Impact of leg lengthening on viscoelastic properties of the deep fascia

<p>Abstract</p> <p>Background</p> <p>Despite the morphological alterations of the deep fascia subjected to leg lengthening have been investigated in cellular and extracellular aspects, the impact of leg lengthening on viscoelastic properties of the deep fascia remains largely unknown. This study aimed to address the changes of viscoelastic properties of the deep fascia during leg lengthening using uniaxial tensile test.</p> <p>Methods</p> <p>Animal model of leg lengthening was established in New Zealand white rabbits. Distraction was initiated at a rate of 1 mm/day and 2 mm/day in two steps, and preceded until increases of 10% and 20% in the initial length of tibia had been achieved. The deep fascia specimens of 30 mm × 10 mm were clamped with the Instron 1122 tensile tester at room temperature with a constant tensile rate of 5 mm/min. After 5 load-download tensile tests had been performed, the specimens were elongated until rupture. The load-displacement curves were automatically generated.</p> <p>Results</p> <p>The normal deep fascia showed typical viscoelastic rule of collagenous tissues. Each experimental group of the deep fascia after leg lengthening kept the properties. The curves of the deep fascia at a rate of 1 mm/day with 20% increase in tibia length were the closest to those of normal deep fascia. The ultimate tension strength and the strain at rupture on average of normal deep fascia were 2.69 N (8.97 mN/mm²) and 14.11%, respectively. The increases in ultimate tension strength and strain at rupture of the deep fascia after leg lengthening were statistically significant.</p> <p>Conclusion</p> <p>The deep fascia subjected to leg lengthening exhibits viscoelastic properties as collagenous tissues without lengthening other than increased strain and strength. Notwithstanding different lengthening schemes result in varied viscoelastic properties changes, the most comparable viscoelastic properties to be demonstrated are under the scheme of a distraction rate of 1 mm/day and 20% increase in tibia length.</p

Assessment of nerve involvement in the lumbar spine: agreement between magnetic resonance imaging, physical examination and pain drawing findings

<p>Abstract</p> <p>Background</p> <p>Detection of nerve involvement originating in the spine is a primary concern in the assessment of spine symptoms. Magnetic resonance imaging (MRI) has become the diagnostic method of choice for this detection. However, the agreement between MRI and other diagnostic methods for detecting nerve involvement has not been fully evaluated. The aim of this diagnostic study was to evaluate the agreement between nerve involvement visible in MRI and findings of nerve involvement detected in a structured physical examination and a simplified pain drawing.</p> <p>Methods</p> <p>Sixty-one consecutive patients referred for MRI of the lumbar spine were - without knowledge of MRI findings - assessed for nerve involvement with a simplified pain drawing and a structured physical examination. Agreement between findings was calculated as overall agreement, the p value for McNemar's exact test, specificity, sensitivity, and positive and negative predictive values.</p> <p>Results</p> <p>MRI-visible nerve involvement was significantly less common than, and showed weak agreement with, physical examination and pain drawing findings of nerve involvement in corresponding body segments. In spine segment L4-5, where most findings of nerve involvement were detected, the mean sensitivity of MRI-visible nerve involvement to a positive neurological test in the physical examination ranged from 16-37%. The mean specificity of MRI-visible nerve involvement in the same segment ranged from 61-77%. Positive and negative predictive values of MRI-visible nerve involvement in segment L4-5 ranged from 22-78% and 28-56% respectively.</p> <p>Conclusion</p> <p>In patients with long-standing nerve root symptoms referred for lumbar MRI, MRI-visible nerve involvement significantly underestimates the presence of nerve involvement detected by a physical examination and a pain drawing. A structured physical examination and a simplified pain drawing may reveal that many patients with "MRI-invisible" lumbar symptoms need treatment aimed at nerve involvement. Factors other than present MRI-visible nerve involvement may be responsible for findings of nerve involvement in the physical examination and the pain drawing.</p

Colostomia tipo hartmann em ratos: alterações morfológicas e dosagem de hidroxiprolina

A colostomia tem sido um procedimento cirúrgico freqüentemente empregado nas doenças colônicas, lesões traumáticas e neoplásicas. Este trabalho experimental, em ratos, visou estudar as progressivas mudanças morfológicas no cólon proximal e distal , após uma laparotomia e colostomia terminal, tipo Hartmann, que foram estudadas histologicamente e através da dosagem tecidual de hidroxiprolina. Utilizaram-se 40 ratos, machos, raça Wistar, com peso médio de 200 gramas, alocados em dois grupos (grupo I ou experimento e grupo II ou controle), subdivididos em quatro subgrupos: A,B,C e D com 10 animais em cada subgrupo. Os animais do grupo I (subgrupos A e B) foram submetidos à colostomia tipo Hartmann, no cólon distal, a 7,5cm do canal anal. Nos ratos do grupo II foi praticada apenas uma laparotomia mediana. Os animais dos subgrupo A e C foram sacrificados no 30º dia de P.O., enquanto que os animais dos subgrupos B e D o sacrifício foi no 60º dia de P.O. A análise histológica dos segmentos colônicos permitiu observar infiltrado inflamatório agudo e crônico na lâmina própria, achatamento pronunciado das criptas, diminuição do número de criptas e da celularidade epitelial, redução das células caliciformes e da mucossecreção, adelgaçamento da muscular da mucosa, mais intensos no coto colônico distal dos animais submetidos à colostomia terminal tipo Hartmann (subgrupos A e B). Os segmentos proximais apresentavam estas alterações, porém mais discretas. A dosagem de hidroxiprolina nos tecidos colônicos não revelou alterações estatisticamente significativas quanto ao conteúdo de colágeno ou do peso desidratado. Estes achados permitem demonstrar alterações morfológicas inflamatórias e hipotróficas mais pronunciadas no cólon distal de ratos submetidos à colostomia tipo Hartmann

Impact of Bariatric Surgical Intervention on Peripheral Blood Neutrophil (PBN) Function in Obesity.

AIM The aim of this study was to investigate the impact of weight loss following gastric band surgery on multiple measures of peripheral blood neutrophil (PBN) function. MATERIAL AND METHODS Twenty-three obese patients undergoing gastric band surgery were recruited to a longitudinal intervention study, alongside non-obese, healthy gender- and age-matched controls. Eighteen pairs of patients and controls completed all stages of the study. PBNs were isolated by density centrifugation and a comprehensive analysis of PBN function was undertaken at various stages of the patients' bariatric surgical care pathway. RESULTS Obese patients exhibited exaggerated PBN activity in response to various stimuli, characterised by higher reactive oxygen species (ROS) generation (n = 18, p < 0.001) and release of pro-inflammatory cytokines (n = 10, p < 0.05) and lower PBN extracellular trap (NET) formation (n = 18, p < 0.01). PBN chemotactic accuracy was also impaired prior to surgery (n = 18, p < 0.01). Weight loss was associated with normalised NET production and lower ROS production and cytokine release relative to healthy controls. However, chemotactic accuracy remained impaired in patients. CONCLUSIONS Weight loss following gastric band surgery was associated with a decrease in the pro-inflammatory activities of peripheral blood neutrophils (PBNs). A hyper-inflammatory PBN phenotype, involving excess ROS and cytokine release, reduced NET formation and chemotaxis, may lead to a reduced ability to eliminate infection, alongside inflammation-mediated tissue damage in obese individuals