Skeletal muscle ultrasound

Abstract

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Muscle ultrasound is a convenient technique to visualize normal and pathological muscle tissue as it is non-invasive and real-time. Neuromuscular disorders give rise to structural muscle changes that can be visualized with ultrasound: atrophy can be objectified by measuring muscle thickness, while infiltration of fat and fibrous tissue increases muscle echo intensity, i.e. the muscles become whiter on the ultrasound image. Muscle echo intensity needs to be quantified to correct for age-related increase in echo intensity and differences between individual muscles. This can be done by gray scale analysis, a method that can be easily applied in daily clinical practice. Using this technique, it is possible to detect neuromuscular disorders with predictive values of 90%. Only in young children and metabolic myopathies the sensitivity is lower. Ultrasound is a dynamic technique and therefore capable of visualizing normal and pathological muscle movements. Fasciculations can easily be differentiated from other muscle movements. Ultrasound appeared to be even more sensitive in detecting fasciculations compared to Electromyography (EMG) and clinical observations, because it can visualize a large muscle area and deeper located muscles. With improving resolution and frame rate it has recently become clear that also smaller scale spontaneous muscle activity such as fibrillations can be detected by ultrasound. This opens the way to a broader use of muscle ultrasound in the diagnosis of peripheral nerve and muscle disorders.     

Skeletal muscle growth defect in human growth hormone transgenic rat is accompanied by phenotypic changes in progenitor cells

Growth hormone (GH) is known to have a pivotal role in the maintenance of skeletal muscle mass. Sarcopenia, the loss of skeletal muscle mass, is a common phenomenon in aging, and it is widely accepted that sarcopenia is largely attributed to age-related decline in GH secretion. In the present study, we tested if human growth hormone transgenic rats (GH-TG rats) whose plasma GH levels are maintained relatively low could be an appropriate model for sarcopenia. Analyses of GH-TG rats revealed that they exhibit skeletal muscle growth defect as well as atrophy of myofibers. The number of myofibers in tibialis anterior muscle was comparable to that of WT rats, while the proportion of type I slow myofibers in tibialis anterior muscle was increased in GH-TG rats after 5 months. Neither increased expression of ubiquitin ligases, MuRF1 and MAFbx, nor indication of apoptotic cell death was observed. Notably, myogenic differentiation potential of skeletal muscle progenitor cells in GH-TG rats was lower than WT rats, and this was accompanied by increased adipogenic potential. These results indicate that GH-TG rats could be a useful model to elucidate the mechanism of sarcopenia induced by reduced GH action and raised the possibility that decreased GH action may cause an alteration of differentiation potential of skeletal muscle progenitor cells.     

广东省韶关市饮水型氟中毒现状调查

目的了解改水后广东省韶关市所辖乐昌市和始兴县地方性氟中毒(地氟病)病区病情现状。方法采用流行病学调查方法,8～12岁儿童氟斑牙采用Deans法分度诊断；饮水氟测定采用离子选择电极法。结果乐昌市廊田镇岩前村委的5个村饮冷泉水的水氟均值1．63mg/L,8～12岁儿童氟斑牙检出率44．45%,16岁以上人群氟骨症临床检出率3．80%,氟骨症X线临床检出率8．0%。始兴县的6个病区村改水后饮水氟范围在0．23～0．59mg/L,8～12岁儿童氟斑牙总检出率8．61%；罗坝镇廖屋村饮水氟均值为2．10 mg/L,8～12岁儿童氟斑牙检出率68．75%。结论乐昌市廊田镇岩前村委5个饮用冷泉水的自然村为饮水型氟中毒轻病区；始兴县罗坝镇廖屋村还是饮水型地氟病病区,需要改换饮用水源,才能控制地氟病的流行。     

Effect of duration of maternal alcohol consumption on calcium metabolism and bone in the fetal rat

BACKGROUND: Prenatal ethanol exposure can retard fetal growth and delay skeletal development. Ethanol also impairs maternal calcium (Ca) homeostasis and this impairment could mediate some of ethanol's effects on the fetal skeleton. Our previous studies suggest that the duration of maternal ethanol consumption may be an important factor for determining the severity of ethanol's effects on Ca homeostasis and fetal skeletal development. The purpose of this study was, therefore, to determine the effect of the duration of maternal ethanol consumption on fetal growth and skeletal development and to investigate the possibility that ethanol's effects may be related to perturbations in fetal/maternal Ca homeostasis. METHODS: Rats were fed ethanol (36% ethanol-derived calories) in liquid diets for 3 weeks (days 1-21 of gestation) or 6 weeks (for 3 weeks before and throughout gestation). Fetuses were collected on day 21 of gestation, and body weight and length were measured. Fetuses were stained to determine the degree of skeletal ossification, and fetal blood was analyzed for ethanol, Ca (total and ionic Ca), albumin, parathyroid hormone (PTH), and osteocalcin. RESULTS: Maternal ethanol consumption decreased fetal growth and delayed fetal skeletal development. Although there was a trend for fetal body length and serum osteocalcin levels to be more severely affected with an increased duration of maternal ethanol consumption, duration had no effect on fetal body weight or skeletal ossification. Fetal Ca homeostasis was also affected by ethanol exposure, with fetal hypocalcemia apparent after 6 weeks of maternal ethanol intake. A significant inverse relationship was found between fetal blood Ca levels and blood alcohol concentration (BAC), suggesting that the severity of the fetal hypocalcemia may have been related to differences in fetal BAC, rather than duration of maternal ethanol intake. Fetal serum PTH levels did not differ significantly among treatment groups indicating that the fetal hypocalcemia was not caused by a decrease in PTH levels. CONCLUSIONS: Prenatal ethanol exposure impaired Ca homeostasis and skeletal development in the fetal rat. The severity of ethanol's effects was only marginally dependent on the duration of maternal ethanol consumption per se and seemed to be more related to the relative exposure of the fetus to ethanol (fetal BAC). The relationship between the ethanol-induced fetal hypocalcemia and skeletal effects remains to be determined.     

Skeletal stem cells: phenotype, biology and environmental niches informing tissue regeneration

Advances in our knowledge of the biology of skeletal stem cells, together with an increased understanding of the regeneration of normal tissue offer exciting new therapeutic approaches in musculoskeletal repair. Skeletal stem cells from various adult tissues such as bone marrow can be identified and isolated based on their expression of a panel of markers associated with smooth muscle cells, pericytes and endothelial cells. Thus, skeletal stem cell-like populations within bone marrow may share a common perivascular stem cell niche within the microvascular network. To date, the environmental niche that nurtures and maintains the stromal stem cell at different anatomical sites remains poorly understood. However, an understanding of the osteogenic and perivascular niches will inform identification of the key growth factors, matrix constituents and physiological conditions that will enhance the ex vivo amplification and differentiation of osteogenic stem cells to mimic native tissue critical for tissue repair. This review will examine skeletal stem cell biology, the advances in our understanding of the skeletal and perivascular niche and interactions therein and the opportunities to harness that knowledge for musculoskeletal regeneration.     

Exercise training improves the IL-10/TNF-α cytokine balance in the gastrocnemius of rats with heart failure

Objective

This study examined the effects of exercise training (ExT) upon concentration of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and interleukin-10 (IL-10) in the gastrocnemius of rats with heart failure (HF) induced by left coronary artery ligation.

儿童青少年骨性Ⅱ类错(牙合)畸形矫治后面型变化的研究

目的:对比分析儿童青少年骨性Ⅱ类错(牙合)畸形患儿拔牙与非拔牙矫治前后的软组织侧貌变化差异.方法:由近年代向远年代抽取在该院口腔正畸科完成矫治的44例骨性Ⅱ类错(牙合)畸形患儿为研究对象,根据是否拔牙矫治分为拔牙组和非拔牙组,各22例.拔牙组患儿均拔除4颗双尖牙.对矫治前后的X线头颅侧位定位片进行软组织美学指标的测量分析.结果:拔牙组除颏唇沟角(Li-B'-Pos)和面角(NsPg'-FH)矫治前后的变化差异无统计学意义(P＞0.05)外,其余各测量指标均向面突度减小的方向变化,前后差异均有统计学意义(P＜0.05);非拔牙组矫治前后仅下唇倾角(B'Li-FH)和上唇凸距(Ls～REP)的变化差异有统计学意义(P＜0.05).矫治前两组患儿上唇倾角(A'Ls-FH)、Ls-REP、下唇凸距(Li-REP)、Z角和颏沟倾角(Pg'B'-FH)比较,差异均有统计学意义(P＜0.05).矫治后拔牙组的A'Ls-FH、上下唇角(A'Ls-B'Li)、Z角和Pg'B'-FH均大于非拔牙组,差异均有统计学意义(P＜0.05).结论:软组织侧面型较突的骨性Ⅱ类错(牙合)畸形患儿通过拔牙矫治有望获得较大的面型改变,而非拔牙矫治对患儿的侧貌影响较小.     

2001年陕西省饮水型氟中毒重点病区调查结果分析

为了给陕西省政府提供制定地氟病防制规划的依据，对位于不同自然地理环境的定边、蒲城和泾阳3县饮水型地氟病区的环境氟含量、病情和改水进展等情况进行了调查。结果显示经过20年的不懈努力，3县已有50.17％的病区人口进行了改水。改水后环境氟含量和病情均有明显降低，与1980年相比，水氟含量下降了50.60％；儿童氟斑牙患病率下降了38．12％；3d度氟骨症患病率下降了78．64％，再次证明改水预防饮水型氟中毒是行之有效的重要措施。同时调查结果也提示，改水后符合国家卫生标准的水样仅占31．12％。本次以水氟含量划定的病区与1980年划定的病区相比，符合率为65.38％。因此认为要制定全省改水防制规划，为防止陈旧的资料造成误导，应重新进行一次流行病学调查，保证资料的科学性。调查结果还提示水氟含量受件型和井深的影响较大。     

The effect of variability in maturational tempo and midparent height on variability in linear body measurements

Background: Information on the effect of variability in maturational tempo on variability in height attained at the same age is not readily available.

Aim: The study obtained this information from the data of the First Zurich Longitudinal Study.

Subjects and methods: Yearly measurements of standing height, sitting height and leg length, yearly assessments of bone age (RUS (Radius, Ulna and Short bones), TW3 method) and midparent height for 232 children from the First Zurich Longitudinal Growth Study are included in a correlational analysis.

Results: The course of the squared correlations of standing height, sitting height and leg length with attained RUS bone age, midparent height and both as a function of age are presented.

Conclusions: During puberty, up to 50% of the height variation in boys and 40% in girls is explained by maturational tempo.

Résumé. Arrière plan: L’information concernant l’effet de la variabilitè du rythme de la maturation sur celle de la stature á un âge donnè, n’est pas disponible.

But: Cette ètude a obtenu de l’information á partir de la première ètude longitudinale de Zurich.

Sujet0s y mèthodes: Une analyse de corrèlation est effectuèe á partir de mensurations annuelles de la stature, de la taille assis et de la longueur de la jambe, de contröles annuels de l’âge osseux (RUS, TW3) et de la stature mèdiale des parents pour 232 enfants de la première ètude de croissance de Zurich.

Résultats: On prèsente les valeurs des carrès des corrèlations pour la stature, la taille assis et la longueur de la jambe avec l’âge osseux atteint (RUS radius, ulna et os courts), avec la stature mèdiale des parents et les deux comme une fonction de l’âge.

Conclusions: Pendant la pubertè, jusqu’á 50% de la variation de la stature des garons et 40% de celle des filles, sont expliquès par le rythme de maturation.

Zusammenfassung. Hintergrund: Informationen über die Auswirkungen von Schwankungen im reifungsbedingten Wachstumstempo auf unterschiedliche im gleichen Alter erzielte Größen sind nicht in geeigneter Form verfügbar.

Ziel: Die vorliegende Arbeit versucht, Informationen zur angesprochenen Problematik aus den Daten der ersten Züricher Longitudinalstudie zu erlangen.

Inhalt und Methodik: Die jährlichen Daten aus Größenmessungen in den Positionen Stehen, Sitzen sowie Beinlänge und die jährlichen Bewertungsergebnisse der Knochenalter (RUS, TW3) als auch die Medium-Elterngrößen von 232 Kindern aus der ersten Züricher Longitudinalgrößenstudie werden in einer Wechselbeziehungsanalyse erfaßt.

Ergebnisse: Die Verläufe der quadrierten Verhältnisse von Steh-, Sitzgröße beziehungsweise Beinlänge mit denen von Knochenaltern nach RUS-Methode (Radius [Speiche], Ulna [Elle], Short bones [kleine Knochen]) beziehungsweise Medium-Elterngröße werden präsentiert. Beide Datenmengen werden außerdem als Funktionen des Alters dargestellt.

Schlußfolgerungen: Während des Stadiums der Pubertät lassen sich Größenunterschiede bei bis zu 50% der Jungen und bis zu 40% der Mädchen mit den Schwankungen im reifungsbedingten Wachstumstempo erklären.

Resumen. Antecedentes: No es fácil disponer de información acerca del efecto que tiene la variabilidad en el ritmo madurativo sobre la variabilidad estatural alcanzada a la misma edad.

Objetivo: El estudio obtuvo esta información a partir de los datos del Primer Estudio Longitudinal de Zurich (First Zurich Longitudinal Study).

Sujetos y métodos: Se han incluido en un análisis de correlaciones las medidas anuales de la estatura, la talla sentado y la longitud de la pierna así como las estimaciones anuales de la edad ósea (RUS, TW3) y la estatura media de los progenitores, de 232 niños del Primer Estudio Longitudinal de Zurich (First Zurich Longitudinal Study).

Resultados: Se presentan las variaciones de las correlaciones cuadráticas de la estatura, la talla sentado y la longitud de la pierna con la edad ósea alcanzada basada en el mètodo RUS (radio, ulna y huesos cortos), la estatura media de los progenitores y ambas en función de la edad.

Conclusiones: Durante la pubertad, hasta el 50% de la variación estatural de los chicos y el 40% de la de las chicas se explica por el ritmo madurativo.