Treatment of segmental tibial defects using acute bone shortening followed by gradual lengthening with circular external fixator

The aim of this study was to clinically and radiographically evaluate acute bone shortening followed by gradual lengthening in the treatment of large segmental tibia defects induced in seven clinically normal dogs. A circular external fixator was assembled with one proximal 5/8-circle ring, one middle ring and one distal ring connected with three rods. Thirty per cent of the tibia and fibula were removed in the middle and distal parts of the diaphyses, between the middle and distal rings. Acute bone shortening with compression of proximal and distal segments was performed. A subperiosteal osteotomy was performed between the half-ring and middle ring. Bone distraction started 7 days after surgery; after lengthening, the apparatus was left in place for 14 weeks for consolidation of regenerated bone. The frame was removed at the end of this period, and the dogs observed for four more weeks. Functional results were considered excellent in two, good in three and fair in the other two dogs. Bone regeneration within the distraction gap was obtained 14 weeks after neutral fixation period. We concluded that acute bone shortening followed by gradual lengthening by Ilizarov method can be used to treat extensive tibial defects in dogs, although it presents limb temporary abnormal limb shape and unequal length as early disadvantages.

Effects of muscarinic receptor antagonists on acetylcholine-induced contractions of jejunal smooth muscle in horses

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Acute shortening and subsequent lengthening of the radius and ulna for the treatment of an infected nonunion in a dog

A 3-year-old, male crossbred dog with osteomyelitis of the radius and ulna was treated using Ilizarov's method. Two centimeters of infected bone was resected, then acute bone shortening and subsequent lengthening of a healthy bone site were performed. The infection was eradicated, but a residual leg-length discrepancy was present.

ALPHA-CONTRACTIONS AND ATTRACTORS FOR DISSIPATIVE SEMILINEAR HYPERBOLIC-EQUATIONS AND SYSTEMS

In this paper we discuss the existence of compact attractor for the abstract semilinear evolution equation u = Au + f (t, u); the results are applied to damped partial differential equations of hyperbolic type. Our approach is a combination of Liapunov method with the theory of alpha-contractions.

Differential antagonism by conotoxin p-TIA of contractions mediated by distinct alpha(1)-adrenoceptor subtypes in rat vas deferens, spleen and aorta

The ability of the conotoxin p-TIA, a 19-amino acid peptide isolated from the marine snail Conus tulipa, to antagonize contractions induced by noradrenaline through activation of alpha(1A)-adrenoceptors in rat vas deferens, alpha(1B)-adrenoceptors in rat spleen and alpha(ID)-adrenoceptors in rat aorta, and to inhibit the binding of [I-125]HEAT (2-[[beta-(4-hydroxyphenyl)ethyl]aminomethyl]-1-tetralone) to membranes of human embryonic kidney (HEK) 293 cells expressing each of the recombinant rat alpha(1)-adrenoceptors was investigated. p-TIA (100 nM to 1 muM) antagonized the contractions of vas deferens and aorta in response to noradrenaline without affecting maximal effects and with similar potencies (pA(2)similar to7.2, n=4). This suggests that p-TIA is a competitive antagonist of alpha(1A)- and alpha(1D)-adrenoceptors with no selectivity between these subtypes. Incubation of p-TIA (30 to 300 nM) with rat spleen caused a significant reduction of the maximal response to noradrenaline, suggesting that p-TIA is a non-competitive antagonist at alpha(1B)-adrenoceptors. After receptor inactivation with phenoxybenzamine, the potency of p-TIA in inhibiting contractions was examined with similar occupancies (similar to25%) at each subtype. Its potency (pIC(50)) was 12 times higher in spleen (8.3 +/- 0.1, n=4) than in vas deferens (7.2 +/- 0.1, n=4) or aorta (7.2 0.1, n=4). In radioligand binding assays, p-TIA decreased the number of binding sites (B,,,,,,) in membranes from HEK293 cells expressing the rat alpha(1B)-adrenoceptors without affecting affinity (K-D), In contrast, in HEK293 cells expressing rat alpha(1A)- or alpha(1D)-adrenoceptors, p-TTA decreased the KD without affecting the B-max. It is concluded that p-TIA will be useful for distinguishing the role of particular alpha(1)-adrenoceptor subtypes in native tissues. (C) 2004 Elsevier B.V. All rights reserved.

A novel biomagnetic method to study gastric antral contractions

A novel non-invasive method to study the motion associated with gastric antral contractions is discussed. The method is based on magnetic flux changes detected by an a.c. biosusceptometer, produced by a magnetic test meal within the stomach. Measurements are made at the surface of the torso and are easy to perform. Simultaneous measurements were made with electrogastrography and scintigraphy showing remarkable coincidence. The effect of a drug on the amplitude of antral contractions was also assayed with the new method.

Analysis of various conditions in order to measure electromyography of isometric contractions in water and on air

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of the rest interval duration between contractions on muscle fatigue

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Force patterns of hypoxic myocardium applied to oxygenated muscle preparations: Comparison with effects of regional ischemia on the contraction of non-ischemic myocardium

Objective: To examine the basis for local wall motion abnormalities commonly seen in patients with ischemic heart disease, computer-controlled isolated muscle studies were carried out. Methods: Force patterns of physiologically sequenced contractions (PSCs) from rat left ventricular muscle preparations under well-oxygenated conditions and during periods of hypoxia and reoxygenation were recorded and stored in a computer. Force patterns of hypoxic-reoxygenating and oxygenated myocardium were applied to oxygenated and hypoxic-reoxygenating myocardium, respectively. Results: Observed patterns of shortening and lengthening closely resemble those obtained from ischemic and non-ischemic myocardial segments using ultrasonic crystals in intact dog hearts during coronary occlusion and reperfusion, and are similar to findings reported in angiographic studies of humans with coronary artery disease. Conclusion: The current study, demonstrating motions of oxygenated isolated muscle preparations which are similar to those in perfused segments of intact hearts with regional ischemia, supports the concept that the multiple motions of both ischemic and non-ischemic segments seen in regional myocardial disease can be explained by interactions of strongly and weakly contracting muscle during the physiologic cardiac cycle.

Leg muscles recruitment pattern in soccer players and active individuals during isometric contractions

This study aimed to compare the torque, torque ratio (Hamstrings:Quadriceps - H:Q), electromyographic (EMG) activity and EMG ratio (knee flexors:knee extensors EMG) in soccer players (SG, N=10) and active subjects (AG, N=10). Subjects performed three maximal voluntary isometric knee extensions and flexions at 45° and 90° to determine the peak torque and EMG activity. Torque and EMG activity of the knee flexor (biceps femoris [BF] and semitendinosus [ST]) were divided by the torque and EMG activity of the knee extensor (vastuls lateralis [VL] and rectus femoris [RF]) to calculate torque ratios (H:Q) and EMG ratios (BF:VL, BF:RF, ST:VL, ST:RF). The flexion torque was significantly higher for SG (p<0.05) in 45° and 90°. EMG activity for SG was significantly higher in agonist contractions for VL, RF and ST, and significantly lower in antagonist contractions for RF and ST when compared to AG Torque and EMG ratios were similar between groups and there were good correlations between torque ratio and BF:VL ratio (r=0.71, p=0.02) and BF:RF ratio (r=0.81, p=0.004) at 45. The EMG results could overestimate the joint balance calculated using torque ratios. Differences in recruitment pattern between soccer players and non-athletes can be related to the training routines and the EMG ratios presents applicable in trained populations.

The influence of resistance exercise with emphasis on specific contractions (concentric vs. eccentric) on muscle strength and post-exercise autonomic modulation: a randomized clinical trial

Contextualização:Ações concêntricas apresentam maior estresse cardiovascular quando comparadas às excêntricas. Entretanto, não se sabe a influência desses tipos de ações no comportamento da modulação autonômica cardíaca durante o processo de recuperação pós-esforço.Objetivo:Comparar o efeito de um treinamento resistido para o grupo extensor do joelho realizado com ênfase concêntrica vs excêntrica sobre a força muscular e a recuperação pós-exercício considerando índices de variabilidade de frequência cardíaca (VFC) em jovens saudáveis.Método:Cento e cinco homens, com idades entre 18 e 30 anos, foram randomizados em quatro grupos: controle concêntrico (CCONC), controle excêntrico (CEXC), treinamento concêntrico (TCONC) e treinamento excêntrico (TEXC). Os grupos CCONC e CEXC realizaram uma sessão de exercício reduzido (ER) para o grupo extensor do joelho [três séries de uma repetição a 100% de uma repetição máxima (1RM)], e os grupos TCONC e TEXC realizaram dez sessões de treinamento. A VFC foi analisada no momento basal e na recuperação após as sessões (T1, T2, T3 e T4).Resultados:Observou-se aumento da força muscular para o grupo TEXC. Em relação à modulação autonômica cardíaca, observou-se, em comparação ao momento basal, aumento dos índices SDNN e SD2 no momento T1 nos grupos CCONC e CEXC e aumento dos índices RMSSD, SD1 e AF (ms2) nos momentos T1, T2 e T4 no grupo TEXC.Conclusões:Conclui-se que o treinamento resistido realizado com ênfase em contrações excêntricas promoveu ganho de força e aumento da modulação vagal cardíaca durante o processo de recuperação em relação à condição basal.

Open-Flap Versus Flapless Esthetic Crown Lengthening: 12-Month Clinical Outcomes of a Randomized Controlled Clinical Trial

Background: Excessive gingival display (EGD) has a negative impact on a pleasant smile. Minimally invasive therapeutic modalities have become the standard treatment in many dentistry fields. Therefore, the aim of this study is to compare the clinical outcomes of open-flap (OF) and minimally invasive flapless (FL) esthetic crown lengthening (ECL) for the treatment of EGD.Methods: A split-mouth randomized controlled trial was conducted in 28 patients presenting with EGD. Contralateral quadrants received ECL using OF or FL techniques. Clinical parameters were evaluated at baseline and 3, 6, and 12 months post-surgery. The local levels of receptor activator of nuclear factor-kappa B ligand (RANKL) and osteoprotegerin (OPG) were assessed by enzyme-linked immunosorbent assay at baseline and 3 months. Patients' perceptions regarding morbidity and esthetic appearance were also evaluated. Periodontal tissue dimensions were obtained by computed tomography at baseline and correlated with the changes in the gingival margin (GM).Results: Patients reported low morbidity and high satisfaction with esthetic appearance for both procedures (P > 0.05). RANKL and OPG concentrations were increased in the OF group at 3 months (P < 0.05). Probing depths were reduced for both groups at all time points, compared with baseline (P < 0.05). There were no differences between groups for GM reduction at any time point (P > 0.05).Conclusions: FL and OF surgeries produced stable and similar clinical results up to 12 months. FL ECL may be a predictable alternative approach for the treatment of EGD.

Influence of neuromuscular fatigue on co-contraction between vastus medialis and vastus lateralis during isometric contractions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The extract of the jellyfish Phyllorhiza punctata promotes neurotoxic effects

Phyllorhiza punctata (P. punctata) is a jellyfish native to the southwestern Pacific. Herewith we present the biochemical and pharmacological characterization of an extract of the tentacles of P. punctata. The tentacles were subjected to three freezethaw cycles, homogenized, ultrafiltered, precipitated, centrifuged and lyophilized to obtain a crude extract (PHY-N). Paralytic shellfish poisoning compounds such as saxitoxin, gonyautoxin-4, tetrodotoxin and brevetoxin-2, as well as several secretory phospholipase A2 were identified. PHY-N was tested on autonomic and somatic neuromuscular preparations. In mouse vas deferens, PHY-N induced phasic contractions that reached a peak of 234 +/- 34.7% of control twitch height, which were blocked with either 100 mu m of phentolamine or 1m m of lidocaine. In mouse corpora cavernosa, PHY-N evoked a relaxation response, which was blocked with either L-NG-Nitroarginine methyl ester (0.5 m m) or 1m m of lidocaine. PHY-N (1, 3 and 10 mu g ml(-1)) induced an increase in tonus of the biventercervicis neuromuscular preparation that was blocked with pre-treatment of galamine (10 mu m). Administration of 6 mg kg(-1) PHY-N intramuscularly produced death in broilers by spastic paralysis. In conclusion, PHY-N induces nerve depolarization and nonspecifically increases neurotransmitter release. Copyright (C) 2011 John Wiley & Sons, Ltd.

Respostas lactacidêmicas de ratos ao treinamento intermitente de alta intensidade

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)