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1.
Soc Sci Med ; 301: 114902, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35306269

RESUMO

AIMS: This study explores the effects of two evidence-based alcohol reduction counseling interventions on readiness to change, alcohol abstinence self-efficacy, social support, and alcohol abstinence stigma among people with HIV (PWH) who have hazardous alcohol use in Vietnam. METHODS: PWH receiving antiretroviral therapy (ART) were screened for hazardous drinking and randomized to one of three study arms: combined intervention (CoI), brief intervention (BI), and standard of care (SOC). A quantitative survey was conducted at baseline (N = 440) and 3-month post-intervention (N = 405), while in-depth interviews were conducted with a subset of BI and CoI participants at baseline (N = 14) and 3 months (N = 14). Data was collected from March 2016 to August 2017. A concurrent mixed-methods model was used to triangulate quantitative and qualitative data to cross-validate findings. RESULTS: At 3 months, receiving the BI and CoI arms was associated with 2.64 and 3.50 points higher in mean readiness to change scores, respectively, compared to the SOC group (BI: ß = 2.64, 95% CI: 1.17-4.12; CoI: ß = 3.50, 95% CI 2.02-4.98). Mean alcohol abstinence self-efficacy scores were 4.03 and 3.93 points higher among the BI and CoI arm at 3 months, compared to SOC (BI: ß = 4.03, 95% CI: 0.17-7.89; CoI: ß = 3.93, 95% CI: 0.05-7.81). The impacts of the interventions on social support and alcohol abstinence stigma were not significant. Perceived challenges to refusing drinks at social events remained due to strong alcohol abstinence stigma and perceived negative support from family and friends who encouraged participants to drink posed additional barriers to reducing alcohol use. CONCLUSIONS: Both the CoI and BI were effective in improving readiness to change and alcohol abstinence self-efficacy among PWH. Yet, participants still faced significant barriers to reducing their drinking due to social influences and pressure to drink. Interventions at different levels addressing social support and alcohol abstinence stigma are warranted.


Assuntos
Abstinência de Álcool , Infecções por HIV , Consumo de Bebidas Alcoólicas/psicologia , Povo Asiático , Infecções por HIV/complicações , Infecções por HIV/psicologia , Humanos , Estigma Social , Vietnã
2.
Radiography (Lond) ; 28(1): 142-147, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34598897

RESUMO

INTRODUCTION: The COVID-19 pandemic, with associated pressures on healthcare services and workforce, had implications for final year Diagnostic Radiography students completing their training and transitioning into employment. The aim of this study was to explore their experience as novice practitioners starting work and integrating into the workforce during a time of national crisis. METHODS: Five early career Diagnostic Radiographers, eligible to join the temporary HCPC register, were recruited. One to one interviews were completed online exploring their thoughts, feelings and experiences. Participants had the option of using photographs to aid communication. RESULTS: Interviews were transcribed, emerging themes identified and coded. Four main themes emerged specifically related to the COVID-19 pandemic, (i) perceived challenges associated with joining the workforce, (ii) managing expectations and unexpected outcomes during transition, (iii) adapting to changes in systems and structures, (iv) sense of uncertainty relating to professional identity. The impacts were experienced beyond the work environment into social and personal lives. Participants demonstrated resilience as they adapted to their shifting lives and drew on the support of clinical colleagues and University academics for help. They did report feelings of concern and anxiety. The participants all expressed a sense of feeling valued and supported in their new roles. CONCLUSION: The Pandemic was unprecedented and created uncertainty in terms of workforce requirements. This study highlights the personal impact and professional responses of novice practitioners, who felt a sense of duty and care to help support the NHS and others. IMPLICATIONS FOR PRACTICE: This will help in the understanding of the transition of student into employment and what wider support needs to be in place prior, during and after this phase.


Assuntos
COVID-19 , Pandemias , Humanos , SARS-CoV-2 , Estudantes , Recursos Humanos
3.
Sci Rep ; 9(1): 10045, 2019 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-31296876

RESUMO

Vitamin B1 is an essential exogenous micronutrient for animals. Mass death and reproductive failure in top aquatic consumers caused by vitamin B1 deficiency is an emerging conservation issue in Northern hemisphere aquatic ecosystems. We present for the first time a model that identifies conditions responsible for the constrained flow of vitamin B1 from unicellular organisms to planktivorous fishes. The flow of vitamin B1 through the food web is constrained under anthropogenic pressures of increased nutrient input and, driven by climatic change, increased light attenuation by dissolved substances transported to marine coastal systems. Fishing pressure on piscivorous fish, through increased abundance of planktivorous fish that overexploit mesozooplankton, may further constrain vitamin B1 flow from producers to consumers. We also found that key ecological contributors to the constrained flow of vitamin B1 are a low mesozooplankton biomass, picoalgae prevailing among primary producers and low fluctuations of population numbers of planktonic organisms.


Assuntos
Organismos Aquáticos , Cadeia Alimentar , Hidrobiologia , Modelos Biológicos , Tiamina/metabolismo , Animais , Biomassa , Mudança Climática , Peixes , Plâncton , Deficiência de Vitaminas do Complexo B
4.
Eur J Cancer Care (Engl) ; 27(2): e12664, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28185324

RESUMO

Breast reconstruction using the latissimus dorsi (LD) flap following mastectomy is an important management option in breast cancer. However, one common, but often ignored, complication following LD flap is shoulder dysfunction. The aim of this critical review was to comprehensively assess the musculoskeletal impact of LD breast reconstruction and evaluate the functional outcome following surgery. Five electronic databases were searched including; Medline, Embase, CINAHL Plus (Cumulative Index to Nursing and Allied Health), PubMed and Web of Science. Databases were searched from 2006 to 2016, and only full text, English language articles were included. Twenty-two observational studies and two surveys were reviewed with sample sizes ranging from six to 206 participants. The majority of studies had small sample sizes and were retrospective in nature. Nevertheless, there is evidence to suggest that there is some degree of weakness and reduced mobility at the shoulder following LD muscle transfer. The literature demonstrates that there is considerable morbidity in the immediate post-operative period with functional recovery varying between studies. The majority of work tends to be limited and often gives conflicting results; therefore, further investigation is required in order to determine underlying factors that contribute to a reduction in function and activities of daily living.


Assuntos
Neoplasias da Mama/cirurgia , Mamoplastia/métodos , Doenças Musculoesqueléticas/etiologia , Articulação do Ombro/fisiopatologia , Músculos Superficiais do Dorso/cirurgia , Retalhos Cirúrgicos , Feminino , Humanos , Mamoplastia/efeitos adversos , Mastectomia , Estudos Retrospectivos
5.
Harm Reduct J ; 14(1): 62, 2017 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-28882143

RESUMO

BACKGROUND: Persons who use opioids have a high risk of overdose and associated mortality. In Vietnam, little is known about the characteristics of this population and the persons who are witness to those overdoses. One approach to combatting fatal overdose has been the use of peer interventions in which a friend or injecting partner administers overdose reversal medication, but availability in Vietnam of these medications is limited to pilot programs with aims to expand in the future (Le Minh and V.F. Go, Personal Communication, 2016). The primary objective of this paper is to explore the characteristics associated with witnessing three or more overdoses in a lifetime. METHODS: This cross-sectional analysis used baseline data from a four-arm randomized control trial conducted in Thai Nguyen, Vietnam, known as the Prevention for Positives project. One thousand six hundred seventy-three PWID were included in the analysis. We conducted bivariable and multivariable logistic regression to identify characteristics associated with witnessing three or more overdoses in a lifetime. Characteristics explored included education, employment, marital status, risky drug use behaviors, locations for accessing syringes, recent overdose, history of incarceration, drug treatment, and having slept outside in the past 3 months. RESULTS: Seventy-two percent (n = 1203) of participants had witnessed at least one overdose in their lifetime, and 46% had witnessed three or more overdoses (n = 765). In the multivariable model, having less than secondary education (AOR 0.70; 95% CI 0.57, 0.86), having slept outside in the past 3 months (AOR 1.77; 95% CI 1.31, 2.40), having a history of incarceration (AOR 1.33; 95% CI 1.07, 1.65), having a history of drug treatment (AOR 1.41; 95% CI 1.12, 1.77), experiencing a recent non-fatal overdose (AOR 3.84; 95% CI 2.36, 6.25), injecting drugs daily (AOR 1.79; 95% CI 1.45, 2.20), receptive needle sharing (AOR 1.30; 95% CI 1.04, 1.63), and number of years injecting (AOR 1.04; 95% CI 1.02, 1.07) were significantly associated with witnessing three or more overdoses. CONCLUSIONS: Targeted interventions are needed to train persons witnessing an overdose to administer overdose-reversal medication. This includes targeting persons prior to release from prisons, drug treatment centers, and those accessing syringe exchange programs. Additional research should assess the burden of witnessing an overdose as well as locations for medication distribution. Assessments of the training capacity and needs for implementing these programs among drug using peers in Vietnam are of the utmost importance.


Assuntos
Overdose de Drogas/epidemiologia , Usuários de Drogas/estatística & dados numéricos , Transtornos Relacionados ao Uso de Opioides/epidemiologia , Abuso de Substâncias por Via Intravenosa/epidemiologia , Adulto , Criminosos/estatística & dados numéricos , Estudos Transversais , Escolaridade , Emprego/estatística & dados numéricos , Feminino , Redução do Dano , Pessoas Mal Alojadas/estatística & dados numéricos , Humanos , Estado Civil/estatística & dados numéricos , Uso Comum de Agulhas e Seringas/estatística & dados numéricos , Programas de Troca de Agulhas/estatística & dados numéricos , Fatores de Risco , Assunção de Riscos , Fatores Socioeconômicos , Vietnã/epidemiologia
6.
Ann R Coll Surg Engl ; 89(6): W6-8, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18201463

RESUMO

Chronic neck pain is an extremely common symptom in the general population. Most cases have underlying musculoskeletal aetiologies and are managed conservatively. However, a very small number of patients presenting with chronic neck pain will have significant underlying pathology, e. g. a spinal cord tumour. Intramedullary spinal cord tumours are uncommon at all ages, particularly in adults, and there are some controversies in their treatment. The case of an 18-year-old man with chronic neck pain who was subsequently shown to have a pilocytic intramedullary astrocytoma is presented. This report highlights the need to consider rare, but potentially serious, diagnoses in individuals presenting with non-resolving, but seemingly innocent, symptoms over a prolonged period.


Assuntos
Astrocitoma/complicações , Cervicalgia/etiologia , Neoplasias da Medula Espinal/complicações , Adolescente , Astrocitoma/diagnóstico , Astrocitoma/cirurgia , Vértebras Cervicais , Doença Crônica , Humanos , Imageamento por Ressonância Magnética , Masculino , Cervicalgia/cirurgia , Neoplasias da Medula Espinal/diagnóstico , Neoplasias da Medula Espinal/cirurgia , Vértebras Torácicas
7.
Infect Agent Cancer ; 1: 2, 2006 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-17150131

RESUMO

BACKGROUND: Infections with certain human herpesviruses have been established as risk factors for some cancer types. For example, Epstein-Barr Virus is considered a cause of Burkitt's lymphoma and other immunosuppression related lymphomas, Hodgkin lymphoma, and nasopharyngeal cancer. Several other human herpesviruses have been linked to cancers but the totality of evidence is inconclusive. METHODS: We conducted a systematic sub-study from within an ongoing case control study of adult black South Africans to investigate the relationship between antibodies to six human herpesviruses and seven cancer groups that may be caused by infectious agents. Subjects had incident cancers of the oral cavity (n = 88), the cervix (n = 53), the prostate (n = 66), Hodgkin lymphoma (n = 83), non-Hodgkin lymphoma (n = 80), multiple myeloma (n = 94) or leukaemia (n = 203). For comparison, patients with other cancers (n = 95) or cardiovascular disease (n = 101) were randomly selected from within the study. Patients were interviewed and their blood was tested for IgG antibodies against HSV-1, HSV-2, VZV, EBV-EBNA, CMV and HHV-6 using enzyme linked immunosorbent assays. Because these viruses are highly prevalent in this population, optical density results from the assays were used as an indirect, quantitative measure of antibody level. RESULTS: There was significant variation in the mean log antibody measures for HSV-2, VZV, CMV and HHV-6 between the disease groups. However, none of the specific cancer groups had significantly higher mean log antibody measures for any of the viruses compared to either control group. In a more detailed examination of seven associations between cancers and herpesviruses for which there had been prior reports, two statistically significant associations were found: a decreasing risk of myeloid leukaemia and an increasing risk of oral cancer with increasing tertiles of antibodies against HHV-6 compared to all other patients (p-trend = 0.03 and 0.02, respectively). Odds ratios for the top tertile compared to the bottom tertile were 0.58 (95%CI 0.3-1.0) for myeloid leukaemia and 2.21 (95% CI 1.1-4.3) for oral cancer. CONCLUSION: In this population, using these tests for IgG, neither mean antibody measure nor high antibody measure against human herpesviruses 1-6 was strongly associated with any of the seven cancer groups. However, we may not have had sufficient power to detect weak associations or associations with a sub-type of cancer if they were present.

8.
FEBS Lett ; 574(1-3): 73-9, 2004 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-15358542

RESUMO

The lytic transglycosylases cleave the bacterial cell wall heteropolymer peptidoglycan with the same specificity as the muramidases (lysozymes), between the N-acetylmuramic acid and N-acetylglucosamine residues, with the concomitant formation of a 1,6-anhydromuramoyl residue. The putative catalytic residue in the family 3 lytic transglycosylase from Pseudomonas aeruginosa, Glu162 as identified by sequence alignment to the homologous enzyme from Escherichia coli, was replaced with both Ala and Asp by site-directed mutagenesis. Neither mutant enzyme differed structurally from the wild-type enzyme, as judged by CD spectroscopy, but both were enzymatically inactive confirming the essential role of Glu162 in the mechanism of action of this lytic transglycosylase. The beta-hexosaminidase inhibitor NAG-thiazoline was shown to inhibit the activity of lytic transglycosylase activity, thus providing the first direct evidence that the formation of the 1,6-anhydromuramoyl residue may proceed through an oxazolinium ion intermediate involving anchimeric assistance. Using surface plasmon resonance and difference absorbance spectroscopy, Kd values of 1.8 and 1.4 mM, respectively, were determined for NAG thiazoline, while its parent compound N-acetylglucosamine neither inhibited nor appeared to bind the lytic transglycosylase with any significant affinity.


Assuntos
Acetilglucosamina/farmacologia , Inibidores Enzimáticos/farmacologia , Glicosídeo Hidrolases/antagonistas & inibidores , Glicosiltransferases/antagonistas & inibidores , Proteínas de Membrana/antagonistas & inibidores , Tiazóis/farmacologia , Acetilglucosamina/análogos & derivados , Sequência de Bases , Primers do DNA , Mutagênese Sítio-Dirigida
9.
Bull World Health Organ ; 80(4): 277-81, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12075363

RESUMO

OBJECTIVE: To evaluate the effectiveness of universal vaccination against viral hepatitis B in South Africa among 18-month-old rural children. METHODS: Children were immunized with a course of low-dose (1.5 microg), plasma-derived hepatitis B vaccine at 6, 10 and 14 weeks of age, and blood samples from the children were tested for three hepatitis B markers: hepatitis B surface antigen (HBsAg), anti-HBs and anti-HBc. FINDINGS: One year after vaccination, a protective anti-HBs antibody titre of at least 10 IU/l was present in 669/769 (87.0%) of blood serum samples tested. Only 3/756 children (0.4%) were HBsAg positive and a fourth child was anti-HBc positive (HBsAg negative). This is a marked decrease compared to the hepatitis B prevalences reported in previous studies. Among rural migrant mine-workers, for example, HBsAg prevalence was 9.9%, and was 10.1% among children 0-6 years of age in the Eastern Cape Province. CONCLUSION: The low-dose, plasma-derived hepatitis B vaccine, which is affordable to most developing countries, was very successful in controlling endemic hepatitis B infection, where the virus is predominantly spread by horizontal transmission among infants and young children.


Assuntos
Vacinas contra Hepatite B/administração & dosagem , Programas de Imunização/estatística & dados numéricos , Biomarcadores , Criança , Pré-Escolar , Estudos Transversais , Países em Desenvolvimento , Soropositividade para HIV/epidemiologia , Anticorpos Anti-Hepatite B/sangue , Vacinas contra Hepatite B/economia , Humanos , Lactente , Recém-Nascido , Prevalência , Avaliação de Programas e Projetos de Saúde , África do Sul/epidemiologia
12.
J Infect ; 43(2): 128-31, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11676519

RESUMO

OBJECTIVES: To determine the level of immunity to polio in adult personnel at the National Institute for Virology (NIV), South Africa. METHODS: Polio neutralizing antibodies results on 776 NIV staff members tested between 1979 and 1999 and seroresponses in seronegative personnel given a booster vaccination were analysed. RESULTS: 613 of the 776 (79%) personnel had neutralizing polio antibodies to all three types, independent of age, gender, race or job category. Types 1 and 2 antibodies were found in 92% and 94%, respectively, but type 3 was less prevalent at 87%. Of the 93 persons seronegative to one or more types, 13 failed to respond to the first booster vaccination and 8 remained as non-responders after two booster vaccinations. Of the 19 personnel who were bled four days after booster vaccination, 16 (84%) had already developed an antibody response. CONCLUSIONS: Most (79%) adult laboratory personnel retained detectable levels of neutralizing antibodies to polio, independent of age, gender, race or job category, and even in those persons lacking detectable antibodies, most (84%) responded with a secondary immune response. Nevertheless the immunity gap, particularly to type 3, mandates routine screening of personnel potentially exposed to wild-type polio virus and a booster vaccination for seronegatives.


Assuntos
Pessoal Técnico de Saúde , Poliomielite/epidemiologia , Poliovirus/isolamento & purificação , Adulto , Anticorpos Antivirais/análise , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Exposição Ocupacional , Estudos Retrospectivos , Estudos Soroepidemiológicos , África do Sul/epidemiologia
13.
J Biol Inorg Chem ; 6(5-6): 567-77, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11472020

RESUMO

Binding of the Cu(I)-specific ligands 2,6-dimethylphenyl isocyanide (DIMPI) and isopropyl isocyanide (IPI) to the reduced form of peptidylglycine monooxygenase (PHM) is reported. Both ligands bind to the methionine-containing CuM center, eliciting FTIR bands at 2,138 and 2,174 cm(-1), respectively, but appear unable to coordinate at the histidine-containing CuH center in the wild-type enzyme. This chemistry parallels that previously observed for CO binding to the reduced PHM catalytic core (PHMcc). However, in contrast to the CO chemistry, peptide substrate binding did not induce binding of the isocyanide at CuH. XAS confirmed the binding of DIMPI at CuM via the observation of a short Cu-C interaction at 1.87 A and by the lengthening of the Cu-S(methionine) bond length by 0.06 A. Similarly, FTIR studies on DIMPI binding to the M314I and H172A mutant forms of reduced PHMcc confirmed the assignment of the 2,138-cm(-1) IR band as a CuM-DIMPI complex, but surprisingly also showed DIMPI binding to CuH, as indicated by a band at 2,148 cm(-1). An inorganic complex, [Cu(1,2-Me2Im)2(DIMPI)](PF6), was synthesized and its crystal structure was determined as a model for the interaction of isocyanides with imidazole-containing Cu(I) complexes. Comparison of EXAFS data for the protein and model suggests that DIMPI probably binds to CuM in a tilted fashion, similar to that of ethyl isocyanide binding to myoglobin.


Assuntos
Cobre/metabolismo , Cianetos/metabolismo , Oxigenases de Função Mista/química , Oxigenases de Função Mista/metabolismo , Complexos Multienzimáticos/química , Complexos Multienzimáticos/metabolismo , Domínio Catalítico , Cristalografia por Raios X , Cianetos/química , Ligantes , Oxigenases de Função Mista/genética , Complexos Multienzimáticos/genética , Mutação , Nitrilas/química , Nitrilas/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier
14.
Biochemistry ; 40(23): 6867-75, 2001 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-11389601

RESUMO

A derivative of peptidylglycine monooxygenase which lacks the CuH center has been prepared and characterized. This form of the enzyme is termed the half-apo protein. Copper-to-protein stoichiometric measurements establish that the protein binds only one of the two copper centers (CuM and CuH) found in the native enzyme. Confirmation that the methionine-containing CuM has been retained has been obtained from EXAFS experiments which show that the characteristic signature of the Cu-S(Met) interaction is preserved. The half-apo derivative binds 1 equiv of CO per copper with an IR frequency of 2092 cm(-1), and this monocarbonyl also displays the Cu-S(Met) interaction in its EXAFS spectrum. These results allow unambiguous assignment of the 2092 cm(-1) band as a CuM-CO species. Binding of CO in the presence of peptide substrate was also investigated. In the native enzyme, substrate induced binding of a second CO molecule with an IR frequency of 2062 cm(-1), tentatively assigned to a CO complex of the histidine-containing CuH site. Unexpectedly, this reactivity is also observed in the half-apo derivative, although the intensity distribution of the CO stretches now indicates that the copper has been partially transferred to a second site, believed to be CuH. The implications of this observation are discussed in terms of a possible additional peptide binding site close to the CuH center.


Assuntos
Cobre/metabolismo , Oxigenases de Função Mista/química , Complexos Multienzimáticos , Animais , Apoenzimas/química , Apoenzimas/metabolismo , Sítios de Ligação , Células CHO , Monóxido de Carbono/química , Cobre/química , Cricetinae , Oxigenases de Função Mista/metabolismo , Oligopeptídeos/metabolismo , Consumo de Oxigênio , Espectrofotometria Infravermelho , Análise Espectral , Especificidade por Substrato , Raios X
15.
J Mol Evol ; 52(1): 78-84, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11139297

RESUMO

The lytic transglycosylases are a class of autolysins which cleave the bacterial cell wall heteropolymer peptidoglycan (murein) to facilitate its biosynthesis and turnover. A search of the National Center for Biotechnology Information (NCBI) databases using the primary sequences of the six characterized lytic transglycosylases of Escherichia coli, a membrane-bound form of the enzyme from Pseudomonas aeruginosa, and the endolysins of lambda bacteriophage permitted the identification of a total of 127 known and hypothetical enzymes from a wide variety of bacteria and bacteriophage. These amino acid sequences have been arranged into four families based on alignments, and consensus motifs have been identified. Family 1 represents a superfamily comprising 86 sequences which are subdivided into five (1A--1E) subfamilies.


Assuntos
Escherichia coli/genética , Glicosiltransferases/química , Glicosiltransferases/genética , Hexosiltransferases/química , Hexosiltransferases/genética , Família Multigênica , Pseudomonas aeruginosa/genética , Motivos de Aminoácidos , Sequência de Aminoácidos , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Bacteriófago lambda/enzimologia , Bacteriófago lambda/genética , Bases de Dados Factuais , Endopeptidases/química , Endopeptidases/genética , Escherichia coli/enzimologia , Evolução Molecular , Glicosiltransferases/classificação , Hexosiltransferases/classificação , Dados de Sequência Molecular , Estrutura Molecular , Filogenia , Pseudomonas aeruginosa/enzimologia
16.
Microb Ecol ; 42(3): 395-406, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12024264

RESUMO

Viral lysis of specific bacterial populations has been suggested to be an important factor for structuring marine bacterioplankton communities. In the present study, the influence of bacteriophages on the diversity and population dynamics of four marine bacterial phage-host systems was studied experimentally in continuous cultures and theoretically by a mathematical model. By use of whole genome DNA hybridization toward community DNA, we analyzed the dynamics of individual bacterial host populations in response to the addition of their specific phage in continuous cultures of mixed bacterial assemblages. In these experiments, viral lysis had only temporary effects on the dynamics and diversity of the individual bacterial host species. Following the initial lysis of sensitive host cells, growth of phage-resistant clones of the added bacteria resulted in a distribution of bacterial strains in the phage-enriched culture that was similar to that in the control culture without phages after about 50-60 h incubation. Consequently, after a time frame of 5-10 generations after lysis, it was the interspecies competition rather than viral lysis of specific bacterial strains that was the driving force in the regulation of bacterial species composition in these experiments. The clonal diversity, on the other hand, was strongly influenced by viral activity, since the clonal composition of the four species in the phage-enriched culture changed completely from phage-sensitive to phage-resistant clones. The model simulation predicted that viral lysis had a strong impact on the population dynamics, the species composition, and the clonal composition of the bacterial community over longer time scales (weeks). However, according to the model, the overall density of bacteria in the system was not affected by phages, since resistant clones complemented the fluctuations caused by viral lysis. Based on the model analysis, we therefore suggest that viral lysis can have a strong influence on the dynamics of bacterial populations in planktonic marine systems.

17.
Health Info Libr J ; 18(4): 203-12, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11791860

RESUMO

This research focuses on identifying the information needs of health professionals, social workers and staff from voluntary agencies, who work together in the provision of services for people with a mental illness. The aim is to provide a fully integrated library and information service for mental health and social care. A number of recent government reports have prompted this research. These have culminated in the publication of the National Service Framework for Mental Health. It was decided to conduct a qualitative study using 17 semistructured interviews with individuals and multi-professional groups. A thematic analysis highlighted a number of key themes including: information need, information seeking behaviour and information flows. Results have indicated that because of the dispersed nature of mental health services, across primary and secondary care, and from statutory and non-statutory organisations, information technology is viewed as the only realistic vehicle to provide the required information. As specialist mental health trusts are configured, covering wider geographical areas, this can only increase the reliance on information technology, for information access and information sharing.


Assuntos
Serviços Comunitários de Saúde Mental/normas , Educação de Pessoa com Deficiência Intelectual , Relações Interprofissionais , Serviços de Biblioteca/normas , Avaliação das Necessidades , Adulto , Anedotas como Assunto , Comportamento Cooperativo , Inglaterra , Humanos , Bibliotecários , Bibliotecas Médicas/normas , Educação de Pacientes como Assunto , Psicologia , Serviço Social , Inquéritos e Questionários , Voluntários
18.
Anal Biochem ; 284(2): 388-93, 2000 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-10964424

RESUMO

An assay has been developed to monitor the activity of the lytic transglycosylases which does not involve the use of radiolabel. Samples of lytic transglycosylase were incubated with isolated and purified insoluble peptidoglycan as substrate for varying lengths of time. Residual insoluble material was removed by ultracentrifugation in a microfuge and the solubilized components were treated with sodium borohydride prior to acid hydrolysis. The optimal conditions for this acid hydrolysis were established to be incubation at 96 degrees C for 1 h in 6 M HCl, in vacuo. The hydrolyzed samples were subjected to amino acid/sugar analysis by cation-exchange chromatography on a Beckman System Gold amino acid analyzer. To effect a clear resolution of muramic acid from serine and glutamic acid, the equilibration buffer was modified to be composed of 33 mM sodium citrate, pH 3.12. The product of the lyase reaction of the lytic transglycosylases are 1,6-anhydromuramyl residues, which are not reduced by the sodium borohydride treatment. On the other hand, the muramyl residues arising at the reducing ends of peptidoglycan after treatment with muramidases (hydrolyases) are reduced to muramitol residues, which elute from the amino acid analyzer prior to aspartic acid. This assay thus distinguishes the activity of the two enzymes and was applied to determine the initial activities of increasing concentrations of a soluble derivative of lytic transglycosylase B from the opportunistic pathogen Pseudomonas aeruginosa.


Assuntos
Glicosiltransferases/metabolismo , Aminoácidos/análise , Sequência de Carboidratos , Carboidratos/análise , Cromatografia por Troca Iônica , Cinética , Muramidase/metabolismo
20.
J Pediatr ; 137(1): 78-84, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10891826

RESUMO

OBJECTIVES: To determine the burden of viral associated severe lower respiratory tract infections (SLRTI) in human immunodeficiency virus-infected (HIV+) and HIV-uninfected (HIV-) urban black South African children. METHODS: Children with SLRTI aged 2 to 60 months were enrolled between March 1997 and March 1998. Monoclonal antibody immunofluorescent testing was performed on nasopharyngeal aspirates to detect respiratory syncytial virus (RSV), influenza A and B, parainfluenza 1-3, and adenovirus-specific antigens. RESULTS: Of the 990 children studied, 44.6% were HIV+. The estimated burden of disease of viral associated SLRTI in children under 2 years was increased for RSV, influenza A/B viruses, parainfluenza 1-3 viruses, and adenovirus in children who were HIV+ compared with children who were HIV- (P <.001). Viral pathogens, however, were identified less frequently (15.7% vs 34.8%, P < 10(-5)) and bacterial pathogens more frequently (12.5% vs 5.8%, P <.0001) in children who were HIV+ than in children who were HIV- and had SLRTI. The seasonal peak for RSV in late summer-early autumn observed in children who were HIV- was less evident in children who were HIV+ (P =.02). Children who were HIV+ and had virus-associated SLRTI had a higher mortality rate (7. 5%) than did children who were HIV- (0%, P < 10(-3)). CONCLUSIONS: The contribution of viral associated SLRTI differs between HIV+ and HIV- children. In HIV+ children in South Africa, RSV isolation is not limited by season.


Assuntos
Infecções por HIV/complicações , HIV-1 , Infecções Respiratórias/complicações , Infecções por Adenovirus Humanos/complicações , Pré-Escolar , Feminino , Humanos , Lactente , Influenza Humana/complicações , Masculino , Infecções por Paramyxoviridae/complicações , Estudos Prospectivos , Infecções por Vírus Respiratório Sincicial/complicações , Infecções Respiratórias/virologia , Estações do Ano
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