RESUMO
BACKGROUND: Clinical audit is a sustained cyclical quality improvement process seeking to improve patient care and outcomes by evaluating services against explicit standards and implementing necessary changes. National audits aim to improve population-level clinical care by identifying unwarranted variations and making recommendations for clinicians, managers and service commissioners. The National Clinical Audit of Anxiety and Depression aimed to improve clinical care for people admitted to English hospitals for treatment of anxiety and depression, to provide comparative data on quality of care, and to support local quality improvement initiatives by identifying and sharing examples of best practice. PROCEDURES: Thirteen standards were developed based on NICE guidelines, literature review and feedback from a steering committee and reference group of service users and carers. All providers of NHS inpatient mental health services in England were asked to submit details of between 20 and 100 eligible service users/patients admitted between April 2017 and September 2018. To ascertain data reliability, participating services re-audited 5 sets of case-notes with a second auditor, and the coordinating team checked 10 randomly-selected sets of case-notes from 3 services, also selected at random. The reference group and steering committee identified key findings and developed a series of recommendations, which were discussed in regional quality improvement workshops and on-line webinars. FINDINGS: Data from 3795 case notes were analysed. A sizeable proportion of records indicated that at least one important aspect of initial assessment was not documented. Many service users/patients who could have benefited from an intervention targeted at optimising physical health did not receive it. Only a minority (39%) were referred for psychological therapy. Use of outcome measures varied considerably but no single outcome measure was being used routinely. Most individuals had a care plan recorded in the notes, but a review date was documented in only two-thirds, and almost half of individuals had not received a copy. CONCLUSIONS: There was considerable variation between English mental health services across many variables, and much scope for improvement. Clinicians should ensure that care plans are developed collaboratively with service users/patients and identified carers should be provided with information about support services. Health services should investigate the reasons for low referral rates for psychological therapies. Clinicians should ensure all service users have jointly developed crisis plans in place at discharge. Service managers should agree outcome measures to evaluate the treatment provided and clinicians should use these measures at initial assessment and review appointments. The implementation of such changes provides an opportunity for collaborative research into mental health service delivery and quality.
Assuntos
Transtorno Depressivo , Serviços de Saúde Mental , Ansiedade , Auditoria Clínica , Depressão/diagnóstico , Depressão/terapia , Transtorno Depressivo/diagnóstico , Transtorno Depressivo/terapia , Humanos , Pacientes Internados , Reprodutibilidade dos TestesRESUMO
Bacterial spores resist environmental extremes and protect key spore macromolecules until more supportive conditions arise. Spores germinate upon sensing specific molecules, such as nutrients. Germination is regulated by specialized mechanisms or structural features of the spore that limit contact with germinants and enzymes that regulate germination. Importantly, germination renders spores more susceptible to inactivating processes such as heat, desiccation, and ultraviolet radiation, to which they are normally refractory. Thus, germination can be intentionally induced through a process called germination-induction and subsequent treatment of these germinated spores with common disinfectants or gentle heat will inactivate them. However, while the principle of germination-induction has been shown effective in the laboratory, this strategy has not yet been fully implemented in real-word scenarios. Here, we briefly review the mechanisms of bacterial spore germination and discuss the evolution of germination-induction as a decontamination strategy. Finally, we examine progress towards implementing germination-induction in three contexts: biodefense, hospital settings and food manufacture. SIGNIFICANCE AND IMPACT: This article reviews implementation of germination-induction as part of a decontamination strategy for the cleanup of bacterial spores. To our knowledge this is the first time that germination-induction studies have been reviewed in this context. This article will provide a resource which summarizes the mechanisms of germination in Clostridia and Bacillus species, challenges and successes in germination-induction, and potential areas where this strategy may be implemented.
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Descontaminação/métodos , Esporos Bacterianos/crescimento & desenvolvimento , Bacillus/efeitos dos fármacos , Bacillus/fisiologia , Clostridioides difficile/efeitos dos fármacos , Clostridioides difficile/fisiologia , Desinfetantes/farmacologia , Temperatura Alta , Esporos Bacterianos/efeitos dos fármacos , Esporos Bacterianos/fisiologia , Raios UltravioletaRESUMO
AIMS: In an attempt to devise decontamination methods that are both effective and minimally detrimental to the environment, we evaluated germination induction as an enhancement to strategies for Bacillus anthracis spore decontamination. To determine an optimal method for the recovery of germinating spores from different matrices, it was critical to ensure that the sampling procedures did not negatively impact the viability of the germinating spores possibly confounding the results and downstream analyses of field trial data. METHODS AND RESULTS: Therefore, the two main objectives of this study were the following: (i) development of an effective processing protocol capable of recovering the maximum number of viable germinating or germinated spores from different surface materials; and (ii) using a model system of spore contamination, employ this protocol to evaluate the potential applicability of germination induction to wide-area decontamination of B. anthracis spores. We examined parameters affecting the sampling efficiencies of B. anthracis and the surrogate species Bacillus thuringiensis on nonporous and porous materials. CONCLUSIONS: The most efficient extraction from all matrices was observed using PBS with 0·01% Tween 80 extraction buffer. The addition of a sonication and/or extended vortex treatment did not yield significant increases in spore or germinated spore recovery. SIGNIFICANCE AND IMPACT OF THE STUDY: Our data demonstrate that previous germination-induction experiments performed in suspension can be reproduced when Bacillus spores are deposited onto reference surfaces materials. Our proof of concept experiment illustrated that a germination pretreatment step significantly improves conventional secondary decontamination strategies and remediation plans.
Assuntos
Bacillus anthracis/crescimento & desenvolvimento , Bacillus thuringiensis/crescimento & desenvolvimento , Técnicas Bacteriológicas/métodos , Esporos Bacterianos/crescimento & desenvolvimento , Descontaminação , PapelRESUMO
New Zealand, like other southern hemisphere countries with a temperate climate, has been in the winter period with seasonal influenza activity. New Zealand has also experienced a dramatic increase in the number of cases of pandemic influenza A(H1N1)v virus. Early reports from the northern hemisphere at the beginning of the pandemic showed that the virus was sensitive to the antiviral drug oseltamivir. In this study we report that pandemic influenza A(H1N1)v viruses currently circulating in New Zealand are sensitive to oseltamivir, but seasonal influenza A(H1N1) viruses - the co-circulating predominant seasonal strain, is resistant to oseltamivir.
Assuntos
Antivirais/farmacologia , Surtos de Doenças/prevenção & controle , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Influenza Humana/tratamento farmacológico , Oseltamivir/farmacologia , Humanos , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Influenza Humana/epidemiologia , Influenza Humana/virologia , Testes de Sensibilidade Microbiana , Nova Zelândia/epidemiologia , Vigilância da PopulaçãoRESUMO
AIMS: Within acute psychiatric inpatient services, patients exhibiting severely disturbed behaviour can be transferred to a psychiatric intensive care unit (PICU) and/or secluded in order to manage the risks posed to the patient and others. However, whether specific patient groups are more likely to be subjected to these coercive measures is unclear. Using robust methodological and statistical techniques, we aimed to determine the demographic, clinical and behavioural predictors of both PICU and seclusion. METHODS: Data were extracted from an anonymised database comprising the electronic medical records of patients within a large South London mental health trust. Two cohorts were derived, (1) a PICU cohort comprising all patients transferred from general adult acute wards to a non-forensic PICU ward between April 2008 and April 2013 (N = 986) and a randomly selected group of patients admitted to general adult wards within this period who were not transferred to PICU (N = 994), and (2) a seclusion cohort comprising all seclusion episodes occurring in non-forensic PICU wards within the study period (N = 990) and a randomly selected group of patients treated in these wards who were not secluded (N = 1032). Demographic and clinical factors (age, sex, ethnicity, diagnosis, admission status and time since admission) and behavioural precursors (potentially relevant behaviours occurring in the 3 days preceding PICU transfer/seclusion or random sample date) were extracted from electronic medical records. Mixed effects, multivariable logistic regression analyses were performed with all variables included as predictors. RESULTS: PICU cases were significantly more likely to be younger in age, have a diagnosis of bipolar disorder and to be held on a formal section compared with patients who were not transferred to PICU; female sex and longer time since admission were associated with lower odds of transfer. With regard to behavioural precursors, the strongest predictors of PICU transfer were incidents of physical aggression towards others or objects and absconding or attempts to abscond. Secluded patients were also more likely to be younger and legally detained relative to non-secluded patients; however, female sex increased the odds of seclusion. Likelihood of seclusion also decreased with time since admission. Seclusion was significantly associated with a range of behavioural precursors with the strongest associations observed for incidents involving restraint or shouting. CONCLUSIONS: Whilst recent behaviour is an important determinant, patient age, sex, admission status and time since admission also contribute to risk of PICU transfer and seclusion. Alternative, less coercive strategies must meet the needs of patients with these characteristics.
Assuntos
Serviços de Emergência Psiquiátrica , Pacientes Internados , Unidades de Terapia Intensiva , Transtornos Mentais/psicologia , Serviços de Saúde Mental , Isolamento de Pacientes/psicologia , Adulto , Fatores Etários , Estudos de Casos e Controles , Feminino , Pesquisa sobre Serviços de Saúde , Humanos , Masculino , Transtornos Mentais/terapia , Pessoa de Meia-Idade , Fatores Sexuais , Fatores de Tempo , Adulto JovemRESUMO
A range of oligosaccharide ester derivatives (OEDs) have been designed as drug delivery matrices for controlled release. The synthetic hormone analogue, leuprolide, was encapsulated within these matrices using hydrophobic ion pairing and solvent spray drying. The particles produced modified the release of leuprolide in vitro (dissolution in phosphate buffered saline) and in vivo (subcutaneous and pulmonary delivery in the rat). Release rate was dependent on drug loading and could be manipulated by choice of OED and by combining different OEDs in different ratios. Leuprolide encapsulated in the OEDs retained biological activity as evidenced by elevation in plasma luteinising hormone levels following subcutaneous injection of leuprolide recovered from OED particles in vitro prior to in vivo administration.
Assuntos
Leuprolida/química , Oligossacarídeos/química , Poliésteres/química , Administração por Inalação , Animais , Cromatografia Líquida de Alta Pressão , Preparações de Ação Retardada/química , Composição de Medicamentos , Estabilidade de Medicamentos , Injeções Subcutâneas , Lactose/análogos & derivados , Lactose/química , Leuprolida/sangue , Ratos , Temperatura , Trealose/análogos & derivados , Trealose/químicaRESUMO
Despite the development of community care and associated processes of de-institutionalisation, the hospital remains the hub of mental health services in the UK. However, previous quantitative and survey research indicates that quality of care in acute psychiatric (admission) wards has been compromised or is under threat, and points to a bleak experience for people who are admitted. Indicators of this include that there have been increases in admission rates, the proportion of compulsory admissions, and bed occupancy rates. There is also evidence of violence, sexual harassment and substance misuse in this setting, accompanied by rapid staff turnover, low staff morale, and an increasing proportion of 'difficult' patients (especially young men with schizophrenia). This paper reviews the evidence about life on psychiatric wards, focusing on how it is experienced by patients in acute settings. Research conducted in the UK in the 1990s, supports the impression that organisational pressures are having a negative impact on the quality of care. It shows that: nurse-patient (N-P) relationships are perceived to be an important aspect of care, but that N-P contact has declined; and patients are critical of conditions on the ward and view life there as both boring and unsafe. However, very little in-depth ethnographic research has been conducted on acute wards in the UK (and none since the 1970s) leaving us with a 'black box' view of in-patient care in this setting. Studies conducted during earlier 'care paradigms', notably those in the USA by Goffman and Strauss et al., provide useful insights into the patient's experience, but the extent to which these can be conceptually generalised to the present situation is unknown. The paper concludes by outlining questions and priorities for future investigation, focusing on the role of qualitative research.
Assuntos
Auxiliares de Psiquiatria/organização & administração , Qualidade da Assistência à Saúde/normas , Qualidade de Vida/psicologia , Humanos , Serviços de Saúde Mental/normas , Relações Enfermeiro-Paciente , Auxiliares de Psiquiatria/psicologia , Inquéritos e Questionários , Reino UnidoRESUMO
Research on "risk behaviour" in the time of AIDS has emphasised how social relationships influence individuals' responses to risk. Yet the social relationship remains an under-utilised unit of analysis in risk behaviour research. Drawing on qualitative research with illicit drug users in London, this paper illustrates how drug users' sexual relationships act as key sites of risk management in individuals' drug use and everyday lifestyles. First, while recent research has almost exclusively focused on the dangers of disease transmission, our findings show that drug users perceived their sexual relationships as influencing a variety of risks associated with heroin and other opioid drugs. Here, two types of relationships--"gear" and "straight" relationships--were perceived to be particularly important. Second, while research has tended to focus on drug and health risks as an outcome of relationships, drug users' accounts emphasise that managing risks to their relationships is an important facet of everyday risk management made complicated by drug use. It is argued that risk is a product of social interactions, and that the sexual relationship is an important site of risk management in this process. Future interventions should target drug users' sexual relationships as agents of risk management and behaviour change.
Assuntos
Infecções por HIV/prevenção & controle , Transtornos Relacionados ao Uso de Opioides/psicologia , Assunção de Riscos , Comportamento Sexual/psicologia , Parceiros Sexuais , Adulto , Feminino , Humanos , Relações Interpessoais , Estilo de Vida , Londres , MasculinoRESUMO
A powder formulation of live-attenuated measles vaccine is being developed for administration to the lungs. The safety and efficacy of the powder will be assessed by insufflation into cynomolgus monkeys. A Penn Century insufflator has been evaluated for powder dosing to the monkeys using an insulin formulation having similar physicochemical characteristics to the vaccine powder. Insulin pharmacokinetics were compared following dosing by powder insufflation, solution instillation into the trachea and subcutaneous injection. The insulin dosed to the lungs and trachea was more rapidly absorbed than that administered subcutaneously. Insulin bioavailability was greater from the inhaled powder than from the instilled solution. The findings confirm that the Penn Century device is suitable for vaccine powder dosing to the deep lung.
Assuntos
Insulina/farmacocinética , Pulmão/metabolismo , Administração por Inalação , Animais , Área Sob a Curva , Glicemia/efeitos dos fármacos , Injeções Subcutâneas , Insuflação/métodos , Insulina/administração & dosagem , Insulina/farmacologia , Macaca fascicularis , Masculino , PósRESUMO
The process of implementing a research-based protocol (the Second Stage Labor Nursing Management) at 40 sites in North America is described. Both positive and negative factors involved in implementing and adhering to the protocol are presented based on the reports of site coordinators. Key findings from the process data are: (a) the term "research utilization" causes confusion, (b) it is essential that nurses collaborate with other disciplines when attempting to change practice, (c) administrative endorsement of research utilization is important for practice change to occur, (d) nurses know their own practice sites and how to facilitate protocol acceptance, and (e) practice change may not need to occur all at once.
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Pesquisa em Enfermagem Clínica , Protocolos Clínicos , Difusão de Inovações , Trabalho de Parto , Enfermagem Obstétrica , Postura , Feminino , Humanos , Relações Interprofissionais , Trabalho de Parto/fisiologia , América do Norte , Obstetrícia , GravidezRESUMO
The effect of 0, 5, 10 and 25 mg l-1 cadmium on the growth of Saccharomyces cerevisiae in defined medium has been investigated. It was found that the length of the lag phase increased with cadmium concentration and that metal uptake during the lag phase occurred only at a cadmium concentration of 25 mg l-1. However, metal uptake occurred at all cadmium concentrations during the exponential phase. The yeast was gradually adapted to cadmium by a series of subcultures which resulted in a decrease in the length of the lag phase. Adaptation also caused a reduction in the cadmium uptake during the lag phase at 25 mg l-1 cadmium but did not affect uptake during the exponential phase at any concentration. A single passage through cadmium-free medium partially reversed the adaptation process. Sulphide production was enhanced significantly when the yeast was grown in the presence of increasing cadmium concentrations. However, at 5 mg l-1 cadmium, adapted cells produced less sulphide than unadapted cells, whilst at 10 and 25 mg l-1 cadmium the production of sulphide was similar for adapted and unadapted cells.
Assuntos
Cádmio/farmacologia , Saccharomyces cerevisiae/crescimento & desenvolvimento , Cádmio/metabolismo , Meios de Cultura , Glucose/metabolismo , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/metabolismo , Sulfetos/metabolismoRESUMO
The production of the extracellular nuclease secreted by Staphylococcus aureus (Foggi strain) was studied in a fermentor in an attempt to improve yield and allow large-scale production of the enzyme. In shake flask cultures, 600 units/mL of the enzyme were produced routinely. However, only 450 units/mL of the enzyme at best were obtained in a small-scale fermentor (3 L). The supplementation of the air supply to the fermentor with carbon dioxide [20% (v/v)] increased levels of enzyme in the culture medium to 770 units/mL. Subsequently, this result was reproduced in larger fermentors (10 and 150 L). The possible mechanisms of the effect of carbon dioxide upon the growth of Staphylococcus aureus (Foggi) and the production of the enzyme are discussed.
RESUMO
The mechanisms of metal resistance of a cadmium-resistant Alcaligenes sp. were studied. Growth in a defined medium was unaffected by cadmium at concentrations up to 0.1 mM, while at concentrations up to 2.5 mM, growth occurred after an extended lag phase. The increase in length of the lag phase was abolished by repeated subculturing at these higher concentrations. However, subculture in the absence of cadmium reversed the adaptation process. Plasmid DNA was not detected in adapted cells, suggesting that adaptation is not plasmid mediated. Increased sulfide production in response to cadmium was observed, although the levels were too low to account fully for cadmium resistance. Adaptation of cells to cadmium resulted in the appearance of a major new membrane protein (molecular weight, 34,500) whose presence was not dependent upon the method of membrane preparation. This protein was induced at cadmium concentrations of 0.1 mM and above, but below this level the protein was absent. The onset of growth at concentrations above 0.1 mM was coincident with the appearance of this protein, which was also induced by zinc (0.4 mM) but not by manganese or nickel. The protein was only solubilized by a sodium dodecyl sulfate-2-mercaptoethanol mixture. Similar solubility properties were shown by a second major membrane protein (molecular weight, 33,000). These two proteins proved to be similar by peptide-mapping experiments and amino acid analysis. The appearance of the 34,500-molecular-weight protein and its possible role in cadmium resistance are discussed.
Assuntos
Alcaligenes/genética , Cádmio/farmacologia , Alcaligenes/efeitos dos fármacos , Alcaligenes/crescimento & desenvolvimento , Resistência Microbiana a Medicamentos , Manganês/farmacologia , Proteínas de Membrana/genética , Níquel/farmacologia , Fatores R , Zinco/farmacologiaRESUMO
The conditions for refolding reduced and denatured human serum albumin (HSA) were investigated with a view to maximising the yield of native monomeric albumin. Refolding by dialysis was found to be preferable to dilution as a means of chaotrope (urea) and reductant (2-mercaptoethanol) removal. Dialysis of denatured HSA solutions containing 4-8 M urea and 14 mM 2-mercaptoethanol at pH 10.0 was found to be optimal for HSA refolding. The yield of monomeric HSA was maximal (94%) for dialysis in the presence of EDTA (1 mM) and sodium palmitate (20 microM). Using this protocol it was possible to refold HSA at concentrations in excess of 5 mg.ml-1 whilst maintaining a high recovery of native monomer. These results represent a considerable improvement on established methods of HSA refolding.
Assuntos
Albumina Sérica , Bilirrubina/sangue , Densitometria , Diálise , Eletroforese em Gel de Poliacrilamida , Humanos , Oxirredução , Mapeamento de Peptídeos , Ligação Proteica , Conformação Proteica , Desnaturação Proteica , Compostos de Sulfidrila/sangue , UltrafiltraçãoRESUMO
Epidemiological estimates of the sexual risk behavior of drug users have provided essential indicators to the current and future prevalence of HIV transmission. An overview of recent research shows the majority of drug injectors to be sexually active, low levels of reported condom use, a significant minority of female injectors to be involved in prostitution, relatively high levels of sexual mixing between drug injectors and noninjectors, and only scant indications of sexual behavior change. Epidemiological studies of risk, however, are unable to yield the data required to understand the interaction between individual risk behavior and social relationships. This is required if obstacles to safer sex compliance and sexual behavior change are to be overcome, and demands recognition of the influence and importance of social context on the production of sexual risk behavior in future research and intervention designs. In response, the paper explores the future role of qualitative research in understanding the social relations of "risk" and in contributing toward theoretical advancements in explanations of risk perception and risk behavior. The paper concludes by discussing the implications of this analysis for developing interventions which aim to target social relationships as agents of social network and community change.
Assuntos
Infecções por HIV/transmissão , Comportamento Sexual , Abuso de Substâncias por Via Intravenosa/epidemiologia , Preservativos/estatística & dados numéricos , Feminino , Infecções por HIV/prevenção & controle , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Fatores de Risco , Trabalho Sexual/estatística & dados numéricos , Parceiros Sexuais , Apoio Social , Abuso de Substâncias por Via Intravenosa/psicologiaRESUMO
To describe forms of unsafe protected sex (vaginal or anal intercourse where condoms are used unsafely) among a sample of drug users in London, data are drawn from a qualitative study of the sexual and drug taking lifestyles of opioid and stimulant users. Depth one-to-one interviews (n = 96) elicited detailed descriptions from interviewees of their sexual behaviour, including the last occasions they had protected and unprotected sex. Analysis of these accounts identified the phenomenon of 'unsafe protected sex' (UPS). Three forms of UPS were identified: (1) Condoms for ejaculation only. This is where a condom was used for penetrative sex, but only when ejaculation was imminent. In these situations, the perceived function of the condom related more to the prevention of unwanted pregnancy than the prevention of HIV/STDs. (2) Condoms after limited unprotected penetration. This is where sexual partners commenced unprotected penetration but used a condom soon after. Participants tended to see such unprotected penetration as a coerced or collaborative transgression from their usual safer sexual practices. (3) Condom failure. This is where condoms split or came off during penetration. This was sometimes only discovered after ejaculation and withdrawal, and was invariably perceived by participants to have been unsafe. The likelihood of condom failure may be increased in penetrative sex prolonged through the use of drugs. Findings point to the possibility that surveys of sexual risk behaviour underestimate levels of unprotected and unsafe sex. A broader and more sophisticated definition of 'sexual risk behaviour' is required with regard to condom use, one which incorporates UPS. If some forms of UPS are perceived to be 'safer sex', future interventions need to highlight the STD transmission risks associated with this activity. Also, some people may view UPS as a transgression towards unsafe behaviour, and this may be proffered as a rationalization for not using condoms at all.
Assuntos
Preservativos/estatística & dados numéricos , Assunção de Riscos , Comportamento Sexual , Transtornos Relacionados ao Uso de Substâncias/psicologia , Adolescente , Adulto , Atitude Frente a Saúde , Coito , Feminino , Humanos , Londres , Masculino , Parceiros SexuaisRESUMO
Lipopolysaccharide (LPS) of Pseudomonas morsprunorum was extracted with hot phenol and purified by repeated centrifuging followed by either block electrophoresis or gel filtration. LPS from a virulent isolate exhibited specific phage inactivation (PI50 = 0.05 mug LPS ml-1), whereas LPS from an avirulent phage-resistant mutant did not. LPS was considered pure when a single band was detected following sodium dodecyl sulphate-cellulose acetate electrophoresis (pH 7.4). It was not phytotoxic when inoculated into cherry leaves at concentrations up to I mg ml-1, but produced weak chlorosis in bean and tobacco at 2 mg ml-1: no visible symptoms appeared after treatment with lower concentrations. The chemical composition of the LPS was partly determined.
Assuntos
Bacteriófagos , Lipopolissacarídeos/fisiologia , Polissacarídeos Bacterianos/fisiologia , Pseudomonas/análise , Lipopolissacarídeos/análise , Lipopolissacarídeos/farmacologia , Plantas/efeitos dos fármacos , Polissacarídeos Bacterianos/análise , Polissacarídeos Bacterianos/farmacologiaRESUMO
A mixed population, enriched and established in a defined medium, from a sewage sludge inoculum was capable of complete mineralization of 4-chlorobenzoate. An organism, identified as Arthrobacter sp., was isolated from the consortium and shown to be capable of utilizing 4-chlorobenzoate as the sole carbon and energy source in pure culture. This organism (strain TM-1), dehalogenated 4-chlorobenzoate as the initial step in the degradative pathway. The product, 4-hydroxybenzoate, was further metabolized via protocatechuate. The ability of strain TM-1 to degrade 4-chlorobenzoate in liquid medium at 25 degrees C was improved by the use of continuous culture and repeated sequential subculturing. Other chlorinated benzoates and the parent compound benzoate did not support growth of strain TM-1. An active cell extract was prepared and shown to dehalogenate 4-chloro-, 4-fluoro-, and 4-bromobenzoate. Dehalogenase activity had an optimum pH of 6.8 and an optimum temperature of 20 degrees C and was inhibited by dissolved oxygen and stimulated by manganese (Mn). Strain improvement resulted in an increase in the specific activity of the cell extract from 0.09 to 0.85 nmol of 4-hydroxybenzoate per min per mg of protein and a decrease in the doubling time of the organism from 50 to 1.6 h.
RESUMO
Recombinant human albumin produced in the yeast Saccharomyces cerevisial and human serum albumin derived from blood fractionation were compared by a series of analytical techniques. These demonstrated that the two proteins were equivalent structurally. However, differences observed in some of the assays indicated that the recombinant product had lower levels of structural heterogeneity than the blood-derived protein.
Assuntos
Albuminas/química , Albuminas/metabolismo , Proteínas Recombinantes/metabolismo , Albumina Sérica/metabolismo , Albuminas/genética , Aminoácidos/análise , Fracionamento Químico , Eletroforese , Humanos , Conformação Proteica , Engenharia de Proteínas/normas , Processamento de Proteína Pós-Traducional , Proteínas Recombinantes/química , Albumina Sérica/químicaRESUMO
An attempt has been made to purify factors present in aqueous extracts of pig epidermis which inhibit epidermal cell proliferation. A lipophilic factor of low molecular weight (less than 10,000), has been shown to inhibit DNA synthesis as measured by the uptake of tritiated thymidine in mouse ear epidermis. Purification by alcohol precipitation, ethyl acetate extraction and silicic acid column chromatography produced a fifteen-fold increase in the specific activity of the inhibitory action. It seems likely that aggregation or absorption of this low molecular weight factor may explain the high molecular weight of epidermal cell proliferation inhibitors previously studied, as well as the difficulty in their characterization.