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1.
Eur J Dent Educ ; 22(3): e602-e611, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29696731

RESUMO

INTRODUCTION: This study aimed to explore United Kingdom (UK) and Australian (Aus) dental hygiene and dental therapy students' (DHDTS) perception of stress and well-being during their undergraduate education. Upon qualification, DHDTS in the UK register as dental therapists (DT), and in Australia, they register as Oral Health Therapists (OHT). MATERIALS AND METHODS: A questionnaire was distributed to years 1, 2 and 3 DHDTS at the University of Portsmouth Dental Academy (UPDA) in the UK and La Trobe Rural Health School in Australia. The questionnaire consisted of 5 well-used measurement instruments which included the following: Dental Environment Stress questionnaire (DES); Depression Anxiety Stress Scales (DASS-21); Scales of Psychological Well-Being (SPWB); Valuing Questionnaire (VQ); and the Adult Hope Scale (AHS) to collect data on students' perception of levels of stress and well-being. RESULTS: A response rate of 58% (UK) and 55% (Australia) was achieved. Clinical factors and academic work were perceived as stressful for DHDTS in both the UK and Australia. The Australian DHDTS-perceived stress in the educational environment was significantly higher (P < .002) than the UK DHDTS. The majority of respondents reported levels of depression, anxiety and stress to be within the normal-to-moderate range. All students reported high levels of positive well-being, with no significant differences between the 2 groups. CONCLUSIONS: DHDTS in the UK and Australia identified sources of stress within their undergraduate education, but also perceived themselves as positively functioning individuals.


Assuntos
Higienistas Dentários/psicologia , Percepção , Estresse Psicológico , Estudantes de Odontologia/psicologia , Estudantes de Ciências da Saúde/psicologia , Adulto , Ansiedade , Austrália , Meio Ambiente , Feminino , Humanos , Masculino , Inquéritos e Questionários , Reino Unido , Adulto Jovem
2.
Br Dent J ; 223(1): 22-26, 2017 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-28684834

RESUMO

Aims To use a qualitative approach to further explore the stress and well-being of dental hygiene and dental therapy students (DHDTS) during their undergraduate training.Subjects and methods Semi-structured individual interviews to explore motivation, goals, and perceived stress, were conducted with eight DHDTS from across all three years of study at the University of Portsmouth Dental Academy (UPDA). Thematic analysis of the data was undertaken using Braun and Clarke's (2006) six phases of thematic analysis.Results Three main themes of 'fulfilment', 'the learning environment', and 'perception of stress' were identified. Within these themes, a further 12 sub-themes were identified. Analysis suggested that a strong sense of passion to become a clinician mitigated most, but not all, of the stressful experiences of the DHDTS undergraduate learning environment.Conclusions DHDTS' perceived sources of stress during their undergraduate programme were strongly linked to a sense of meaningfulness.Listen to the author talk about the key findings in this paper in the associated video abstract. Available in the supplementary information online and on the BDJ Youtube channel via http://go.nature.com/bdjyoutube.


Assuntos
Assistentes de Odontologia/educação , Higienistas Dentários/educação , Ajustamento Emocional , Estresse Psicológico/etiologia , Estudantes de Ciências da Saúde/psicologia , Feminino , Humanos , Entrevistas como Assunto , Estresse Psicológico/psicologia
3.
Br Dent J ; 222(2): 101-106, 2017 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-28127002

RESUMO

Aims To explore dental hygiene and dental therapy students' (DHDTS') perception of stress and well-being during their undergraduate education and establish base-line data for further studies of this group of dental professionals.Subjects and methods A questionnaire was distributed to Years 1, 2 and 3 DHDTS and final year outreach dental students (DS) (as a comparison group), at the University of Portsmouth Dental Academy (UPDA), during summer 2015. Data were collected on students' perception of levels of stress and well-being. Statistical analyses were undertaken using SPSS software. Mann-Whitney U tests with Bonferroni corrections were used and the level for a statistically significant difference was set at p <0.002.Results A response rate of 81% (DHDTS) and 85% (DS) was achieved. Clinical factors and academic work were perceived as stressful for both DHDTS and DS, with no significant difference between the groups. The majority of respondents reported levels of depression, anxiety, and stress to be within the normal range. All students reported high levels of positive well-being, with DHDTS scoring significantly higher than DS in the dimensions of personal growth, purpose in life, self-acceptance and positive relations with others (p <0.002).Conclusions DHDTS and DS identified sources of stress within their undergraduate education, but also perceived themselves as positively-functioning individuals.


Assuntos
Atitude , Estresse Psicológico , Estudantes de Odontologia/psicologia , Adulto , Humanos , Autorrelato , Estresse Psicológico/etiologia , Adulto Jovem
4.
Epidemiol Infect ; 143(11): 2408-15, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25519212

RESUMO

Several epidemiological studies suggest a possible involvement of viral infection in the development of epilepsy. While recent research from in vitro studies increasingly supports the role of herpes simplex virus type 1 (HSV-1) in the pathogenesis of epilepsy, little is known about the role of other viral infections such as influenza. Using data from the Clinical Practice Research Datalink (CPRD), we conducted a matched case-control analysis to assess the association between GP-diagnosed influenza infections and the risk of developing an incident diagnosis of epilepsy. During the study period 11 244 incident epilepsy cases and 44 976 matched control patients were identified. Prior exposure to influenza was reported in 7·5% of epilepsy cases and 6·7% of controls [adjusted odds ratio (aOR) 1·12, 95% confidence interval (CI) 1·03-1·22]. Prior history of 'complicated influenza', i.e. influenza associated with a possible super-infection, was associated with a slightly increased epilepsy risk (aOR 1·64, 95% CI 1·10-2·46), particularly if recorded within the 2 months preceding the epilepsy diagnosis (aOR 6·03, 95% CI 1·10-33·2). Our findings suggest that prior influenza exposure does not appear to materially alter the risk of developing epilepsy. By contrast, influenza episodes accompanied by complications were associated with a slightly increased epilepsy risk.


Assuntos
Epilepsia/epidemiologia , Influenza Humana/epidemiologia , Superinfecção/epidemiologia , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Razão de Chances , Fatores de Risco , Adulto Jovem
5.
Psychol Health ; 29(4): 422-41, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24215123

RESUMO

Research on the usefulness of mindfulness and self-compassion for dieting has focused on meditative practices. However, meditation can be difficult to maintain, especially while dieting. Thus, the present research attempted to induce mindfulness and self-compassion by using food diaries that required the participant to either focus on concrete (i.e. how they are eating) construals or abstract (i.e. why they are eating) construals. The concrete construals were expected to increase mindfulness and self-compassion, as well as decrease avoidance and negative thoughts (which would further aid the development of mindfulness and self-compassion). Study 1 found that mindfulness and self-compassion mediated the inverse relationship of avoidance and negative thoughts with weight loss. Study 2 showed that concrete construal diaries increased mindfulness and self-compassion, decreased avoidance and negative thoughts, and supported weight loss significantly more than the abstract construal diaries. Study 3, then, compared the concrete construal diaries with a mindful self-compassionate meditation programme. There was no difference in weight loss at the end of the intervention, but at a three-month follow-up, the diaries performed better at weight maintenance. Thus, the concrete construal diaries may promote mindfulness and self-compassion and potentially promote long-term weight loss.


Assuntos
Registros de Dieta , Dieta/psicologia , Empatia , Atenção Plena , Autoimagem , Programas de Redução de Peso/métodos , Adolescente , Adulto , Feminino , Seguimentos , Humanos , Masculino , Meditação , Avaliação de Programas e Projetos de Saúde , Redução de Peso , Adulto Jovem
6.
Cancer Epidemiol ; 37(6): 897-904, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24042024

RESUMO

PURPOSE: Non-steroidal anti-inflammatory drugs (NSAIDs) have many anticarcinogenic properties via the inhibition of cyclooxygenase 2 (COX-2). Only one study, a cohort study examining risk of all cancers, investigated their role in cervical cancer with inconsistent findings between non-aspirin NSAIDs and aspirin. The aim of this study was to further investigate NSAID/aspirin use and cervical cancer risk. METHODS: Using the United Kingdom Clinical Practice Research Datalink, 724 women diagnosed with cervical cancer between 1 January, 1995 and December 2010 were compared to 3479 women (without cervical cancer) matched on year of birth and general practice. Conditional logistic regression analysis adjusted for smoking, sexually transmitted infections, HRT and contraceptive use, was used to calculate odds ratios (OR) and 95% confidence intervals (CI) for cervical cancer risk among users of any oral NSAIDs, non-aspirin NSAIDs and aspirin, as assessed from primary care prescribing data. RESULTS: Excluding the year prior to diagnosis, there was no association in adjusted analyses between ever vs. never use of an NSAID (OR 0.92, 95% CI 0.77-1.09), non-aspirin NSAID (OR 0.95, 95% CI 0.80-1.13) or low-dose aspirin (OR 1.07, 0.80-1.44) and cervical cancer risk. In analysis of daily defined doses, there was no association with cervical cancer risk comparing the highest users to non-users of NSAIDs (OR 0.98, 95% CI 0.69-1.39) or non-aspirin NSAIDs (OR 1.00, 95% CI 0.70-1.43) or low-dose aspirin (OR 1.04, 95% CI 0.59-1.81). CONCLUSION: This large historical cohort study found no evidence of an association between non-aspirin NSAID or aspirin use and cervical cancer risk.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Aspirina/uso terapêutico , Neoplasias do Colo do Útero/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Razão de Chances , Prognóstico , Fatores de Risco , Reino Unido , Neoplasias do Colo do Útero/cirurgia , Adulto Jovem
7.
Br J Cancer ; 108(5): 1178-81, 2013 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-23449358

RESUMO

BACKGROUND: Evidence for non-steroidal anti-inflammatory drugs (NSAIDs) preventing head and neck cancer (HNC) is inconclusive; however, there is some suggestion that aspirin may exert a protective effect. METHODS: Using data from the United States National Cancer Institute Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial, we examined the association between aspirin and ibuprofen use and HNC. RESULTS: Regular aspirin use was associated with a significant 22% reduction in HNC risk. No association was observed with regular ibuprofen use. CONCLUSION: Aspirin may have potential as a chemopreventive agent for HNC, but further investigation is warranted.


Assuntos
Anti-Inflamatórios não Esteroides/administração & dosagem , Aspirina/administração & dosagem , Neoplasias de Cabeça e Pescoço/epidemiologia , Ibuprofeno/administração & dosagem , Idoso , Consumo de Bebidas Alcoólicas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Risco , Fumar , Estados Unidos/epidemiologia
8.
Liver Transpl ; 16(4): 478-81, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20373459

RESUMO

We report an emergency paired donor interchange living donor liver transplant performed on January 13, 2009. The 4 operations (2 liver transplants) were performed simultaneously. The aim was to avoid 2 ABO-incompatible liver transplants. One recipient in acute liver failure underwent transplantation in a high-urgency situation. The abdomen of the other recipient had severe adhesions from previous spontaneous bacterial peritonitis that rendered the recipient operation almost impossible. The ethical and logistical issues are discussed. Approaches adopted in anticipation of potential adverse outcomes are explained in view of the higher donor and recipient mortality and morbidity rates in comparison with kidney transplantation.


Assuntos
Sistema ABO de Grupos Sanguíneos/imunologia , Incompatibilidade de Grupos Sanguíneos/imunologia , Transplante de Fígado/métodos , Adolescente , Adulto , Feminino , Sobrevivência de Enxerto , Humanos , Terapia de Imunossupressão , Imunossupressores/uso terapêutico , Fígado/imunologia , Fígado/patologia , Doadores Vivos , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Resultado do Tratamento
9.
J Fish Dis ; 31(11): 811-23, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18681902

RESUMO

Sequence data were generated for portions of the E2 and nsP3 genes of 48 salmonid alphaviruses from farmed Atlantic salmon (AS), Salmo salar L., and rainbow trout (RT), Oncorhynchus mykiss (Walbaum), in marine and freshwater environments, respectively, from the Republic of Ireland, Northern Ireland, England, Scotland, Norway, France, Italy and Spain between 1991 and 2007. Based on these sequences, and those of six previously published reference strains, phylogenetic trees were constructed using the parsimony method. Trees generated with both gene segments were similar. Clades corresponding to the three previously recognized subtypes were generated and in addition, two further new clades of viruses were identified. A single further strain (F96-1045) was found to be distinct from all of the other strains in the study. The percentage of nucleotide divergence within clades was generally low (0-4.8% for E2, 0-6.6% for nsP3). Interclade divergence tended to be higher (3.4-19.7% for E2, 6.5-28.1% for nsP3). Based on these results and using current SAV terminology, the two new clades and F96-1045 were termed SAV subtypes 4, 5 and 6, respectively. SAV4 contained AS strains from Ireland and Scotland, while SAV5 contained only Scottish AS strains. Recently identified SAV strains from RT in Italy and Spain were shown to belong to SAV2. In addition, marine AS strains belonging to SAV2 were identified for the first time. Analysis of the origin of several clusters of strains with identical E2 and nsP3 sequences strongly support horizontal transmission of virus between farms and aquaculture companies. Evidence in support of vertical transmission was not found.


Assuntos
Infecções por Alphavirus/veterinária , Alphavirus/genética , Proteínas de Ligação a DNA/genética , Epidemiologia Molecular , Filogenia , Proteínas não Estruturais Virais/genética , Alphavirus/classificação , Infecções por Alphavirus/virologia , Animais , Sequência de Bases , Europa (Continente)/epidemiologia , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/virologia , Oncorhynchus mykiss/virologia , RNA Viral/genética , Salmo salar/virologia
10.
Environ Sci Technol ; 40(10): 3163-7, 2006 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-16749676

RESUMO

In situ analyses with a laser ionization mass spectrometer have shown that a large fraction of aerosols in the bottom few kilometers of the stratosphere contain small amounts of mercury (1). Electron microscopy of particles collected near the tropopause has also detected mercury. The distribution of mercury onto many particles, including those less than 20 nm in diameter, indicates that the mercury is from local condensation of mercury compounds onto particles rather than transport of mercury-rich aerosols from surface sources. Although the results are only semiquantitative, they suggest that most of the mercury in the lower stratosphere is converted into the particulate phase. Mercury-containing particles were present at both middle latitudes and the tropics in two seasons. There is therefore good reason to believe that particulate mercury above the tropopause is global and could affect the atmospheric lifetime of mercury. There are indications that bromine and/ or iodine may be involved in the conversion of mercury from the gas to particle phase. Measurements at altitudes below 5 km did not find mercury in any particles despite sampling some particles that clearly originated in the stratosphere. This indicates that the particulate mercury from the lower stratosphere may be volatile enough to evaporate or decompose once particles reach warmer temperatures.


Assuntos
Aerossóis/análise , Poluentes Atmosféricos/análise , Exposição Ambiental , Monitoramento Ambiental , Mercúrio/análise , Aerossóis/química , Movimentos do Ar , Poluentes Atmosféricos/química , Altitude , Humanos , Tamanho da Partícula , Medição de Risco , Estações do Ano , Temperatura , Volatilização
11.
J Clin Endocrinol Metab ; 91(8): 3219-23, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16705075

RESUMO

CONTEXT: Adiponectin has been suggested to play a role in the etiopathogenesis of at least some forms of insulin resistance, in part based on a strong correlation between plasma levels of adiponectin and measures of insulin sensitivity. OBJECTIVE: The objective of the study was to establish whether this relationship is maintained at extreme levels of insulin resistance. DESIGN/SETTING: This was a cross-sectional study in a university teaching hospital of subjects recruited from the United Kingdom and the United States. PARTICIPANTS: Participants included 75 subjects with a range of syndromes of severe insulin resistance and 872 nondiabetic controls. OUTCOME MEASURES: Fasting plasma insulin, adiponectin, and leptin were measured. RESULTS: Unexpectedly, subjects with mutations in the insulin receptor, despite having the most severe degree of insulin resistance, had elevated plasma adiponectin [median 24.4 mg/liter; range 6.6-36.6 (normal adult range for body mass index 20 kg/m(2) = 3-19 mg/liter)], whereas all other subjects had low adiponectin levels (median 2.0 mg/liter; range 0.12-11.2). Plasma leptin in all but one subject with an insulin receptoropathy was low or undetectable [median 0.5 ng/ml; range 0-16: normal adult range for body mass index of < 25 kg/m(2) = 2.4-24.4 (female) and 0.4-8.3 ng/ml (male)]. CONCLUSIONS: We conclude that the relationship between plasma adiponectin and insulin sensitivity is complex and dependent on the precise etiology of defective insulin action and that the combination of high plasma adiponectin with low leptin may have clinical utility in patients with severe insulin resistance as a marker of the presence of a genetic defect in the insulin receptor.


Assuntos
Adiponectina/sangue , Resistência à Insulina/genética , Mutação , Receptor de Insulina/genética , Adolescente , Adulto , Índice de Massa Corporal , Criança , Pré-Escolar , Jejum , Feminino , Humanos , Lactente , Recém-Nascido , Insulina/sangue , Leptina/sangue , Masculino , Síndrome
12.
Int J Tuberc Lung Dis ; 10(4): 396-401, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16602403

RESUMO

SETTING: Tuberculosis (TB) and hepatitis C virus (HCV) infection have emerged as major public health problems in former Soviet republics. OBJECTIVE: To determine the prevalence and risk factors for the human immunodeficiency virus (HIV) and HCV co-infection among patients with TB in Georgia, a cross-sectional study was carried out at hospitals in four Georgian cities. RESULTS: Of 272 hospitalized patients with TB, 61 (22%) were found to be HCV-seropositive and three (1%) were HIV-seropositive. The median age of those with TB was 35 years (range 18-74 years); 74% were male. In multivariate analysis, risk factors for HCV co-infection included previous incarceration (OR 4.6, 95%CI 1.9-10.8), history of receiving a tattoo (OR 2.6, 95%CI 1.2-5.7), previous diagnosis of a sexually transmitted infection (OR 7.2, 95%CI 1.4-37.8), and age 26-45 years (OR 2.1, 95%CI 1.0-4.6). CONCLUSION: HCV co-infection was common among hospitalized patients with TB in Georgia. Incarceration and receiving a tattoo, a common practice among inmates in Georgian and former Soviet correctional facilities, were important independent risk factors associated with HCV infection among those with TB. Further studies are needed to assess the impact of the high prevalence of HCV co-infection on treatment outcomes, including tolerability and risk of anti-tuberculosis drug induced hepatotoxicity.


Assuntos
Hepatite C/epidemiologia , Tuberculose/complicações , Adolescente , Adulto , Idoso , Feminino , República da Geórgia/epidemiologia , HIV , Infecções por HIV/complicações , Infecções por HIV/epidemiologia , Hepacivirus/imunologia , Hepatite C/complicações , Hepatite C/virologia , Anticorpos Anti-Hepatite C/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Tuberculose/epidemiologia
13.
Heredity (Edinb) ; 94(3): 370-8, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15523504

RESUMO

Biogeographic boundaries are characterised by distinct faunal and floral assemblages restricted on either side, but patterns among groups of taxa often vary and may not be discrete. Historical biogeography as a consequence, while providing crucial insights into the relationship between biological diversity and earth history, has some limitations. Patterns of intraspecific molecular variation, however, may show unambiguous evidence for such historical divides, and can be used to test competing biogeographic hypotheses (often based on the dispersal-vicariance debate). Here, we utilise this method to test the hypothesis that a major biogeographic transition zone between the Sundaic and Indochinese biotas, located just north of the Isthmus of Kra in SE Asia, is the result of Neogene marine transgressions that breached the Isthmus in two locations for prolonged periods of time (>1 million year duration). Phylogeographic analyses of a freshwater decapod crustacean, the giant freshwater prawn Macrobrachium rosenbergii, strongly supports the historical existence of the more northerly postulated seaway. Results presented here highlight the power of utilising intraspecific molecular variation in testing biogeographical hypotheses.


Assuntos
Genética Populacional , Geografia , Palaemonidae/genética , Filogenia , Animais , Ásia , Variação Genética , Dinâmica Populacional
14.
Brain ; 127(Pt 6): 1302-12, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15069020

RESUMO

This study analyses the evolution of metabolite changes in an 8-year-old boy with focal Rasmussen encephalitis. Five MRI examinations, including magnetic resonance spectroscopy (MRS) were performed over 9 months. Following complex partial status, T2-weighted imaging showed transient dramatic signal increase in the left superior temporal gyrus and mesial temporal structures. Subsequent scans showed resolution of the swelling and signal normalization, with development of slight focal atrophy. MRS after status showed a reduction in N-acetylaspartate, total creatine and trimethylamines. Subsequent scans showed complete resolution of these metabolite abnormalities, followed later by development of further abnormal metabolite values. Lactate and glutamine/glutamate were elevated after status. After surgery, ex vivo high-field (1)H and (31)P MRS confirmed metabolite abnormalities (elevated choline and decreased aspartate, N-acetylaspartate, [(1)H]glutamate together with altered [(31)P]phospholipid ratios. These findings suggested active disease process in the anterior region of the excised superior temporal gyrus. We conclude that Rasmussen encephalitis is a combination of progressive encephalitic damage and fluctuating seizure effects, in which neuronal injury and recovery can occur. MRS measurements at a single time point should consider the fluctuating metabolite profile related to seizure activity.


Assuntos
Encefalite/metabolismo , Epilepsia Parcial Complexa/metabolismo , Criança , Encefalite/patologia , Encefalite/cirurgia , Epilepsia Parcial Complexa/patologia , Epilepsia Parcial Complexa/cirurgia , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Masculino , Prognóstico , Lobo Temporal/metabolismo
15.
Science ; 301(5641): 1886-9, 2003 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-14512623

RESUMO

Unexpectedly high concentrations of ultrafine particles were observed over a wide range of latitudes in the upper troposphere and lower stratosphere. Particle number concentrations and size distributions simulated by a numerical model of ion-induced nucleation, constrained by measured thermodynamic data and observed atmospheric key species, were consistent with the observations. These findings indicate that, at typical upper troposphere and lower stratosphere conditions, particles are formed by this nucleation process and grow to measurable sizes with sufficient sun exposure and low preexisting aerosol surface area. Ion-induced nucleation is thus a globally important source of aerosol particles, potentially affecting cloud formation and radiative transfer.

16.
Curr Drug Targets ; 4(5): 389-408, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12816348

RESUMO

Influenza is a highly contagious, acute upper respiratory tract disease caused by influenza virus, a member of the Orthomyxoviridae family. The viral particles have two surface antigens, haemagglutinin and sialidase (neuraminidase) that extensively decorate the surface of the virus and have been implicated in viral attachment and fusion, and the release of virion progeny, respectively. The receptor for haemagglutinin is the terminal sialic acid residue of host cell surface sialyloligosaccharides, while sialidase catalyses the hydrolysis of terminal sialic acid residues from sialyloligosaccharides. Extensive crystallographic studies of both these proteins have revealed that the residues that interact with the sialic acid are strictly conserved. Therefore, these proteins make attractive targets for the design of drugs to halt the progression of the virus. Recent successful efforts in the search for new cures for influenza have led to the development of three clinically-useful anti-influenza drugs. All three are potent, selective inhibitors of influenza virus A and B sialidase. Strategies for the development of haemagglutinin inhibitors have also been devised.


Assuntos
Antivirais/química , Inibidores Enzimáticos/química , Orthomyxoviridae/efeitos dos fármacos , Antivirais/administração & dosagem , Antivirais/farmacologia , Sítios de Ligação , Desenho de Fármacos , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/farmacologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Humanos , Influenza Humana/tratamento farmacológico , Influenza Humana/virologia , Lipossomos , Micelas , Neuraminidase/antagonistas & inibidores , Neuraminidase/química , Relação Estrutura-Atividade
17.
J Dairy Sci ; 84(3): 543-50, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11286405

RESUMO

Carbonation, flavor, culture type, pH, and storage time were varied to investigate the effects of these variables and their interactions on the growth of both typical and nontypical yogurt cultures and some contaminating bacteria. Two types of yogurt cultures (YC-470 and YC-180) were used as the source of typical yogurt bacteria, Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus. In addition, Lactobacillus acidophilus (LA-K) and Bifidobacterium longum ATCC 15707 were added as nontypical yogurt cultures to make sweetened low fat (1%) Swiss-style plain, strawberry, and lemon yogurts. Samples were incubated at 43 degrees C until pH values of 5.0 or 4.2 were reached. Strawberry yogurts at low (4.2) and high (5.0) pHs were divided into three portions, which were separately inoculated with contaminating bacteria, Bacillus licheniformis ATCC 14580, Escherichia coli ATCC 11775, and Listeria monocytogenes Scott A. After incorporation of carbon dioxide (1.10 to 1.27 volume of CO2 gas dissolved in water), the yogurt was stored at 4 degrees C for a 90-d period. Carbon dioxide did not affect the growth of typical or nontypical yogurt bacteria. Also, CO2 did not inhibit the growth of undesirable microorganisms. In general, low levels of CO2 did not affect the bacterial population in yogurt. The microflora of yogurt were influenced by culture type, pH, flavor type, and storage time or their interactions.


Assuntos
Bactérias/crescimento & desenvolvimento , Manipulação de Alimentos , Microbiologia de Alimentos , Iogurte/microbiologia , Bacillus/crescimento & desenvolvimento , Bacillus/metabolismo , Bactérias/metabolismo , Bifidobacterium/crescimento & desenvolvimento , Bifidobacterium/metabolismo , Dióxido de Carbono , Contagem de Colônia Microbiana , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/metabolismo , Fermentação , Concentração de Íons de Hidrogênio , Lactobacillus/crescimento & desenvolvimento , Lactobacillus/metabolismo , Listeria monocytogenes/crescimento & desenvolvimento , Listeria monocytogenes/metabolismo , Streptococcus/crescimento & desenvolvimento , Streptococcus/metabolismo , Paladar , Temperatura , Fatores de Tempo , Iogurte/análise
18.
Science ; 291(5506): 1026-31, 2001 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-11161213

RESUMO

Large particles containing nitric acid (HNO3) were observed in the 1999/2000 Arctic winter stratosphere. These in situ observations were made over a large altitude range (16 to 21 kilometers) and horizontal extent (1800 kilometers) on several airborne sampling flights during a period of several weeks. With diameters of 10 to 20 micrometers, these sedimenting particles have significant potential to denitrify the lower stratosphere. A microphysical model of nitric acid trihydrate particles is able to simulate the growth and sedimentation of these large sizes in the lower stratosphere, but the nucleation process is not yet known. Accurate modeling of the formation of these large particles is essential for understanding Arctic denitrification and predicting future Arctic ozone abundances.

19.
Bioorg Med Chem ; 8(3): 657-64, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10732983

RESUMO

Several C-9 modified N-acetylneuraminic acid derivatives have been synthesised and evaluated as substrates of N-acetylneuraminic acid aldolase. Simple C-9 acyl or ether modified derivatives of N-acetylneuraminic acid were found to be accepted as substrates by the enzyme, albeit being transformed more slowly than Neu5Ac itself. 1H NMR spectroscopy was used to evaluate the extent of the enzyme catalysed transformation of these compounds. Interestingly, the chain-extended Neu5Ac derivative 16 is not a substrate for N-acetylneuraminate lyase and behaves as an inhibitor of the enzyme.


Assuntos
Ácido N-Acetilneuramínico/química , Oxo-Ácido-Liases/metabolismo , Proteínas de Bactérias , Sítios de Ligação , Escherichia coli/enzimologia , Cinética , Membranas Artificiais , Sondas Moleculares , Ácido N-Acetilneuramínico/análogos & derivados , Ácido N-Acetilneuramínico/síntese química , Oxo-Ácido-Liases/antagonistas & inibidores , Oxo-Ácido-Liases/química , Especificidade por Substrato
20.
Bioorg Med Chem Lett ; 10(24): 2791-4, 2000 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-11133093

RESUMO

1H NMR spectroscopy has been used to investigate the transfer of sialic acid from sialic acid donor molecules to acceptor molecules using the trans-sialidase from Typanosoma cruzi. It is clearly demonstrated that NMR spectroscopy is an efficient and powerful means of monitoring the trans-sialidase promoted transfer of sialic acid from donor to acceptor.


Assuntos
Glicoproteínas/metabolismo , Ácido N-Acetilneuramínico/metabolismo , Neuraminidase/metabolismo , Ressonância Magnética Nuclear Biomolecular , Sialiltransferases/metabolismo , Trypanosoma cruzi/enzimologia , Amino Açúcares/química , Amino Açúcares/metabolismo , Animais , Doença de Chagas/enzimologia , Doença de Chagas/etiologia , Doença de Chagas/parasitologia , Glicoproteínas/química , Lactose/análogos & derivados , Lactose/química , Lactose/metabolismo , Ácido N-Acetilneuramínico/química , Neuraminidase/química , Prótons , Ácidos Siálicos/química , Ácidos Siálicos/metabolismo , Sialiltransferases/química
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