Muscle glycogenosis

Summary This review describes clinical, biochemical and genetic features of the four inborn errors affecting muscle glycogen breakdown, namely deficiencies of phosphorylase, phosphorylase kinase, amylo-1,6-glucosidase and acid -glucosidase. They are characterized by a wide spectrum of clinical manifestation, affecting age of onset, clinical features, progress of disease and tissue involvement. Biochemically, variability of all four enzyme deficiencies is evident in terms of differences in residual enzyme present in tissues, and in the presence or absence of enzyme protein. Genetic heterogeneity, which has been documented in each of the enzyme deficiencies, manifests itself in terms of the presence, absence, quantity or size of mRNA. In phosphorylase deficiency heterogeneity has also been documented at the DNA level. In acid maltase deficiency nine mutant phenotypes have been described affecting various stages of lysosomal enzyme processing.     

Muscle cramps

Painful involuntary skeletal muscle contractions, or cramps, are common patient complaints and may be classified as examples of true cramp, tetany, contracture, or dystonia. The pathophysiologic and clinical features of each of these diagnoses are described. The approach to the patient with cramps should emphasize the history, physical examination, and, if the diagnosis is unclear, minimal routine laboratory data. Although many therapies have been proposed for ordinary cramps, the best evidence supports stretching exercises and quinine. Areas for future study of this common symptom are proposed.     

Muscle Fiber-Type Distribution Pattern in the Human Cricopharyngeus Muscle

Our previous studies described that the human cricopharyngeus (CP) is composed of two neuromuscular compartments (NMCs), horizontal and oblique. The present study was designed to explore the differences in muscle fiber-type distribution between the NMCs within the human CP and to examine the oxidative capacity of the muscle fibers. Seven adult human CP muscles obtained from autopsies were stained for myofibrillar ATPase, reduced nicotinamide adenine dinucleotide tetrazolium reductase (NADH-TR), and succinic dehydrogenase (SDH) to analyze enzyme-histochemical fiber-type characteristics. Notable findings obtained from this study are as follows: (1) Different NMCs within the human CP contained different percentages of muscle fiber types. The horizontal CP (CPh) contained more slow-twitch fibers than the oblique CP (CPo). (2) Each of the NMCs was dividable histochemically into two layers or subcompartments: a slow fiber-type inner layer and a relatively fast fiber outer layer. (3) As a whole, type I fibers had higher levels of NADH-TR and SDH than type II fibers. However, in both type I and II muscle fiber types, different patterns of oxidative enzyme activity were seen. Histochemically defined fiber layers of the CP are not seen in other mammals, suggesting that CP function is more specialized in humans.     

氧化型低密度脂蛋白抑制人内皮细胞组织因子通路抑制子mRNA的表达

为探讨氧化型低密度脂蛋白在血栓形成过程中的作用及机制,用超速离心法从正常人血浆中分离出低密度脂蛋白后,用Ｃｕ＾２＋使之氧化变成氧化型低密度脂蛋白。在人脐静脉内皮细胞的培养基中加入一定深度的低深度脂蛋白或氧化型低密度脂蛋白,培养一定时间后,是硫氰酸胍法抽提细胞总ＲＮＡ,用反转录聚合酶链反应方法检测人脐静脉内皮细胞中组织因子通路抑制子ｍＲＮＡ的表达,以观察氧化型低密度脂蛋白对人脐静脉内皮细胞表达因子通     

Muscle strain injuries

Muscle injuries--lacerations, contusions or strains--are by far the most common injuries in sports. After first aid following the RICE principle (Rest, Ice, Compression and Elevation), therapy must be tailored according to the severity of the injury and based on the knowledge gained from experimental studies on regeneration of injured muscle. Most muscle injuries can be treated conservatively with excellent recovery, but complete ruptures with complete loss of function should be managed surgically. Immediately after the injury, a short period of immobilization is needed to accelerate formation of the scar between the stumps of the ruptured myofibers, to which the stumps adhere. The optimal length of immobilization depends on the grade of the injury, and should not be longer than needed for the scar to bear the pulling forces without rerupture. Early mobilization is required to invigorate adhesion, orientation of the regenerating muscle fibers, revascularization and resorption of the connective tissue scar. Another important aim of early mobilization, especially in clinical sports medicine, is to minimize inactivity-induced atrophy as well as loss of strength and extensibility, which are rapidly appearing adverse sequelae of prolonged immobilization.     

左旋硝基精氨酸所致肺动脉高压大鼠外周血管多巴胺-1受体反应性的变化

为研究一氧化氮合酶抑制剂左旋硝基精氨酸诱导的肺动脉高压大鼠各部位离体血管环对多巴胺－１受体反应性的影响,采用大鼠肺动脉、肠系膜动脉和肾动脉离体血管标本,在去甲肾上腺素收缩血管后,用多巴胺－１受体选择性激动剂非诺多泮使血管舒张,所有实验在吲哚美辛（１０μｍｏｌ／Ｌ）和普萘洛尔（３μｍｏｌ／Ｌ）存在下进行。左旋硝基精氨酸组大鼠各动脉对非诺多泮的反应性均有没程度的降低,以肺动脉最明显,最大舒张占预收缩的     

Muscle rehabilitation in haemophilia

Summary. Musculoskeletal dysfunction is a common manifestation of haemophilia. This dysfunction may be associated with imbalances between muscle groups. Evidence emerging from the literature suggests that the rehabilitation of this dysfunction is very relevant for the patient with musculoskeletal problems. Treatment of muscle imbalance may be linked with a reduction in recurrence of symptoms. Further research is needed to establish the relevance of this area in patients with haemophilia but the clinical evidence supports the developing work in this field.     

Exogastric Smooth Muscle Tumors

Gastric smooth muscle tumors may occasionally be largely exogastric in location simulating extrinsic masses. The features which help to localize these masses to the gastric wall are discussed and illustrative cases are presented.     

Aging and Muscle Loss

Aging is associated with a decrease in fat-free mass, an increase in fat mass, and progressive impairment of muscle function and performance. Diminishing anabolic hormone levels and progressive declines in muscle protein turnover contribute to the multifactorial pathophysiology of age-associated sarcopenia. The potential effects of anabolic hormone replacement on body composition and functional capacity are only beginning to be studied.