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1.
Prog Orthod ; 22(1): 25, 2021 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-34514529

RESUMO

BACKGROUND: Apps have been shown to be an effective tool in changing patients' behaviours in orthodontics and can be used to improve their compliance with treatment. The Behaviour Change Techniques (BCTs) and quality (using MARS) within these apps have previously not been published. OBJECTIVES: 1. To evaluate the quality of these apps aiming to change behaviour. 2. To assess BCTs used in patient focused orthodontic apps. METHODS: The UK Google Play and Apple App Stores were searched to identify all orthodontic apps and 305 apps were identified. All 305 apps were assessed for the presence of BCTs using an accepted taxonomy of BCTs (Behaviour Change Wheel (BCW)), widely utilised in healthcare. Of those containing BCTs, the quality was assessed using the Mobile App Rating Scale (MARS), a validated and multi-dimensional tool which rates apps according to 19 objective criteria. Data collection was carried out by two calibrated, independent assessors and repeated after 6 weeks for 25% of the apps by both assessors. RESULTS: BCTs were found in 31 apps, although only 18 of them were analysed for quality and 13 apps were excluded. Six different BCTs were identified: these were most commonly 'prompts/cues', and 'information about health consequences'. All apps were shown to be of moderate quality (range 3.1-3.7/5). Inter-rater and intra-rater reliability for BCT and quality assessment were excellent. CONCLUSIONS: The current availability of orthodontic apps of sufficient quality to recommend to patients is very limited. There is therefore a need for high-quality orthodontic apps with appropriate BCTs to be created, which may be utilised to improve patients' compliance with treatment.


Assuntos
Aplicativos Móveis , Terapia Comportamental , Humanos , Cooperação do Paciente , Reprodutibilidade dos Testes
2.
Br Dent J ; 223(1): 53-58, 2017 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-28684806

RESUMO

Objectives To investigate factors affecting career satisfaction and work-life balance in specialist orthodontists in the UK/ROI.Design and setting Prospective questionnaire-based study.Subjects and methods The questionnaire was sent to specialist orthodontists who were members of the British Orthodontic Society.Results Orthodontists reported high levels of career satisfaction (median score 90/100). Career satisfaction was significantly higher in those who exhibited: i) satisfaction with working hours; ii) satisfaction with the level of control over their working day; iii) ability to manage unexpected home events; and iv) confidence in how readily they managed patient expectations. The work-life balance score was lower than the career satisfaction score but the median score was 75/100. Work-life balance scores were significantly affected by the same four factors, but additionally were higher in those who worked part-time.Conclusions Orthodontists in this study were highly satisfied with their career and the majority responded that they would choose orthodontics again. Work-life balance scores were lower than career satisfaction scores but still relatively high. It is important for the profession to consider ways of maintaining, or improving, career satisfaction and work-life balance; including maintaining flexibility of working hours and ensuring that all clinicians have ready access to appropriate training courses throughout their careers (for example, management of patient expectations).


Assuntos
Satisfação no Emprego , Ortodontistas/psicologia , Equilíbrio Trabalho-Vida , Feminino , Humanos , Irlanda , Masculino , Pessoa de Meia-Idade , Ortodontistas/estatística & dados numéricos , Estudos Prospectivos , Sociedades Odontológicas/estatística & dados numéricos , Especialidades Odontológicas/estatística & dados numéricos , Inquéritos e Questionários , Reino Unido
3.
Med Hypotheses ; 69(5): 1064-9, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17467190

RESUMO

Hepatic encephalopathy (HE) is a common neuropsychiatric complication of liver disease affecting about 20-30% patients with cirrhosis. HE may only affect quality of life (e.g. impairments in attention; coordination; driving ability), but in some patients this progresses to coma and death; defining mortality in those with acute liver failure. HE is thought to occur through accumulation of ammonia as a by-product of protein metabolism. In liver failure ammonia accumulates to toxic levels, resulting in ammonia-associated brain swelling. Presently, there is no proven therapy for HE though recent studies suggest that during liver failure, ammonia removal by skeletal muscle (by conversion to glutamine) can be manipulated; also that ammonia and amino acid metabolism should be viewed in terms of their interorgan relationship. This led us to develop a novel concept for ammonia removal. Preliminary studies provide the proof of concept that the combination of L-ornithine (amino acid) with phenylactetate, as L-ornithine phenylacetate (OP), reduces toxic levels of ammonia by (1) L-ornithine acting as a substrate for glutamine synthesis from ammonia in skeletal muscle and (2) phenylacetate excreting the ornithine-related glutamine as phenylacetylglutamine in the kidneys. As both L-ornithine and phenylacetate are already available for human use, data showing its usefulness in ammonia lowering could translate quickly into providing the much needed therapy for HE patients.


Assuntos
Amônia/metabolismo , Encefalopatia Hepática/metabolismo , Hiperamonemia/metabolismo , Fígado/metabolismo , Músculo Esquelético/metabolismo , Ornitina/administração & dosagem , Fenilacetatos/administração & dosagem , Quimioterapia Combinada , Encefalopatia Hepática/tratamento farmacológico , Humanos , Hiperamonemia/tratamento farmacológico , Fígado/efeitos dos fármacos , Modelos Biológicos , Músculo Esquelético/efeitos dos fármacos
5.
Gut ; 52(8): 1182-7, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12865279

RESUMO

BACKGROUND: The role of proinflammatory cytokines in the pathogenesis of portal hypertension is unclear. AIMS AND METHODS: This study tests the hypothesis that tumour necrosis factor alpha (TNF-alpha) is an important mediator of the circulatory disturbances in alcoholic hepatitis (AH) and evaluates the acute and short term effect of a single infusion of the monoclonal chimeric anti-TNF-alpha antibody (Infliximab) on portal and systemic haemodynamics in 10 patients with severe biopsy proven AH. Cardiovascular haemodynamics, hepatic venous pressure gradient (HVPG), and hepatic and renal blood flow were measured before, 24 hours after Infliximab, and prior to hospital discharge. RESULTS: Serum bilirubin (p<0.05), C reactive protein (p<0.001), and white cell count (p<0.01) were reduced significantly, as were plasma levels of interleukin (IL)-6 and IL-8 after treatment. Of the 10 patients, nine were alive at 28 days. Mean HVPG decreased significantly at 24 hours (23.4 (2.8) to 14.3 (1.9) mm Hg; p<0.001) with a sustained reduction prior to discharge (12.8 (1.9) mm Hg; p<0.001). Mean arterial pressure and systemic vascular resistance increased significantly (p<0.001and p<0.01, respectively), mirrored by a reduction in cardiac index (5.9 (0.5) to 4.7 (0.5) l/min/m(2); p<0.05) prior to discharge. Hepatic and renal blood flow also increased significantly (506.2 (42.9) to 646.3 (49.2) ml/min (p=0.001) and 424.3 (65.12) to 506.3 (85.7) ml/min (p=0.001), respectively) prior to discharge. CONCLUSION: The results of this study illustrate that anti-TNF-alpha treatment in AH patients produces a highly significant, early, and sustained reduction in HVPG, possibly through a combination of a reduction in cardiac output and intrahepatic resistance. In addition, there was a reduction in hepatic inflammation and improved organ blood flow, suggesting an important role for TNF-alpha in mediating the circulatory disturbances in AH.


Assuntos
Anticorpos Monoclonais/farmacologia , Fármacos Gastrointestinais/farmacologia , Hemodinâmica/efeitos dos fármacos , Hepatite Alcoólica/fisiopatologia , Fator de Necrose Tumoral alfa/fisiologia , Adulto , Idoso , Pressão Sanguínea/efeitos dos fármacos , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Hipertensão Portal/fisiopatologia , Infliximab , Circulação Hepática/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Nitratos/metabolismo , Nitritos/metabolismo , Circulação Renal/efeitos dos fármacos
6.
J Clin Pathol ; 55(12): 897-9, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12461052

RESUMO

AIMS: Gulf War veterans report a high prevalence of musculoskeletal symptoms. The aim of this study was to establish whether there were abnormalities in bone turnover and remodelling in a group of symptomatic subjects who had served in the Gulf War. METHODS: Iliac crest bone biopsies were obtained from 17 Gulf War veterans who were seeking litigation and compared with those of 13 age and sex matched healthy controls. Bone histomorphometry was performed using image analysis. RESULTS: Cancellous bone area was significantly lower in Gulf War veterans than in control subjects (p = 0.027) and this was associated with a significantly reduced mineral apposition rate (p = 0.002), mean wall width (p < 0.0001), and bone formation rate at the tissue level (p < 0.0001). CONCLUSIONS: These results demonstrate that in this group of Gulf War veterans there was a significant reduction in bone formation at both the cellular and tissue level and this was associated with a reduction in cancellous bone area. The cause of these abnormalities is unknown but might be related to potentially harmful exposures during service in the Gulf War or to changes in life style as a result of chronic ill health. The clinical relevance of the observed reduction in bone formation remains to be established.


Assuntos
Osteogênese , Síndrome do Golfo Pérsico/fisiopatologia , Veteranos , Adulto , Biópsia , Densidade Óssea , Osso e Ossos/patologia , Calcificação Fisiológica , Estudos de Casos e Controles , Poluentes Ambientais/efeitos adversos , Colo do Fêmur/fisiopatologia , Humanos , Vértebras Lombares/fisiopatologia , Masculino , Pessoa de Meia-Idade , Militares , Síndrome do Golfo Pérsico/patologia
7.
Nutrition ; 17(4): 315-21, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11369171

RESUMO

Increasing evidence indicates a significant role for vitamin K in bone metabolism and osteoporosis. In this study, we found a large geographic difference in serum vitamin K2 (menaquinone-7; MK-7) levels in postmenopausal women. Serum MK-7 concentrations were 5.26 +/- 6.13 ng/mL (mean +/- SD) in Japanese women in Tokyo, 1.22 +/- 1.85 in Japanese women in Hiroshima, and 0.37 +/- 0.20 in British women. We investigated the effect of Japanese fermented soybean food, natto, on serum vitamin K levels. Natto contains a large amount of MK-7 and is eaten frequently in eastern (Tokyo) but seldom in western (Hiroshima) Japan. Serum concentrations of MK-7 were significantly higher in frequent natto eaters, and natto intake resulted in a marked, sustained increase in serum MK-7 concentration. We analyzed the relation between the regional difference in natto intake and fracture incidence. A statistically significant inverse correlation was found between incidence of hip fractures in women and natto consumption in each prefecture throughout Japan. These findings indicate that the large geographic difference in MK-7 levels may be ascribed, at least in part, to natto intake and suggest the possibility that higher MK-7 level resulting from natto consumption may contribute to the relatively lower fracture risk in Japanese women.


Assuntos
Fraturas do Colo Femoral/epidemiologia , Osteoporose Pós-Menopausa/etiologia , Soja/química , Vitamina K 2/análogos & derivados , Vitamina K 2/sangue , Idoso , Idoso de 80 Anos ou mais , Bacillus/isolamento & purificação , Fezes/microbiologia , Feminino , Fermentação , Humanos , Incidência , Japão/epidemiologia , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/prevenção & controle , Fatores de Risco , Soja/metabolismo , Triglicerídeos/sangue , Reino Unido/epidemiologia , Vitamina K 1/sangue
8.
Eur J Orthod ; 23(1): 91-7, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11296514

RESUMO

Failure of orthodontic bands occurs most frequently at the band-cement interface, when conventional glass ionomer cements are used. Modification of the band surface may improve clinical performance by increasing the mechanical interlock at this junction. The aim of this prospective study was to compare the retention of micro-etched and untreated first molar orthodontic bands in a randomized, half-mouth trial. Seventy-nine patients had 304 bands cemented as part of routine fixed appliance therapy. The effect of micro-etching, patient age and gender, operator, molar crossbite, treatment mechanics, and arch on band failure was investigated. Failure rates and survival times were compared for each variable assessed. Micro-etched molar bands showed a significant reduction in clinical failure rate over untreated molar bands and an increase in mean survival time (P < 0.001). Of the other variables examined, only the presence of a molar crossbite had any significant effect on band failure (P = 0.004).


Assuntos
Condicionamento Ácido do Dente/métodos , Colagem Dentária/métodos , Dente Molar , Braquetes Ortodônticos , Adolescente , Adulto , Fatores Etários , Criança , Intervalos de Confiança , Falha de Equipamento , Aparelhos de Tração Extrabucal , Feminino , Cimentos de Ionômeros de Vidro/química , Humanos , Masculino , Má Oclusão/terapia , Modelos de Riscos Proporcionais , Estudos Prospectivos , Cimentos de Resina/química , Fatores Sexuais , Propriedades de Superfície , Análise de Sobrevida , Técnicas de Movimentação Dentária/instrumentação
9.
J Orthod ; 27(4): 303-6, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11099567

RESUMO

Two cases are described of indelible enamel staining following fixed appliance therapy. The acquired pigmentation occurred in patients with an identifiable enamel defect prior to treatment. The interaction of factors to cause the staining is discussed and it's prevention in future cases highlighted. Subsequent restoration of the affected teeth is shown.


Assuntos
Aparelhos Ortodônticos/efeitos adversos , Descoloração de Dente/etiologia , Amelogênese Imperfeita/complicações , Criança , Ligas de Cromo/efeitos adversos , Corrosão , Hipoplasia do Esmalte Dentário/complicações , Facetas Dentárias , Microabrasão do Esmalte , Feminino , Humanos , Incisivo , Maxila , Aço Inoxidável/efeitos adversos , Descoloração de Dente/terapia
10.
Lancet ; 354(9192): 1791-2, 1999 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-10577647

RESUMO

Bone histomorphometric analysis in 24 agricultural workers with chronic organophosphate exposure showed significantly lower bone formation at tissue and cellular level than in healthy controls.


Assuntos
Doenças dos Trabalhadores Agrícolas/induzido quimicamente , Remodelação Óssea/efeitos dos fármacos , Inseticidas/efeitos adversos , Compostos Organofosforados , Densidade Óssea/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade
11.
J Clin Periodontol ; 26(4): 252-6, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10223397

RESUMO

This study aimed to detect the levels of osteocalcin in gingival crevicular fluid (GCF) from healthy (< or =3 mm sulcus depth and non-bleeding) and diseased sites (> or =6 mm probing depth and bleeding) in subjects with adult periodontitis, in order to further investigate its potential as a possible marker of the disease process. Periodontal probing depths, attachment levels and gingival indices were recorded from one healthy and one diseased site in each of 20 subjects with adult periodontitis. Both GCF accumulated in the periodontal pocket or sulci and GCF flowing into the periodontal pocket or sulci over a three-minute interval were sampled. The amounts of osteocalcin in each GCF sample was determined using immunoassays. A mean of 2.34 ng/site (2.7 microg/ml) osteocalcin was found at diseased sites and a mean of 2.47 ng/site (5.47 microg/ml) was found at healthy sites for the accumulated GCF collection method. A mean of 0.17 ng/ site (2.17 microg/ml) osteocalcin was found at diseased sites and a mean of 0.14 ng/ site (1.85 microg/ml) at healthy sites for the flow method of GCF collection. There were no statistically significant differences between osteocalcin levels in diseased and healthy sites in subjects with adult periodontitis.


Assuntos
Líquido do Sulco Gengival/química , Osteocalcina/análise , Periodontite/metabolismo , Adulto , Idoso , Progressão da Doença , Feminino , Hemorragia Gengival/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Perda da Inserção Periodontal/metabolismo , Perda da Inserção Periodontal/patologia , Índice Periodontal , Bolsa Periodontal/metabolismo , Bolsa Periodontal/patologia , Periodontite/patologia , Periodonto/metabolismo , Periodonto/patologia , Projetos Piloto
12.
Int J Paediatr Dent ; 9(3): 207-11, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10815578

RESUMO

Tooth and nail syndrome, an autosomal dominant condition, is characterized by hypodontia and nail dysplasia. Mandibular incisors, second molars and maxillary canines are the most frequently missing teeth. Tooth shape may vary and conical and narrow crowns are common. Nail dysplasia affects fingernails and toenails and is often more severe in childhood. Nails may be spoon-shaped, ridged, slow growing and easily broken. The clinical and radiographic features of a father and son presenting with this rare condition are described.


Assuntos
Anodontia/patologia , Displasia Ectodérmica/patologia , Unhas Malformadas , Adulto , Anodontia/etiologia , Anodontia/genética , Criança , Displasia Ectodérmica/complicações , Displasia Ectodérmica/genética , Genes Dominantes , Humanos , Masculino , Síndrome
13.
J Clin Periodontol ; 25(8): 662-5, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9722271

RESUMO

Phylloquinone is a lipid soluble vitamin which is an absolute growth requirement for black-pigmented anaerobes, many of which are implicated in the aetiology of periodontal diseases. This cross-sectional study aimed to detect the levels of phylloquinone in GCF from healthy and diseased sites in subjects with adult periodontitis, in order to investigate further its potential role in the disease process. The sample consisted of eighteen patients with adult periodontitis. Periodontal probing depths, attachment levels and gingival indices were recorded from one healthy and one diseased site in each subject. GCF was sampled and the amount of phylloquinone in each sample was determined using reverse-phase high performance liquid chromatography coupled to electrochemical detection. The mean amount of phylloquinone in accumulated GCF from diseased sites was 406 pg/site and 80 pg/site from healthy sites (p=0.013). When the amounts of phylloquinone in GCF were expressed as concentrations the values were 228 ng/ml and 3350 ng/ml for diseased and healthy sites respectively (p=0.084). These findings suggest the levels of phylloquinone in GCF differs in periodontal health and disease in subjects with adult periodontitis. The total phylloquinone at diseased sites may provide the nutritional requirements favouring the growth of black-pigmented anaerobes.


Assuntos
Líquido do Sulco Gengival/química , Periodontite/metabolismo , Vitamina K 1/análise , Adulto , Bactérias Anaeróbias/crescimento & desenvolvimento , Bactérias Anaeróbias/metabolismo , Cromatografia Líquida de Alta Pressão , Estudos Transversais , Eletroquímica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Perda da Inserção Periodontal/metabolismo , Índice Periodontal , Bolsa Periodontal/metabolismo , Periodontite/microbiologia , Periodonto/metabolismo , Vitamina K 1/metabolismo
14.
Br J Oral Maxillofac Surg ; 35(3): 161-5, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9212290

RESUMO

Patients with chronic facial pain including those with facial arthromyalgia (TMJ dysfunction syndrome) were investigated for evidence of abnormal systemic and intra-articular free radical activity. Chronic facial pain patients showed significantly raised serum 2,3-dihydroxybenzoic acid after an oral dose of 1.2 g of aspirin which indicates increased systemic free radical activity. This was reflected in the TMJ aspirates of the facial arthromyalgia patients which contained thiobarbituric acid-reactive substance (TBA-RS) which is also a product of free radical activity. The synovial aspirates also contained high levels of the hyperalgesic eicosanoid 15-HETE. However, there was no difference between the painful and symptom-free joints, which suggested that in part the clinical features are probably determined by asymmetrical masticatory function or as yet unknown algesic factors such as local cytokine production.


Assuntos
Dor Facial/etiologia , Gentisatos , Espécies Reativas de Oxigênio/fisiologia , Administração Oral , Adulto , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/farmacocinética , Aspirina/administração & dosagem , Aspirina/farmacocinética , Estudos de Casos e Controles , Doença Crônica , Citocinas/metabolismo , Dinoprostona/análise , Dor Facial/metabolismo , Feminino , Radicais Livres/metabolismo , Radicais Livres/farmacologia , Humanos , Hidroxibenzoatos/sangue , Ácidos Hidroxieicosatetraenoicos/análise , Quelantes de Ferro/análise , Leucotrieno B4/análise , Masculino , Mastigação , Pessoa de Meia-Idade , Espécies Reativas de Oxigênio/metabolismo , Líquido Sinovial/química , Articulação Temporomandibular/metabolismo , Síndrome da Disfunção da Articulação Temporomandibular/etiologia , Síndrome da Disfunção da Articulação Temporomandibular/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/análise
16.
Br J Orthod ; 24(4): 297-300, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9459028

RESUMO

The familial nature of supernumerary teeth is discussed in this paper and illustrated with a report showing the development of supernumeraries in siblings. The orthodontic treatment and possible sequelae to the development of supernumerary teeth in the premolar region is highlighted.


Assuntos
Dente Pré-Molar/anormalidades , Dente Supranumerário/genética , Adolescente , Dente Pré-Molar/diagnóstico por imagem , Criança , Dente Canino/diagnóstico por imagem , Dente Canino/cirurgia , Dentição Mista , Feminino , Seguimentos , Humanos , Masculino , Dente Molar/diagnóstico por imagem , Radiografia , Dente Impactado/diagnóstico por imagem , Dente Impactado/etiologia , Dente Impactado/cirurgia , Dente Supranumerário/diagnóstico por imagem , Dente não Erupcionado/diagnóstico por imagem , Dente não Erupcionado/etiologia
17.
Cytokine ; 7(3): 287-90, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7640347

RESUMO

Naphthoquinone vitamins (vitamins K) are widely recognized for their role in the gamma-carboxylation of specific glutamyl residues in coagulation, anti-coagulation and extra-hepatic proteins. Recently, however, there have been reports that these compounds can exert actions other than those normally associated with protein gamma-carboxylation. These observations suggest that naphthoquinones may have effects on the production of inflammatory mediators including cytokines. Fibroblasts are now recognized as a rich source of cytokines and we have examined the effect of various naphthoquinones on the production of interleukin 6 (IL-6) by lipopolysaccharide-stimulated human gingival fibroblasts. Compounds examined in this study include: phylloquinone (K1), menaquinone-4 (K2), menadione (K3), 2,3-dimethoxy-1,4-naphthoquinone (DMK) and a synthetic product of vitamin K catabolism, 2-methyl, 3-(2'methyl)-hexanoic acid-1,4-naphthoquinone (KCAT). All of these compounds are capable of inhibiting IL-6 production with a rank order of potency: KCAT > K3 > DMK > K2 > K1. The most potent compound, KCAT, inhibited IL-6 production with an IC50 of 3 x 10(-7)M. The mechanism of action of these naphthoquinones on fibroblast IL-6 production is unknown. Given that K3 and KCAT are inactive in the gamma-carboxylation reaction, we suggest that this activity is not essential for the inhibition of IL-6 production and that activity may be related to the redox capacity of these naphthoquinones.


Assuntos
Fibroblastos/efeitos dos fármacos , Interleucina-6/biossíntese , Lipopolissacarídeos/farmacologia , Vitamina K/farmacologia , Células Cultivadas , Gengiva/citologia , Gengiva/efeitos dos fármacos , Gengiva/metabolismo , Humanos , Lipopolissacarídeos/antagonistas & inibidores , Estimulação Química
18.
J Bone Miner Res ; 8(10): 1241-5, 1993 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8256661

RESUMO

We measured the serum levels of phylloquinone (vitamin K1) and of the menaquinones, MK-7 and MK-8, in a group of 51 women with a mean age of 81 years who were studied within a few hours after a hip fracture. A group of 38 healthy age-matched women randomly chosen from the same population served as controls. Patients with hip fracture had a marked reduction in serum vitamin K1 (336 +/- 302 versus 585 +/- 490 pg/ml, p < 0.01), MK-7 (120 +/- 84 versus 226 +/- 178 pg/ml, p < 0.001), and MK-8 (89 +/- 113 versus 161 +/- 145 pg/ml, p < 0.01), and a large number had undetectable levels, especially of MK-8. Vitamin K levels were not correlated with the time elapsed after fracture or with serum cortisol or other biochemical variables. These data suggest that patients with hip fracture have vitamin K deficiency, an abnormality that could affect bone metabolism through an impairment of the gamma carboxylation of the gla-containing proteins of bone.


Assuntos
Fraturas do Quadril/sangue , Vitamina K 1/sangue , Vitamina K/sangue , Idoso , Idoso de 80 Anos ou mais , Cromatografia Líquida de Alta Pressão , Feminino , Humanos , Hidrocortisona/sangue , Estudos Prospectivos
19.
J Bone Miner Res ; 8(8): 1005-8, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8213250

RESUMO

Vitamin K plays an essential role in the gamma carboxylation of the gla-containing proteins of bone matrix, such as osteocalcin. We have measured the concentration of vitamin K1 (VK) and of the menaquinones MK-6, MK-7, and MK-8, the three major vitamin K2 moieties, in trabecular and cortical bone taken from the femoral neck of patients undergoing hip replacement. Both bone compartments were found to contain large amounts of VK, MK-6, MK-7, and MK-8. Concentrations were as high as those reported for the liver, the major storage organ for vitamin K. Further research is required to examine the association between vitamin K in bone and the gamma carboxylation of vitamin K-dependent bone proteins.


Assuntos
Osso e Ossos/química , Vitamina K 1/análise , Vitamina K 2/análogos & derivados , Vitamina K/análogos & derivados , Vitamina K/análise , Idoso , Cromatografia Líquida de Alta Pressão , Feminino , Colo do Fêmur , Humanos , Masculino , Pessoa de Meia-Idade
20.
Bone ; 12(6): 387-9, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1797053

RESUMO

Vitamin K1 functions in the conversion of glutamate residues, present in certain bone peptides, into the putatively active gamma-carboxyglutamate form. We have shown previously that the circulating levels of vitamin K1 are depressed in osteoporotic patients. However, it is known that menaquinones (vitamin K2:MK) may be more effective than vitamin K1 in this conversion of the inactive to active form of glutamate residues. A procedure for measuring such menaquinones has now demonstrated a marked deficiency of MK-7 and MK-8 in patients with osteoporotic fractures. It is suggested that estimates of circulating levels of K1, MK-7, and MK-8 might provide a biochemical risk marker of osteoporotic fractures.


Assuntos
Fraturas do Colo Femoral/sangue , Osteoporose/complicações , Fraturas da Coluna Vertebral/sangue , Vitamina K 2/análogos & derivados , Vitamina K/análogos & derivados , Idoso , Idoso de 80 Anos ou mais , Feminino , Fraturas do Colo Femoral/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Fraturas da Coluna Vertebral/etiologia , Vitamina K/sangue
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