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1.
Int J Colorectal Dis ; 34(10): 1763-1769, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31506799

RESUMO

PURPOSE: Recurrent prolapse of the posterior pelvic organ compartment presents a management challenge, with the best surgical procedure remaining unclear. We present functional outcome and patient satisfaction after laparoscopic and robotic ventral mesh rectopexy (VMR) with biological mesh in patients with recurrence. METHODS: We analyzed data from 30 patients with recurrent posterior pelvic organ prolapse who underwent VMR with biological mesh from August 2012 to January 2018. Data included patient demographics and intra- and postoperative findings; functional outcome as assessed by Cleveland Clinic Constipation Score (CCCS), Obstructed Defecation Score Longo (ODS), and Cleveland Clinic Incontinence Score (CCIS); and patient satisfaction. RESULTS: CCCS, CCIS, and ODS were significantly improved at 6-12 months postoperatively and at last follow-up. Patient satisfaction (visual analog scale [VAS] 6.7 [0 to 10]), subjective symptoms (+ 3.4 [scale - 5 to + 5]), and quality of life improvement (+ 3.0 [scale from - 5 to + 5]) were high at last follow-up. The rates of morbidity and major complications were 13% and 3%, respectively. There were no mesh-related complications or deaths. Difference in type of previous surgery (abdominal or transanal/perineal) had no significant effect on results. CONCLUSIONS: VMR with biological mesh is a safe and effective option for patients with recurrent posterior pelvic organ prolapse. It reduces functional symptoms, has a low complication rate, and promotes patient satisfaction.


Assuntos
Prolapso de Órgão Pélvico/cirurgia , Reto/cirurgia , Telas Cirúrgicas , Adulto , Idoso , Idoso de 80 Anos ou mais , Defecografia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Prolapso de Órgão Pélvico/diagnóstico por imagem , Complicações Pós-Operatórias/etiologia , Reto/diagnóstico por imagem , Recidiva , Resultado do Tratamento
2.
Int J Colorectal Dis ; 33(4): 449-457, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29442156

RESUMO

PURPOSE: Ventral mesh rectopexy (VMR) is an established, minimally invasive, nerve-sparing procedure for the treatment of various symptomatic morphological changes in the posterior pelvic compartment. We present the short-term functional outcome and patient satisfaction after laparoscopic and robotic VMR with biological mesh. METHODS: We analyzed data from 123 patients who underwent laparoscopic ventral mesh rectopexy (LVMR) or robotic ventral mesh rectopexy (RVMR) from August 2012 to January 2017. Included in these data were patient demographics, intra- and postoperative findings, Cleveland Clinic Constipation Score (CCCS), Obstructed Defecation Score Longo (ODS), Cleveland Clinic Incontinence Score (CCIS), and patient satisfaction as measured by visual analog scale (0-10). RESULTS: Improvements in CCCS, CCIS, and ODS were statistically significant at 6 and 12 months (p < 0.001). Patient satisfaction was excellent at 6 and 12 months (8.2/10 and 8.3/10, respectively). The overall complication rate was 14%, with a major complication rate of 2%. No mesh-related complications were observed. The need for surgical re-intervention because of relapse, symptom persistence or recurrence, or new symptoms was 3%. Outcome appears to be similar between LVMR and RVMR. CONCLUSIONS: Both LVMR and RVMR with biological mesh are safe and effective in reducing symptoms, as measured by CCCS, CCIS, and ODS, and patient satisfaction is high.


Assuntos
Procedimentos Cirúrgicos do Sistema Digestório , Reto/cirurgia , Telas Cirúrgicas , Idoso , Idoso de 80 Anos ou mais , Constipação Intestinal/fisiopatologia , Demografia , Procedimentos Cirúrgicos do Sistema Digestório/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Complicações Pós-Operatórias/etiologia , Reto/fisiopatologia , Recidiva , Resultado do Tratamento , Adulto Jovem
3.
Phys Chem Chem Phys ; 18(18): 12733-41, 2016 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-27098151

RESUMO

The model reaction of photoinduced donor-acceptor interaction in linked systems (dyads) has been used to study the comparative reactivity of a well-known anti-inflammatory drug, (S)-naproxen (NPX) and its (R)-isomer. (R)- or (S)-NPX in these dyads is linked to (S)-N-methylpyrrolidine (Pyr) using a linear or cyclic amino acid bridge (AA or CyAA), to give (R)-/(S)-NPX-AA-(S)-Pyr flexible and (R)-/(S)-NPX-CyAA-(S)-Pyr rigid dyads. The donor-acceptor interaction is reminiscent of the binding (partial charge transfer, CT) and electron transfer (ET) processes involved in the extensively studied inhibition of the cyclooxygenase enzymes (COXs) by the NPX enantiomers. Besides that, both optical isomers undergo oxidative metabolism by enzymes from the P450 family, which also includes ET. The scheme proposed for the excitation quenching of the (R)- and (S)-NPX excited state in these dyads is based on the joint analysis of the chemically induced dynamic nuclear polarization (CIDNP) and fluorescence data. The (1)H CIDNP effects in this system appear in the back electron transfer in the biradical-zwitterion (BZ), which is formed via dyad photoirradiation. The rate constants of individual steps in the proposed scheme and the fluorescence quantum yields of the local excited (LE) states and exciplexes show stereoselectivity. It depends on the bridge's length, structure and solvent polarity. The CIDNP effects (experimental and calculated) also demonstrate stereodifferentiation. The exciplex quantum yields and the rates of formation are larger for the dyads containing (R)-NPX, which let us suggest a higher contribution from the CT processes with the (R)-optical isomer.


Assuntos
Anti-Inflamatórios não Esteroides/química , Naproxeno/química , Aminoácidos/química , Transporte de Elétrons , Luz , Modelos Moleculares , Processos Fotoquímicos , Pirrolidinas/química , Espectrometria de Fluorescência , Estereoisomerismo
4.
Eur J Clin Nutr ; 70(7): 790-4, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26508463

RESUMO

BACKGROUND/OBJECTIVES: Plasma ghrelin secretion over time in humans is characterized by pre-prandial increases and by post-prandial decreases all day long. However, some authors who measured ghrelin concentrations around meals showed a rise in plasma ghrelin concentration after meal initiation followed by the typical post-prandial decrease. In order to confirm this observation that has never been discussed, we described ghrelin profiles around four eating episodes in the morning in adult men. SUBJECTS/METHODS: Twenty normal-weight and 17 obese men were instructed to eat four fixed meals (706 kJ) 10 min long at 0800 h, 0900 h, 1000 h and 1100 h. Using frequent blood sampling, we determined plasma acyl-ghrelin concentrations around those eating episodes. Glucose, insulin and GLP-1 concentrations were also measured. RESULTS: The meals consumption induced a significant increase in plasma acyl-ghrelin concentrations 10 min after meal initiation (P<0.0001): +20.9±5.8 and +10.7±3.3 pg/ml in normal-weight and obese subjects for the first meal; +10.4±3.0 and +5.5±3.9 pg/ml in normal-weight and obese subjects for the second meal; +12.4±3.6 and +4.2±2.1 pg/ml in normal-weight and obese subjects for the third meal; and +4.4±4.1 and +3.3±2.61 pg/ml in normal-weight and obese subjects for the fourth meal. CONCLUSIONS: This study is the first to describe and discuss the post-meal initiation ghrelin increase. This finding is consistent in normal-weight and obese individuals.


Assuntos
Ingestão de Alimentos/fisiologia , Jejum/fisiologia , Grelina/sangue , Refeições/fisiologia , Adulto , Glicemia/metabolismo , Índice de Massa Corporal , Peptídeo 1 Semelhante ao Glucagon/sangue , Humanos , Insulina/sangue , Masculino , Obesidade/sangue , Período Pós-Prandial , Valores de Referência
5.
Phys Rev Lett ; 115(15): 156403, 2015 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-26550738

RESUMO

Raman scattering experiments on stoichiometric, Mott-insulating LaTiO_{3} over a wide range of excitation energies reveal a broad electronic continuum which is featureless in the paramagnetic state, but develops a gap of ~800 cm^{-1} upon cooling below the Néel temperature T_{N}=146 K. In the antiferromagnetic state, the spectral weight below the gap is transferred to well-defined spectral features due to spin and orbital excitations. Low-energy phonons exhibit pronounced Fano anomalies indicative of strong interaction with the electron system for T>T_{N}, but become sharp and symmetric for T

6.
J Occup Environ Med ; 57(6): 643-8, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25647318

RESUMO

PURPOSE: This study explores how highly correlated time variables (occupational cohort time scales) contribute to confounding and ambiguity of interpretation. METHODS: Occupational cohort time scales were identified and organized through simple equations of three time scales (relational triads) and the connections between these triads (time scale web). The behavior of the time scales was examined when constraints were imposed on variable ranges and interrelationships. RESULTS: Constraints on a time scale in a triad create high correlations between the other two time scales. These correlations combine with the connections between relational triads to produce association paths. High correlation between time scales leads to ambiguity of interpretation. CONCLUSIONS: Understanding the properties of occupational cohort time scales, their relational triads, and the time scale web is helpful in understanding the origins of otherwise obscure confounding bias and ambiguity of interpretation.


Assuntos
Estudos de Coortes , Fatores de Confusão Epidemiológicos , Doenças Profissionais/epidemiologia , Saúde Ocupacional , Fatores Etários , Berílio/efeitos adversos , Modificador do Efeito Epidemiológico , Humanos , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/mortalidade , Exposição Ocupacional
7.
J Occup Environ Med ; 57(2): 184-7, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25427172

RESUMO

OBJECTIVE: To describe how smoking correction factors based on comparing worker smoking prevalence with population smoking prevalence are biased if applied to an occupational incidence cohort. METHODS: Relative rates of smoking for shorter-tenure workers derived from occupational cohort lung cancer studies were applied to incidence and prevalence population tenure distributions to calculate relative smoking estimates. RESULTS: High smoking rates in short-tenure workers have little effect on prevalent worker rates (relative smoking estimates, 1.04 and 1.02) and much larger effect in occupational incidence populations (relative smoking estimates, 1.58 and 1.21), which have a much higher proportion of short tenure-workers. CONCLUSIONS: Smoking correction estimates derived from surveys of smoking habits in prevalent workers may introduce bias when applied to incidence workers because of very different proportions of short-tenure workers (length-time biased sampling).


Assuntos
Emprego/estatística & dados numéricos , Neoplasias Pulmonares/mortalidade , Doenças Profissionais/mortalidade , Fumar/epidemiologia , Viés , Estudos de Coortes , Humanos , Incidência , Prevalência , Estatística como Assunto , Fatores de Tempo
8.
Horm Metab Res ; 46(6): 390-6, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24806747

RESUMO

Our aim was to characterize the effects and the underlying mechanisms of the lipid-regulating agent Niaspan(®) on both insulin action and triglyceride decrease in 20 nondiabetic, dyslipidemic men with metabolic syndrome receiving Niaspan(®) (2 g/day) or placebo for 8 weeks in a randomized, cross-over study. The effects on plasma lipid profile were characterized at the beginning and the end of each treatment period; insulin sensitivity was assessed using the 2-step euglycemic hyperinsulinemic clamp and VLDL-triglyceride turnover by measuring plasma glycerol enrichment, both at the end of each treatment period. The mechanism of action of nicotinic acid was studied in HuH7 and mouse primary hepatocytes. Lipid profile was improved after Niaspan(®) treatment with a significant-28% decrease in triglyceride levels, a+17% increase in HDL-C concentration and unchanged levels of fasting nonesterified fatty acid. VLDL-tri-glyceride production rate was markedly reduced after Niaspan(®) (-68%). However, the treatment induced hepatic insulin resistance, as assessed by reduced inhibition of endogenous glucose production by insulin (0.7±0.4 vs. 1.0±0.5 mg/kg · min, p<0.05) and decrease in fasting hepatic insulin sensitivity index (4.8±1.8 vs. 3.2±1.6, p<0.05) in the Niaspan(®) condition. Nicotinic acid also reduced insulin action in HuH7 and primary hepatocytes, independently of the activation of hepatic PKCε. This effect was associated with an increase in diacylglycerol and a decrease in tri-glyceride contents that occurred in the absence of modification of DGAT2 expression and activity. Eight weeks of Niaspan(®) treatment in dyslipidemic patients with metabolic syndrome induce hepatic insulin resistance. The mechanism could involve an accumulation of diacylglycerol and an alteration of insulin signaling in hepatocytes.


Assuntos
Insulina/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/metabolismo , Niacina/farmacologia , Animais , Linhagem Celular Tumoral , Diglicerídeos/metabolismo , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Cinética , Lipoproteínas VLDL/metabolismo , Masculino , Camundongos , Pessoa de Meia-Idade , Niacina/administração & dosagem , Proteína Quinase C/antagonistas & inibidores , Proteína Quinase C/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Transdução de Sinais/efeitos dos fármacos , Triglicerídeos/metabolismo
9.
J Orofac Orthop ; 75(3): 226-39, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24825834

RESUMO

BACKGROUND: Primary failure of eruption (PFE) may be associated with pathogenic mutations in the PTHR1 gene. It has numerous manifestations and is characterized by severe posterior open bite. However, there are also phenotypically similar types of eruption anomalies not associated with a known pathogenic PTHR1 mutation. The purpose of this study was to evaluate whether a distinction can be made between PTHR1-mutation carriers and noncarriers based on clinical and radiological findings. PATIENTS AND METHODS: A total of 36 patients with suspected PFE diagnoses were included and analyzed in accordance with specific clinical and radiographic criteria. In addition, all patients underwent Sanger DNA sequencing analysis of all coding sequences (and the immediate flanking intronic sequences) of the PTHR1 gene. RESULTS: Of these patients, 23 exhibited a heterozygous pathogenic mutation in the PTHR1 gene (PTHR1-mutation carriers), while molecular genetic analysis revealed nosequence alteration in the other 13 patients (non-PTHR1-mutation carriers). Relevant family histories were obtained from 5 patients in the carrier group; hence, this group included a total of 13 familial and 10 simplex cases. The group of noncarriers revealed no relevant family histories. All patients in the carrier group met six of the clinical and radiographic criteria explored in this study: (1) posterior teeth more often affected; (2) eruption disturbance of an anterior tooth in association with additional posterior-teeth involvement; (3) affected teeth resorbing the alveolar bone located coronal to them; (4) involvement of both deciduous and permanent teeth; (5) impaired vertical alveolar-process growth; and (6) severe subsequent finding of posterior open bite. None of the analyzed criteria were, by contrast, met by all patients in the noncarrier group. All patients in the carrier group could be assigned to one of three classifications indicating the extent of eruption disturbance, whereas 4 of the 13 noncarriers presented none of these three patterns. The clinical and radiographic criteria employed in this study would have correctly identified 10 of the 13 PFE patients in the noncarrier group as possessing no detectable PTHR1 mutation. CONCLUSION: The evaluation of clinical and radiographic characteristics can heighten the specificity of ruling out suspected PTHR1 involvement in PFE patients. A hereditary element of PTHR1-associated PFE is clearly identifiable. More studies with more patients are needed to optimize the sensitivity of this preliminary approach on the differential identification of PTHR1-mutation carriers versus noncarriers by multivariate analysis.


Assuntos
Predisposição Genética para Doença/genética , Técnicas de Diagnóstico Molecular/métodos , Radiografia Dentária/métodos , Receptor Tipo 1 de Hormônio Paratireóideo/genética , Doenças Dentárias/diagnóstico por imagem , Doenças Dentárias/genética , Adolescente , Criança , Diagnóstico Diferencial , Feminino , Marcadores Genéticos/genética , Humanos , Masculino , Mutação/genética , Variações Dependentes do Observador , Polimorfismo de Nucleotídeo Único/genética , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto Jovem
10.
Phys Rev Lett ; 111(15): 157205, 2013 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-24160626

RESUMO

We report on the epitaxial fabrication and electronic properties of a topological phase in strained α-Sn on InSb. The topological surface state forms in the presence of an unusual band order not based on direct spin-orbit coupling, as shown in density functional and GW slab-layer calculations. Angle-resolved photoemission including spin detection probes experimentally how the topological spin-polarized state emerges from the second bulk valence band. Moreover, we demonstrate the precise control of the Fermi level by dopants.

11.
Spinal Cord ; 51(3): 183-7, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23184030

RESUMO

STUDY DESIGN: A pilot study measuring the levels of serum-soluble CD95 ligand (CD95L) in eight spinal cord-injured patients. OBJECTIVES: To determine the soluble concentration of CD95L in spinal cord injury (SCI) patients after trauma. METHODS: We collected blood samples from eight patients with acute traumatic SCI. Soluble CD95L serum levels were determined using an enzyme-linked immunosorbent assay. American Spinal Injury Association (ASIA) was determined according to ASIA classification. The patients were monitored, and venous blood was drawn after arrival at the hospital on the 1st and 3rd day and during the 1st, 2nd, 4th, 8th and 12th weeks after trauma. RESULTS: The average patient age was 48.1 years (18-86 years). Three patients were paraplegic (two incomplete, one complete), five were quadriplegic (one complete, four incomplete). The serum concentration of soluble CD95L (sCD95L) decreased during the 1st week (41 ng(- l)) and increased after the 2nd week in all eight patients. It peaked during the 4th week (68.5 ng (- l)) and reached a plateau during the 12th week (76.2 ng (- l)). There are many possible explanations for not being able to detect a statistical significance, one of course being the small sample size. CONCLUSION: Promising results for anti-CD95L therapy have already been documented in lab studies with rodents. Anti-CD95L blocks the pro-apoptotic and proinflammatory activity of membrane-bound CD95L during the acute phase of SCI. We observed that sCD95L levels are elevated during the subacute and intermediate phases of SCI. It would be of great interest to study a larger group of patients to determine whether higher sCD95 levels are correlated with improved or impaired neurological outcome or with increasing levels of autoimmune components in peripheral blood.


Assuntos
Proteína Ligante Fas/sangue , Terapia de Alvo Molecular/métodos , Traumatismos da Medula Espinal/sangue , Traumatismos da Medula Espinal/diagnóstico , Doença Aguda , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Terapia de Alvo Molecular/tendências , Projetos Piloto , Solubilidade , Traumatismos da Medula Espinal/terapia , Adulto Jovem
12.
J Appl Physiol (1985) ; 113(11): 1763-71, 2012 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-23019315

RESUMO

Combining accelerometry (ACC) with heart rate (HR) monitoring is thought to improve activity energy expenditure (AEE) estimations compared with ACC alone to evaluate the validity of ACC and HR used alone or combined. The purpose of this study was to estimate AEE in free-living conditions compared with doubly labeled water (DLW). Ten-day free-living AEE was measured by a DLW protocol in 35 18- to 55-yr-old men (11 lean active; 12 lean sedentary; 12 overweight sedentary) wearing an Actiheart (combining ACC and HR) and a RT3 accelerometer. AEE was estimated using group or individual calibration of the HR/AEE relationship, based on an exercise-tolerance test. In a subset (n = 21), AEE changes (ΔAEE) were measured after 1 mo of detraining (active subjects) or an 8-wk training (sedentary subjects). Actiheart-combined ACC/HR estimates were more accurate than estimates from HR or ACC alone. Accuracy of the Actiheart group-calibrated ACC/HR estimates was modest [intraclass correlation coefficient (ICC) = 0.62], with no bias but high root mean square error (RMSE) and limits of agreement (LOA). The mean bias of the estimates was reduced by one-third, like RMSE and LOA, by individual calibration (ICC = 0.81). Contrasting with group-calibrated estimates, the Actiheart individual-calibrated ACC/HR estimates explained 40% of the variance of the DLW-ΔAEE (ICC = 0.63). This study supports a good level of agreement between the Actiheart ACC/HR estimates and DLW-measured AEE in lean and overweight men with varying fitness levels. Individual calibration of the HR/AEE relationship is necessary for AEE estimations at an individual level rather than at group scale and for ΔAEE evaluation.


Assuntos
Actigrafia , Metabolismo Energético , Frequência Cardíaca , Atividade Motora , Sobrepeso/fisiopatologia , Comportamento Sedentário , Magreza/fisiopatologia , Aceleração , Actigrafia/instrumentação , Actigrafia/normas , Atividades Cotidianas , Adolescente , Adulto , Calibragem , Óxido de Deutério , Teste de Esforço , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Sobrepeso/metabolismo , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Magreza/metabolismo , Fatores de Tempo , Adulto Jovem
13.
J Endocrinol Invest ; 35(1): 54-62, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21422800

RESUMO

BACKGROUND AND AIM: There is limited data on the effects of inactivity (prolonged bed-rest) on parameters of endocrine and metabolic function; we therefore aimed to examine changes in these systems during and after prolonged (56- day) bed-rest in male adults. SUBJECTS AND METHODS: Twenty healthy male subjects underwent 8 weeks of strict bed-rest and 12 months of follow-up as part of the Berlin Bed Rest Study. Subjects were randomized to an inactive group or a group that performed resistive vibration exercise (RVE) during bed-rest. All outcome parameters were measured before, during and after bed-rest. These included body composition (by whole body dual X-ray absorptiometry), SHBG, testosterone (T), estradiol (E2), PRL, cortisol (C), TSH and free T3 (FT3). RESULTS: Serum SHBG levels decreased in inactive subjects but remained unchanged in the RVE group (p<0.001). Serum T concentrations increased during the first 3 weeks of bed-rest in both groups (p<0.0001), while E2 levels sharply rose with re-mobilization (p<0.0001). Serum PRL decreased in the control group but increased in the RVE group (p=0.021). C levels did not change over time (p≥0.10). TSH increased whilst FT3 decreased during bed-rest (p all ≤0.0013). CONCLUSIONS: Prolonged bed-rest has significant effects on parameters of endocrine and metabolic function, some of which are related to, or counteracted by physical activity.


Assuntos
Adaptação Fisiológica , Repouso em Cama , Sistema Endócrino/fisiologia , Terapia por Exercício , Exercício Físico/fisiologia , Imobilização , Globulina de Ligação a Hormônio Sexual/metabolismo , Absorciometria de Fóton , Adulto , Berlim , Composição Corporal , Seguimentos , Humanos , Masculino
14.
Med Phys ; 39(6Part27): 3959-3960, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28519970

RESUMO

PURPOSE: Robust registration of prone and supine colonie surfaces acquired during CT colonography may lead to faster and more accurate detection of colorectal cancer and polyps. Any directional bias when registering one surface to the other could precipitate incorrect anatomical correspondence and engender reader error. Despite this, non-rigid registration methods are often implemented asymmetrically, which could negatively influence the registration. We aimed to reduce directional bias and so increase robustness by adapting a cylindrical registration algorithm to be both symmetric and inverse-consistent. METHODS: The registration task can be simplified by mapping both prone and supine colonie surfaces onto regular cylinders. Spatial correspondence can then be established in cylindrical space using the original surfaces' local shape indices. We implemented a symmetric formulation of the popular non-rigid B-spline image registration method in cylindrical space. A symmetric similarity measure computes the sum of squared differences between both cylindrical representations of prone-to-supine and supine-to-prone directions simultaneously. Inverse consistency of the transformation is enforced by adding an appropriately weighted penalty term to the optimisation function. RESULTS: We selected 8 CT colonography patient cases with marked variation in luminal distension and surface morphology. We randomly allocated 4 of these for tuning an optimal set of registration parameters and 4 for validation. The mean inverse-consistency error was reduced by 32% from 4.8mm to 3.2mm by the new symmetric formulation. The mean registration error improved from 8.2mm to 7.3mm for 330 manually chosen reference points on the 4 validation sets. CONCLUSIONS: A symmetric formulation of prone and supine surface registration improves the quality of registration. Information from both prone-to-supine and supine-to-prone directions helps enforce convergence towards a more accurate solution due to reduced directional bias. A more robust and accurate registration will facilitate interpretation of CT colonography and has the potential to improve existing computer-aided detection methods. The authors gratefully acknowledge financial support for this work from the NIHR program: â€Å“Imaging diagnosis of colorectal cancer: Interventions for efficient and acceptable diagnosis in symptomatic and screening populationsâ€.

15.
Restor Neurol Neurosci ; 29(6): 507-16, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22204927

RESUMO

PURPOSE: This narrative review discusses the neurophysiology of human motor cortex as it influences gait, and recent advances in the application of non-invasive brain stimulation to the lower limb motor cortex of stroke survivors. Although walking is a high priority following stroke, the efficacy of promising new therapies has yet to warrant their widespread clinical use. For the upper limb, numerous brain stimulation protocols have been described. These protocols, adapted for the leg, are now being used to examine the cortical control of gait. This research discounts the long-held notion that "we walk from our spinal cords". METHODS: Our review describes this research as it relates to the lower limb, especially the use of non-invasive brain stimulation to enhance neuroplasticity. The review also discusses the possible development of a prognostic algorithm for walking recovery after stroke. CONCLUSION: This review concludes with the expectation that novel brain stimulation protocols combined with therapy will eventually demonstrate a level of effectiveness sufficient to promote their wide acceptance in neurorehabilitation settings.


Assuntos
Estimulação Elétrica/métodos , Transtornos Neurológicos da Marcha/etiologia , Transtornos Neurológicos da Marcha/terapia , Córtex Motor/fisiologia , Acidente Vascular Cerebral/complicações , Caminhada/fisiologia , Humanos , Recuperação de Função Fisiológica
16.
J Musculoskelet Neuronal Interact ; 11(1): 34-45, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21364273

RESUMO

OBJECTIVES: Assessment of additive impact of alfacalcidol 1 µg daily (Alfa) on bone mineral density (BMD) and on bone strength in postmenopausal women treated with alendronate 70 mg weekly + 500 mg calcium daily. SUBJECTS AND METHODS: In a randomized, double-blind, placebo controlled study, 279 postmenopausal women with osteoporosis or osteopenia participated (intention to treat analysis [ITT]; aged 73.6∓4.7 years) and were treated with 70 mg alendronate (ALN) weekly and 500 mg calcium daily for 36 months. In addition, these patients received either 1 µg alfacalcidol (Alfa) or placebo (PLC) daily. BMD was measured with Dual-Energy-X-ray-Absorptiometry (DXA) at the lumbar spine and proximal femur and at forearm and tibia with peripheral quantitative computed tomography (pQCT) at regular intervals for 36 months. RESULTS: DXA-BMD of lumbar spine (L1-4) increased after 36 months, by 6.65% (p<0.0001) in the Alfa/ALN group versus 4.17% (p<0.0001) in the PLC/ALN group. Group difference was significant after 3 years (p=0.026). At the end of the study, significant differences were found in favor of the Alfa/ALN group in trabecular density (tibia) (p=0.002), cortical density (midshaft tibia) (p=0.043), and bone strength (p=0.001). The remaining parameters showed no differences between the treatment arms, apart cortical bone density at midshaft radius. CONCLUSIONS: Alfacalcidol significantly increases the efficacy of alendronate treatment in osteopenic/osteoporotic postmenopausal women on spinal DXA-BMD, cortical and trabecular BMD of the tibia and also bending stiffness of the tibia.


Assuntos
Alendronato/administração & dosagem , Conservadores da Densidade Óssea/administração & dosagem , Densidade Óssea/efeitos dos fármacos , Reabsorção Óssea/tratamento farmacológico , Osso e Ossos/efeitos dos fármacos , Hidroxicolecalciferóis/administração & dosagem , Osteoporose Pós-Menopausa/tratamento farmacológico , Idoso , Alendronato/efeitos adversos , Densidade Óssea/fisiologia , Conservadores da Densidade Óssea/efeitos adversos , Reabsorção Óssea/fisiopatologia , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Humanos , Hidroxicolecalciferóis/efeitos adversos , Osteoporose Pós-Menopausa/diagnóstico por imagem , Osteoporose Pós-Menopausa/fisiopatologia , Radiografia
17.
Osteoporos Int ; 22(1): 231-40, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20556359

RESUMO

UNLABELLED: Vitamin D deficiency is associated with increased fracture risk. The observational study aimed to investigate vitamin D status and supplementation in ambulatory patients. Only 20% of patients had optimal serum 25-hydroxyvitamin D [25(OH)D] levels. Commonly recommended dosages were insufficient to achieve clinically relevant increase of 25(OH)D levels. Higher dosages were safe and effective under clinical practice conditions. INTRODUCTION: Vitamin D deficiency is associated with adverse health outcome. The study aimed to investigate vitamin D status and supplementation in ambulatory patients. METHODS: Nine hundred seventy-five women and 188 men were evaluated for bone status from January 2008 to August 2008 within an observational study; 104 patients (n = 70 osteoporosis) received follow-up after 3 months. Dosage of vitamin D supplementation was documented and serum 25(OH)D and parathyroid hormone (PTH) determined. RESULTS: In all patients (age, 60.4 ± 14.1 years), distribution of 25(OH)D was 56.3 ± 22.3 nmol/L (normal range, 52-182 nmol/L) and PTH 53.8 ± 67.5 ng/L (normal range, 11-43 ng/L). The proportion of patients with 25(OH)D < 25, 25 to <50, 50 to <75, ≥75 nmol/L was 7.5%, 33.3%, 38.9% and 20.2% in the total group and 20.1%, 38.5%, 30.8%, 10.6% at baseline in the follow-up group, respectively. After 3 months, 3.9% had still 25(OH)D < 25 nmol/L; only 12.5% achieved 25(OH)D ≥ 75 nmol/L. In osteoporosis patients, 25(OH)D increased more in those taking ≥1,500 (median, 3,000) IU vitamin D per day (33.1 ± 14.7 nmol/L) compared with ≤1,000 (median, 800) IU/day (10.6 ± 20.0 nmol/L) (p < 0.0008). PTH decreased more in patients taking ≥1,500 IU/day (-13.2 ± 15.2 ng/L) compared with ≤1,000 IU/day (-7.6 ± 19.2 ng/L; p = 0.29). 25(OH)D was negatively correlated to PTH (r = -0.49, p < 0.0001). An increase of 25(OH)D ≥ 75 nmol/L resulted in normalised PTH. CONCLUSION: Supplementation with higher vitamin D dosages (2,000-3,000 IU/day) is required to achieve a relevant increase of 25(OH)D and normalisation of PTH.


Assuntos
Suplementos Nutricionais , Deficiência de Vitamina D/tratamento farmacológico , Vitamina D/administração & dosagem , Idoso , Densidade Óssea , Osso e Ossos/metabolismo , Relação Dose-Resposta a Droga , Feminino , Colo do Fêmur/fisiopatologia , Seguimentos , Humanos , Hiperparatireoidismo Primário/sangue , Hiperparatireoidismo Primário/complicações , Vértebras Lombares/fisiopatologia , Masculino , Pessoa de Meia-Idade , Osteoporose/sangue , Osteoporose/etiologia , Hormônio Paratireóideo/sangue , Vitamina D/análogos & derivados , Vitamina D/sangue , Vitamina D/uso terapêutico , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/complicações
18.
Injury ; 42(8): 758-64, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21168135

RESUMO

Radiological studies are the standard method to monitor fracture healing but they do not allow a timely assessment of bone healing. Biochemical markers react rapidly to changes in bone metabolism during fracture healing and could be an additional tool to monitor this process. The goal of this study was to observe changes in serum biomarkers and evaluate the possible differences in the serum levels of tartrate-resistant acid phosphatase 5b (TRACP 5b), total N-terminal propeptide of type I collagen (PINP), bone-specific alkaline phosphatase (BAP), and C-terminal cross-linking telopeptide of type I collagen (CTX) in patients with normal and delayed fracture healing. Several serum samples were collected for one year after the surgical treatment of long bone fractures in 248 patients. From this large pool, 15 patients with atrophic nonunion were matched to 15 patients with normal bone healing. Post-operative changes in osteological markers were monitored during the 1st, 2nd, 4th, 8th, 12th and 52nd weeks. The patients were followed both clinically and radiologically for the entire one-year duration of the study. In the first week, the absolute values of CTX decreased significantly (p=0.0164) in cases of delayed fracture healing. The relative values of TRACP 5b were significantly decreased at weeks 4 (p=0.0066) and 8 (p=0.0043). BAP and PINP levels decreased in the first week followed by an increase, but there were no significant differences in the absolute or relative values during the healing process in both patient groups. For the first time, we have demonstrated changes in serum concentrations of TRACP 5b, PINP, BAP, and CTX during normal and delayed fracture healing. Characteristic changes in systemic TRACP 5b and CTX levels could reflect the initial process of successful fracture healing and may be used in clinical practice to monitor the healing process. Furthermore, it could be very important for determining the beneficial effects of additional treatments such as ultrasound or BMPs in clinical trials.


Assuntos
Fosfatase Ácida/sangue , Colágeno Tipo I/sangue , Consolidação da Fratura/fisiologia , Fraturas Ósseas/sangue , Isoenzimas/sangue , Adulto , Idoso , Biomarcadores/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteogênese/fisiologia , Estudos Prospectivos , Fosfatase Ácida Resistente a Tartarato , Adulto Jovem
19.
Osteoporos Int ; 21(4): 597-607, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19536451

RESUMO

UNLABELLED: During and after prolonged bed rest, changes in bone metabolic markers occur within 3 days. Resistive vibration exercise during bed rest impedes bone loss and restricts increases in bone resorption markers whilst increasing bone formation. INTRODUCTION: To investigate the effectiveness of a resistive vibration exercise (RVE) countermeasure during prolonged bed rest using serum markers of bone metabolism and whole-body dual X-ray absorptiometry (DXA) as endpoints. METHODS: Twenty healthy male subjects underwent 8 weeks of bed rest with 12 months follow-up. Ten subjects performed RVE. Blood drawings and DXA measures were conducted regularly during and after bed rest. RESULTS: Bone resorption increased in the CTRL group with a less severe increase in the RVE group (p = 0.0004). Bone formation markers increased in the RVE group but decreased marginally in the CTRL group (p < 0.0001). At the end of bed rest, the CTRL group showed significant loss in leg bone mass (-1.8(0.9)%, p = 0.042) whereas the RVE group did not (-0.7(0.8)%, p = 0.405) although the difference between the groups was not significant (p = 0.12). CONCLUSIONS: The results suggest the countermeasure restricts increases in bone resorption, increased bone formation, and reduced bone loss during bed rest.


Assuntos
Repouso em Cama/efeitos adversos , Reabsorção Óssea/prevenção & controle , Atrofia Muscular/prevenção & controle , Treinamento Resistido/métodos , Vibração/uso terapêutico , Absorciometria de Fóton/métodos , Adulto , Biomarcadores/sangue , Biomarcadores/urina , Composição Corporal , Densidade Óssea/fisiologia , Reabsorção Óssea/etiologia , Reabsorção Óssea/fisiopatologia , Osso e Ossos/metabolismo , Cálcio/sangue , Cálcio/urina , Seguimentos , Humanos , Masculino , Atrofia Muscular/etiologia
20.
Phys Rev Lett ; 103(10): 107205, 2009 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-19792341

RESUMO

High-resolution resonant inelastic x-ray scattering has been used to determine the momentum dependence of orbital excitations in Mott-insulating LaTiO(3) and YTiO(3) over a wide range of the Brillouin zone. The data are compared to calculations in the framework of lattice-driven and superexchange-driven orbital ordering models. A superexchange model in which the experimentally observed modes are attributed to two-orbiton excitations yields the best description of the data.

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