening should be integrated into SRH and HIV prevention programs for AYP.


Assuntos
Infecções por HIV , Masculino , Feminino , Humanos , Adulto Jovem , Adolescente , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Infecções por HIV/psicologia , Saúde Reprodutiva , Saúde Mental , África do Sul/epidemiologia , Estudos Transversais , Comportamento Sexual
2.
Gates Open Res ; 5: 154, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35445170

RESUMO

Background: Substance use is a significant public health problem worldwide, with consequences including violence, risky behaviours, and even death. Substance use amongst adolescents is increasing in South Africa, and limited research on frequency, risk and protective factors means that prevention interventions are difficult to design. This paper aims to describe and discuss factors associated with substance use among school-going adolescents in three peri-urban South African settings. Methods: A cross-sectional analysis was conducted using baseline data from participants in the Girls Achieve Power (GAP Year) trial. Grade 8 learners (N=2383), aged 11-18, were recruited from 26 lowest quintile public high schools in three townships: Soweto and Thembisa in Gauteng Province, and Khayelitsha in Western Cape Province. A baseline survey gathered demographic and behavioural data. Questions relevant to substance use and social support were used for this analysis. Multivariate logistic regression analyses were conducted to identify factors associated with substance use. The final variables were included in an unadjusted and adjusted logistic regression for current substance use, and a multinomial logistic regression for frequency of substance use. Results: A total of 22.5% (534) of participants indicated they had ever used substances. Being male was strongly associated with substance use (P<0.001), and less strongly with frequency of substance use. Age significantly predicted substance use, with older adolescents being more likely to engage in substance use (P<0.001); having a parent/guardian employed was negatively associated with substance use (P=0.021). Family-related social support variables were predictive of substance use. Being able to count on friends when things went wrong was predictive of lower frequency of substance use (P=0.019). Conclusions: These results can inform the targeting of prevention interventions to males and younger learners, as well as ensuring youth interventions build family and peer support to make substance use less likely and less frequent.

3.
Br J Sports Med ; 51(1): 26-28, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27354717

RESUMO

The recent increased use of injury and illness surveillance programmes has the potential to greatly advance our knowledge about risk factors and treatment effectiveness. Maximising this potential requires that data be entered in a format that can be interpreted and analysed. One remaining challenge concerns whether and when an increase in symptoms should be documented within an existing injury record (eg, exacerbation) versus a new injury record. In this review, we address this challenge using the principles of the multistate framework for the analysis of subsequent injury in sport (M-FASIS). In brief, we argue that a new injury record should be documented whenever there is an increase in symptoms due to activity-related exposures that is beyond the normal day-to-day symptom fluctuations, regardless of whether the athlete was in a 'healthy state' immediately before the event. We illustrate the concepts with concrete examples of shoulder osteoarthritis, ankle sprains and ACL tears.


Assuntos
Traumatismos em Atletas/diagnóstico , Medicina Esportiva/normas , Traumatismos do Tornozelo/diagnóstico , Lesões do Ligamento Cruzado Anterior/diagnóstico , Transtornos Traumáticos Cumulativos/diagnóstico , Humanos , Osteoartrite/diagnóstico , Fatores de Risco , Articulação do Ombro/fisiopatologia
4.
AIDS Res Hum Retroviruses ; 32(3): 303-10, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25905681

RESUMO

Mutations in functionally constrained sites of the HIV envelope (Env) can affect entry efficiency and are potential targets for vaccine and drug design. We investigated Du151, a dual-infected individual with rapid disease progression. At her death 19 months postinfection (mpi), she was infected with a recombinant variant, which outgrew both parental viruses. We aimed to determine whether the recombinant virus had enhanced Env entry efficiency compared to the parental viruses and to identify the functional determinant. We generated 15 env clones at 1, 2, 8, and 19 mpi. Pseudovirus carrying a recombinant Env clone (PSV clone), C18 (19 mpi), had significantly higher entry efficiency compared to the parents, suggesting that the recombinant virus had enhanced fitness. To identify the functional determinant, we compared two recombinant PSV clones (C18 and C63)-differing in entry efficiency (2-fold) and by four and three amino acids in gp120 and gp41, respectively. The increased entry efficiency of a C18-gp41 PSV chimera indicated that the three amino acids in the C18 gp41 region were involved (K658, G671, and F717). Site-directed mutagenesis of the three amino acids of C63 showed that a single amino acid mutation, R658K, increased pseudovirion entry efficiency. The introduction of R658 into two PSV clones (C1 and C18) decreased their entry efficiency, suggesting that R658 carries a fitness cost. Thus, our data suggest that a recombinant virus emerged at 19 mpi with enhanced Env entry efficiency. Therefore, K658 in gp41 could in part be a contributing factor to the increased viral load and rapid disease progression of Du151.


Assuntos
Infecções por HIV/patologia , Infecções por HIV/virologia , HIV-1/genética , HIV-1/fisiologia , Recombinação Genética , Internalização do Vírus , Produtos do Gene env do Vírus da Imunodeficiência Humana/genética , Análise Mutacional de DNA , Progressão da Doença , Feminino , HIV-1/isolamento & purificação , Humanos , Mutagênese Sítio-Dirigida , Proteínas Mutantes/genética , Carga Viral
5.
Australas Emerg Nurs J ; 15(3): 133-47, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22947686

RESUMO

BACKGROUND: In 2007, the Mater Children's Hospital Emergency Department participated in the Emergency Care Pain Management Initiative funded by the National Health and Medical Research Council National Institute of Clinical Studies (NHMRC-NICS). The findings of this NHMRC-NICS research across eleven paediatric emergency departments highlighted deficits in pain management of abdominal pain. Specifically pain assessment, timeliness of analgesia, and pain management guidelines were found to be lacking. METHODS: In response to the NICS report local practice was reviewed and a pilot research project undertaken to develop a clinical guideline for the pain management of abdominal pain in children presenting to the emergency department. The guideline was developed by an expert panel and trialled using a pre and post intervention design. RESULTS: The results demonstrated improved compliance to assessment and documentation of pain scores and assimilation of the best practice principles recommended in the guideline. CONCLUSIONS: This project raised local awareness in the pain management of abdominal pain and provides baseline information for future improvement. The guideline has been trialled in the clinical setting of paediatric emergency and has the potential to improve pain management practices in children presenting to the emergency department with abdominal pain.


Assuntos
Dor Abdominal/terapia , Serviço Hospitalar de Emergência/organização & administração , Tratamento de Emergência , Hospitais Pediátricos/organização & administração , Manejo da Dor , Analgésicos/administração & dosagem , Austrália , Criança , Pré-Escolar , Humanos , Avaliação de Processos e Resultados em Cuidados de Saúde , Medição da Dor , Enfermagem Pediátrica/métodos
6.
S Afr Med J ; 102(6): 461-4, 2012 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-22668937

RESUMO

A number of membrane proteins are enzymatically cleaved or 'shed' from the cell surface, resulting in the modulation of biological events and opening novel pharmaceutical approaches to diverse diseases by targeting shedding. Our focus has been on understanding the shedding of angiotensin-converting enzyme (ACE), an enzyme that plays a pivotal role in blood pressure regulation. The identification of novel hereditary ACE mutations that result in increased ACE shedding has advanced our understanding of the role of ACE shedding in health and disease. Extensive biochemical and molecular analysis has helped to elucidate the mechanism of ACE shedding. These findings point to the potential therapeutic role of targeting shedding in regulating tissue ACE levels in cardiovascular disease.


Assuntos
Hipertensão/enzimologia , Proteínas de Membrana/metabolismo , Peptidil Dipeptidase A/metabolismo , Proteínas ADAM/metabolismo , Humanos , Hipertensão/tratamento farmacológico , Metaloproteinases da Matriz/metabolismo , Proteínas de Membrana/genética , Terapia de Alvo Molecular , Peptidil Dipeptidase A/genética
7.
PLoS One ; 6(10): e25952, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21998728

RESUMO

BACKGROUND: Angiotensin I-converting enzyme (ACE) metabolizes a range of peptidic substrates and plays a key role in blood pressure regulation and vascular remodeling. Thus, elevated ACE levels may be associated with an increased risk for different cardiovascular or respiratory diseases. Previously, a striking familial elevation in blood ACE was explained by mutations in the ACE juxtamembrane region that enhanced the cleavage-secretion process. Recently, we found a family whose affected members had a 6-fold increase in blood ACE and a Tyr465Asp (Y465D) substitution, distal to the stalk region, in the N domain of ACE. METHODOLOGY/PRINCIPAL FINDINGS: HEK and CHO cells expressing mutant (Tyr465Asp) ACE demonstrate a 3- and 8-fold increase, respectively, in the rate of ACE shedding compared to wild-type ACE. Conformational fingerprinting of mutant ACE demonstrated dramatic changes in ACE conformation in several different epitopes of ACE. Cell ELISA carried out on CHO-ACE cells also demonstrated significant changes in local ACE conformation, particularly proximal to the stalk region. However, the cleavage site of the mutant ACE--between Arg1203 and Ser1204--was the same as that of WT ACE. The Y465D substitution is localized in the interface of the N-domain dimer (from the crystal structure) and abolishes a hydrogen bond between Tyr465 in one monomer and Asp462 in another. CONCLUSIONS/SIGNIFICANCE: The Y465D substitution results in dramatic increase in the rate of ACE shedding and is associated with significant local conformational changes in ACE. These changes could result in increased ACE dimerization and accessibility of the stalk region or the entire sACE, thus increasing the rate of cleavage by the putative ACE secretase (sheddase).


Assuntos
Membrana Celular/metabolismo , Proteínas Mutantes/sangue , Proteínas Mutantes/metabolismo , Mutação , Peptidil Dipeptidase A/sangue , Peptidil Dipeptidase A/metabolismo , Proteólise , Animais , Sítios de Ligação , Células CHO , Membrana Celular/efeitos dos fármacos , Biologia Computacional , Cricetinae , Cricetulus , Análise Mutacional de DNA , Endopeptidases/metabolismo , Células HEK293 , Humanos , Modelos Moleculares , Mutagênese Sítio-Dirigida , Proteínas Mutantes/química , Proteínas Mutantes/genética , Peptidil Dipeptidase A/química , Peptidil Dipeptidase A/genética , Multimerização Proteica/efeitos dos fármacos , Estrutura Terciária de Proteína , Proteólise/efeitos dos fármacos
8.
Pharm Stat ; 7(1): 4-8, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-17370280

RESUMO

The ICH E9 guideline on Statistical Principles for Clinical Trials is a pivotal document for statisticians in clinical research in the pharmaceutical industry guiding, as it does, statistical aspects of the planning, conduct and analysis of regulatory clinical trials. New statisticians joining the industry require a thorough and lasting understanding of the 39-page guideline. Given the amount of detail to be covered, traditional (lecture-style) training methods are largely ineffective. Directed reading, perhaps in groups, may be a helpful approach, especially if experienced staff are involved in the discussions. However, as in many training scenarios, exercise-based training is often the most effective approach to learning. In this paper, we describe several variants of a training module in ICH E9 for new statisticians, combining directed reading with a game-based exercise, which have proved to be highly effective and enjoyable for course participants.


Assuntos
Ensaios Clínicos como Assunto/estatística & dados numéricos , Interpretação Estatística de Dados , Jogos Experimentais , Guias como Assunto , Leitura , Projetos de Pesquisa , Estatística como Assunto/educação , Ensaios Clínicos como Assunto/normas , Europa (Continente) , Fidelidade a Diretrizes , Guias como Assunto/normas , Humanos , Modelos Educacionais , Desenvolvimento de Programas , Avaliação de Programas e Projetos de Saúde
9.
Biochemistry ; 46(31): 9019-31, 2007 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-17630779

RESUMO

Angiotensin I-converting enzyme (ACE, peptidyl dipeptidase, EC 3.4.15.2) is a key enzyme in cardiovascular pathophysiology. A wide spectrum of monoclonal antibodies to different epitopes on the N and C domains of human ACE has been used to study different aspects of ACE biology. In this study we characterized the monoclonal antibody (mAb) 5F1, developed against the N domain of human ACE, which recognizes both the catalytically active and the denatured forms of ACE. The epitope for mAb 5F1 was defined using species cross-reactivity, synthetic peptide (PepScan technology) and phage display library screening, Western blotting, site-directed mutagenesis, and protein modeling. The epitope for mAb 5F1 shows no overlap with the epitopes of seven other mAbs to the N domain described previously and is localized on the other side of the N domain globule. The binding of mAb 5F1 to ACE is carbohydrate-dependent and increased significantly as a result of altered glycosylation after treatment with alpha-glucosidase-1 inhibitor, N-butyldeoxynojirimycin (NB-DNJ), or neuraminidase. Out of 17 species tested, mAb 5F1 showed strict primate ACE specificity. In addition, mAb 5F1 recognized human ACE in Western blots and on paraffin-embedded sections. The sequential part of the epitope for mAb 5F1 is created by the N-terminal part of the N domain, between residues 1 and 141. A conformational region of the epitope was also identified, including the residues around the glycan attached to Asn117, which explains the sensitivity to changes in glycosylation state, and another stretch localized around the motif 454TPPSRYN460. Site-directed mutagensis and inhibition assays revealed that mAb 5F1 inhibits ACE activity at high concentrations due to binding of residues on both sides of the active site cleft, thus supporting a hinge-bending mechanism for substrate binding of ACE.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/farmacologia , Anticorpos Monoclonais/farmacologia , Mapeamento de Epitopos , Peptidil Dipeptidase A/imunologia , Sequência de Aminoácidos , Substituição de Aminoácidos , Inibidores da Enzima Conversora de Angiotensina/imunologia , Animais , Anticorpos Monoclonais/imunologia , Western Blotting , Células CHO , Catálise/efeitos dos fármacos , Cricetinae , Cricetulus , Ensaio de Imunoadsorção Enzimática , Epitopos/genética , Epitopos/imunologia , Glicosilação , Humanos , Imunoprecipitação , Modelos Moleculares , Dados de Sequência Molecular , Mutação , Biblioteca de Peptídeos , Peptidil Dipeptidase A/química , Peptidil Dipeptidase A/genética , Polissacarídeos/metabolismo , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos
10.
Biochem J ; 371(Pt 2): 437-42, 2003 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-12542396

RESUMO

Angiotensin I-converting enzyme (ACE) is a highly glycosylated type I integral membrane protein. A series of underglycosylated testicular ACE (tACE) glycoforms, lacking between one and five N-linked glycosylation sites, were used to assess the role of glycosylation in tACE processing, crystallization and enzyme activity. Whereas underglycosylated glycoforms showed differences in expression and processing, their kinetic parameters were similar to that of native tACE. N-glycosylation of Asn-72 or Asn-109 was necessary and sufficient for the production of enzymically active tACE but glycosylation of Asn-90 alone resulted in rapid intracellular degradation. All mutants showed similar levels of phorbol ester stimulation and were solubilized at the same juxtamembrane cleavage site as the native enzyme. Two mutants, tACEDelta36-g1234 and -g13, were successfully crystallized, diffracting to 2.8 and 3.0 A resolution respectively. Furthermore, a truncated, soluble tACE (tACEDelta36NJ), expressed in the presence of the glucosidase-I inhibitor N -butyldeoxynojirimycin, retained the activity of the native enzyme and yielded crystals belonging to the orthorhombic P2(1)2(1)2(1) space group (cell dimensions, a=56.47 A, b=84.90 A, c=133.99 A, alpha=90 degrees, beta=90 degrees and gamma=90 degrees ). These crystals diffracted to 2.0 A resolution. Thus underglycosylated human tACE mutants, lacking O-linked oligosaccharides and most N-linked oligosaccharides or with only simple N-linked oligosaccharides attached throughout the molecule, are suitable for X-ray diffraction studies.


Assuntos
Peptidil Dipeptidase A/química , Testículo/enzimologia , Animais , Células CHO , Cricetinae , Cristalização , Glicosilação , Humanos , Cinética , Masculino , Mutagênese Sítio-Dirigida , Peptidil Dipeptidase A/isolamento & purificação , Peptidil Dipeptidase A/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA