RESUMO
INTRODUCTION: Anecdotal evidence from clinical data in Johannesburg suggests that there is a high burden of dental caries among children with special health care needs (CSHCN) in Johannesburg. OBJECTIVES: To determine the prevalence of dental caries and Unmet Treatment Needs in children with cerebral palsy, hearing, learning and mental disabilities attending special needs schools in Johannesburg and to compare these with data from the National Children's Oral Health Survey (NCOHS) METHODS: This cross-sectional analytical study comprised of 882 children attending five special needs schools in Johannesburg. Stratified randomised sampling of the participating schools was done and the schools were stratified by disability. Caries status was recorded via the dmft/DMFT index using WHO criteria and guidelines. RESULTS: The mean age of the participants was 10.5 years; with a caries prevalence of 27.55% and 33.56% in the primary and permanent dentition respectively. The highest unmet treatment need of 100% was found in the permanent dentition of the hearing impaired group followed by 90.77% in the primary dentition of the cerebral palsy group. In general no significant difference was found when the dmft/DMFT for CSHCN and NCOHS were compared except in the hearing impaired age groups four to five and six (both primary dentition) where significantly higher dmft scores (3.58 vs. 2.4; 3.85 vs. 2.9; p < 0.05) were found. CONCLUSION: Children with special health care needs had lower caries prevalence compared with the general population and higher unmet treatment needs regardless of the type of disability.
Assuntos
Cárie Dentária/epidemiologia , Crianças com Deficiência/estatística & dados numéricos , Necessidades e Demandas de Serviços de Saúde/estatística & dados numéricos , Adolescente , Fatores Etários , Paralisia Cerebral/epidemiologia , Criança , Pré-Escolar , Estudos Transversais , Índice CPO , Inquéritos de Saúde Bucal , Restauração Dentária Permanente/estatística & dados numéricos , Humanos , Deficiências da Aprendizagem/epidemiologia , Pessoas com Deficiência Auditiva/estatística & dados numéricos , Pessoas com Deficiência Mental/estatística & dados numéricos , Prevalência , África do Sul/epidemiologia , Perda de Dente/epidemiologia , Dente Decíduo/patologiaRESUMO
INTRODUCTION: There is a lack of data about the prevalence and clinical consequences of dental caries in the West Rand. However dental caries does appear to be a substantial public health problem in Gauteng. OBJECTIVE: This study set out to determine the prevalence and clinical consequences of dental caries among school children in the West Rand district of Gauteng. METHODOLOGY: This was a cross-sectional study comprised of 800 pre-school and primary school children six to eight years old. Cluster sampling was used to select the participating schools. The oral health status was determined by using the DMFT/dmft and PUFA/pufa indices. RESULTS: Of the 800 children, 282 were in the four to five year old age group and 518 were six to eight years old. For four to five year olds the mean dmft score was 2.24 and the prevalence of caries 49%. The clinical consequence of caries was scored with a mean pufa index of 2.9 and the percentage of untreated decay was 47%. For six to eight year olds the mean DMFT/dmft scores were 0.1 and 2.4 respectively and the prevalence of caries 46%. The clinical consequence of caries scored with the PUFA/pufa index was 0.0 and 3.4 respectively and the percentage of untreated decay was 44%. CONCLUSION: There are high levels of untreated caries in children in this district. The pufa scores ndicate that children suffer serious consequences of untreated decay.
Assuntos
Cárie Dentária/epidemiologia , Abscesso/epidemiologia , Fatores Etários , Criança , Pré-Escolar , Estudos Transversais , Índice CPO , Fístula Dentária/epidemiologia , Doenças da Polpa Dentária/epidemiologia , Restauração Dentária Permanente/estatística & dados numéricos , Feminino , Necessidades e Demandas de Serviços de Saúde/estatística & dados numéricos , Humanos , Masculino , Úlceras Orais/epidemiologia , Prevalência , África do Sul/epidemiologia , Perda de Dente/epidemiologia , Raiz Dentária/patologia , Dente Decíduo/patologiaRESUMO
UNLABELLED: Dental trauma remains one of the major oral health problems in childhood and is the cause of much pain and distress. It may occur as a result of a sports mishap, an altercation or a fall while playing inside the school premises. Prompt and appropriate management of traumatised teeth is essential for a good prognosis of an injured tooth. AIM AND OBJECTIVE: The aim of the study was to assess teachers' knowledge of emergency management of traumatized teeth in early childhood developmental centres (ECDCs). METHOD: A cross sectional self-administered questionnaire was used to collect data among teachers in ECDCs in Hillbrow and Berea suburbs, Johannesburg, South Africa. RESULTS AND CONCLUSION: Almost all respondents (98.1%) were female; 59.6% were between 20 and 29 years of age. Almost a quarter of the centres were not registered and 39.1% of the school teachers were not formally qualified as ECDCs teachers. A small percentage (11.5%) received dental emergency training as a part of their school health education programs. Knowledge of ECDCs teachers on the emergency management of traumatized teeth appeared inadequate; in the event of emergency dental trauma, substantial number of teachers would not be able to respond appropriately. All teachers should have training on basic management of dental trauma.
Assuntos
Tratamento de Emergência , Educação em Saúde Bucal , Escolas Maternais , Ensino , Traumatismos Dentários/terapia , Adulto , Criança , Pré-Escolar , Estudos Transversais , Feminino , Primeiros Socorros , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Incisivo/lesões , Lactente , Masculino , Pessoa de Meia-Idade , Soluções para Preservação de Órgãos/classificação , Autorrelato , África do Sul , Inquéritos e Questionários , Avulsão Dentária/terapia , Fraturas dos Dentes/terapia , Reimplante Dentário , Dente Decíduo/lesões , Adulto JovemRESUMO
UNLABELLED: Compulsory Community Service (CCS) was introduced into the health service by the government to address the shortage and maldistribution of health professionals within the public sector. The aim of this study was to assess the perceptions of oral hygiene (OH) students, registered in 2004 at the five dental universities regarding the introduction of a 1-year-long CCS. OBJECTIVES: To determine: (a) the students' socio-demographic profile and (b) their attitudes towards CCS. METHODS: A self-administered questionnaire was hand delivered to all OH students who were registered during 2004 at the respective dental universities. RESULTS: The study yielded a response rate of 70% (109) with the average age of participants being 21.4 years. Most students were female (94%) and more than half were White (52%). More than half (53%) did not want to perform CCS even though 75% acknowledged its' importance. The most common concern for not supporting CCS was security (89%). Ninety per cent (90%) indicated that their preferred tasks would be to engage in clinical work and oral health promotion. CONCLUSION: Although the majority of participants supported the principles of CCS, a significant number were against the introduction citing security as their main concern. Most of the students preferred to perform clinical work and preventive programmes during their CCS.
Assuntos
Atitude do Pessoal de Saúde , Odontologia Comunitária , Higienistas Dentários/psicologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Programas Obrigatórios , Características de Residência , África do Sul , Inquéritos e Questionários , População Branca , Recursos HumanosRESUMO
UNLABELLED: Group I oral lesions have been strongly associated with HIV and in resource-poor settings could be useful predictors of HIV. No study has evaluated the predictability of these lesions in diagnosing HIV/AIDS in patients who attend dental public facilities in South Africa. OBJECTIVES: To determine the HIV status, prevalence of Group I oral lesions and their predictive value amongst patients attending a dental clinic in Soweto, South Africa. METHODS: This cross sectional analytical study comprised of adult patients attending a dental facility over one week in 2006. All patients underwent a clinical examination by calibrated dentists. RESULTS: A total of 165 patients (100% response) were screened of which 87 (53%) were female. The HIV prevalence was 28% (n = 46) and of those who tested positive, 15% (7) manifested with Necrotizing Ulcerative Gingivitis (NUG). This proved to be highly predictive for HIV (positive predictive value = 93.8%, specificity = 99.6% and likelihood ratio = 40). CONCLUSION: The high prevalence rate of HIV in dental facilities confirms the heavy burden of the HIV epidemic. NUG proved to be a good predictor of HIV in this setting.
Assuntos
Gengivite Ulcerativa Necrosante/epidemiologia , Infecções por HIV/diagnóstico , Soroprevalência de HIV , Saliva/virologia , Síndrome da Imunodeficiência Adquirida/diagnóstico , Síndrome da Imunodeficiência Adquirida/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Comorbidade , Estudos Transversais , Feminino , Gengivite Ulcerativa Necrosante/virologia , Infecções por HIV/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Doenças da Boca/classificação , Doenças da Boca/epidemiologia , Doenças da Boca/virologia , Valor Preditivo dos Testes , Odontologia em Saúde Pública , Sensibilidade e Especificidade , Método Simples-Cego , África do Sul/epidemiologia , Adulto JovemRESUMO
UNLABELLED: The risk of dental assistants acquiring injury and infections from the dental clinics has received little attention, especially in South Africa. OBJECTIVES: To determine the prevalence of occupational exposures among dental assistants working in public health care facilities in Limpopo Province. METHODS: A cross-section study on infection control practice and occupational exposures was conducted among 73 dental assistants. RESULTS: The sample was predominantly female (95%) with a mean age of 40.2 years (age range 23-54 years). Almost half the respondents (49.1%) had no formal training for their occupation, 22% were nursing assistants and only 10.2% had qualified at a technical college (Technicon). The mean number of clinicians assisted by each participant was 3.8 (SD +/- 1.9). Nearly half of the dental assistants (n = 26) reported an occupational exposure, half of which in turn occurred while handling instruments and 42.3% while assisting. The most common type of injury was a direct puncture (65.3%). Treatment included antiretroviral therapy (19.2%) and wound-cleaning (38.4%), while 42.3% reported that they had had no treatment at all. About 23% of incidents were not reported. Eighty percent changed gloves routinely between patients but 67% did not use protective eye glasses; 62.7% were not vaccinated against HBV. CONCLUSION: Occupational exposure was found to be unacceptably high and compliance of infection control guidelines was low.
Assuntos
Assistentes de Odontologia , Controle de Infecções Dentárias , Exposição Ocupacional , Adulto , Estudos Transversais , Feminino , Fidelidade a Diretrizes , Humanos , Transmissão de Doença Infecciosa do Paciente para o Profissional/prevenção & controle , Masculino , Pessoa de Meia-Idade , Odontologia em Saúde Pública , Inquéritos e QuestionáriosRESUMO
In many communities of South Africa, traditional healers are often the only means of health care delivery available. The level of knowledge and ability to recognize oral lesions of 32 traditional healers and 17 care-givers were assessed after a two-day workshop. The data collection instrument was a structured questionnaire, complimented by enlarged clinical photographs of the common oral manifestations of HIV/AIDS. Prior to the workshop, 46 (93.9%) of the 49 respondents had never had any formal information on oral health and 43 (87.8%) were unfamiliar with the symptoms of oral diseases. Thirty-five (71.4%) recognized bleeding gums from A4-size photographs and 11 (22.4%) recognized oral thrush. The recognition of other oral manifestations of HIV/AIDS were; oral hairy leukoplakia (41.0%), angular cheilitis (43.6%), herpes virus infection (56.4%), oral ulcerations (56.8%), and in children, parotid enlargement (27.3%), and moluscum contagiosum (56.8%). Traditional healers and caregivers constitute an untapped resource with enormous potential. A positive bridge should be built to link traditional healing with modem medicine in the struggle against HIV/AIDS.
Assuntos
Cuidadores , Infecções por HIV/diagnóstico , Educação em Saúde , Medicinas Tradicionais Africanas , Doenças da Boca/diagnóstico , Adulto , Criança , Infecções por HIV/terapia , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Doenças da Boca/terapia , Fotografação , África do SulAssuntos
Educação de Pós-Graduação em Medicina , Hospitais Públicos , Área Carente de Assistência Médica , Médicos/provisão & distribuição , Seguridade Social , Adulto , Estudos Transversais , Equipamentos e Provisões Hospitalares , Feminino , Humanos , Masculino , Admissão e Escalonamento de Pessoal , Médicos/estatística & dados numéricos , Encaminhamento e Consulta , África do Sul , Carga de TrabalhoRESUMO
BACKGROUND: Informed consent and autonomy are the major ethical principles that define the relationship between health workers and the patient. A patient should be given adequate information on the risks and benefits of treatment to be undertaken and also alternative treatment options. OBJECTIVES: To investigate what and how much information dental patients perceived to had been given by oral health workers about treatment, benefits, risks and management alternatives in order to take decisions and give informed consent about their treatment. DESIGN: Cross sectional descriptive survey. SETTING: The study was conducted at Ann Latsky Nursing College, Johannesburg. SUBJECTS: The sample size consisted of 173 student nurses in their first, second and third years of training. Only students who had treatment in the previous three years were included in the study. RESULTS: The majority of the students were treated in the private sector (85.0%) by male oral health workers (61.6%) and dentists (89.5%) as opposed to dental therapists or oral hygienists. The study indicated that the majority of the respondents (75.6%) were given information about the treatment to be undertaken. The information appeared to have pertained to costs, pain, chances of success and duration of treatment. One hundred (74.07%) gave verbal consent and (16.30%) gave both verbal and written consent. Only 37.79% of the respondents were told of alternative options available, 47.17% of the benefits, and 38.6% of the risks of treatment. CONCLUSION: These findings have ethical implications for oral health workers. There is an urgent need to sensitise oral health workers on the specifics of informed consent.
Assuntos
Assistência Odontológica , Consentimento Livre e Esclarecido , Saúde Bucal , Educação de Pacientes como Assunto , Adolescente , Adulto , Estudos Transversais , Inquéritos de Saúde Bucal , Feminino , Humanos , MasculinoRESUMO
The intention of Minimal Intervention Dentistry (MI) is to preserve as much tooth tissue as possible and to offer less threatening care to fearful patients. MI is based on a new understanding of cariology and the therapeutic value of biomimetic materials such as Glass lonomers. It has particular relevance to a new caries classification and employs treatment concepts such as selective caries removal and sealed restorations. The MI approach is appropriate for the vast majority of the population in South Africa; it addresses the public fear of dental treatment. It can be an effective private practice builder and is thus applicable to private and public services.
Assuntos
Cárie Dentária/terapia , Preparo da Cavidade Dentária/métodos , Restauração Dentária Permanente/métodos , Materiais Biomiméticos/química , Cárie Dentária/classificação , Materiais Dentários/química , Humanos , África do SulRESUMO
Self reported oral health knowledge and practices of 83 traditional healers in Zonkizizwe (56) and Dube (27) Gauteng Province, South Africa were carried out using a questionnaire and clinical photographs of common oral conditions. The mean age for the total group was 49.5 with 35 males and 48 females. Although only 17 of the healers were members of a professional association, many indicated their willingness to join one. 40 (71%) of healers in Zonkizizwe kept written client records but far fewer 3 (11%) did so in Dube. More than 90% of traditional healers from both areas correctly identified photographs of gingival inflammation, dental caries and oral candidiasis. Over 50% of healers from both areas had patients who presented with mouth problems. Ninety percent of healers in Zonkizizwe referred patients to the formal health care sector but less than 50% in Dube did so. A vast majority of healers gave oral health advice to their patients, many of whom gave specific tooth brush instruction. The study provides an initial understanding of the practices of healers regarding oral health.
Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Medicinas Tradicionais Africanas , Saúde Bucal , Adolescente , Adulto , Idoso , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Equipe de Assistência ao Paciente , Fotografia Dentária , África do Sul , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Oral diseases is still a major problem in most developing countries. Within the Republic of South Africa, there remains areas where few or no studies have been done on the oral health status. The emerging district health system with decentralisation of health services to address past inequity in health care in South Africa also provides compelling case for data collection at regional levels. OBJECTIVES: To assess the prevalence and severity of dental caries of school children; determine the caries patterns of the study population and to provide useful data for the planning of oral health services in this region. DESIGN: Descriptive analytical study. SETTING: School children in the Donald Fraser Health District, Venda in the Northern province, Republic of South Africa. SUBJECTS/METHODS: A total of 519 school children in the age groups 6, 12 and 15 years were examined by a calibrated examiner for dental caries using WHO diagnostic criteria. Both the schools, which were divided into rural and peri-urban locations and the children that participated were randomly selected. RESULTS: A mean dmft(sd) of 2.68(3.29) in six year olds and a mean DMFT (sd) scores of 0.61(1.50) and 1.26 (2.18) were recorded in the 12 and 15 year olds respectively. In the six year olds the upper anterior teeth showed highest susceptibility to caries, clearly indicating that black children suffer from early infant caries. At ages of 12 and 15 the mandibular molars were the teeth most affected. The decayed component constituted the main part of the dmft and DMFT scores. Ninety-nine percent of these lesions were untreated and the restorative care was almost nil. CONCLUSION: An important finding was the doubling of the mean DMFT from the 12-year-olds to 15-year olds and the caries levels for all age groups was higher than the provincial average. The treatment required were mostly extractions and simple fillings, the majority of which could be managed by dental auxiliaries using the Atraumatic Restorative Treatment Technique. This study indicates that preventive oral health measures should be implemented on the younger age groups in order to control dental caries.
Assuntos
Cárie Dentária/epidemiologia , Adolescente , Distribuição por Idade , Criança , Inquéritos de Saúde Bucal , Feminino , Humanos , Masculino , Prevalência , Saúde da População Rural/estatística & dados numéricos , Distribuição por Sexo , África do Sul/epidemiologia , Saúde da População Urbana/estatística & dados numéricosRESUMO
The Division of Public Oral Health at the University of the Witwatersrand conducted a 2-week ART training course for 5th year dental students in the School of Oral Health Sciences. Students were taught both theoretical knowledge and clinical skills in ART. Course evaluation showed that the course achieved its aims and objectives and was considered a worthwhile experience by students. However, there were some limitations to the format of the programme. We recommend that ART should be integrated as part of clinical student training in the BDS curriculum.
Assuntos
Restauração Dentária Permanente/métodos , Educação em Odontologia , Adolescente , Criança , Estágio Clínico , Competência Clínica , Ansiedade ao Tratamento Odontológico/prevenção & controle , Assistência Odontológica para Crianças , Cárie Dentária/terapia , Restauração Dentária Permanente/instrumentação , Avaliação Educacional , Feminino , Educação em Saúde Bucal , Humanos , Masculino , Programas de Rastreamento , Higiene Bucal , Atenção Primária à Saúde , Avaliação de Programas e Projetos de Saúde , Ensino/métodosRESUMO
Human immunodeficiency virus (HIV) infection constitutes an unparalleled public health challenge. The unique nature of most oral health procedures, instrumentation and patient-care settings requires specific strategies and protocols aimed at preventing the transmission of HIV/AIDS between oral health care providers and patients, as well as between patients themselves. The present study investigated the level of information and training about protocols and policies for preventing the transmission of HIV/AIDS in oral health care settings in South Africa. The data collection techniques utilised available information, in-depth interviews and an open-ended questionnaire. The respondents were 20 purposively selected key informants who were senior officers for HIV/AIDS programmes and/or oral health organisations. Sixteen (80%) of the respondents reported that there were no existing oral health policies on HIV/AIDS in their health care institutions or organisations. None of the interviewees knew of any specific protocols on HIV/AIDS in the oral health care setting that emanated from South Africa. In addition, none of the dental professional associations had established an infection control committee or a support system for members who might become infected with HIV and develop AIDS. Territorial boundaries existed between sectors within the medical disciplines, as well as between the medical and oral health disciplines. Numerous general impediments were identified, such as prejudice, denial and fear, inadequate training and/or information about the infection, lack of representation and resources for policy planning, a lack of interest from the business sector, and approaching HIV/AIDS in the workplace as a 'one-time issue' Other obstacles identified included unemployment, poverty, illiteracy, disempowerment of women and inadequate communication of policies to service providers. Additional issues raised included the migrant labour systeM, complexities of language and culture, the large unstructured sex industry, high prevalence of sexually transmitted infections and lack of funding. All of these have an impact on oral health. Future policy directions identified included 'increasing access to HIV information and postexposure prophylaxis' 'shift towards care and support for those living with HIV/AIDS with emphasis on community and home-based care' and 'improving intersectoral co-ordination and collaboration'. The study demonstrated gaps in availability and access to policies and protocols on HIV/AIDS by managers and health workers. Specific strategic recommendations are made for oral health.
Assuntos
Assistência Odontológica para Doentes Crônicos/normas , Transmissão de Doença Infecciosa/prevenção & controle , Infecções por HIV/transmissão , Política de Saúde/tendências , Controle de Infecções Dentárias/estatística & dados numéricos , Guias de Prática Clínica como Assunto , Competência Clínica/estatística & dados numéricos , Auxiliares de Odontologia/psicologia , Auxiliares de Odontologia/estatística & dados numéricos , Assistência Odontológica para Doentes Crônicos/estatística & dados numéricos , Odontólogos/psicologia , Odontólogos/estatística & dados numéricos , Previsões , Infecções por HIV/prevenção & controle , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Cultura Organizacional , Formulação de Políticas , África do Sul/epidemiologia , Inquéritos e Questionários , Precauções Universais/estatística & dados numéricos , Precauções Universais/tendênciasRESUMO
The Atraumatic Restorative Treatment (ART) approach has been adopted in public dental services in South Africa as an appropriate and economical means to provide basic restorative care in communities where it was not possible before. The approach also offers a less-traumatic treatment concept for fearful patients and children in the private dental practice. In 2000, the Division of Community Dentistry, University of the Witwatersrand, implemented a training, research and service programme in the ART approach. The aim of these activities was the promotion of ART at various levels within the oral health care system in the Republic of South Africa. The objectives of the programme were to initiate and provide training of oral health workers in ART, to evaluate the outcome of training and service programmes and to disseminate results. This paper describes the Division's ART activities in 2000, regarding public, private and refugee health services.
Assuntos
Cárie Dentária/terapia , Restauração Dentária Permanente/métodos , Adulto , Criança , Odontologia Comunitária/educação , Análise Custo-Benefício , Ansiedade ao Tratamento Odontológico/prevenção & controle , Adaptação Marginal Dentária , Materiais Dentários/química , Educação em Odontologia , Humanos , Prática Privada , Avaliação de Programas e Projetos de Saúde , Odontologia em Saúde Pública , Refugiados , População Rural , África do Sul , População Suburbana , Extração DentáriaRESUMO
The serine protease urokinase plasminogen activator (uPA) is thought to play a central role in tumor metastasis and angiogenesis. Molecular modeling studies suggest that 5-thiomethylthiopheneamidine inhibits uPA by binding at the S1 pocket of the active site. Further structure based elaboration of this residue resulted in a novel class of potent and selective inhibitors of uPA.
Assuntos
Antimetabólitos/farmacologia , Tiofenos/farmacologia , Ativador de Plasminogênio Tipo Uroquinase/antagonistas & inibidores , Antimetabólitos/síntese química , Antimetabólitos/química , Sítios de Ligação , Humanos , Relação Estrutura-Atividade , Tiofenos/síntese química , Tiofenos/química , Ativador de Plasminogênio Tipo Uroquinase/fisiologiaRESUMO
The serine protease urokinase (uPa) has been implicated in the progression of both breast and prostate cancer. Utilizing structure based design, the synthesis of a series of substituted 4-[2-amino-1,3-thiazolyl]-thiophene-2-carboxamidines is described. Further optimization of this series by substitution of the terminal amine yielded urokinase inhibitors with excellent activities.
Assuntos
Amidinas/síntese química , Amidinas/farmacologia , Ativadores de Plasminogênio/antagonistas & inibidores , Tiazóis/farmacologia , Ativador de Plasminogênio Tipo Uroquinase/antagonistas & inibidores , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Relação Estrutura-Atividade , Tiazóis/síntese química , Tiofenos/síntese química , Tiofenos/farmacologiaAssuntos
Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Imunoglobulinas/química , Proteínas Proto-Oncogênicas , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo , Motivos de Aminoácidos , Sítios de Ligação , Subunidade alfa 2 de Fator de Ligação ao Core , DNA/metabolismo , Dimerização , Modelos Moleculares , Estrutura Terciária de Proteína , Especificidade por Substrato , Fator de Transcrição AP-2RESUMO
Molybdenum cofactor (Moco) biosynthesis is an evolutionarily conserved pathway present in eubacteria, archaea and eukaryotes, including humans. Genetic deficiencies of enzymes involved in Moco biosynthesis in humans lead to a severe and usually fatal disease. Moco contains a tricyclic pyranopterin, termed molybdopterin (MPT), that bears the cis-dithiolene group responsible for molybdenum ligation. The dithiolene group of MPT is generated by MPT synthase, which consists of a large and small subunits. The 1.45 A resolution crystal structure of MPT synthase reveals a heterotetrameric protein in which the C-terminus of each small subunit is inserted into a large subunit to form the active site. In the activated form of the enzyme this C-terminus is present as a thiocarboxylate. In the structure of a covalent complex of MPT synthase, an isopeptide bond is present between the C-terminus of the small subunit and a Lys side chain in the large subunit. The strong structural similarity between the small subunit of MPT synthase and ubiquitin provides evidence for the evolutionary antecedence of the Moco biosynthetic pathway to the ubiquitin dependent protein degradation pathway.
Assuntos
Escherichia coli/enzimologia , Evolução Molecular , Sulfurtransferases/química , Sulfurtransferases/metabolismo , Ubiquitinas/química , Ubiquitinas/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , Sequência Conservada , Cristalografia por Raios X , Espectrometria de Massas , Modelos Moleculares , Dados de Sequência Molecular , Estrutura Quaternária de Proteína , Estrutura Secundária de Proteína , Alinhamento de Sequência , Eletricidade Estática , Relação Estrutura-AtividadeRESUMO
In this study, 1,325 school children from 7 farm schools were examined. Their mean age (+/- SD) was 10.5 +/- 3.0 (range 6-11) years. At baseline, the mean DMFT score was 1.1 +/- 1.7 and 36.4% of the children had caries. The prevalence of fluorosis among the children was 12.6%. Curative treatment was offered to all the children. A total of 113 children (8.5%) with one-surface cavities on permanent teeth and without fluorosis were treated using the atraumatic restorative treatment (ART) approach. A total number of 163 cavities were included in the study, of which 82 were treated with Fuji IX glass-ionomer cement and 81 with Ketac-MOLAR (hand mix). One year after treatment, restoration and sealant parts of ART fillings were examined. Caries status was also determined. The placing of the ART fillings and their evaluation were performed by different practitioners. A total number of 108 restorations (58 with Fuji IX, 50 with Ketac-MOLAR) were evaluated. Results of ART fillings showed a survival rate of 93.1% with Fuji and 94.0% with Ketac-MOLAR. Retention of the sealant parts of ART fillings was observed in 81% of restorations with Fuji IX and 76% with Ketac-MOLAR, not connected to the filled cavity. Caries was absent on all teeth restored with Fuji IX and noted in only one tooth restored with Ketac-MOLAR, not connected to the filled cavity. The retention rate after a 12-month period was acceptable and ART approach proved to be an appropriate technique for restoring teeth in this population group. There were no statistically significant differences between the survival rates of the two glass-ionomer restorative materials (P > 0.05).