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1.
Ann Rheum Dis ; 74(9): 1697-705, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24817417

RESUMO

AIM: To test the efficiency of tumour necrosis factor blockers (adalimumab) in patients with painful refractory (non-responders to analgesics and non-steroidal anti-inflammatory drugs (NSAIDs)) hand osteoarthritis (OA). METHODS: We performed a randomised, double-blind, placebo-controlled, parallel group, multicentre study. Patients were randomised to: 1/1 adalimumab 40 mg for two subcutaneous injections at a 15-day interval or placebo and monitored for 6 months. The primary outcome was the percentage of patients with an improvement of more than 50% in global pain (Visual Analogue Scale) between week 0 (W0) and week 6 (W6). Secondary outcomes included the number of painful joints, swollen joints, morning stiffness duration, patient and practitioner global assessments, functional indexes for hand OA, and consumption of analgesics. Analysis on the mean primary outcome measure was done on patients who received at least one injection. RESULTS: 99 patients were recruited and 85 patients were randomised. Among them, 37 patients in the placebo group and 41 in the adalimumab group received at least one injection and were evaluated at W6 (n=78) on the main efficacy outcome. Mean age was 62 years, 85% were women, and mean level of pain was 62 mm at W0. At W6, 35.1% in the adalimumab group versus 27.3% in the placebo group had a pain reduction ≥50% (RR 1.12 (95% CI 0.82 to 1.54; p=0.48). There were no statistical differences for all secondary end points. The rate of adverse events was similar in the two groups. CONCLUSIONS: Adalimumab was not superior to placebo to alleviate pain in patients with hand OA not responding to analgesics and NSAIDs. TRIALS REGISTRATION NUMBER: NCT00597623.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Antirreumáticos/uso terapêutico , Articulação da Mão , Osteoartrite/tratamento farmacológico , Dor/tratamento farmacológico , Adalimumab , Idoso , Analgésicos/uso terapêutico , Anti-Inflamatórios não Esteroides/uso terapêutico , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite/complicações , Dor/etiologia , Medição da Dor , Falha de Tratamento , Resultado do Tratamento
2.
Clin Chim Acta ; 322(1-2): 121-32, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12104091

RESUMO

BACKGROUND: In the European Prospective Osteoporosis Study (EPOS), a past spine fracture increased risk of an incident fracture 3.6 - 12-fold even after adjusting for BMD. We examined the possibility that biochemical marker levels were associated with this unexplained BMD-independent element of fracture risk. METHODS: Each of 182 cases in EPOS of spine or non-spine fracture that occurred in 3.8 years of follow-up was matched by age, sex and study centre with two randomly assigned never-fractured controls and one case of past fracture. Analytes measured blind were: osteocalcin, bone-specific alkaline phosphatase, total alkaline phosphatase, serum creatinine, calcium, phosphate and albumin, together with the collagen cross-links degradation products serum CTS and urine CTX. Most subjects also had bone density measured by DXA. RESULTS: Cases who had recent fractures did not differ in marker levels from cases who had their last fracture more than 3 years previously. No statistically significant effect of recent fracture was found for any marker except osteocalcin, which was 17.6% lower in recent peripheral cases compared to unfractured controls (p<0.05) and this was independent of BMD. CONCLUSION: Past fracture as a risk indicator for future fracture is not strongly mediated through increased bone turnover.


Assuntos
Remodelação Óssea , Fraturas Ósseas/complicações , Fraturas Ósseas/metabolismo , Fraturas da Coluna Vertebral/complicações , Fraturas da Coluna Vertebral/metabolismo , Idoso , Envelhecimento , Fosfatase Alcalina/metabolismo , Biomarcadores/análise , Densidade Óssea/fisiologia , Cálcio/análise , Colágeno/metabolismo , Creatinina/sangue , Feminino , Seguimentos , Fraturas Ósseas/diagnóstico , Fraturas Ósseas/etiologia , Humanos , Masculino , Análise por Pareamento , Pessoa de Meia-Idade , Osteocalcina/análise , Fosfatos/análise , Prognóstico , Recidiva , Caracteres Sexuais , Fraturas da Coluna Vertebral/diagnóstico , Fraturas da Coluna Vertebral/etiologia , Vitamina D/análise
3.
J Bone Miner Res ; 16(1): 89-96, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11149494

RESUMO

The aims of this study performed in ewes were: (1) to confirm in this animal model the effects on bone of ovariectomy (OVX) alone or associated with Lentaron (L), a potent peripheral aromatase inhibitor, used to amplify the effects of OVX and (2) to evaluate the effects of a new selective estrogen receptor modulator (SERM; MDL 103,323) on bone remodeling. Thirty-nine old ewes were divided into five groups: sham (n = 7); OVX (n = 8); OVX + L (n = 8); OVX + L + MDL; 0.1 mg/kg per day (n = 8); and OVX + L + MDL 1 mg/kg per day (n = 8). The animals were treated for 6 months. Biochemical markers of bone turnover (urinary excretion of type 1 collagen C-telopeptide [CTX], serum osteocalcin [OC], and bone alkaline phosphatase [BAP]) were measured each month. Bone biopsy specimens were taken at the beginning and after death at the end of the experiment. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (DXA) on the lumbar spine and femur. OVX induced a significant increase in biochemical markers. This effect was the highest after 3 months for CTX (+156% vs. sham) and after 4 months for OC and BAP (+74% and +53% vs. sham, respectively). L tended to amplify the effect of OVX on OC and BAP. OVX induced significant increases in the porosity, eroded, and osteoid surfaces in cortical bone but no effect was observed in cancellous bone. MDL treatment reduced the bone turnover as assessed by bone markers, which returned to sham levels as well as histomorphometry both in cortical and in cancellous bone. Cancellous osteoid thickness decreased by 27% (p < 0.05), mineralizing perimeter by 81% (p < 0.05), and activation frequency by 84% (p < 0.02) versus OVX + L. Femoral and spinal BMD were increased by MDL and tended to return to the sham values. The effects of OVX on bone turnover were different on cortical and cancellous bone. These effects on cortical bone were reflected by changes in biochemical markers. MDL markedly reduces bone turnover and increases BMD suggesting that this new agent may prevent postmenopausal bone loss.


Assuntos
Androstenodiona/análogos & derivados , Osso e Ossos/efeitos dos fármacos , Clomifeno/farmacologia , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Fosfatase Alcalina/sangue , Androstenodiona/farmacologia , Animais , Aromatase/metabolismo , Inibidores da Aromatase , Biomarcadores , Densidade Óssea/efeitos dos fármacos , Remodelação Óssea/efeitos dos fármacos , Osso e Ossos/enzimologia , Osso e Ossos/metabolismo , Clomifeno/análogos & derivados , Colágeno/urina , Feminino , Fêmur/efeitos dos fármacos , Fêmur/metabolismo , Ílio/citologia , Ílio/efeitos dos fármacos , Ílio/metabolismo , Osteocalcina/sangue , Osteoporose , Ovariectomia , Fragmentos de Peptídeos/urina , Ovinos , Coluna Vertebral/efeitos dos fármacos , Coluna Vertebral/metabolismo , Fatores de Tempo
4.
Ann Intern Med ; 128(10): 801-9, 1998 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-9599191

RESUMO

BACKGROUND: Elderly persons who have osteoporotic hip fracture are often undernourished, particularly with respect to protein. Protein malnutrition may contribute to the occurrence and outcome of hip fracture. OBJECTIVE: To investigate whether oral protein supplements benefit bone metabolism in patients with recent hip fracture. DESIGN: 6-month, randomized, double-blind, placebo-controlled trial with a 6-month post-treatment follow-up. SETTING: University orthopedic ward. PATIENTS: 82 patients (mean age, 80.7 +/- 7.4 years) with recent osteoporotic hip fracture. Patients received calcium supplementation, 550 mg/d, and one dose of vitamin D, 200,000 IU (at baseline). INTERVENTION: Protein supplementation, 20 g/d, or isocaloric placebo (among controls). MEASUREMENTS: Bone mineral density, biochemical markers of bone remodeling, calciotropic hormone levels, biochemically evaluated nutritional and immunologic status, and muscle strength were measured every 6 months. RESULTS: Compared with controls, patients who received protein supplements had significantly greater increases in serum levels of insulin-like growth factor-I (85.6% +/- 14.8% and 34.1% +/- 7.2% at 6 months; difference, 51.5 percentage points [95% CI, 18.6 to 84.4 percentage points]; P = 0.003) and an attenuation of the decrease in proximal femur bone mineral density (-2.29% +/- 0.75% and -4.71% +/- 0.77% at 12 months; difference, 2.42 percentage points [CI, 0.26 to 4.59 percentage points]; P = 0.029). Seven and 13 new vertebral deformities were found among patients who received protein supplements and controls, respectively (P > 0.2). Median stay in rehabilitation wards was shorter for patients who received protein supplements than for controls (33 days [CI, 29 to 56 days] and 54 days [CI, 44 to 62 days]; difference, 21 days [CI, 4 to 25 days]; P = 0.018). CONCLUSION: Protein repletion after hip fracture was associated with increased serum levels of insulin-like growth factor-I, attenuation of proximal femur bone loss, and shorter stay in rehabilitation hospitals.


Assuntos
Densidade Óssea , Proteínas Alimentares/administração & dosagem , Suplementos Nutricionais , Fêmur/metabolismo , Fraturas do Quadril/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Osteoporose/complicações , Atividades Cotidianas , Idoso , Idoso de 80 Anos ou mais , Método Duplo-Cego , Feminino , Seguimentos , Fraturas do Quadril/etiologia , Fraturas do Quadril/terapia , Humanos , Imunoglobulina M/sangue , Tempo de Internação , Masculino , Placebos , Pré-Albumina/metabolismo , Deficiência de Proteína/prevenção & controle , Albumina Sérica/metabolismo
5.
Bone ; 20(5): 451-5, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9145242

RESUMO

This study was an attempt to develop an animal model of steroid-induced low bone formation, potentially suitable for testing bone forming agents. The short-term effects of corticosteroids on bone remodeling were analyzed in ewes. One group of 16 animals (mean age: 9 +/- 1 years) received a daily intramuscular injection of 16 mg of methylprednisone (MP group) for 3 months. The other group of 16 animals was considered the control group. At the end of treatment, significant decreases of osteoblastic (-50%) and mineralizing (-64%) perimeters and wall width (-5%) were noted in the MP group. The bone formation rate at the tissue level was significantly decreased by 91%. In contrast, at the cell level, there was no reduction in the daily production of matrix by the osteoblasts: Aj.AR was 40% lower than in controls, but the difference was not significant. At the end of the treatment, a significant increase in eroded perimeter (+97%) was associated with a significant decrease of osteoclast number. Biochemical markers of bone formation (osteocalcin and bone-specific alkaline phosphatase) and urinary cAMP were unchanged. Due to the short duration of the treatment, neither bone volume nor microarchitecture parameters were modified. The decreases of both the activation frequency and osteoclast number associated with the increase in eroded surfaces suggest a prolongation of the reversal phase due to an inhibition of osteoblast differentiation. Changes of bone formation in ewes induced by short-term administration of MP were similar to those reported after 3 months of treatment in humans. Thus, corticosteroid-treated ewes may represent a suitable animal model of low bone formation.


Assuntos
Remodelação Óssea/efeitos dos fármacos , Glucocorticoides/farmacologia , Prednisona/análogos & derivados , Fosfatase Alcalina/metabolismo , Animais , Densidade Óssea/efeitos dos fármacos , Osso e Ossos/anatomia & histologia , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/metabolismo , Feminino , Glucocorticoides/administração & dosagem , Humanos , Osteoblastos/efeitos dos fármacos , Osteocalcina/metabolismo , Osteoclastos/efeitos dos fármacos , Prednisona/administração & dosagem , Prednisona/farmacologia , Ovinos , Especificidade da Espécie , Fatores de Tempo
6.
J Clin Endocrinol Metab ; 82(3): 719-24, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9062471

RESUMO

Increased levels of circulating undercarboxylated osteocalcin (ucOC), measured indirectly with the hydroxyapatite (HAP) binding assay, have been shown to predict hip fracture risk in a small group of elderly institutionalized women. The aim of this study was to confirm these findings in a prospective cohort study (EPIDOS prospective study) of 7598 healthy, independently living women over 75 yr of age. One hundred and four women who sustained a hip fracture during a 22-month follow-up period were age matched with 255 controls who did not fracture. Baseline samples were collected before hip fracture for measurement of total OC and ucOC, assessed either with the HAP binding assay or directly with a new enzyme-linked immunosorbent assay (ELISA). This direct ELISA uses human recombinant noncarboxylated OC as a standard and two monoclonal antibodies, one of which was raised against the 14-30 Glu synthetic peptide. We found that the intra- and interassay variations are less than 11%, and this assay exhibits a 5% cross-reactivity with purified human bone OC, used as a source of carboxylated OC. ucOC levels measured with this ELISA correlated well with the HAP binding assay in the population of 359 elderly women (r = 0.82; P < 0.0001). We estimated the risk of hip fracture for women with levels of ucOC in the highest quartile of values for the 255 controls. We found that increased levels of ucOC measured by ELISA were associated with increased hip fracture risk with an odds ratio (OR) of 1.9 (95% confidence interval, 1.2-3.0), and the ELISA had a greater sensitivity than the HAP assay. In contrast, total OC was not associated with hip fracture risk. After adjustment for femoral neck bone mineral density (BMD) and mobility status assessed by gait speed, ucOC still predicted hip fracture with an OR of 1.8 (1.0-3.0). Women with both femoral neck BMD in the lowest quartile and ucOC in the highest quartile were at higher risk of hip fracture, with an OR of 5.5 (2.7-11.2), than those with only low BMD or high ucOC levels. In conclusion, we have developed a new specific ELISA for serum ucOC, with low cross-reactivity with carboxylated OC and increased specificity and sensitivity over the HAP assay. Using this new ELISA, we found that ucOC, but not total OC, predicts hip fracture risk independently of femoral neck BMD in elderly women drawn from the general population. Thus, ucOC measurement could be combined with bone mass determination to improve the assessment of hip fracture risk in elderly women.


Assuntos
Envelhecimento/fisiologia , Ácidos Carboxílicos/metabolismo , Ensaio de Imunoadsorção Enzimática/métodos , Fraturas do Quadril , Osteocalcina/sangue , Osteocalcina/metabolismo , Idoso , Anticorpos Monoclonais , Estudos de Coortes , Durapatita/metabolismo , Feminino , Previsões , Humanos , Estudos Prospectivos , Fatores de Risco
7.
Bone ; 16(6): 603-10, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7669436

RESUMO

Parathyroid hormone (PTH) and its (1-34) fragment are stimulators of bone turnover that have an anabolic effect increasing trabecular bone mass when administered intermittently by daily subcutaneous injections. Its clinical use in osteoporosis, however, has been limited by the concomitant increased bone resorption and deleterious effect on cortical bone. To evaluate if a treatment combining PTH and a potent inhibitor of bone resorption would retain the anabolic effect of PTH without increasing bone resorption, we analyzed the effects of PTH (1-34) (500 IU/d) with or without the bisphosphonate tiludronate (1 mg/kg per day) for 3 months on biochemical and histological indices of bone turnover in old female sheep, an animal model which has a slow bone remodeling activity that resembles the one of elderly women. As expected, PTH (1-34) induced a significant increase of urinary pyridinoline and hydroxyproline (reflecting bone resorption), and of serum osteocalcin and alkaline phosphatase (reflecting bone formation), that were consistent with an increase of resorption and tetracycline-based formation of bone measured on iliac crest biopsy. In contrast, all biochemical and histological indices of bone turnover were decreased in sheep receiving tiludronate, a potent inhibitor of bone resorption. Surprisingly, in the combined therapy group, biochemical and histological indices of both resorption and formation did not differ from the control groups. Thus, the model of old sheep, which closely resembles the situation in old human, shows that the anabolic effect of PTH on bone is not maintained when PTH is coadministered with a bisphosphonate, in marked contrast to results noted in the growing rat.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Desenvolvimento Ósseo/efeitos dos fármacos , Reabsorção Óssea/tratamento farmacológico , Difosfonatos/farmacologia , Osteoporose Pós-Menopausa/tratamento farmacológico , Hormônio Paratireóideo/uso terapêutico , Fragmentos de Peptídeos/uso terapêutico , Fosfatase Alcalina/sangue , Aminoácidos/urina , Análise de Variância , Animais , Fenômenos Biomecânicos , Densidade Óssea/efeitos dos fármacos , Reabsorção Óssea/induzido quimicamente , Difosfonatos/administração & dosagem , Difosfonatos/uso terapêutico , Modelos Animais de Doenças , Feminino , Humanos , Hidroxiprolina/urina , Ílio/efeitos dos fármacos , Ílio/metabolismo , Injeções Subcutâneas , Osteocalcina/sangue , Osteoclastos/citologia , Osteoclastos/efeitos dos fármacos , Hormônio Paratireóideo/administração & dosagem , Hormônio Paratireóideo/farmacologia , Fragmentos de Peptídeos/administração & dosagem , Fragmentos de Peptídeos/farmacologia , Ovinos , Teriparatida
8.
Bone ; 16(4): 427-30, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7605702

RESUMO

The purpose of this study was to define the bone metabolic properties during the postfracture period in elderly women with hip fracture. Osteocalcin (Oc), a marker of bone formation, was measured in 58 women with hip fracture (77 +/- 7 years) admitted to the hospital from their own homes. Serum samples were taken on average 5 h (range 1-21) from fracture and at follow-up, on average 4.6 months later. Comparison was made with 58 age-matched (79 +/- 5 years) women. Women with hip fracture had initially 30% lower Oc levels compared to the controls (p = 0.0001). The Oc level was independent of time elapsed from trauma, within 18 h, after which the level further decreased. At follow-up, Oc showed a 44% increase (p = 0.0001) and had reached the level of the controls, but not beyond it. A concomitant, but less marked increase was noted for alkaline phosphatase (ALP) (p = 0.0001). We conclude that although the bone formation, as assessed by Oc, is apparently lower in elderly women who sustain a hip fracture, the ability to induce a fracture response, with an increased bone turnover during fracture healing is intact. Subsequently, it is essential that a time perspective is applied, as the bone metabolic changes in patients having sustained a fracture are related to the time elapsed from fracture.


Assuntos
Osso e Ossos/metabolismo , Consolidação da Fratura/fisiologia , Fraturas do Quadril/sangue , Osteocalcina/sangue , Idoso , Idoso de 80 Anos ou mais , Estudos de Avaliação como Assunto , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade
9.
Calcif Tissue Int ; 56(3): 177-80, 1995 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7750019

RESUMO

Physical activity has been suggested to be one of the determinants of bone turnover and to prevent age-related bone loss. To examine this we measured the serum levels of osteocalcin (bone Gla-protein, BGP), C-terminal procollagen peptide (PICP), serum alkaline phosphatase, bone-specific alkaline phosphatase, and S-calcium as indices of bone formation in 19 actively performing and 15 ex-lifters. All were nationally or internationally ranked male athletes. Their values were compared with those from 38 age- and gender-matched controls. Actively performing weight lifters had 35% higher (P < 0.05) serum concentration of osteocalcin than the controls. The ex-lifters did not differ from the age-matched controls. Also serum calcium was elevated in active lifters (6%) (P < 0.01) but not in ex-lifters. No difference was found for serum-ALP, B-ALP, or PICP in either of the groups. Our study indicates that in addition to an already documented and well-known higher bone mineral density in heavily exercising athletes, they have an indication of higher bone formation as measured by biochemical markers. In athletes who have retired from competitional training, however, the bone formation does not differ from that of more sedentary controls.


Assuntos
Desenvolvimento Ósseo/fisiologia , Levantamento de Peso/fisiologia , Adulto , Envelhecimento/sangue , Fosfatase Alcalina/sangue , Biomarcadores/sangue , Cálcio/sangue , Humanos , Ensaio Imunorradiométrico , Modelos Lineares , Masculino , Osteocalcina/sangue , Osteoporose/prevenção & controle , Fragmentos de Peptídeos/sangue , Pró-Colágeno/sangue
10.
J Cell Biol ; 127(4): 1149-58, 1994 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7962073

RESUMO

Osteocalcin, also called Bone Gla Protein (BGP), is the most abundant of the non-collagenous proteins of bone produced by osteoblasts. It consists of a single chain of 46-50 amino acids, according to the species, and contains three vitamin K-dependent gamma-carboxyglutamic acid residues (GLA), involved in its binding to calcium and hydroxylapatite. Accumulating evidences suggest its involvement in bone remodeling, its physiological role, however, is still unclear. In this study the adhesion properties and the biological effects of osteocalcin on osteoclasts have been analyzed using as an experimental model, human osteoclast-like cells derived from giant cell tumors of bone (GCT). Osteocalcin promoted adhesion and spreading of these cells, triggering the release of bone sialoprotein (BSP), osteopontin (OPN) and fibronectin (FN), that in turn induced the clustering in focal adhesions of beta 1 and beta 3 integrin chains. Spreading was dependent upon the synthesis of these proteins. In fact, when the cells were incubated in the presence of monensin during the adhesion assay, they still adhered but spreading did not occur, focal adhesions disappeared and BSP, OPN, and FN were accumulated in intracellular granules. Furthermore osteocalcin induced chemotaxis in a dose-dependent manner. The action of BGP on osteoclasts was mediated by an intracellular calcium increase due to release from thapsigargin-sensitive stores. These results provide evidences that BGP exerts a role in the resorption process, inducing intracellular signaling, migration and adhesion, followed by synthesis and secretion of endogenous proteins.


Assuntos
Cálcio/metabolismo , Quimiotaxia/efeitos dos fármacos , Proteínas da Matriz Extracelular/biossíntese , Osteocalcina/farmacologia , Osteoclastos/fisiologia , Transdução de Sinais/fisiologia , Neoplasias Ósseas , Adesão Celular/efeitos dos fármacos , Citosol/metabolismo , Fibronectinas/biossíntese , Tumores de Células Gigantes , Humanos , Sialoproteína de Ligação à Integrina , Integrinas/fisiologia , Cinética , Osteoclastos/efeitos dos fármacos , Osteopontina , Sialoglicoproteínas/biossíntese , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo , Células Tumorais Cultivadas
11.
J Bone Miner Res ; 8(12): 1417-26, 1993 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8304041

RESUMO

The physiologic role of osteocalcin (OC), a vitamin K-dependent protein specific to bone, remains elusive. It has been shown that rats maintained on chronic treatment with vitamin K1 and its antagonist warfarin exhibit a marked decrease in bone osteocalcin because noncarboxylated osteocalcin does not bind to bone hydroxyapatite. To assess the role of OC in bone remodeling, we applied the warfarin model to growing lambs. We analyzed the bone changes after 3 months of concurrent warfarin and vitamin K1 treatment. Four groups of four lambs were constituted at birth and received daily a saline solution (control group, CT), 4 mg/kd/day of vitamin K1 (vitamin K group), 4 mg/kg/day of vitamin K1 + 75 or 150 mg/kg/day of warfarin (W75 and W150 group, respectively). In warfarin-treated animals, bone osteocalcin levels were decreased, both in the metaphysis (9% compared to controls) and the diaphysis (30% compared to controls) of the metacarpals. The fraction of noncarboxylated osteocalcin measured every month in the serum was significantly higher in warfarin-treated lambs than in controls at each timing point (37.6 +/- 2.6% in W75 and 48.7 +/- 5.2% in W150 versus 14.4 +/- 3.8% in controls at 3 months). Compared to non-warfarin-treated animals (NW), the main histomorphometric parameters measured on the iliac crest after tetracycline double labeling were significantly reduced in the warfarin-treated lambs: 12.2 +/- 5.2 versus 18.6 +/- 4.7% in NW (p < 0.03) for the cancellous bone area, which reflects the trabecular bone density; 14.7 +/- 6.1 versus 21.0 +/- 3.6% in NW (p < 0.03) for the eroded perimeter, and 0.315 +/- 0.064 versus 0.561 +/- 0.23 microns 3/microns 2/day in NW (p < 0.02) for the tetracycline-based bone formation rate. In conclusion, the depletion of osteocalcin in the bone of lambs induced within 3 months a marked osteopenia that resulted from a decrease in resorption and a more pronounced decrease in bone formation. Our data suggest that the presence of osteocalcin, the major gla-containing protein of bone, may be important for the maintenance of a normal bone mass and remodeling of trabecular bone.


Assuntos
Doenças Ósseas Metabólicas/fisiopatologia , Remodelação Óssea , Osso e Ossos/metabolismo , Modelos Animais de Doenças , Osteocalcina/metabolismo , Varfarina/farmacologia , Animais , Animais Recém-Nascidos , Peso Corporal/efeitos dos fármacos , Doenças Ósseas Metabólicas/induzido quimicamente , Doenças Ósseas Metabólicas/metabolismo , Remodelação Óssea/efeitos dos fármacos , Cálcio/sangue , Creatinina/sangue , Masculino , Hormônio Paratireóideo/sangue , Radioimunoensaio , Distribuição Aleatória , Ovinos , Vitamina K 1/farmacologia
12.
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
13.
Calcif Tissue Int ; 53(3): 162-9, 1993 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8242467

RESUMO

Hip fracture is one of the most severe consequences of osteoporosis affecting aged women. However, abnormalities of bone turnover responsible for bone loss in this condition have not been clearly defined. To further evaluate the bone metabolic status of women sustaining hip fracture, we have prospectively measured serum osteocalcin as a marker of bone formation and urinary excretion of pyridinoline (Pyr) and deoxypyridinoline (D-pyr) cross-links as markers of bone collagen degradation in 174 independently living women (80 +/- 8 years) within a few hours after a hip fracture. Comparison was made with 77 age-matched controls (80 +/- 5 years) and 17 premenopausal women (39 +/- 3 years). In addition 15 of the patients were followed with daily measurements during the first postoperative week. At the time of admission osteocalcin was 20% lower in the fractured women compared to the elderly controls (7.6 +/- 3.8 vs. 9.5 +/- 4.5 ng/ml, P = 0.001). Pyr and D-pyr were 36% and 40% higher, respectively (P = 0.0001), than in elderly controls and 85% and 76% higher than in premenopausal controls (P = 0.0001). Serum osteocalcin did not correlate with the cortisol level measured at the same time (r = 0.03, ns), nor with serum albumin and creatinine. Serum osteocalcin remained unchanged within 18 hours after fracture, whereafter it progressively decreased until the third postoperative day. No correlation was noted between the excretion of pyridinoline cross-links and the time elapsed from fracture.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Osso e Ossos/metabolismo , Fraturas do Quadril/metabolismo , Osteoporose/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Aminoácidos/urina , Reabsorção Óssea , Feminino , Humanos , Pessoa de Meia-Idade , Osteocalcina/sangue , Osteogênese , Osteoporose/fisiopatologia , Estudos Prospectivos , Radioimunoensaio , Espectrometria de Fluorescência
14.
Bone Miner ; 22(2): 95-103, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8251769

RESUMO

Chronic alcoholism represents a high risk for fractures and osteopenia. Previous histomorphometric studies reported a decreased bone formation, but it has never been established whether ethanol has a direct toxic effect on osteoblasts. This present in vitro study was performed on human osteoblast cells derived from bone explants after collagenase digestion. The direct effect of ethanol was determined after 4 days of exposure to various doses, ranging from 0.01 to 5 g/l on the alkaline phosphatase (AP) activity, osteocalcin secretion and [3H]thymidine incorporation. The influence of the duration of exposure to 0.8 g/l ethanol was also determined. A significant and dose-dependent decrease in the cell proliferation was observed. AP activity was significantly decreased by high doses of ethanol (2-5 g/l). A biphasic effect of ethanol was noted on osteocalcin secretion according to the dose: it decreased at doses lower than 0.8 g/l and increased at the highest concentrations. At the dose of 0.8 g/l, whatever the duration of exposure, the decrease of the proliferation was of the same magnitude and no significant change in AP activity was observed. Significant ethanol-induced effects on osteocalcin secretion were observed only after 4 and 8 days of exposure. These data demonstrate that ethanol may have a direct toxic effect on osteoblast activity and proliferation. This could be one of the mechanisms of alcohol-induced osteopenia which has a multifactorial pathophysiology.


Assuntos
Etanol/toxicidade , Osteoblastos/efeitos dos fármacos , Alcoolismo , Fosfatase Alcalina/efeitos dos fármacos , Fosfatase Alcalina/metabolismo , Doenças Ósseas Metabólicas/induzido quimicamente , Calcitriol/farmacologia , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Interações Medicamentosas , Feminino , Humanos , Masculino , Osteoblastos/citologia , Osteocalcina/metabolismo
15.
J Bone Miner Res ; 6(11): 1211-6, 1991 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1666807

RESUMO

Osteocalcin, also called bone gla protein, is a unique noncollagenous protein of the extracellular matrix of bone that circulates in blood. Oseteocalcin contains three residues of the vitamin K-dependent gamma-carboxyglutamic acid (gla) responsible for the affinity of osteocalcin for bone mineral. In animals treated with the vitamin K antagonist warfarin, the osteocalcin content of bone is markedly reduced and the fraction of osteocalcin released into the circulation is increased. Most studies have shown that osteocalcin increases with aging in women, reflecting an increase in bone turnover, especially after the menopause. To determine if this increase in osteocalcin could be associated with impaired carboxylation, we measured total and noncarboxylated osteocalcin in the serum of 72 women of various ages: 22 premenopausal (31 +/- 7 years old), 20 early postmenopausal (54 +/- 3 years), and 30 elderly women (85 +/- 8 years). As previously reported, total serum osteocalcin was significantly increased in early postmenopausal and elderly women. Noncarboxylated serum osteocalcin was slightly increased in early postmenopausal women (0.95 +/- 0.4 versus 0.65 +/- 0.5 ng/ml in premenopausal women), markedly elevated in elderly women (1.59 +/- 1.1 ng/ml, p less than 0.001), and correlated with age (r = 0.47, p less than 0.001). Elderly women had values of the same magnitude as in 10 patients on chronic warfarin therapy (1.94 +/- 1.1 ng/ml). As a consequence, the increase in carboxylated serum osteocalcin was significant in early postmenopausal women but not in elderly women. Serum levels of vitamin K1 and of menaquinones 6, 7, and 8 were measured in some of the young and elderly women.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Osteocalcina/sangue , Vitamina K/sangue , Varfarina/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento , Durapatita , Feminino , Humanos , Hidroxiapatitas/metabolismo , Pessoa de Meia-Idade , Osteocalcina/metabolismo , Radioimunoensaio , Vitamina K/análogos & derivados , Vitamina K/antagonistas & inibidores , Vitamina K 1/sangue , Varfarina/uso terapêutico
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