Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 29
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Medicine (Baltimore) ; 103(4): e37040, 2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38277572

RESUMO

Ramadan intermittent fasting (RIF) presents unique challenges and opportunities for public health and clinical practice, especially in populations with a high prevalence of non-communicable diseases. This study aims to investigate the impact of RIF on weight change among Indian Muslims and explore the associated demographic, dietary, and behavioral factors. A cross-sectional survey was conducted with a sample of Indian Muslim adults who observed RIF. Participants were asked to report their demographic information, family and personal health history, and dietary and lifestyle behaviors before and during Ramadan month. The primary outcome was body weight change, with secondary outcomes including changes in dietary patterns, physical activity, and other health-related lifestyle behaviors. The study found that during Ramadan, nearly half of the participants (48.5%) self-reported a retained initial weight, while a significant fraction (30.9%) self-reported a modest weight reduction between 0.5 to 2.5 kg at the end of Ramadan. Additionally, self-reported eating practices demonstrated moderately altered by about half (48.4%) of the study participants, with 32.2% reporting minor changes and 8.2% indicating substantial changes. An urban residence was associated with a higher likelihood of weight gain, where urban residents showed 3 times the odds of increased weight compared to rural inhabitants. Employment status emerged as a significant determinant for weight fluctuation, influencing both weight gain and loss. During Ramadan, there was a significant rise in snacking frequency, increasing from 21.7% to 32.6% in comparison with pre-Ramadan. The consumption of large quantities of food more frequently grew from 14.9% to 36%, and the incidence of eating despite not being hungry went up from 17.4% to 33.2%. The study demonstrates that RIF is associated with variable changes in body weight among adult Indian Muslims, influenced by urbanization, employment status, and dietary changes. The findings suggest that clinicians should provide tailored advice about body weight regulation during Ramadan and consider integrating community-based health initiatives within religious settings to improve health outcomes.


Assuntos
COVID-19 , Adulto , Humanos , Estudos Transversais , COVID-19/epidemiologia , Jejum/fisiologia , Redução de Peso , Aumento de Peso , Islamismo
2.
Int J Pharm ; 650: 123684, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38070659

RESUMO

The objective of this study was to explore the benefits of transdermal drug delivery systems as an alternative option for patients who are unable to tolerate oral administration of drugs, such as ibuprofen (IB). To achieve this, nonionic surfactants and three cosolvents were employed to develop new microemulsions (MEs) that contained IB as nanocarriers. The aim was to enhance the solubility and bioavailability of the drug after transdermal administration. The MEs were characterised by droplet size, polydispersity index (PDI), and rheological properties. Furthermore, the flux of IB was evaluated by Franz diffusion cells using excised rat skin and in vivo bioavailability using rats. The results showed that the MEs had ideal viscosity and droplet size below 100 nm. Moreover, using the developed MEs, an improvement in the solubility (170 mg/mL) and flux through the rat skin (94.6 ± 8.0 µg/cm2.h) was achieved. In addition, IB demonstrated a maximum plasma level of 0.064 mg/mL after 8 h of transdermal administration in rats using the ME with an increase in the bioavailability of about 1.5 times in comparison to the commercial IB gel. In conclusion, the developed nonionic MEs containing IB can be ideal nanocarriers and promising formulations for the transdermal administration of IB.


Assuntos
Ibuprofeno , Pele , Humanos , Ratos , Animais , Administração Cutânea , Solubilidade , Emulsões/metabolismo , Pele/metabolismo , Sistemas de Liberação de Medicamentos , Disponibilidade Biológica
3.
Biol Sport ; 38(4): 495-506, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34937958

RESUMO

Symptoms of psychological distress and disorder have been widely reported in people under quarantine during the COVID-19 pandemic; in addition to severe disruption of peoples' daily activity and sleep patterns. This study investigates the association between physical-activity levels and sleep patterns in quarantined individuals. An international Google online survey was launched in April 6th, 2020 for 12-weeks. Forty-one research organizations from Europe, North-Africa, Western-Asia, and the Americas promoted the survey through their networks to the general society, which was made available in 14 languages. The survey was presented in a differential format with questions related to responses "before" and "during" the confinement period. Participants responded to the Pittsburgh Sleep Quality Index (PSQI) questionnaire and the short form of the International Physical Activity Questionnaire. 5056 replies (59.4% female), from Europe (46.4%), Western-Asia (25.4%), America (14.8%) and North-Africa (13.3%) were analysed. The COVID-19 home confinement led to impaired sleep quality, as evidenced by the increase in the global PSQI score (4.37 ± 2.71 before home confinement vs. 5.32 ± 3.23 during home confinement) (p < 0.001). The frequency of individuals experiencing a good sleep decreased from 61% (n = 3063) before home confinement to 48% (n = 2405) during home confinement with highly active individuals experienced better sleep quality (p < 0.001) in both conditions. Time spent engaged in all physical-activity and the metabolic equivalent of task in each physical-activity category (i.e., vigorous, moderate, walking) decreased significantly during COVID-19 home confinement (p < 0.001). The number of hours of daily-sitting increased by ~2 hours/days during home confinement (p < 0.001). COVID-19 home confinement resulted in significantly negative alterations in sleep patterns and physical-activity levels. To maintain health during home confinement, physical-activity promotion and sleep hygiene education and support are strongly warranted.

4.
Biol Sport ; 38(1): 9-21, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33795912

RESUMO

Although recognised as effective measures to curb the spread of the COVID-19 outbreak, social distancing and self-isolation have been suggested to generate a burden throughout the population. To provide scientific data to help identify risk factors for the psychosocial strain during the COVID-19 outbreak, an international cross-disciplinary online survey was circulated in April 2020. This report outlines the mental, emotional and behavioural consequences of COVID-19 home confinement. The ECLB-COVID19 electronic survey was designed by a steering group of multidisciplinary scientists, following a structured review of the literature. The survey was uploaded and shared on the Google online survey platform and was promoted by thirty-five research organizations from Europe, North Africa, Western Asia and the Americas. Questions were presented in a differential format with questions related to responses "before" and "during" the confinement period. 1047 replies (54% women) from Western Asia (36%), North Africa (40%), Europe (21%) and other continents (3%) were analysed. The COVID-19 home confinement evoked a negative effect on mental wellbeing and emotional status (P < 0.001; 0.43 ≤ d ≤ 0.65) with a greater proportion of individuals experiencing psychosocial and emotional disorders (+10% to +16.5%). These psychosocial tolls were associated with unhealthy lifestyle behaviours with a greater proportion of individuals experiencing (i) physical (+15.2%) and social (+71.2%) inactivity, (ii) poor sleep quality (+12.8%), (iii) unhealthy diet behaviours (+10%), and (iv) unemployment (6%). Conversely, participants demonstrated a greater use (+15%) of technology during the confinement period. These findings elucidate the risk of psychosocial strain during the COVID-19 home confinement period and provide a clear remit for the urgent implementation of technology-based intervention to foster an Active and Healthy Confinement Lifestyle AHCL).

5.
Artigo em Inglês | MEDLINE | ID: mdl-33921852

RESUMO

BACKGROUND: The COVID-19 lockdown could engender disruption to lifestyle behaviors, thus impairing mental wellbeing in the general population. This study investigated whether sociodemographic variables, changes in physical activity, and sleep quality from pre- to during lockdown were predictors of change in mental wellbeing in quarantined older adults. METHODS: A 12-week international online survey was launched in 14 languages on 6 April 2020. Forty-one research institutions from Europe, Western-Asia, North-Africa, and the Americas, promoted the survey. The survey was presented in a differential format with questions related to responses "pre" and "during" the lockdown period. Participants responded to the Short Warwick-Edinburgh Mental Wellbeing Scale, the Pittsburgh Sleep Quality Index (PSQI) questionnaire, and the short form of the International Physical Activity Questionnaire. RESULTS: Replies from older adults (aged >55 years, n = 517), mainly from Europe (50.1%), Western-Asia (6.8%), America (30%), and North-Africa (9.3%) were analyzed. The COVID-19 lockdown led to significantly decreased mental wellbeing, sleep quality, and total physical activity energy expenditure levels (all p < 0.001). Regression analysis showed that the change in total PSQI score and total physical activity energy expenditure (F(2, 514) = 66.41 p < 0.001) were significant predictors of the decrease in mental wellbeing from pre- to during lockdown (p < 0.001, R2: 0.20). CONCLUSION: COVID-19 lockdown deleteriously affected physical activity and sleep patterns. Furthermore, change in the total PSQI score and total physical activity energy expenditure were significant predictors for the decrease in mental wellbeing.


Assuntos
COVID-19 , África do Norte , Idoso , Ásia Ocidental , Controle de Doenças Transmissíveis , Europa (Continente) , Exercício Físico , Humanos , SARS-CoV-2 , Sono , Inquéritos e Questionários
7.
PLoS One ; 15(11): e0240204, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33152030

RESUMO

BACKGROUND: Public health recommendations and government measures during the COVID-19 pandemic have enforced restrictions on daily-living. While these measures are imperative to abate the spreading of COVID-19, the impact of these restrictions on mental health and emotional wellbeing is undefined. Therefore, an international online survey (ECLB-COVID19) was launched on April 6, 2020 in seven languages to elucidate the impact of COVID-19 restrictions on mental health and emotional wellbeing. METHODS: The ECLB-COVID19 electronic survey was designed by a steering group of multidisciplinary scientists, following a structured review of the literature. The survey was uploaded and shared on the Google online-survey-platform and was promoted by thirty-five research organizations from Europe, North-Africa, Western-Asia and the Americas. All participants were asked for their mental wellbeing (SWEMWS) and depressive symptoms (SMFQ) with regard to "during" and "before" home confinement. RESULTS: Analysis was conducted on the first 1047 replies (54% women) from Asia (36%), Africa (40%), Europe (21%) and other (3%). The COVID-19 home confinement had a negative effect on both mental-wellbeing and on mood and feelings. Specifically, a significant decrease (p < .001 and Δ% = 9.4%) in total score of the SWEMWS questionnaire was noted. More individuals (+12.89%) reported a low mental wellbeing "during" compared to "before" home confinement. Furthermore, results from the mood and feelings questionnaire showed a significant increase by 44.9% (p < .001) in SMFQ total score with more people (+10%) showing depressive symptoms "during" compared to "before" home confinement. CONCLUSION: The ECLB-COVID19 survey revealed an increased psychosocial strain triggered by the home confinement. To mitigate this high risk of mental disorders and to foster an Active and Healthy Confinement Lifestyle (AHCL), a crisis-oriented interdisciplinary intervention is urgently needed.


Assuntos
Infecções por Coronavirus/psicologia , Saúde Mental , Pneumonia Viral/psicologia , Quarentena/psicologia , Adolescente , Adulto , Afeto , Betacoronavirus , COVID-19 , Estudos Transversais , Feminino , Humanos , Internacionalidade , Masculino , Pessoa de Meia-Idade , Pandemias , SARS-CoV-2 , Inquéritos e Questionários , Adulto Jovem
8.
J Family Med Prim Care ; 9(8): 3797-3806, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33110770

RESUMO

INTRODUCTION: Fasting is observed as a religious custom in various forms across the globe. Among them, the Ramadan fasting is very common and widely practiced. People with diabetes observe fasting with or without obtaining medical advice. Uncontrolled diabetes appears to be a risk factor for COVID-19 infection and its poorer outcomes. Fasting during Ramadan is challenging in people with diabetes. This year, the background of COVID-19 made it difficult for both the patients and health care workers to effectively manage diabetes and its complications during Ramadan. Because of a lack of sufficient evidence, clinicians were perplexed in handling this difficult situation. MATERIALS AND METHODS: We accessed PubMed, Google Scholar, various guidelines and other evidence-based articles to review the available current literature which deals with diabetes, Ramadan, and COVID-19. RESULTS: The importance of pre-Ramadan assessment, adequate nutrition, and hydration, choosing the right therapy has been emphasized. This review tries to address the common practical challenges and relevant possible solutions for the same. Due consideration has been given to various socio-cultural practices that can influence the management of diabetes patients in the setting of Ramadan and COVID-19 pandemic. CONCLUSIONS: Diabetes is associated with increased severity and susceptibility to COVID-19. People with diabetes should go through systemic and structure-based management during fasting. Family physicians who deliver personalized care play a vital role in managing diabetes during this crisis period. Telemedicine is emerging as an effective mode of managing various needs of individuals.

9.
Diabetes Metab Syndr ; 14(6): 1815-1819, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32956926

RESUMO

BACKGROUND AND AIMS: Lockdown during the COVID-19 pandemic imposed many restrictions on the public. Loss of continuum of care along with improper lifestyle was expected to worsen glycemic control in people with type 2 diabetes (T2D). We aimed to identify the effects of lockdown on their glycemic status, lifestyle changes and psychosocial health. METHODS: The pre- and post-lockdown data of 110 adults with T2D who were under regular follow up was collected by direct interview during their visit to the diabetes clinic. The variables analyzed included demographic data, HbA1c, body weight, lifestyle changes, psychosocial factors and use of technology. RESULT: The overall physical activity and dietary adherence remained unchanged in more than 80% of the participants. There was increased consumption of vegetables (80.9%), fruits (42.7%), and decreased unhealthy snacking (63%). 90% of them had access to medications. No significant change was noted in the mean HbA1c and body weight before and after lockdown. Most of them (99%) watched television and 73.6% of them spent time with their family members. Those with mental stress and poor sleep had unhealthy dietary habits. Poor glycemic control was seen in those with less physical activity and an unhealthy diet. CONCLUSION: Lockdown did not cause a major change in the overall glycemic control. Measures to promote healthy lifestyle practices along with ways to reduce psychosocial stress must be implemented for better T2D management during such restricted times.


Assuntos
COVID-19 , Controle de Doenças Transmissíveis , Diabetes Mellitus Tipo 2/terapia , Dieta/estatística & dados numéricos , Exercício Físico , Hipoglicemiantes/uso terapêutico , Saúde Mental , Estresse Psicológico/psicologia , Fatores Etários , Idoso , Estudos Transversais , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/psicologia , Família , Feminino , Frutas , Hemoglobinas Glicadas/metabolismo , Acessibilidade aos Serviços de Saúde , Humanos , Índia , Estilo de Vida , Masculino , Pessoa de Meia-Idade , SARS-CoV-2 , Fatores Sexuais , Lanches , Inquéritos e Questionários , Televisão , Verduras
10.
Artigo em Inglês | MEDLINE | ID: mdl-32867287

RESUMO

Public health recommendations and governmental measures during the new coronavirus disease (COVID-19) pandemic have enforced numerous restrictions on daily living including social distancing, isolation, and home confinement. While these measures are imperative to mitigate spreading of COVID-19, the impact of these restrictions on psychosocial health is undefined. Therefore, an international online survey was launched in April 2020 to elucidate the behavioral and lifestyle consequences of COVID-19 restrictions. This report presents the preliminary results from more than one thousand responders on social participation and life satisfaction. METHODS: Thirty-five research organizations from Europe, North-Africa, Western Asia, and the Americas promoted the survey through their networks to the general society, in 7 languages (English, German, French, Arabic, Spanish, Portuguese, and Slovenian). Questions were presented in a differential format with questions related to responses "before" and "during" confinement conditions. RESULTS: 1047 participations (54% women) from Asia (36%), Africa (40%), Europe (21%), and others (3%) were included in the analysis. Findings revealed psychosocial strain during the enforced COVID-19 home confinement. Large decreases (p < 0.001) in the amount of social activity through family (-58%), friends/neighbors (-44.9%), or entertainment (-46.7%) were triggered by the enforced confinement. These negative effects on social participation were also associated with lower life satisfaction (-30.5%) during the confinement period. Conversely, the social contact score through digital technologies significantly increased (p < 0.001) during the confinement period with more individuals (+24.8%) being socially connected through digital technology. CONCLUSION: These preliminary findings elucidate the risk of psychosocial strain during the early COVID-19 home confinement period in 2020. Therefore, in order to mitigate the negative psychosocial effects of home confinement, implementation of national strategies focused on promoting social inclusion through a technology-based solution is strongly suggested.


Assuntos
Infecções por Coronavirus/psicologia , Satisfação Pessoal , Pneumonia Viral/psicologia , Participação Social , África do Norte , América , Ásia Ocidental , Betacoronavirus , COVID-19 , Infecções por Coronavirus/prevenção & controle , Europa (Continente) , Feminino , Humanos , Masculino , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , SARS-CoV-2
11.
Br J Haematol ; 143(1): 115-28, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18691168

RESUMO

One-third of the UK haemophilia A population was screened to establish a national database of mutations and pedigrees and advance knowledge of the disease. The following mutations were found: 131 intron 22- and 13 intron1-breaking inversions; 11 gross deletions and an insertion; 65 frameshifts; three in-frame deletions and one insertion; 46 nonsense; 30 intronic mutations affecting splice sites and four generating new sites; 469 non-synonymous mutations due to 203 different base substitutions of which four affected, and nine were predicted to affect, splicing; three promoter mutations; two synonymous exon 14 mutations possibly affecting splicing; two VWF mutations. Of the above mutations, 176 are not listed in the Haemophilia A Mutation, Structure, Test and Resource Site (HAMSTeRS). Four gross deletions arose by non-homologous end-joining; we detected unexpected splicing in some mutations; substitution of amino acids conserved for less than 90 million years are rare; the risk of developing inhibitors for patients with nonsense mutations is greater when the stop codon is in the 3' half of the mRNA; changes likely to generate splice sites causing frameshifts are over-represented among non-synonymous mutations associated with inhibitors; our data and those in HAMSTeRS enabled the size of the spectrum of specific mutations causing the disease to be estimated and to determine how much of it is known.


Assuntos
Hemofilia A/genética , Mutação , Processamento Alternativo , Inversão Cromossômica , Códon sem Sentido , Análise Mutacional de DNA , Bases de Dados Genéticas , Feminino , Mutação da Fase de Leitura , Deleção de Genes , Humanos , Íntrons/genética , Masculino , Programas de Rastreamento , Mutação de Sentido Incorreto , Prevalência , Regiões Promotoras Genéticas/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Reino Unido
12.
Br J Ophthalmol ; 90(6): 718-23, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16714263

RESUMO

BACKGROUND/AIM: MERTK, a tyrosine kinase receptor protein expressed by the retinal pigment epithelium (RPE), is mutated in both rodent models and humans affected by retinal disease. This study reports a survey of families for Mertk mutations and describes the phenotype exhibited by one family. METHODS: 96 probands with retinal dystrophy, consistent with autosomal recessive segregation, were screened by direct sequencing. A family homozygous for a likely null allele was investigated clinically. RESULTS: A novel frame shifting deletion was identified in one of 96 probands. Other polymorphisms were detected. The deletion allele occurred on both chromosomes of four affected family members. Electrophysiology demonstrated early loss of scotopic and macular function with later loss of photopic function. Visual acuities and visual fields were preserved into the second decade. Perception of light vision was present in a patient in the fourth decade. A "bull's eye" appearance and a hyperautofluorescent lesion at the central macula were consistent clinical findings. CONCLUSIONS: Mutations in Mertk are a rare cause of ARRP in humans. The study extends the phenotypic characteristics of this retinal dystrophy and shows distinctive clinical signs that may improve its clinical identification. The moderate severity and presence of autofluorescence implies that outer segment phagocytosis is not entirely absent.


Assuntos
Proteínas do Olho/genética , Mutação da Fase de Leitura/genética , Mutação de Sentido Incorreto/genética , Proteínas Proto-Oncogênicas/genética , Receptores Proteína Tirosina Quinases/genética , Degeneração Retiniana/genética , Adulto , Sequência de Aminoácidos , Sequência de Bases , Criança , Análise Mutacional de DNA/métodos , Eletrorretinografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Linhagem , Fenótipo , Reação em Cadeia da Polimerase/métodos , Degeneração Retiniana/fisiopatologia , Acuidade Visual , Testes de Campo Visual/métodos , Campos Visuais , c-Mer Tirosina Quinase
14.
J Biol Chem ; 276(13): 10168-77, 2001 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-11094057

RESUMO

The proliferating cell nuclear antigen (PCNA) is a highly conserved protein required for the assembly of the DNA polymerase delta (pol delta) holoenzyme. Because PCNAs from Saccharomyces cerevisiae and human do not complement each other using in vitro or in vivo assays, hybrids of the two proteins would help identify region(s) involved in the assembly of the pol delta holoenzyme. Two mutants of human PCNA, HU1 (D21E) and HU3 (D120E), and six hybrids of human and S. cerevisiae PCNA, HC1, HC5, CH2, CH3, CH4, and CH5, were prepared by swapping corresponding regions between the two proteins. In solution, all PCNA assembled into trimers, albeit to different extents. These PCNA variants were tested for stimulation of pol delta and in vitro replication of M13 and SV40 DNA as well as to stimulate the ATPase activity of replication factor C (RF-C). Our data suggest that in addition to the interdomain connecting loop and C terminus, an additional site in the N terminus is required for pol delta interaction. PCNA mutants and hybrids that stimulated pol delta and RF-C were deficient in M13 and SV40 DNA replication assays, indicating that PCNA-induced pol delta stimulation and RF-C-mediated loading are not sufficient for coordinated DNA synthesis at a replication fork.


Assuntos
Proteínas de Homeodomínio , Antígeno Nuclear de Célula em Proliferação/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2 , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Repressoras , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Adenosina Trifosfatases/metabolismo , Animais , Sítios de Ligação , Bovinos , Cromatografia em Gel , Reagentes de Ligações Cruzadas/farmacologia , DNA/biossíntese , DNA/metabolismo , DNA Polimerase III/metabolismo , DNA Complementar/metabolismo , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Dimerização , Relação Dose-Resposta a Droga , Eletroforese em Gel de Poliacrilamida , Humanos , Immunoblotting , Antígenos de Histocompatibilidade Menor , Modelos Biológicos , Mutagênese Sítio-Dirigida , Mutação , Plasmídeos/metabolismo , Antígeno Nuclear de Célula em Proliferação/química , Antígeno Nuclear de Célula em Proliferação/genética , Dobramento de Proteína , Estrutura Terciária de Proteína , Proteínas Recombinantes de Fusão/química , Proteína de Replicação C , Saccharomyces cerevisiae/química , Timo/metabolismo
15.
Br J Haematol ; 107(4): 766-71, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10606882

RESUMO

We have constructed a confidential U.K. database of haemophilia A mutations and pedigrees by characterizing the gene defect of one index patient in each U.K. family. Mutations were identified by screening all coding regions of the factor VIII (FVIII) mRNA, using solid-phase fluorescent chemical cleavage of mismatch and examining additional non-coding regions of the gene. Here we report two haemophilia A patients (UK 114 FVIII:C 2% and UK 243 FVIII:C < 1%) with an abnormal FVIII mRNA due to an A to G point mutation, 1.4 kb downstream from exon 1 in the FVIII gene. This mutation creates a new donor splice site in intron 1 and leads to insertion of a 191 bp novel exon in the mRNA. Haplotype analysis suggests that the mutation may have originated in a common ancestor of the two patients, who further illustrate how mRNA analysis allows higher efficiency of haemophilia A mutation detection, because their mutation would not have been identified by direct analysis of the factor VIII gene.


Assuntos
Fator VIII/genética , Hemofilia A/genética , Íntrons/genética , Mutação Puntual/genética , Sequência de Bases , Éxons/genética , Regulação da Expressão Gênica , Haplótipos , Humanos , Dados de Sequência Molecular , Linhagem , Splicing de RNA/genética
16.
Br J Haematol ; 105(4): 1123-6, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10554831

RESUMO

In some families with mild haemophilia higher results are obtained for factor VIII activity (FVII:C) determined by one-stage assay than by two-stage or chromogenic assays. Amino-acid substitutions in the A1, A2 and A3 domains of factor VIII have been described in affected individuals with this phenotype. We describe a case of mild haemophilia A in which FVIII:C measured by one-stage assay was normal at 106%. However, FVIII:C levels measured by two-stage and chromogenic assays were 18% and 35% respectively. DNA analysis revealed a novel mutation in the A3 domain of factor VIII, His1954-->Leu. In a molecular model of the FVIII A domains, His1954 is placed in close proximity to two other mutations that have previously been shown also to be associated with one-stage/two-stage discrepancies. In this patient the diagnosis of haemophilia A would be missed if only the one-stage assay was used.


Assuntos
Substituição de Aminoácidos/genética , Fator VIII/genética , Hemofilia A/diagnóstico , Mutação/genética , Ensaio de Imunoadsorção Enzimática , Imunofluorescência , Hemofilia A/genética , Humanos , Masculino , Pessoa de Meia-Idade
17.
Thromb Haemost ; 81(6): 900-5, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10404764

RESUMO

A national strategy for optimising genetic services in haemophilia A has been initiated in the UK. Solid phase fluorescent chemical cleavage of mismatch is used to screen the entire coding region of factor VIII in six segments: four amplified from the trace of mRNA in blood lymphocytes and two from genomic DNA for the 3.4 kb exon 14 and flanking intron sequences. These segments are analysed in two threefold multiplexes so that the genes of 18 patients can be screened in a single ABI 377 gel. The promoter and polyadenylation signal region are amplified and sequenced directly. We have analysed 142 unrelated patients and identified 141 factor VIII mutations and one Normandy type von Willebrand homozygote. The former mutations include 89 missense, 10 nonsense, 5 frameshift, one 24 bp deletion and one splice signal defect. These comprise 71 different changes, of which 39 have not been previously observed.


Assuntos
Pareamento Incorreto de Bases , Bases de Dados Factuais , Fator VIII/genética , Hemofilia A/genética , Humanos , Análise de Sequência de DNA , Reino Unido
18.
Methods Mol Med ; 31: 133-49, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-21340990

RESUMO

Hemophilia A is an X-linked disorder that leads to a defect in blood coagulation. This is caused by mutations in the factor VIII gene, which results in its activity being reduced or abolished in the blood-clotting cascade. The factor VIII gene is 186 kb long with 26 exons, varying from 69 bp (exon 5) to 3106 bp (exon 14) (1). The factor VIII mRNA is 9028 bases in length with a 7053 nucleotides long coding region (2).

19.
Gene ; 215(2): 269-79, 1998 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-9714826

RESUMO

Keratins are a family of highly homologous proteins expressed as pairs of acidic and basic forms which make intermediate filaments in epithelial cells. Keratin 13 (K13) is the major acidic keratin, which together with K4, its basic partner, is expressed in the suprabasal layers of non-cornified stratified epithelia. The mechanism which allows mucosal-specific expression of this keratin remains unknown. To provide insight into the tissue-specific expression, we have isolated the human K13 gene by screening a chromosome 17 library with a specific K13 cRNA probe. Sequence analysis of unidirectional deletions produced by transposon Tn3 has revealed that the gene is 4601 nucleotides long and contains seven introns and eight exons. When driven by the CMV promoter, the gene produced K13 protein in MCF-7 cells, which normally do not express this protein. Two transcription-start sites were identified, the major being at 61 and the minor at 63 nucleotides upstream of ATG. The upstream sequence contained a TATA box and several other putative transcription factor binding sites. A single copy of the K13 gene was detected in the human genome by Southern hybridisation and polymerase chain reaction. K13 mRNA shows differential expression in cultured keratinocytes, and in A431 cells the RNA levels remained independent of calcium concentrations in the culture medium. Characterisation of the human K13 gene will facilitate elucidation of the molecular mechanism regulating K13 expression in mucosal tissues.


Assuntos
Cromossomos Humanos Par 17 , Queratinócitos/metabolismo , Queratinas/genética , Sequência de Aminoácidos , Sequência de Bases , Sítios de Ligação , Neoplasias da Mama , Células Cultivadas , Mapeamento Cromossômico , Primers do DNA , Éxons , Feminino , Células HeLa , Humanos , Íntrons , Células KB , Queratinas/biossíntese , Queratinas/química , Dados de Sequência Molecular , Especificidade de Órgãos , RNA Mensageiro/biossíntese , RNA Mensageiro/química , RNA Mensageiro/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Fatores de Transcrição/metabolismo , Transfecção , Células Tumorais Cultivadas
20.
Int J Biochem Cell Biol ; 29(7): 971-83, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9375377

RESUMO

Keratin filaments in simple epithelial cells are heteropolymers of keratin 8 (K8) and keratin 18 (K18) polypeptides. The assembly of these polypeptides into intermediate filaments is a complex multi-stage phenomenon that involves several levels of associations. These molecular associations are not very well characterized. Monoclonal antibodies (MAbs) with defined specificities can be used to probe these associations and to isolate various intermediates in the assembly pathway. Here we describe the specificity of a MAb LE65 that has been widely used in keratin expression studies. We report that the MAb LE65 does not recognize individual keratin polypeptides but it instead reacts with a complex of K8 with K18. The MAb also did not react with complexes of K8 or K18 with other keratins. By allowing the antibody to react with complexes reconstituted from keratin fragments plus the complementary keratin, we have mapped the MAb LE65 epitope on the L12 sub-domains of K18, residues 214-231, and K8, residues 234-265, which must associate together to achieve antibody binding. These results suggest that the non-helical linkers, L12, of complementary keratins associate directly during filament assembly. This would explain why microinjection of MAb LE65 has been shown to disrupt keratin filaments. Furthermore, it may also help to explain the mechanism of filament disruption in some skin blistering syndromes induced by spontaneous mutations in the L12 region.


Assuntos
Epitopos , Filamentos Intermediários/metabolismo , Queratinócitos/metabolismo , Queratinas/imunologia , Sequência de Aminoácidos , Anticorpos Monoclonais , Especificidade de Anticorpos , Clonagem Molecular , Ensaio de Imunoadsorção Enzimática , Humanos , Queratinas/química , Queratinas/genética , Dados de Sequência Molecular , Estrutura Secundária de Proteína , Proteínas Recombinantes/imunologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...