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1.
J Hum Nutr Diet ; 33(4): 518-537, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32364292

RESUMO

BACKGROUND: Front of pack labelling (FOPL) provides visible nutritional information and appears to influence knowledge and reformulation. However, a recent Cochrane review found limited and inconsistent evidence for behaviour change. The present review aimed to examine studies published subsequent the Cochrane review, focusing on prepackaged foods, examining the impact of FOPL on purchasing and consumption. METHODS: Controlled experimental/intervention and interrupted time series (ITS) studies were included, with no age/geography restrictions. Exposures were FOPL with objectively measured consumption/purchasing outcomes. Thirteen databases were searched (January 2017 to April 2019) and forward citation searching was undertaken on the included studies. Purchasing data from experimental studies were meta-analysed. Two series of meta-analyses were undertaken; combined FOPL versus no-FOPL and specific FOPL scheme versus no-FOPL. Outcomes were sugar (g 100 g-1 ), calories (kcal 100 g-1 ), saturated fat (g 100 g-1 ) and sodium (mg 100 g-1 ). RESULTS: We identified 14 studies, reporting consumption (experimental; n = 3) and purchasing (n = 8, experimental; n = 3, ITS). Meta-analysis of experimental studies showed sugar and sodium content of purchases was lower for combined FOPL versus no-FOPL (-0.40 g sugar 100 g-1 , P < 0.01; -24.482 mg sodium 100 g-1 , P = 0.012), with a trend for lower energy and saturated fat (-2.03 kcal 100 g-1 , P = 0.08; -0.154 g saturated fat 100 g-1 , P = 0.091). For specific FOPL, products purchased by 'high in' FOPL groups had lower sugar (-0.67 g sugar 100 g-1 , P ≤ 0.01), calories (-4.43 kcal 100 g-1 , P < 0.05), sodium (-33.78 mg 100 g-1 , P = 0.01) versus no-FOPL; Multiple Traffic Light had lower sodium (-34.94 mg 100 g-1 , P < 0.01) versus no-FOPL. Findings regarding consumption were limited and inconsistent. FOPL resulted in healthier purchasing in ITS studies. CONCLUSIONS: This review provides evidence from experimental and 'real-life' studies indicating that FOPL encourages healthier food purchasing. PROSPERO CRD42019135743.


Assuntos
Comércio/estatística & dados numéricos , Comportamento do Consumidor , Dieta Saudável/psicologia , Rotulagem de Alimentos/métodos , Preferências Alimentares/psicologia , Adolescente , Adulto , Idoso , Comportamento de Escolha , Ensaios Clínicos como Assunto , Dieta Saudável/economia , Dieta Saudável/estatística & dados numéricos , Feminino , Rotulagem de Alimentos/economia , Comportamentos Relacionados com a Saúde , Humanos , Análise de Séries Temporais Interrompida , Masculino , Pessoa de Meia-Idade , Política Nutricional , Adulto Jovem
2.
Plast Surg Int ; 2012: 740378, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22792453

RESUMO

Aims. To study the factors associated with the DSH in the elderly group of 60 years and above and to recommend changes to be implemented in order to improve the management in this specific group. Materials and Methods. Five-year retrospective study was undertaken from July 2005 to July 2010 in the Plastic Surgery Department of the Royal Preston Hospital, NHS Trust. A Performa was designed to collect data about the inpatient admission and included certain areas of key information. The case notes for all patients were extensively analysed in order to gather adequate information for the devised Performa. Results. DSH is getting more common in the elderly group, and males are more affected than females. 60% of the patients had a previous history of DSH. A large number (80%) of patients had a previous history of mental illness. 60% of those DSH patients were living with family. Almost all patients (90%) were reviewed by the Psychiatry Liaison Team. The timing of patients being assessed was highly variable. Conclusions. Marriage is not a protective factor in the prevention of the DSH in the elderly group. A mental health team referral in the early phases of the management would be of huge benefit and a likely step to prevent possible future admissions. The Department would benefit from the creation of a protocol for the management of these patients. There should be a joint effort of the professionals in the management of DSH in the elderly, and GPs play a very important role in the prevention of DSH in the later life.

3.
J Plast Reconstr Aesthet Surg ; 64(6): 816-7, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21030326

RESUMO

What once was simply a cultural tradition is fast becoming a popular phenomenon amongst Western tourists. Temporary henna tattoo designs performed by street or beach vendors are prevalent throughout the Middle East and Asia, particularly in holiday resorts. The public may be mistaken in thinking that the fashionable trend comes without significant risk. The main ingredient in the temporary tattooing method is henna (Lawsonia inermis), a flowering plant with dyeing properties that takes only several hours to be absorbed but provides an effect lasting around ten to fifteen days on the recipient's skin. The side effects of henna tattoos are well documented in the literature, although it is not clear whether the side effects directly relate to the henna ingredient or the additives used to prolong the designs. The most commonly noted complications include allergic contact dermatitis, infection, hypertrophic and keloid scarring and temporary or permanent hypo- or hyperpigmentation. In very rare cases, type 1 hypersensitivity reactions (angioedema and anaphylaxis) have been reported. The following case report highlights several of these complications and the relevant management.


Assuntos
Corantes/efeitos adversos , Dermatite Alérgica de Contato/etiologia , Lawsonia (Planta)/efeitos adversos , Naftoquinonas/efeitos adversos , Fenilenodiaminas/efeitos adversos , Tatuagem/efeitos adversos , Adolescente , Dermatite Alérgica de Contato/diagnóstico , Humanos , Masculino , Índice de Gravidade de Doença , Tatuagem/métodos
4.
Mol Psychiatry ; 14(6): 621-30, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18268499

RESUMO

The HTR1A -1019C>G genotype was associated with major depression in the Utah population. Linkage analysis on Utah pedigrees with strong family histories of major depression including only cases with the HTR1A -1019G allele revealed a linkage peak on chromosome 10 (maximum HLOD=4.4). Sequencing of all known genes in the linkage region revealed disease-segregating single-nucleotide polymorphisms (SNPs) in LHPP. LHPP SNPs were also associated with major depression in both Utah and Ashkenazi populations. Consistent with the linkage evidence, LHPP associations depended on HTR1A genotype. Lhpp or a product of a collinear brain-specific transcript, therefore, may interact with Htr1a in the pathogenesis of major depression.


Assuntos
Transtorno Depressivo Maior/epidemiologia , Transtorno Depressivo Maior/genética , Ligação Genética , Pirofosfatase Inorgânica/genética , Receptor 5-HT1A de Serotonina/genética , Cromossomos Humanos Par 10 , Feminino , Genótipo , Humanos , Judeus/genética , Judeus/estatística & dados numéricos , Masculino , Linhagem , Polimorfismo de Nucleotídeo Único , Fatores de Risco , Utah/epidemiologia
6.
Kidney Int ; 69(8): 1444-9, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16508655

RESUMO

The Dialysis Outcomes Quality Initiative emphasizes increasing arteriovenous fistula prevalence, by promoting referral for fistula creation in patients with stage 4 chronic kidney disease (CKD). The aim is to provide an optimal access for initiation of dialysis, thus avoiding central venous catheter use. The endovascular management of nonmaturing fistulas is more complicated in these patients, where the expected benefit of catheter avoidance must be weighed against the risk of contrast induced nephropathy (CIN). This study reports on the safety of a low-dose radiocontrast regimen, used in performing endovascular fistula salvage procedures in patients with stage 4 CKD. All consecutive endovascular procedures performed over a 2-year period in patients with stage 4 CKD and nonmaturing access were identified. Data collected included the type of procedure, contrast volume per procedure, pre, 2- and 7-day creatinine, need for acute dialysis, and the type of access used to initiate dialysis. Total of 65 procedures were performed in 34 patients. The mean contrast volume was 7.8 ml per procedure. The incidence of CIN (25% increase in serum creatinine) was 4% at 2 days and 4.6% at 1 week. All values returned to baseline within 2 weeks, and no patient required acute dialysis. Among the 33 patients with nonmaturing fistulas, 20 initiated dialysis during the follow-up period, 15 (75%) using their fistula, and five (25%) using a catheter. This study demonstrates that in patients with advanced CKD, fistulas can be successfully salvaged using small contrast volumes with a low incidence of CIN.


Assuntos
Derivação Arteriovenosa Cirúrgica/métodos , Falência Renal Crônica/fisiopatologia , Falência Renal Crônica/terapia , Segurança , Idoso , Idoso de 80 Anos ou mais , Meios de Contraste/administração & dosagem , Meios de Contraste/efeitos adversos , Creatinina/sangue , Diabetes Mellitus/epidemiologia , Diabetes Mellitus/terapia , Feminino , Seguimentos , Taxa de Filtração Glomerular/fisiologia , Humanos , Incidência , Nefropatias/induzido quimicamente , Nefropatias/complicações , Nefropatias/epidemiologia , Falência Renal Crônica/complicações , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Tempo , Estados Unidos/epidemiologia
7.
Eur J Neurosci ; 22(1): 1-9, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16029190

RESUMO

The focus of the present study is the molecular and functional characterization of four splice variants of the human Nav1.3 alpha subunit. These subtypes arise due to the use of alternative splice donor sites of exon 12, which encodes a region of the alpha subunit that resides in the intracellular loop between domains I and II. This region contains several important phosphorylation sites that modulate Na+ channel kinetics in related sodium channels, i.e. Nav1.2. While three of the four Nav1.3 isoforms, 12v1, 12v3 and 12v4 have been previously identified in human, 12v2 has only been reported in rat. Herein, we evaluate the distribution of these splice variants in human tissues and the functional characterization of each of these subtypes. We demonstrate by reverse transcriptase-polymerase chain reaction (RT-PCR) that each subtype is expressed in the spinal cord, thalamus, amygdala, cerebellum, adult and fetal whole brain and heart. To investigate the functional properties of these different splice variants, each alpha subunit isoform was cloned by RT-PCR from human fetal brain and expressed in Xenopus oocytes. Each isoform exhibited functional voltage-dependent Na+ channels with similar sensitivities to tetrodotoxin (TTX) and comparable current amplitudes. Subtle shifts in the V 1/2 of activation and inactivation (2-3 mV) were observed among the four isoforms, although the functional significance of these differences remains unclear. This study has demonstrated that all four human splice variants of the Nav1.3 channel alpha subunit are widely expressed and generate functional TTX-sensitive Na+ channels that likely modulate cellular excitability.


Assuntos
Membrana Celular/metabolismo , Sistema Nervoso Central/metabolismo , Proteínas do Tecido Nervoso/genética , Canais de Sódio/genética , Processamento Alternativo/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Encéfalo/metabolismo , Membrana Celular/genética , Feminino , Humanos , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Dados de Sequência Molecular , Canal de Sódio Disparado por Voltagem NAV1.3 , Proteínas do Tecido Nervoso/isolamento & purificação , Proteínas do Tecido Nervoso/metabolismo , Oócitos , Isoformas de Proteínas/genética , Isoformas de Proteínas/isolamento & purificação , Isoformas de Proteínas/metabolismo , Subunidades Proteicas/genética , Subunidades Proteicas/isolamento & purificação , Subunidades Proteicas/metabolismo , RNA Mensageiro/metabolismo , Ratos , Bloqueadores dos Canais de Sódio/farmacologia , Canais de Sódio/isolamento & purificação , Canais de Sódio/metabolismo , Medula Espinal/metabolismo , Xenopus
8.
Recept Channels ; 9(6): 363-77, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14698964

RESUMO

Potassium channels govern the permeability of cells to potassium ions, thereby controlling the membrane potential. In metazoa, potassium channels are encoded by a large, diverse gene family. Previous analyses of this gene family have focused on its diversity in mammals. Here we have pursued a more comprehensive study in Caenorhabditis elegans, Drosophila melanogaster, and mammalian genomes. The investigation revealed 164 potassium channel encoding genes in C. elegans, D. melanogaster, and mammals, classified into seven conserved families, which we applied to phylogenetic analysis. The trees are discussed in relation to the assignment of orthologous relationships between genes and vertebrate genome duplication.


Assuntos
Canais de Potássio de Abertura Dependente da Tensão da Membrana , Canais de Potássio/genética , Animais , Caenorhabditis elegans , Cálcio/química , Biologia Computacional , Bases de Dados como Assunto , Drosophila melanogaster , Canal de Potássio ERG1 , Canais de Potássio Éter-A-Go-Go , Evolução Molecular , Humanos , Íons , Filogenia , Potássio/química , Potássio/metabolismo , Canais de Potássio Cálcio-Ativados/genética , Estrutura Terciária de Proteína , Ratos , Software
9.
Carcinogenesis ; 22(8): 1189-93, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11470748

RESUMO

The catechins, (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG) and (-)-epigallocatechin gallate (EGCG) are believed to be active constituents of green tea accounting for the reported chemoprevention of certain cancers. The molecular mechanisms by which the measured low concentrations (ca. micromolar) of catechins in humans can reduce the incidence of carcinogenesis is not clear. Using an in vitro plasmid DNA system and radiolytically generating reactive oxygen species (ROS) under constant scavenging conditions, we have shown that all four catechins, when present at low concentrations, ameliorate free radical damage sustained by DNA. A reduction in both prompt DNA single-strand breaks and residual damage to the DNA bases, detected by subsequent incubation with the DNA glycosylases formamidopyrimidine (FPG), endonuclease III (EndoIII) and 5' AP endonuclease exonuclease III (ExoIII), was observed. EGCG was found to be the most active of the catechins, with effects seen at micromolar concentrations. Combined fast-reaction chemistry studies support a mechanism of electron transfer (or H-atom transfer) from catechins to ROS-induced radical sites on the DNA. These results support an antioxidant role for catechins in their direct interaction with DNA radicals.


Assuntos
Catequina/farmacologia , Dano ao DNA , Reparo do DNA/efeitos dos fármacos , Radical Hidroxila , Chá/química , Cinética , Estresse Oxidativo , Plasmídeos
11.
Free Radic Res ; 33(1): 91-103, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10826925

RESUMO

This paper provides evidence that dietary flavonoids can repair a range of oxidative radical damages on DNA, and thus give protection against radical-induced strand breaks and base alterations. We have irradiated dilute aqueous solutions of plasmid DNA in the absence and presence of flavonoids (F) in a "constant *OH radical scavenging environment", k of 1.5 x 10(7) s(-1) by decreasing the concentration of TRIS buffer in relation to the concentration of added flavonoids. We have shown that the flavonoids can reduce the incidence of single-strand breaks in double-stranded DNA as well as residual base damage (assayed as additional single-strand breaks upon post-irradiation incubation with endonucleases) with dose modification factors of up to 2.0+/-0.2 at [F] < 100 microM by a mechanism other than through direct scavenging of *OH radicals. Pulse radiolysis measurements support the mechanism of electron transfer or H* atom transfer from the flavonoids to free radical sites on DNA which result in the fast chemical repair of some of the oxidative damage on DNA resulting from *OH radical attack. These in vitro assays point to a possible additional role for antioxidants in reducing DNA damage.


Assuntos
Dano ao DNA , Flavonoides/farmacologia , Antioxidantes/farmacologia , Catequina/farmacologia , Dieta , Sequestradores de Radicais Livres/farmacologia , Radicais Livres/toxicidade , Humanos , Técnicas In Vitro , Plasmídeos/efeitos dos fármacos
12.
Med Care ; 38(1): 19-34, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10630717

RESUMO

BACKGROUND: Quantified measures of unmet health care needs can be used to evaluate health care interventions, assess the impact of managed care, monitor health status trends in populations, or assess equity of access to medical care across population subgroups. Such a measure needs to be simple, relatively easy to obtain, inexpensive, and appropriately targeted to the population of interest. OBJECTIVE: To develop a measure of unmet health care needs that is specifically targeted to a pediatric population. SUBJECTS: Study participants consisted of children, aged 1 to 5 years (n = 1,031), and adolescent mothers, aged 13 to 19 years (n = 172), predominantly from poor, minority families in New York City. RESEARCH DESIGN: Based on a measure, the symptoms-response ratio, developed for all age groups, this study replicated Taylor's procedures specifically for children and adolescents. Respondents were asked if they had experienced a set of physical symptoms and if they saw a doctor in response. A panel of pediatricians rated the same symptoms as to whether health care should be sought. RESULTS: The measure achieved adequate inter-rater reliability and good construct validity. The children's overall use of health services did not differ from the pediatric panel's expectations, but with differing degrees of unmet needs by symptom. Adolescents sought care less often than the expert panel members believed they should. CONCLUSIONS: The symptoms-response ratio provides a good balance of a simple and inexpensive measure while yielding a fair estimate of unmet needs for primary care. This analysis created a pediatric measure targeted to the needs of young children and adolescent females.


Assuntos
Serviços de Saúde do Adolescente/estatística & dados numéricos , Serviços de Saúde da Criança/estatística & dados numéricos , Centros Comunitários de Saúde/estatística & dados numéricos , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Necessidades e Demandas de Serviços de Saúde/estatística & dados numéricos , Grupos Minoritários/estatística & dados numéricos , Avaliação das Necessidades/classificação , Pobreza/estatística & dados numéricos , Adolescente , Pré-Escolar , Feminino , Indicadores Básicos de Saúde , Humanos , Lactente , Masculino , Morbidade , Avaliação das Necessidades/economia , Cidade de Nova Iorque/epidemiologia , Variações Dependentes do Observador , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Gravidez , Gravidez na Adolescência/psicologia , Gravidez na Adolescência/estatística & dados numéricos , Atenção Primária à Saúde/normas , Reprodutibilidade dos Testes , Inquéritos e Questionários , Saúde da População Urbana
13.
Anesth Analg ; 89(5): 1226-32, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10553839

RESUMO

UNLABELLED: A new adaptive system has been designed to improve patient-controlled analgesia through the use of a variable bolus dose and a variable background infusion of analgesic. A novel hand set allows patients to rate their own pain on a linear scale of 1 to 10. Data derived from the hand set signals are used by an expert algorithm to repeatedly adapt the drug dosage of the bolus and of the background infusion according to both current pain intensity and the patient's response to previous dosage. To test the system, we performed a small pilot clinical study, using a randomized, double-blinded, cross-over design. The new system was alternated with a conventional system every 12 h. Use of the new system was associated with significantly lower pain scores and fewer bolus requests but more analgesic administration, though without increased adverse effects. It was very well accepted by both patients and clinical staff. IMPLICATIONS: Pain relief after surgery is often best provided by patient-controlled analgesia, which uses an IV infusion pump and a patient-activated switch. We have developed a new computer-controlled or "smart" patient-controlled analgesia that rapidly learns a patient's individual needs and provides continuously tailored pain relief.


Assuntos
Analgesia Controlada pelo Paciente , Sistemas Inteligentes , Dor Pós-Operatória/terapia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Analgesia Controlada pelo Paciente/instrumentação , Analgesia Controlada pelo Paciente/métodos , Analgésicos Opioides/administração & dosagem , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Morfina/administração & dosagem , Medição da Dor , Projetos Piloto
14.
IEEE Trans Inf Technol Biomed ; 3(1): 20-7, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10719500

RESUMO

A new adaptive patient-controlled analgesia (PCA) system designed to improve PCA through the use of a variable bolus dose and a variable background infusion is outlined here. The handset allows patients to rate their pain on a scale of 1-10. Data derived from the handset signals are used by an expert algorithm to repeatedly adapt the drug dosage of the bolus and the background infusion according to both pain intensity and patient response to previous dosages. A feasibility study of the system consisted of a small number of randomized, double-blind, crossover clinical trials. The new system was alternated with a conventional system every 12 h. When the new system was active, 12-h questionnaire pain scores were significantly lower and a trend toward fewer bolus requests was found in alternating intervals. In addition, when the new system was used to commence trials, the number of bolus requests were significantly lower and there was a trend toward lower handset scores, lower questionnaire pain scores, and lower verbal pain scores over the entire trial period. The new adaptive PCA system was well accepted by both patients and clinical staff. The trials successfully established the feasibility of the new system. Further development is being carried out as a result.


Assuntos
Analgesia Controlada pelo Paciente/instrumentação , Dor/tratamento farmacológico , Ensaios Clínicos como Assunto , Humanos
16.
Aust Nurs J ; 6(2): suppl 1-4, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10205382

RESUMO

Quality and accreditation have taken great strides in recent years. If you are one of the many who find the subject confusing then blame the relentless changes in concepts and terminology that swept into health care. To put this in perspective, I will look at where we have been, where we are, and where we are headed.


Assuntos
Acreditação/organização & administração , Garantia da Qualidade dos Cuidados de Saúde/organização & administração , Gestão da Qualidade Total/organização & administração , Austrália , Humanos
17.
Ann Thorac Surg ; 63(1): 220-1, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8993269

RESUMO

This report describes a case in which normal surgical manipulation during dissection of the heart while performing a repeat revascularization procedure produced a significant deformity in Palmaz-Schatz stents previously implanted in a saphenous vein graft. The graft had shown satisfactory angiographic appearance immediately before the operation, and consideration was given to leaving it in place. Its replacement, however, prevented a major intraoperative mishap.


Assuntos
Ponte de Artéria Coronária , Complicações Intraoperatórias/prevenção & controle , Stents , Idoso , Angiografia Coronária , Oclusão de Enxerto Vascular/terapia , Humanos , Masculino , Reoperação , Veia Safena/transplante
18.
FEBS Lett ; 398(2-3): 198-200, 1996 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-8977106

RESUMO

Proteins targeted to the thylakoid lumen of plants and cyanobacteria and the periplasmic space of cyanobacteria are synthesised with N-terminal presequences which are removed following translocation across the membrane. These presequences are thought to direct translocation of the preprotein by a sec-type pathway. Detergent extracts of cyanobacterial and chloroplast membranes contain enzymes which are capable of processing precursors to the mature size. We show that the processing of a range of precursors by both cyanobacterial and chloroplast enzymes is inhibited by the penem SB216357. This is the first report of an inhibitor of these enzymes and indicates that they are type 1 signal peptidases.


Assuntos
Cloroplastos/enzimologia , Cianobactérias/enzimologia , Endopeptidases/metabolismo , Lactamas/farmacologia , Inibidores de Proteases/farmacologia , Precursores de Proteínas/metabolismo , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Cloroplastos/efeitos dos fármacos , Cianobactérias/efeitos dos fármacos , Pisum sativum/enzimologia , Complexo de Proteínas do Centro de Reação Fotossintética/metabolismo , Plastocianina/metabolismo
19.
Biochim Biophys Acta ; 1276(3): 246-52, 1996 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-8856106

RESUMO

Part of the petCA operon was cloned and the sequence of the cytochrome f gene from the moderately thermophilic cyanobacterium Phormidium laminosum determined. A partial sequence of the petC gene encoding the Rieske iron-sulphur protein was also obtained. The cytochrome f gene encodes a mature protein of 385 residues and a leader sequence of 45 residues. The mature protein contains several acidic or neutral residues corresponding to basic residues in the turnip protein. Some of the latter are thought to be important for the interaction with plastocyanin via its "eastern' face. Many of the corresponding residues on the eastern face of P. laminosum plastocyanin are either basic or neutral instead of acidic. These comparisons suggested that the local charges on P. laminosum cytochrome f that are important for its interaction with the homologous plastocyanin may be negative rather than positive. The importance of acidic groups was confirmed by measuring the rates of reduction of horse heart cytochrome c and P. laminosum and spinach plastocyanins by the cytochrome bf complex isolated from P. laminosum. P. laminosum plastocyanin gave the highest rates, which decreased at high ionic strength, confirming the importance of positive local charges on this protein. When extrapolated to infinite ionic strength the rates observed with the two kinds of plastocyanin were similar, but cytochrome c became unreactive. An optimum was observed in the ionic strength response with P. laminosum plastocyanin.


Assuntos
Cianobactérias/genética , Citocromos/genética , Citocromos/metabolismo , Plastocianina/metabolismo , Sequência de Aminoácidos , Sequência de Bases , Cianobactérias/química , Grupo dos Citocromos b , Complexo Citocromos b6f , Citocromos/química , Citocromos f , Transporte de Elétrons , Biblioteca Gênica , Genes Bacterianos , Modelos Químicos , Dados de Sequência Molecular , Óperon , Concentração Osmolar , Reação em Cadeia da Polimerase , Potenciometria , Análise de Sequência , Homologia de Sequência de Aminoácidos
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