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1.
Science ; 363(6425): 367-374, 2019 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-30538164

RESUMO

In 2018, Kilauea Volcano experienced its largest lower East Rift Zone (LERZ) eruption and caldera collapse in at least 200 years. After collapse of the Pu'u 'O'o vent on 30 April, magma propagated downrift. Eruptive fissures opened in the LERZ on 3 May, eventually extending ~6.8 kilometers. A 4 May earthquake [moment magnitude (M w) 6.9] produced ~5 meters of fault slip. Lava erupted at rates exceeding 100 cubic meters per second, eventually covering 35.5 square kilometers. The summit magma system partially drained, producing minor explosions and near-daily collapses releasing energy equivalent to M w 4.7 to 5.4 earthquakes. Activity declined rapidly on 4 August. Summit collapse and lava flow volume estimates are roughly equivalent-about 0.8 cubic kilometers. Careful historical observation and monitoring of Kilauea enabled successful forecasting of hazardous events.

2.
Rapid Commun Mass Spectrom ; 29(22): 2140-6, 2015 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-26467226

RESUMO

RATIONALE: Following digestion of proteins with trypsin, digests are typically subjected to further 'clean-up' prior to liquid chromatography/mass spectometry (LC/MS) analysis, in order to reduce the complexity of the digested matrix, as well as helping to remove residual denaturants and reduction/alkylation reagents prior to injection onto the analytical HPLC column. Often, this is carried out using off-line techniques, and is not ideally suited to high-throughput workloads, for example in clinical laboratories. METHODS: Bovine serum albumin (BSA) was used as a model protein. Following denaturation with urea, reduction/alkylation, and digestion with trypsin, the analytical recovery of a selection of proteotypic BSA peptides was assessed using a two-dimensional, turbulent flow chromatography method. Peptides were identified using a Q Exactive™ mass spectometer operating in full-scan mode. RESULTS: Total analysis time (including the on-line sample clean-up) was 15 min per injection. Aside from the most hydrophilic peptide selected, ATEEQLK, recovery using the turbulent flow chromatography systems was greater than 30% for all remaining peptides (N = 17), and exceeded 50% for 12 of the 18 peptides studied. There was a broad correlation between the hydrophobicity factor and the observed recovery. CONCLUSIONS: This study suggests that turbulent flow chromatography offers a rapid, on-line alternative to solid-phase extraction for the analysis of peptide digests by LC/MS. A wide range of column chemistries are available, and the technique can be further optimised for analyses which are targetted to specific peptides. As with turbulent flow chromatography for small-molecule workflows, this approach may be ideally suited to high-throughput applications, such as those which are emerging from within clinical laboratories.


Assuntos
Cromatografia Líquida/métodos , Espectrometria de Massas/métodos , Fragmentos de Peptídeos/análise , Fragmentos de Peptídeos/química , Sequência de Aminoácidos , Animais , Bovinos , Cromatografia Líquida/instrumentação , Desenho de Equipamento , Dados de Sequência Molecular , Fragmentos de Peptídeos/metabolismo , Soroalbumina Bovina , Tripsina/metabolismo
3.
Diabet Med ; 32(2): 267-73, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25251588

RESUMO

AIMS: To assess markers of inflammation and bone turnover at presentation and at resolution of Charcot osteoarthropathy. METHODS: We measured serum inflammatory and bone turnover markers in a cross-sectional study of 35 people with Charcot osteoarthropathy, together with 34 people with diabetes and 12 people without diabetes. In addition, a prospective study of the subjects with Charcot osteoarthropathy was conducted until clinical resolution. RESULTS: At presentation, C-reactive protein (P = 0.007), tumour necrosis factor-α (P = 0.010) and interleukin-6 (P = 0.002), but not interleukin-1ß, (P = 0.254) were significantly higher in people with Charcot osteoarthropathy than in people with and without diabetes. Serum C-terminal telopeptide (P = 0.004), bone alkaline phosphatase (P = 0.006) and osteoprotegerin (P < 0.001), but not tartrate-resistant acid phosphatase (P = 0.126) and soluble receptor activator of nuclear factor-κß ligand (P = 0.915), were significantly higher in people with Charcot osteoarthropathy than in people with and without diabetes. At follow-up it was found that tumour necrosis factor-α (P = 0.012) and interleukin-6 (P = 0.003), but not C-reactive protein (P = 0.101), interleukin-1ß (P = 0.457), C-terminal telopeptide (P = 0.743), bone alkaline phosphatase (P = 0.193), tartrate-resistant acid phosphatase (P = 0.856), osteoprotegerin (P = 0.372) or soluble receptor activator of nuclear factor-kß ligand (P = 0.889), had significantly decreased between presentation and the 3 months of casting therapy time point, and all analytes remained unchanged from 3 months of casting therapy until resolution. In people with Charcot osteoarthropathy, there was a positive correlation between interleukin-6 and C-terminal telopeptide (P = 0.028) and tumour necrosis factor-α and C-terminal telopeptide (P = 0.013) only at presentation. CONCLUSIONS: At the onset of acute Charcot foot, serum concentrations of tumour necrosis factor-α and interleukin-6 were elevated; however, there was a significant reduction in these markers at resolution and these markers may be useful in the assessment of disease activity.


Assuntos
Artropatia Neurogênica/terapia , Reabsorção Óssea/prevenção & controle , Colágeno Tipo I/sangue , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 2/complicações , Regulação para Baixo , Interleucina-6/sangue , Peptídeos/sangue , Adulto , Idoso , Artropatia Neurogênica/sangue , Artropatia Neurogênica/complicações , Artropatia Neurogênica/fisiopatologia , Biomarcadores/sangue , Reabsorção Óssea/etiologia , Estudos de Coortes , Estudos Transversais , Humanos , Imobilização , Mediadores da Inflamação/sangue , Estudos Longitudinais , Pessoa de Meia-Idade , Estudos Prospectivos , Indução de Remissão , Regulação para Cima
4.
Meat Sci ; 96(2 Pt A): 870-5, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24211545

RESUMO

This study evaluated the concentrations of α-tocopherol, ß-carotene, creatine, carnosine, anserine and coenzyme Q10 in Longissimus dorsi (Ld) and Gluteus medius (Gm) muscles of culled dairy cows and the impact of age, production status before slaughter (dry-off vs lactating) and carcass weight on them. The effects of applying a finishing feeding regimen before slaughter were also examined. Gm muscle presented higher levels (P<0.001) of α-tocopherol (5.14 vs 3.61 µg · g(-1)) ß-carotene (0.36 vs 0.27 µg · g(-1)), anserine (59.24 vs 43.25 mg · 100 g(-1)) and coenzyme Q10 (3.33 vs 1.73 mg · 100 g(-1)), and by contrast lower (P<0.05) creatine concentration (502.40 vs 527.28 mg · 100 g(-1)) than Ld. Dry-off and lactating cows differed significantly in α-tocopherol level (P<0.001) but not in the concentrations of the other compounds (P>0.05). The finishing feeding promoted higher mean concentrations of anserine and creatine but lower carnosine values (P>0.05) than directly slaughtered dry-off cows. The variation between muscles and from animal-to-animal makes it difficult to exactly define the antioxidant status of the dairy cow's meat.


Assuntos
Antioxidantes/análise , Carne/análise , Músculo Esquelético/química , Ração Animal/análise , Animais , Anserina/análise , Açores , Peso Corporal , Carnosina/análise , Bovinos , Creatina/análise , Dieta/veterinária , Feminino , Qualidade dos Alimentos , Lactação , Ubiquinona/análogos & derivados , Ubiquinona/análise , alfa-Tocoferol/análise , beta Caroteno/análise
5.
Ann Clin Biochem ; 50(Pt 6): 558-63, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23847034

RESUMO

BACKGROUND: The mechanism surrounding bone suppression after a meal may involve several mediators, but is yet to be clarified. Bile acids (BA) function as signalling molecules in response to feeding, and may be directly involved in bone suppression acutely after a meal. The aim of this study was to test the hypothesis that BA are involved in the acute bone suppression observed after a meal. METHODS: A prospective study in which samples collected from volunteers fed a 400 Kcal test meal after an overnight fast were analysed for parathyroid hormone (PTH), BA, and carboxyterminal of type 1 collagen telopeptide (CTX). The study was carried out in 10 healthy male volunteers. Ethical approval was obtained from the Local Research and Ethics Committee at King's College Hospital. RESULTS: Total BA, glycine conjugated bile acids (GCBA), PTH and CTX showed a response to meal ingestion. There was a negative correlation between percentage change in PTH and CTX (R (2 )= -0.82, P = 0.004), and between PTH and GCBA (R (2 )= -0.39, P = 0.005). CONCLUSION: This study demonstrated an association between GCBA and PTH suppression after a meal. The drop in PTH concentration after a meal may be responsible for the suppression of bone resorption as observed by the decrease in CTX concentration.


Assuntos
Ácidos e Sais Biliares/sangue , Reabsorção Óssea/sangue , Voluntários Saudáveis , Período Pós-Prandial , Reabsorção Óssea/fisiopatologia , Colágeno Tipo I/química , Humanos , Masculino , Hormônio Paratireóideo/sangue , Fragmentos de Peptídeos/sangue , Adulto Jovem
6.
Ann Clin Biochem ; 49(Pt 6): 589-94, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23065529

RESUMO

BACKGROUND: Obesity is associated with hypertension, but the exact mechanism is not fully understood. Bariatric surgery significantly decreases weight and blood pressure (BP). Low plasma nitric oxide (NO) and raised asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NO, concentrations are associated with both obesity and hypertension. Correlations between the changes in these parameters were studied after bariatric surgery. METHODS: Weight, BP, plasma ADMA and NO were measured in 29 obese patients (24 female, 5 male) before and six weeks after bariatric surgery. RESULTS: Patients were 39.2 ± 1.2 (mean ± SEM) years old and weighed 126 ± 3 kg. Six weeks after the surgery, patients had lost 10 ± 0.7 kg (P < 0.0001) and mean arterial pressure (MAP) decreased by 11 ± 1.0 mmHg (P < 0.0001). The plasma ADMA concentration decreased by 24 ± 2% from 5 ± 0.4 to 4.0 ± 0.3 µmol/L (P < 0.0001). The plasma total nitrite concentration increased by 15 ± 1% from 51.4 ± 2.6 to 60 ± 3 µmol/L (P < 0.0001). The correlation between the decrease of ADMA and increase of NO subsequent to weight loss was significant (P < 0.0001). However, MAP was not correlated to the changes in ADMA or NO. CONCLUSIONS: After bariatric surgery, beneficial changes in BP, NO and ADMA occur, but our findings suggest that these BP changes are independent of changes in the NO-ADMA axis. Other causes for the changes in BP should therefore be considered.


Assuntos
Arginina/análogos & derivados , Cirurgia Bariátrica , Pressão Sanguínea , Óxido Nítrico/sangue , Arginina/sangue , Feminino , Humanos , Masculino , Obesidade Mórbida/cirurgia , Redução de Peso
7.
Curr Med Res Opin ; 22(2): 405-15, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16466613

RESUMO

BACKGROUND: Many studies have investigated the prevalence of 25-hydroxy-vitamin D inadequacy throughout the world and found a high prevalence of 25-hydroxy-vitamin D inadequacy in older patients, particularly those with fragility fracture. SCOPE: To review the findings from vitamin D audits from six units across the UK and compare with previously published data from around the world. Results from four units have been previously published (Belfast, Glasgow, London and Medway) and this paper presents new data from Southampton and Carshalton, and further sub-analysis of the data from Medway. FINDINGS: Three audits of patients attending metabolic bone clinics (Carshalton, Medway and Southampton) identified 954 patients, of which overall 49% had a prior fragility fracture. Mean 25-hydroxy-vitamin D levels ranged from 47.7 nmol/L to 62.4 nmol/L. Of these patients 72.9-88.9% had a 25-hydroxy-vitamin D level < 80 nmol/L, 68.8-83.3% < 70 nmol/L and 37.5-59.1% < 50 nmol/L. The mean age of patients ranged from 60.0 to 67.5 years. Sub-analysis of the data by fracture status revealed that patients with fracture had lower mean levels of 25-hydroxy-vitamin D compared with patients without fracture. This was statistically significant in the sub-analysis of the Medway data (45.3 nmol/L versus 49.9 nmol/L, p < 0.005). Three audits identified 330 patients with fragility fracture. Audits from Glasgow and Belfast specifically identified patients with fragility fracture. A subgroup of patients with fracture aged over 50 years from the Medway audit was also included in this group. Mean levels of 25-hydroxy-vitamin D ranged from 40.0 nmol/L to 52.3 nmol/L. 83.7-96.4% of patients had a 25-hydroxy-vitamin D level < 80 nmol/L, 73.3-89.7% < 70 nmol/L and 55.8-73.2% < 50 nmol/L. The mean age of patients ranged from 65.3 to 68.6 years. The audits carried out in Belfast and Medway were also divided by supplementation status. Mean 25-hydroxy-vitamin D levels were 48.1 nmol/L in Belfast and 40.5 nmol/L in Medway in the patients not receiving supplements and 53.8 nmol/L and 59.9 nmol/L, respectively in the patients receiving supplements. The difference was statistically significant in the Medway audit (p < 0.0001), but not in the smaller Belfast audit (p = 0.216). As would be expected, the prevalence of 25-hydroxy-vitamin D inadequacy was higher in the patients not receiving supplements, for example at the 70 nmol/L threshold: 82.6% versus 67.1% in Belfast and 89.6% versus 72.7% in Medway. Three audits specifically identified 694 patients with hip fracture (Belfast, Glasgow and London). Mean levels of 25-hydroxy-vitamin D ranged from 24.7 nmol/L to 36.1 nmol/L. Of these patients 90.7-99.0% had a 25-hydroxy-vitamin D level < 80 nmol/L, 88.4-98.0% < 70 nmol/L and 81.6-92.7% < 50 nmol/L. The mean age of patients ranged from 73.4 to 80.5 years. CONCLUSION: Inadequate 25-hydroxy-vitamin D levels are extremely common in the elderly and particularly so in patients with fragility fracture - specifically in those with hip fracture. Although the differing audit specifications and assay techniques used make direct comparisons difficult, the data do provide a snapshot of 25-hydroxy-vitamin D status across the UK and are consistent with those previously observed elsewhere in Europe and the rest of the world.


Assuntos
Fraturas Ósseas/complicações , Deficiência de Vitamina D/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Auditoria Médica , Prevalência , Estudos Retrospectivos , Reino Unido/epidemiologia , Deficiência de Vitamina D/complicações
8.
Curr Med Res Opin ; 21(12): 1891-4, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16368037

RESUMO

BACKGROUND: It is well established that vitamin D levels are suboptimal in the elderly and that adults with fragility fracture are more likely to have serum vitamin D levels either lower than those of control patients of similar age, or below the normal range. OBJECTIVES: To investigate the prevalence of vitamin D inadequacy in an elderly population with hip fractures from London (UK) and compare levels with data previously presented from Glasgow (UK). RESEARCH DESIGN AND METHODS: A retrospective patient audit was carried out over a 17-month period (September 2003-January 2005). Patient records were searched for hip fracture admissions and cross matched with vitamin D analysis carried out within 3 days of the hip fracture admission. The resulting records were hand searched to exclude patients with a hip fracture resulting from high impact/trauma. RESULTS: There were data for 103 hip fracture patients, 79.6% of the patients were women (n = 82). The mean age at the time of fracture was 73.4 years, 100% were aged 60 years or over and 41% were aged 75 years or over. Around 20% of the patients were receiving supplementation with calcium and/or vitamin D and were not excluded from the analysis. The mean vitamin D level was 32.1 nmol/L (12.9 ng/mL), SD = 19.4 (7.8), however, it is likely that the true mean is lower since in approximately 15% of cases vitamin D levels were reported as < 12.5 nmol/L, but were transcribed at 12.5 nmol/L in order to allow a numerical value to be calculated. Ninety-nine per cent of patients had a vitamin D level < 80 nmol/L, 94.2% < 70 nmol/L and 81.6% < 50 nmol/L. There were no significant differences by patient age or sex, however, there were significant seasonal differences in vitamin D. In the year from September 2003 to August 2004, 82.8% of summer admissions had vitamin D levels < 70 nmol/L compared with 98.0% in winter (p = 0.04). Mean vitamin D levels in the 30 patients with parathyroid hormone (PTH) levels above the reference range were significantly lower than levels in the 71 patients within the range: mean 19.9 nmol/L, SD = 16.2 versus mean 37.5 nmol/L, SD = 18.5 (p < 0.0001). Furthermore, 50% of the patients with PTH levels above the reference range had vitamin D levels < 12.5 nmol/L, reflecting extremely low levels of vitamin D. CONCLUSIONS: This study confirms almost universal vitamin D inadequacy among 103 patients admitted to hospital with hip fracture in London, although the prevalence of inadequacy is slightly lower than that seen in a similar study carried out in Glasgow.


Assuntos
Fraturas do Quadril/metabolismo , Osteoporose/complicações , Deficiência de Vitamina D/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoporose/metabolismo , Hormônio Paratireóideo/sangue , Prevalência , Estudos Retrospectivos , Estações do Ano , Fatores Sexuais , Vitamina D/sangue
10.
Aliment Pharmacol Ther ; 19(10): 1063-71, 2004 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-15142195

RESUMO

BACKGROUND: Crohn's disease is associated with reduced bone density. The power of simple markers of systemic inflammation to identify higher rates of bone loss, in Crohn's disease, is uncertain. This relationship and the role of circulating (peripheral blood) mononuclear cells were investigated in a case-control study. METHODS: Urinary deoxypyridinoline/creatinine and serum osteocalcin concentrations were compared in male and premenopausal females with "active" Crohn's disease (C-reactive protein > or = 10 and/or erythrocyte sedimentation rate > or = 20) (n = 22) and controls with "quiescent" Crohn's disease (C-reactive protein < 10 and erythrocyte sedimentation rate < 20) (n = 21). No patients were receiving corticosteroid therapy. Production of tumour necrosis factor-alpha, interferon-gamma and prostaglandin E(2) by peripheral blood mononuclear cells were measured. RESULTS: Active Crohn's disease was associated with a higher deoxypyridinoline/creatinine (P = 0.02) and deoxypyridinoline/creatinine:osteocalcin ratio (P =0.01) compared with quiescent Crohn's disease, but similar osteocalcin (P = 0.24). These were not explained by vitamin D status, dietary intake or nutritional status. However, production of interferon-gamma by concanavalin A-stimulated peripheral blood mononuclear cells was lower in active Crohn's disease (P = 0.02) and correlated negatively with the deoxypyridinoline/creatinine:osteocalcin ratio (r = -0.40, P = 0.004). CONCLUSION: In Crohn's disease, raised C-reactive protein and erythrocyte sedimentation rate may indicate higher rates of bone loss and, if persistent, the need to assess bone mass even where disease symptoms are mild. This may be partly explained by altered production of interferon-gamma by peripheral blood mononuclear cells.


Assuntos
Remodelação Óssea/fisiologia , Proteína C-Reativa/análise , Doença de Crohn/fisiopatologia , Adulto , Sedimentação Sanguínea , Reabsorção Óssea/fisiopatologia , Estudos de Casos e Controles , Citocinas/metabolismo , Feminino , Humanos , Masculino , Estado Nutricional , Osteocalcina/metabolismo , Prostaglandinas/metabolismo
11.
Aliment Pharmacol Ther ; 19(5): 563-70, 2004 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-14987325

RESUMO

BACKGROUND: Retrospective studies have suggested that hormone replacement therapy may reduce the rate of bone loss in primary biliary cirrhosis, but no controlled data are available. METHODS: Forty-two post-menopausal women with primary biliary cirrhosis were treated with calcium and vitamin D, either alone (n = 21) or together with transdermal hormone replacement therapy (n = 21). Bone densitometry was performed at baseline and at 1 year, and serum and urinary markers of bone turnover were measured at three-monthly intervals. RESULTS: At entry, 17 patients (40%) had spinal or femoral osteopenia (T score - 1 to - 2.5) and nine (21%) had osteoporosis (T < - 2.5). In those given hormone replacement therapy, there was a significant decrease in the mean urinary deoxypyridinoline :creatinine ratios at 3 months (7.8 vs. 6.1 nm/mm creatinine for no hormone replacement therapy vs. hormone replacement therapy; P = 0.04) and a 48% reduction in urinary calcium excretion at 1 year (0.66 vs. 0.32 mm/mm creatinine; P = 0.01). Repeat bone densitometry at 1 year revealed a 2.25% increase in the hormone replacement therapy group (P = 0.02), compared with a non-significant 0.87% decrease in L2-L4 bone mineral density in those not given hormone replacement therapy. Both treatment regimens were well tolerated, with no increase in cholestasis. CONCLUSIONS: Compared with calcium and vitamin D alone, supplemental treatment with transdermal hormone replacement therapy for 1 year improved the vertebral bone density and urinary markers of bone turnover in post-menopausal women with primary biliary cirrhosis.


Assuntos
Densidade Óssea/efeitos dos fármacos , Terapia de Reposição Hormonal/métodos , Cirrose Hepática Biliar/tratamento farmacológico , Administração Cutânea , Idoso , Aminoácidos/urina , Remodelação Óssea/efeitos dos fármacos , Feminino , Terapia de Reposição Hormonal/efeitos adversos , Humanos , Cirrose Hepática Biliar/fisiopatologia , Pessoa de Meia-Idade , Estudos Prospectivos
12.
Bone ; 33(4): 549-56, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14555258

RESUMO

The objective of the study was to investigate bone strength at four different skeletal sites in a chronic animal model of urinary diversion. Young male Wistar rats (120) were allocated randomly to four groups undergoing ileocystoplasty; ileocystoplasty and resection of the ileocecal segment; colocystoplasty; or sham operation (controls). After 8 months the lumbar vertebrae, femora, and tibiae were harvested at necropsy. Bone strength was assessed biomechanically at four different skeletal sites: vertebra L3, femoral middiaphysis, femoral neck, and distal femoral metaphysis. Bone mass and architecture were assessed using standard static histomorphometry of the proximal tibial metaphysis (trabecular bone volume [BV/TV]; trabecular number [Tb.N]) and ash weight. Statistically significant differences of biomechanical parameters between groups were observed at three skeletal sites with corresponding changes in tibial histomorphometry. Isolated ileocystoplasty resulted in decreased maximum load values of L3 (-16.4%; p < 0.0035) and a substantial reduction in tibial BV/TV (-34.7%; p < 0.05). Ileocystoplasty combined with resection of the ileocecal segment led to a significant loss of bone strength of L3 (-32.4%; p < 0.0015) and a dramatic reduction of tibial BV/TV (-45.9%; p < 0.01). Loss of tibial metaphyseal bone mass was predominantly caused by a decrease in Tb.N. (p < 0.01). Colonic augmentation had no significant effect on bone strength or histomorphometric values. In conclusion, this is the first experimental study to demonstrate the relevance of histomorphometrically proven bone loss after enterocystoplasty in terms of biomechanical variables.


Assuntos
Osso e Ossos/fisiologia , Derivação Urinária/efeitos adversos , Acidose/complicações , Animais , Fenômenos Biomecânicos , Densidade Óssea , Masculino , Osteoporose/etiologia , Ratos , Ratos Wistar , Derivação Urinária/métodos
13.
BJU Int ; 92(3): 306-13, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12887489

RESUMO

OBJECTIVE: To investigate skeletal growth and bone metabolism in a chronic animal model of urinary diversion. MATERIALS AND METHODS: Young male Wistar rats (120) were allocated randomly to four groups undergoing: ileocystoplasty, ileocystoplasty and resection of the ileocaecal segment, colocystoplasty, and controls. All animals received antibiotics for 1 week after surgery; half of each group remained on oral antibiotics. Bone-related biochemistry was measured in serum and urine. Dual-energy X-ray absorptiometry and peripheral quantitative computed tomography (pQCT) were used to determine bone mass ex vivo. RESULTS: Most (90%) of the rats survived the study period (8 months); six rats died from bowel obstruction at the level of the entero-anastomosis and four had to be killed because of persistent severe diarrhoea. Vital intestinal mucosa was found in all augmented bladders. There were no differences in bone length and volume. Loss of bone mass was almost exclusively in rats with ileocystoplasty and resection of the ileocaecal segment (-37.5%, pQCT, P < 0.01). There was no hyperchloraemic metabolic acidosis or gross impairment of renal function. Hypomagnesaemia, hypocalcaemia and decreased insulin-like growth factor-binding protein 3 were the only significant findings on blood analysis. Deoxypyridinoline crosslinks in urine were higher in rats with an enterocystoplasty than in controls. CONCLUSIONS: Enterocystoplasty in rats neither impairs skeletal growth nor bone quantity, but leads to significant loss of bone mass when combined with resection of the ileocaecal segment. Rarefaction of the trabecular network is confined to the metabolically highly active cancellous compartment, most likely as a consequence of intestinal malabsorption.


Assuntos
Desenvolvimento Ósseo/fisiologia , Remodelação Óssea/fisiologia , Osso e Ossos/metabolismo , Bexiga Urinária/cirurgia , Absorciometria de Fóton , Animais , Densidade Óssea , Creatinina/sangue , Eletrólitos/sangue , Enzimas/sangue , Masculino , Ratos , Ratos Wistar , Albumina Sérica/análise , Derivação Urinária
14.
Aliment Pharmacol Ther ; 16(11): 1895-902, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12390098

RESUMO

AIM: To establish whether bone disease is present at diagnosis in inflammatory bowel disease and to identify contributory metabolic abnormalities. METHODS: Newly diagnosed patients with inflammatory bowel disease (19 males, 15 females; mean age, 44 years; range, 17-79 years; 23 ulcerative colitis, 11 Crohn's disease) were compared against standard reference ranges and a control group with irritable bowel syndrome (eight males, 10 females; mean age, 40 years; range, 19-64 years). Bone mineral density (g/cm2, dual-energy X-ray absorptiometry: lumbar spine and femoral neck) and biochemical bone markers were measured. RESULTS: Femoral neck bone mineral density, T- and Z-scores (mean +/- s.d., respectively) were lower in inflammatory bowel disease patients than in irritable bowel syndrome controls (0.78 +/- 0.12 vs. 0.90 +/- 0.16, P = 0.0046; - 0.88 +/- 0.92 vs. 0.12 +/- 1.17, P = 0.0018; - 0.30 +/- 0.89 vs. 0.61 +/- 1.10, P = 0.0030). Lumbar spine bone mineral density and T-scores were also significantly lower in patients than controls (0.98 +/- 0.15 vs. 1.08 +/- 0.13, P = 0.0342; - 1.05 +/- 1.39 vs. - 0.14 +/- 1.19, P = 0.0304). Compared with controls, the urinary deoxypyridinoline : creatinine ratio was increased (7.66 vs. 5.70 nmol/mmol, P = 0.0163) and serum 25-hydroxy vitamin D was decreased (18.7 vs. 28.5 micro g/L, P = 0.0016); plasma osteocalcin and serum parathyroid hormone did not differ (P > 0.05). CONCLUSIONS: The bone mineral density is reduced at diagnosis, prior to corticosteroid treatment, in both Crohn's disease and ulcerative colitis. Our data suggest that this is attributable to increased resorption rather than decreased bone formation.


Assuntos
Doenças Ósseas Metabólicas/etiologia , Doenças Inflamatórias Intestinais/complicações , Adolescente , Adulto , Idoso , Biomarcadores/análise , Densidade Óssea , Doenças Ósseas Metabólicas/fisiopatologia , Estudos de Casos e Controles , Colite Ulcerativa/complicações , Colite Ulcerativa/fisiopatologia , Doenças Funcionais do Colo/complicações , Doenças Funcionais do Colo/fisiopatologia , Doença de Crohn/complicações , Doença de Crohn/fisiopatologia , Feminino , Colo do Fêmur/fisiopatologia , Humanos , Doenças Inflamatórias Intestinais/fisiopatologia , Vértebras Lombares/fisiopatologia , Masculino , Pessoa de Meia-Idade
15.
Rheumatology (Oxford) ; 41(9): 1047-51, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12209040

RESUMO

OBJECTIVE: Generalized bone loss in rheumatoid arthritis (RA) is multi-factorial, with the inflammatory disease itself thought to contribute to bone loss. To study the extent to which control of disease activity affects bone turnover in RA and whether treatment with disease-modifying anti-rheumatic drugs (DMARDs) reduces bone turnover and loss of bone mass, we measured bone density and biochemical markers of bone resorption in a group of patients with active RA starting on DMARDS. METHODS: Patients with active RA were enrolled on starting a new DMARD. Patients were mobile and none took steroids or any treatment for osteoporosis. Clinical and laboratory measures of disease activity were made at 3-monthly intervals and an index of disease activity (DAS) calculated. Bone density was assessed at 0, 1 and 2 yr (Hologic QDR 4500c). Urinary deoxypyridinoline (D-PYR) and pyridinoline (PYR) were measured by ELISA at 0, 3, 6, 9 and 12 months. RESULTS: Forty patients were enrolled, mean age 59.5 (range 31-76), 26 female, 14 male, 25 had established RA, 15 had RA for <2 yr. Baseline D-PYR was elevated (8.4+/-4.55 nmol/mmol creatinine) and correlated with ESR (r=0.6, P<0.01) and DAS (r=0.4, P<0.05). On treatment ESR and DAS fell by 38.5 and 29.3%, respectively. D-PYR was reduced by 12.3% by 9 months (P<0.01). Spearman rank order correlation showed ESR to be the most significant determinant of D-PYR over 1 yr (r=0.43, P<0.001). Serial bone density was available on 21 patients. There was no significant change in BMD over the 2 yr. The change in DAS over 0-3 months showed an inverse relationship with the percent change in spine over 1 yr (r=-0.5, P=0.05). The change in D-PYR over 0-3 months was not closely related to the change in BMD at hip or spine at 1 yr. CONCLUSION: Disease activity is a significant determinant of bone turnover in RA. Bone resorption markers fall on treatment of RA with DMARDs and no change in BMD was demonstrated at 2 yr. This study suggests the need to control disease activity in RA in order to prevent systemic bone loss.


Assuntos
Antirreumáticos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Artrite Reumatoide/fisiopatologia , Densidade Óssea/fisiologia , Remodelação Óssea/fisiologia , Osteoporose/tratamento farmacológico , Osteoporose/fisiopatologia , Absorciometria de Fóton , Adulto , Idoso , Artrite Reumatoide/sangue , Biomarcadores/sangue , Feminino , Humanos , Ílio/diagnóstico por imagem , Ílio/metabolismo , Masculino , Pessoa de Meia-Idade , Osteoporose/sangue , Dor/fisiopatologia , Medição da Dor , Estudos Prospectivos , Índice de Gravidade de Doença , Coluna Vertebral/diagnóstico por imagem , Coluna Vertebral/metabolismo
16.
J Bone Miner Res ; 17(5): 891-7, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12009020

RESUMO

Vitamin D and calcium supplementation significantly reduces the incidence of fractures. Evidence suggests vitamin D deficiency impairs neuromuscular function, causing an increase in falls and thereby fractures. The relationship between vitamin D, functional performance, and psychomotor function in elderly people who fall was examined in a prospective cross-sectional study. Patients were recruited from a falls clinic and stratified according to serum 25-hydroxyvitamin-D levels (25OHD): group 1, 25OHD < 12 microg/liter; group 2 25OHD, 12-17 microg/liter; and group 3, 25OHD > 17 microg/liter. Healthy elderly volunteers with 25OHD > 17 microg/liter comprised group 4 (n = 20/group). Measures included aggregate functional performance time (AFPT, seconds), isometric quadriceps strength (Newtons), postural sway (degrees), and choice reaction time (CRT, seconds). Serum bone biochemistry, 25OHD, and parathyroid hormone levels were measured. Patients who fell had significantly impaired functional performance, psychomotor function, and quadriceps strength compared with healthy subjects (AFPT: 51.0 s vs. 32.8 s,p < 0.05; CRT: 1.66 s vs. 0.98 s,p < 0.05; strength: 223N vs. 271N, t = 2.35, p = 0.02). Group 1 had significantly slower AFPT (66.0 s vs. 44.8 s, t = 4.15, p < 0.05) and CRT (2.37 s vs. 0.98 s, t = 3.59, p < 0.05) than groups 2 and 3. Group 1 had the greatest degree of postural sway and the weakest quadriceps strength, although this did not reach significance. Multivariate analysis revealed 25OHD as an independent variable for AFPT, CRT, and postural sway. PTH was an independent variable for muscle strength. Older people who fall have impaired functional performance, psychomotor function, and muscle strength. Within this group, those with 25OHD < 12 microg/liter are the most significantly affected.


Assuntos
Acidentes por Quedas , Calcifediol/sangue , Desempenho Psicomotor/fisiologia , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Estudos Transversais , Humanos , Contração Muscular/fisiologia , Junção Neuromuscular/fisiopatologia , Postura/fisiologia , Estudos Prospectivos , Tempo de Reação/fisiologia
17.
Bone ; 29(3): 209-15, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11557363

RESUMO

We report the development of an assay for measurement of the urinary concentration of collagen type II C-telopeptide fragments. This assay was developed for providing a specific marker of joint metabolism. A monoclonal antibody, recognizing a linear six amino acid epitope from the middle region of the collagen type II C-telopeptide was used in a competitive enzyme-linked immunoassay (ELISA) format for measurement of urine samples. The technical performance and specificity of the assay was evaluated and a panel of samples from patients with rheumatoid arthritis (RA) (n = 27), osteoarthritis (OA) (n = 29), Paget's disease (n = 9), and healthy controls (n = 428) was measured in the assay. The ELISA was specific for the peptide EKGPDP derived from collagen type II C-telopeptide: it did not recognize peptides from the N-telopeptide of the molecule or from other collagen types. Collagen type II C-telopeptide fragments measured in the assay resisted seven freeze-thaw cycles and >20 h of storage at room temperature. RA and OA patients showed significant 2.33-fold (95% confidence interval [CI] 1.50-3.16) and 1.53-fold (CI 1.24-1.82) elevations in CartiLaps concentration, respectively. Paget's disease patients did not have elevated CartiLaps levels. RA patients with radiological evidence of cartilage damage had significantly higher (1.79-fold, CI 1.04-2.54) CartiLaps levels than RA patients without radiological evidence of cartilage destruction. The Cartilaps assay showed high technical precision and an ability to differentiate populations with an elevated joint metabolism from normal controls. This suggests that the assay may have clinical value in assisting in the diagnosis of joint diseases and in monitoring progression and therapy in RA and OA.


Assuntos
Artrite Reumatoide/urina , Cartilagem/patologia , Colágeno Tipo II/análise , Osteoartrite/urina , Animais , Anticorpos Monoclonais , Especificidade de Anticorpos , Artrite Reumatoide/patologia , Biomarcadores , Células Cultivadas , Ritmo Circadiano , Colágeno/análise , Colágeno/imunologia , Colágeno/urina , Colágeno Tipo I , Colágeno Tipo II/imunologia , Colágeno Tipo II/urina , Ensaio de Imunoadsorção Enzimática , Feminino , Técnicas In Vitro , Camundongos , Camundongos Endogâmicos BALB C , Osteíte Deformante/patologia , Osteíte Deformante/urina , Osteoartrite/patologia , Osteoclastos/química , Osteoclastos/citologia , Fragmentos de Peptídeos/análise , Fragmentos de Peptídeos/imunologia , Fragmentos de Peptídeos/urina , Peptídeos/análise , Peptídeos/imunologia , Peptídeos/urina , Coelhos
18.
Med Health R I ; 84(1): 10-4, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11210282

RESUMO

Results from this survey need to be viewed within the context of the small number of responses (20%), which may not fully represent the knowledge base of all house officers. Recommendations established by the Agency for Health Care Policy and Research (AHCPR) define standards of care for acute and chronic pain management and address many of the problems seen nationally with meperidine and its metabolite, normeperidine. Data from this survey have assisted us in providing educational programs which are in line with these guidelines for house officers.


Assuntos
Analgésicos Opioides/uso terapêutico , Meperidina/uso terapêutico , Entorpecentes/uso terapêutico , Padrões de Prática Médica , Analgésicos Opioides/farmacocinética , Humanos , Meperidina/farmacocinética , Entorpecentes/farmacocinética , Dor Pós-Operatória/prevenção & controle , Inquéritos e Questionários
19.
J Rheumatol ; 27(10): 2424-31, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11036840

RESUMO

OBJECTIVE: To conduct a pooled data analysis in a group of patients defined by sex, menopausal status, and underlying disease in order to examine the effect of intermittent cyclical etidronate in the prevention and treatment of corticosteroid induced osteoporosis. METHODS: We selected 5 randomized, placebo controlled studies that examined the efficacy of intermittent cyclical etidronate therapy in which the raw data were available for analysis. Three were prevention studies and 2 treatment studies. The primary outcome was the difference between treatment groups in the percentage change from baseline in lumbar spine bone density. Secondary outcomes included the difference between treatment groups in the percentage change from baseline in femoral neck and trochanter bone density, and vertebral fracture rates. RESULTS: Results are separately pooled for the prevention and treatment studies. The prevention studies had significant mean differences (95% CI) between groups in mean percentage change from baseline in lumbar spine, femoral neck, and trochanter bone density of 3.7 (2.6 to 4.7), 1.7 (0.4 to 2.9), and 2.8% (1.3 to 4.2) after one year of treatment, in favor of the etidronate group. The treatment studies displayed a mean difference between groups in mean percentage change from baseline in lumbar spine bone density of 4.8 (2.7 to 6.9) and 5.4% (2.5 to 8.4) after one and 2 years of therapy. In the prevention studies, a reduced fracture incidence was observed in the etidronate group compared with the placebo group (relative risk 0.50; CI 0.21 to 1.19). CONCLUSION: Etidronate therapy was effective in preventing bone loss in the prevention studies and in preventing or slightly increasing bone mass in the treatment studies. A fracture benefit was observed in postmenopausal women treated with etidronate in the prevention studies.


Assuntos
Ácido Etidrônico/administração & dosagem , Osteoporose/prevenção & controle , Adulto , Idoso , Idoso de 80 Anos ou mais , Densidade Óssea/efeitos dos fármacos , Método Duplo-Cego , Esquema de Medicação , Feminino , Glucocorticoides/efeitos adversos , Humanos , MEDLINE , Masculino , Pessoa de Meia-Idade , Osteoporose/induzido quimicamente , Ensaios Clínicos Controlados Aleatórios como Assunto , Fraturas da Coluna Vertebral/prevenção & controle
20.
Am J Med ; 109(4): 267-76, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10996576

RESUMO

PURPOSE: We conducted a 5-year, double-blind, randomized, placebo-controlled study to determine whether salmon calcitonin nasal spray reduced the risk of new vertebral fractures in postmenopausal women with osteoporosis. SUBJECTS AND METHODS: A total of 1,255 postmenopausal women with established osteoporosis were randomly assigned to receive salmon calcitonin nasal spray (100, 200, or 400 IU) or placebo daily. All participants received elemental calcium (1,000 mg) and vitamin D (400 IU) daily. Vertebral fractures were assessed with lateral radiographs of the spine. The primary efficacy endpoint was the risk of new vertebral fractures in the salmon calcitonin nasal spray 200-IU group compared with the placebo group. RESULTS: During 5 years, 1,108 participants had at least one follow-up radiograph. A total of 783 women completed 3 years of treatment, and 511 completed 5 years. The 200-IU dose of salmon calcitonin nasal spray significantly reduced the risk of new vertebral fractures by 33% compared with placebo [200 IU: 51 of 287, placebo: 70 of 270, relative risk (RR) = 0.67, 95% confidence interval (CI): 0.47- to 0.97, P = 0.03]. In the 817 women with one to five prevalent vertebral fractures at enrollment, the risk was reduced by 36% (RR = 0.64, 95% CI: 0.43- to 0.96, P = 0.03). The reductions in vertebral fractures in the 100-IU (RR = 0.85, 95% CI: 0.60- to 1.21) and the 400-IU (RR = 0.84, 95% CI: 0.59- to 1.18) groups were not significantly different from placebo. Lumbar spine bone mineral density increased significantly from baseline (1% to 1. 5%, P<0.01) in all active treatment groups. Bone turnover was inhibited, as shown by suppression of serum type-I collagen cross-linked telopeptide (C-telopeptide) by 12% in the 200-IU group (P <0.01) and by 14% in the 400-IU group (P<0.01) as compared with placebo. CONCLUSION: Salmon calcitonin nasal spray at a dose of 200 IU daily significantly reduces the risk of new vertebral fractures in postmenopausal women with osteoporosis.


Assuntos
Densidade Óssea/efeitos dos fármacos , Calcitonina/administração & dosagem , Fraturas Espontâneas/prevenção & controle , Osteoporose Pós-Menopausa/tratamento farmacológico , Fraturas da Coluna Vertebral/prevenção & controle , Idoso , Análise de Variância , Distribuição de Qui-Quadrado , Método Duplo-Cego , Feminino , Fraturas Espontâneas/epidemiologia , Fraturas Espontâneas/etiologia , Humanos , Pessoa de Meia-Idade , Cavidade Nasal , Osteoporose Pós-Menopausa/complicações , Osteoporose Pós-Menopausa/diagnóstico , Valores de Referência , Prevenção Secundária , Fraturas da Coluna Vertebral/epidemiologia , Fraturas da Coluna Vertebral/etiologia , Resultado do Tratamento
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