Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Clin Exp Dermatol ; 46(6): 1028-1037, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33583049

RESUMO

BACKGROUND: Dermatology is under-represented in UK undergraduate curricula, and with a diagnostic and educational toolkit that is heavily centred on face-to-face (F2F) clinical examination, dermatology education has been disproportionately affected by the COVID-19 pandemic. Online channel-based messaging apps such as Slack offer an opportunity to engage students in remote, multimodal collaborative learning by reproducing a classroom environment in the virtual space. AIM: To determine the feasibility, acceptability and proof of concept for an online Slack community in undergraduate dermatology education. METHODS: Undergraduate medical students participated in an online classroom for a 6-week programme encompassing case-based discussions, seminars and journal clubs. The platform was facilitated by junior doctors (n = 10) and patient educators (n = 6). Students and faculty completed a post-course evaluation. Students additionally completed a pre- and post-intervention dermatology quiz. Mixed methods analyses included quantitative analyses to explore data trends and qualitative phenomenographic analyses to assimilate key underlying themes. RESULTS: Students (n = 65) were enrolled to join the platform. The evaluation was completed by students (n = 52) from UK universities (n = 27). The majority of students (n = 27) interacted with the platform as passive observers (≤ 5 active interactions with the channel), with a small group (n = 4) of 'super-users' (≥ 100 active interactions). The overall quality of the course was described as 'excellent' by 96% of participants and 100% of faculty. CONCLUSION: A community-based online classroom can act as an enjoyable, acceptable and collaborative means of delivering dermatology education to undergraduate medical students. Its ease of use and supportive nature may also facilitate patient involvement. Such advances may provide vital safeguards against the reduction in F2F learning that has accompanied the COVID-19 pandemic.


Assuntos
COVID-19/epidemiologia , Currículo , Dermatologia/educação , Educação de Graduação em Medicina/métodos , Pandemias , Estudantes de Medicina , Humanos , Projetos Piloto , Reino Unido/epidemiologia
2.
Plant Cell Rep ; 31(5): 945-53, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22238061

RESUMO

Gibberellins (GAs) control many aspects of plant development, including seed germination, shoot growth, flower induction and growth and fruit expansion. Leaf explants of Solanum nigrum (Black Nightshade; Solanaceae) were used for Agrobacterium-mediated delivery of GA-biosynthetic genes to determine the influence of their encoded enzymes on the production of bioactive GAs and plant stature in this species. Constructs were prepared containing the neomycin phosphotransferase (nptII) gene for kanamycin resistance as a selectable marker, and the GA-biosynthetic genes, their expression under the control of the CaMV 35S promoter. The GA-biosynthetic genes comprised AtGA20ox1, isolated from Arabidopsis thaliana, the product from which catalyses the formation of C(19)-GAs, and MmGA3ox1 and MmGA3ox2, isolated from Marah macrocarpus, which encode functionally different GA 3-oxidases that convert C(19)-GAs to biologically active forms. Increase in stature was observed in plants transformed with AtGA20ox1, MmGA3ox2 and MmGA3ox1 + MmGA3ox2, their presence and expression being confirmed by PCR and RT-PCR, respectively, accompanied by an increase in GA(1) content. Interestingly, MmGA3ox1 alone did not induce a sustained increase in plant height, probably because of only a marginal increase in bioactive GA(1) content in the transformed plants. The results are discussed in the context of regulating plant stature, since this strategy would decrease the use of chemicals to promote plant growth.


Assuntos
Giberelinas/biossíntese , Oxigenases de Função Mista/metabolismo , Solanum nigrum/metabolismo , Arabidopsis/enzimologia , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Oxigenases de Função Mista/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Regiões Promotoras Genéticas , Solanum nigrum/genética , Transformação Genética
11.
Trends Plant Sci ; 5(12): 523-30, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11120474

RESUMO

The identification of most of the genes involved in the metabolic pathways for gibberellin hormones has helped us to understand these pathways and their regulation. Many of these enzymes are multifunctional and therefore fewer enzymes than might be expected are required to synthesize the various gibberellin structures. However, several of the enzymes are encoded by multiple genes that are regulated differently, adding unexpected genetic complexity. Several endogenous and environmental factors modify the expression of gibberellin biosynthesis genes, including developmental stage, hormonal status and light. A future challenge will be to dissect the complex, interacting pathways that mediate the regulation of gibberellin metabolism.


Assuntos
Genes de Plantas , Giberelinas/metabolismo , Sequência de Aminoácidos , Arabidopsis/genética , Arabidopsis/metabolismo , Giberelinas/biossíntese , Oxigenases de Função Mista/química , Oxigenases de Função Mista/metabolismo , Dados de Sequência Molecular , Família Multigênica , Homologia de Sequência de Aminoácidos , Transdução de Sinais
12.
Curr Opin Biotechnol ; 11(2): 130-7, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10753762

RESUMO

Modification of plant hormone biosynthesis through the introduction of bacterial genes is a natural form of genetic engineering, which has been exploited in numerous studies on hormone function. Recently, biosynthetic pathways have been largely elucidated for most of the plant hormone classes, and genes encoding many of the enzymes have been cloned. These advances offer new opportunities to manipulate hormone content in order to study their mode of action and the regulation of their biosynthesis. Furthermore, this technology is providing the means to introduce agriculturally useful traits into crops.


Assuntos
Reguladores de Crescimento de Plantas/biossíntese , Reguladores de Crescimento de Plantas/genética , Plantas Geneticamente Modificadas/genética , Ciclopentanos/metabolismo , Citocininas/biossíntese , Citocininas/genética , Etilenos/biossíntese , Giberelinas/biossíntese , Giberelinas/genética , Ácidos Indolacéticos/biossíntese , Ácidos Indolacéticos/genética , Oxilipinas , Plantas Geneticamente Modificadas/metabolismo
13.
J Med Econ ; 18(9): 704-10, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25913916

RESUMO

OBJECTIVE: To explore the effect of age and sex on cost of all-cause and multiple sclerosis (MS)-related inpatient facility encounters. METHODS: Adult patients with an initial MS diagnosis were identified from a national managed-care database (IMS LifeLink Health Plans Database). The analysis included newly diagnosed MS patients with 12 months insurance eligibility before and after their first MS diagnosis. Inpatient facility encounters (stays) were analyzed for all-cause and MS-related events (ICD-9-CM = 340.XX), other demyelinating CNS disease (ICD-9-CM = 341.XX), rehabilitation (ICD-9-CM = V57.89), and a group of symptom-related diagnoses. Costs and length of stay were evaluated using a general linear model controlling for age and sex. RESULTS: A total of 57,236 patients met study criteria; 74.3% were female. Mean age for females was 45.5 years and for males it was 47.5 years. In total, 17.0% had an all-cause inpatient stay in the 360-day post index, and 3.2% had an in patient stay with a MS relapse-related diagnosis as primary discharge diagnosis. Additional MS-related diagnoses that led to inpatient stays included other demyelinating CNS disease (0.3%), symptom-related diagnoses (1.0%), and rehabilitation (1.1%). All-cause inpatient cost was higher for males vs females across all age groups; however, cost for females increased at a greater rate as age increased (p = 0.0007). Symptom-related inpatient cost was flat for males, was lower for females than males at an average age of 30, and was greater for females than males at an average age of 60 (p = 0.0199). Cost for MS inpatient stays ($11,931), other demyelinating CNS-related stays ($14,931), and rehabilitation ($23,643) did not differ by age and sex. The average cost for any MS-related relapse inpatient stay was $13,761 and varied with increasing age (p < 0.0001). CONCLUSION: Burden of illness for relapse among MS patients is substantial. Costs vary by age and sex depending on the discharge diagnosis. Inclusion of symptom-related and rehabilitation inpatient stays may account for an under-recognized proportion of total expenditures.


Assuntos
Gastos em Saúde/estatística & dados numéricos , Pacientes Internados , Tempo de Internação/economia , Esclerose Múltipla/economia , Adulto , Fatores Etários , Feminino , Humanos , Revisão da Utilização de Seguros , Cobertura do Seguro , Seguro Saúde , Masculino , Pessoa de Meia-Idade , Modelos Econométricos , Recidiva , Estudos Retrospectivos , Fatores Sexuais
14.
Gene ; 90(2): 227-33, 1990 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-2129529

RESUMO

The structure and expression of the pea chloroplast atpH gene, encoding ATP synthase CFo subunit III, have been investigated. The atpH gene is situated between the atpI and atpF genes for CFo subunits IV and I, and encodes a hydrophobic polypeptide of 81 amino acid residues which is very similar to subunit III from other species. Analysis of transcripts from the region of chloroplast DNA encoding ATP synthase subunits IV-III-I-alpha shows a complex pattern of transcription, with large transcripts potentially coding for several subunits and also smaller gene-specific transcripts. Two abundant transcripts of 660 nucleotides (nt) and 980 nt specific for atpH were identified. Primer extension and S1 nuclease protection mapping suggested that the 660-nt transcripts were produced by endonucleolytic processing at the sequence, 5'-UGGAAU.


Assuntos
Cloroplastos , DNA/análise , Fabaceae/genética , Família Multigênica , Plantas Medicinais , ATPases Translocadoras de Prótons/genética , Sequência de Aminoácidos , Sequência de Bases , Membrana Celular/enzimologia , Expressão Gênica , Dados de Sequência Molecular , Mapeamento de Nucleotídeos , ATPases Translocadoras de Prótons/biossíntese , Endonucleases Específicas para DNA e RNA de Cadeia Simples , Transcrição Gênica
15.
J Anim Sci ; 78(7): 1861-6, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10907828

RESUMO

Enzymes currently used to tenderize meat are not substrate-specific, resulting in extensive myofibrillar protein degradation that often produces an undesirable texture. Bovine placental metalloproteases, which selectively hydrolyze connective tissue proteins while leaving myofibrillar proteins intact, may tenderize meat without causing texture problems. Therefore, our objective was to extract and crudely purify bovine metalloproteases from bovine placenta for possible use as tenderizers in meat systems. Enzymes were extracted from homogenized tissue and purified by ammonium sulfate precipitation. Samples were collected before (crude enzyme) and after gel filtration on a Sephadex G-100 column. Spectrophotometric analysis identified one major peak (filtered enzyme). Gelatin, casein, and type I acid-soluble collagen zymography were used to determine substrate specificity. Beef myofibrillar proteins were incubated with crude and filtered enzyme fractions, enzymes quenched, and substrate degradation visualized using SDS-PAGE. Active gelatinases and collagenases exhibiting molecular weights of 57 to 65 kDa were detected on zymograms. Banding patterns from crude enzyme indicated two enzymes with both gelatinase and collagenase activity and a third enzyme with gelatinase activity only. Banding patterns from filtered enzyme indicated two enzymes with both gelatinase and collagenase activity. Proteolytic activity was not detected with casein, actin, or myosin heavy-chain substrates. Due to specificity for collagen and gelatin, these enzymes may be capable of improving the tenderness of certain cuts relatively high in connective tissue, while avoiding myofibrillar protein hydrolysis.


Assuntos
Tecido Conjuntivo/metabolismo , Endopeptidases/metabolismo , Manipulação de Alimentos/métodos , Carne/normas , Placenta/enzimologia , Proteínas/metabolismo , Animais , Bovinos , Colágeno/metabolismo , Comportamento do Consumidor , Técnicas de Cultura , Eletroforese em Gel de Poliacrilamida/veterinária , Gelatina/metabolismo , Peso Molecular , Especificidade por Substrato
16.
Meat Sci ; 63(2): 241-7, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22062184

RESUMO

The present study was carried out to investigate the effect of dietary α-tocopherol supplementation on porcine oxymyoglobin (OxyMb) and lipid oxidation (TBARS) in model lipid systems, and to determine the influence of 4-hydroxynonenal (4-HNE), a secondary product of lipid oxidation, on porcine OxyMb stability. Porcine metmyoglobin (MetMb) formation was greater in the presence of 4-HNE than the control (P<0.05). Western blot analyses confirmed the covalent modification of myoglobin (Mb) histidine residues by 4-HNE. When combined with microsomes, both equine and porcine OxyMb oxidation increased with time of incubation, and was greater at 37 than at 25 °C (P<0.05). Lower TBARS values were observed in microsomes prepared from vitamin E-supplemented than control pork livers (P<0.05). α-Tocopherol concentration did not affect OxyMb oxidation in microsomes at 25 or 37 °C (P>0.05). These results differ from those observed with beef muscle microsomes where both OxyMb and lipid oxidation were delayed with elevated α-tocopherol levels. These results suggest that the factors affecting Mb and lipid oxidation interactions may be species-dependent.

17.
Meat Sci ; 57(1): 31-4, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22061164

RESUMO

Consumers often use the color of cooked ground beef as an indicator of doneness. For safety reasons, it is recommended that the center of ground beef products be heated to 71°C. In some instances beef may appear done before reaching 71°C, a condition termed premature browning (PMB). Ground beef (15% fat), with added erythorbic acid (ERY) at 0.04 and 0.06% was formed into patties, wrapped in oxygen permeable film, and stored in the dark at 4°C. Patties were stored for either 10 h or 58 h and then cooked to internal end point temperatures of 60, 66, 71 or 77°C. Internal cooked color L(∗), a(∗) and b(∗) values were measured. For beef patties stored 10 h, there was no effect of ERY on internal cooked color. After 58 h storage, ground beef with 0.04 and 0.06% ERY had higher a(∗) values than controls at 60°C (P<0.05). Beef with 0.04% ERY cooked to an internal temperature of 66°C had higher a(∗) values than 0.06% ERY and controls (P<0.05). There was no effect of ERY on color of beef patties cooked to 71 or 77°C. The presence of 0.04% ERY in ground beef patties stored 58 h appeared to maintain red color at internal temperatures of 60 and 66°C.

18.
Meat Sci ; 58(4): 389-93, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22062429

RESUMO

Myoglobin and lipid oxidation are major causes of quality deterioration in fresh pork. A process to enhance color and lipid stability would prove valuable to the pork industry given the current trend of centralized packaging and distribution to retail markets. Our objective was to determine the effects of dietary α-tocopherol (α-Toc) supplementation on color and lipid stability in ground pork, and loin chops stored in modified atmosphere packaging (MAP). Yorkshire crossbred pigs (n=20) were randomized into two groups and fed diets containing 48 (CON) or 170 mg α-Toc acetate/kg feed (VIT-E) for 6 weeks before slaughter. Plasma α-Toc concentration was measured weekly. Post-slaughter, Boston butt shoulders were ground, formed into patties with or without 1.5% salt, and stored fresh at 4°C for 0, 2, 4, or 6 days, and frozen at -20°C for 45 or 90 days. Pork loin chops were packaged aerobically and stored at 4°C for 0, 2, 4 or 6 days, or in MAP at 4°C for 7, 10 or 13 days prior to Hunter L*,a*,b* and TBARS analyses. α-Toc concentration of longissimus dorsi, psoas major, biceps femoris, semimembranosus and semitendinosus muscles was determined. Plasma α-Toc was greater (P<0.05) in VIT-E animals compared with CON and α-Toc concentrations were greater (P<0.05) in all VIT-E muscles compared with CON. TBARS values of both fresh and salted patties were less in VIT-E than in CON meat following 6 days at 4°C; VIT-E TBARS of salted patties were less (P<0.05) after 45 days at -20°C compared with CON. α-Toc supplementation did not influence (P>0.05) color of aerobically packaged or MAP chops, or of fresh or salted pork patties. α-Toc supplementation reduced TBARS formation in fresh and salted pork but had no significant impact on color.

19.
J Med Econ ; 15(3): 601-9, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22376190

RESUMO

OBJECTIVE: To compare rates of severe relapse and total direct and indirect costs over a 2-year period between US-based employees with multiple sclerosis (MS) who were adherent and non-adherent to disease-modifying drugs (DMDs). METHODS: Employees with ≥1 MS diagnosis (ICD-9-CM: 340.x) and ≥1 DMD pharmacy claim between 1/1/2002-12/31/2007 were identified from a large US administrative claims database. Patients had continuous coverage ≥6 months before (baseline) and ≥24 months after (study period) their index date (first DMD claim). Adherence was measured using medication possession ratio (MPR) over the study period. Patients with MPR ≥80% were considered adherent (n = 448) and those with MPR <80% as non-adherent (n = 200). Multivariate analyses were used to compare rates of severe relapse (inpatient or Emergency Department visit with MS diagnosis) and costs in 2007 dollars between DMD adherent and non-adherent patients. Direct costs were calculated as reimbursements to providers for medical services and prescription drugs excluding DMDs. Indirect costs included disability and medically-related absenteeism costs. RESULTS: DMD adherent patients were on average older (43.5 vs 41.8 years, p = 0.015) and more likely to be male (38.6% vs 26.0%, p = 0.002) compared with non-adherent patients. Adherent patients had lower rates of depression, higher rates of previous DMD use, and higher baseline MS-related costs. After adjusting for differences in baseline characteristics, DMD adherent patients had a lower rate of severe relapse (12.4% vs 19.9%, p = 0.013) and lower total (direct and indirect) costs ($14,095 vs $16,638, p = 0.048) over the 2-year study period. CONCLUSIONS: In this study, DMD adherence was associated with a significantly lower rate of severe relapse and lower total costs over 2 years. Causality cannot be inferred because adherence and outcomes were measured over the same period. The study was subject to limitations associated with use of claims data and the absence of clinical measures.


Assuntos
Emprego , Esclerose Múltipla/tratamento farmacológico , Esclerose Múltipla/prevenção & controle , Cooperação do Paciente , Adulto , Custos e Análise de Custo , Bases de Dados Factuais , Serviço Hospitalar de Emergência/estatística & dados numéricos , Feminino , Hospitalização , Humanos , Revisão da Utilização de Seguros , Masculino , Pessoa de Meia-Idade , Prevenção Secundária , Índice de Gravidade de Doença , Estados Unidos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA