Chronic trapezius myalgia: Morphology and blood flowlstudied in 17 patients

Bilateral open biopsies from the painful upper part of the trapezius muscle were studied in 17 patients with localized chronic myalgia related to static load during repetitive assembly work. Isolated pathologic ragged red fibers were related to the presence of myalgia. The phenomenon indicating disturbed mitochondrial function was confined to the Type 1 fibers. Using a laser-Doppler flowmeter, the muscle blood flow was recorded in the exposed muscle before a biopsy was taken. Pain was assessed and graded as the difference between the two sides, as was the presence of ragged red fibers. The myalgia correlated with reduced local blood flow: the greater the pain difference, the greater the reduction in blood flow. There was a correlation between the presence of mitochondria) changes and reduced muscle blood flow.     

Experimental Limb Disuse and Bone Blood Flow

Muscle biopsies from the descending portion of the trapezius muscle were studied in 9 healthy subjects and in 10 patients with localized chronic myalgia related to static load during repetitive assembly work for 16 (10–31) years, with 10 (4–26) months of sick leave at the time of biopsy. Both categories showed isolated atrophic muscle fibers and occasional abnormal fibers with internally situated nuclei, some variation in fiber diameter, and fiber splitting. Fibers with a “moth-eaten” appearance due to a multifocal loss of oxidative enzyme activity were frequent both in the healthy and in the myalgic individuals. In contrast, isolated pathologic “ragged red” fibers were only found in the cases with myalgia (8 of 10), strongly suggesting mitochondrial damage. The phenomenon was confined to the Type 1 fibers. The frequency of Type 1 fibers was increased. Levels of adenosine triphosphate and adenosine diphosphate were reduced in myalgia patients, whereas lactate, pyruvate, and glycogen levels were normal, as well as phosphoryl creatine and total creatine.     

Muscle changes in work-related chronic myalgia

Muscle biopsies from the descending portion of the trapezius muscle were studied in 9 healthy subjects and in 10 patients with localized chronic myalgia related to static load during repetitive assembly work for 16 (10-31) years, with 10 (4-26) months of sick leave at the time of biopsy. Both categories showed isolated atrophic muscle fibers and occasional abnormal fibers with internally situated nuclei, some variation in fiber diameter, and fiber splitting. Fibers with a "moth-eaten" appearance due to a multifocal loss of oxidative enzyme activity were frequent both in the healthy and in the myalgic individuals. In contrast, isolated pathologic "ragged red" fibers were only found in the cases with myalgia (8 of 10), strongly suggesting mitochondrial damage. The phenomenon was confined to the Type 1 fibers. The frequency of Type 1 fibers was increased. Levels of adenosine triphosphate and adenosine diphosphate were reduced in myalgia patients, whereas lactate, pyruvate, and glycogen levels were normal, as well as phosphoryl creatine and total creatine.     

Muscle changes in work-related chronic myalgia

Muscle biopsies from the descending portion of the trapezius muscle were studied in 9 healthy subjects and in 10 patients with localized chronic myalgia related to static load during repetitive assembly work for 16 (10-31) years, with 10 (4-26) months of sick leave at the time of biopsy. Both categories showed isolated atrophic muscle fibers and occasional abnormal fibers with internally situated nuclei, some variation in fiber diameter, and fiber splitting. Fibers with a “moth-eaten” appearance due to a multifocal loss of oxidative enzyme activity were frequent both in the healthy and in the myalgic individuals. In contrast, isolated pathologic “ragged red” fibers were only found in the cases with myalgia (8 of 10), strongly suggesting mitochondrial damage. The phenomenon was confined to the Type 1 fibers. The frequency of Type 1 fibers was increased. Levels of adenosine triphosphate and adenosine diphosphate were reduced in myalgia patients, whereas lactate, pyruvate, and glycogen levels were normal, as well as phosphoryl creatine and total creatine.     

Trapezius muscle changes unrelated to static work load. Chemical and morphologic controlled studies of 22 women with and without neck pain.

From a cross-sectional study of 82 women who were engaged in assembly work that involved static muscle loading of the shoulder muscles, 11 cases with complaints of neck tension (all except 1 arising at work) and 11 individually matched, exposed control cases without neck pain were studied. In addition, 10 matched, unexposed control cases were studied. Upon histochemical examination and study of the trapezius muscle, morphologic changes of type ragged red fibers were found in 8/11 neck-pain cases, in 7/11 exposed controls, and in 4/10 unexposed controls. The pathologic and clinical importance of rare, ragged red fibers in the trapezius muscle thus seems uncertain.     

Anesthetic management of a patient with MERRF syndrome

There are several specific considerations regarding anesthesia in patients with mitochondrial disease. We describe the successful administration of a combined general and epidural anesthesia with sevoflurane maintenance in a patient with myoclonic epilepsy with ragged red fibers (MERRF syndrome) scheduled for surgical treatment of bilateral clubfoot.     

Multifocal rhabdomyoma of the neck. Report of a case studied by fine-needle aspiration, light and electron microscopy, histochemistry, and immunohistochemistry

A 32-year-old Caucasian man presented with a tumor in the right side of the neck. Preoperative fine-needle aspiration showed large multinucleated cells with abundant granular cytoplasm that were consonant with the features of a granular cell tumor. At surgery, two separate tumors were found. Histologically, the tumor proved to be an adult rhabdomyoma, the 11th such multifocal case reported. The striated muscle origin of this benign tumor was confirmed by immunohistochemical and ultrastructural studies. The tumor cells were desmin-, myoglobin-, and actin-positive. They showed variable numbers of thick and thin filaments, as well as hypertrophic Z-band material. Histochemical studies showed the presence of basophilic muscle cells, vesicular nuclei, ragged red fibers, and diffuse acid phosphatase positivity. These features, together with the absence of actual muscle cell proliferation and the assumption that the mass of the tumor could be explained by the enormous swelling of the muscle cells, lead us to conclude that an adult rhabodomyoma is merely the result of a process of disorderly degeneration and regeneration rather than a real neoplasm or a hamartomatous lesion.     

Ultrastructural changes in paravertebral muscles associated with degenerative spondylolisthesis

STUDY DESIGN: The paravertebral muscle of 30 patients with spondylolisthesis and 30 control patients were investigated histologically. OBJECTIVE: To propose myopathologic paravertebral muscle changes in cases of degenerative lumbar spondylolisthesis. SUMMARY OF BACKGROUND DATA: The stability of the vertebral column is based on both active and passive systems. The passive system is composed of the vertebrae, the intervertebral discs, and the ligaments. Surrounding muscles and tendons constitute the active system. The autochthonous back muscles take over support functions if the passive system is ineffective. In some cases, muscles are overstrained for a long period, ultimately leading to muscular changes. This study was performed to determine the histopathologic correlates of this permanent strain. METHODS: Between July 1998 and July 1999, paravertebral muscle biopsies were performed for 30 patients with monosegmental degenerative spondylolisthesis undergoing posterior lumbar interbody fusion. The tissue samples were submitted to histologic analysis including immune and enzyme histochemistry and electron microscopy. In addition, the muscle fibers were submitted to morphometry. RESULTS: Severe pathologic alterations were found. The findings showed that 22 patients (73.3%) had ragged red fibers with evident ultrastructural mitochondrial anomalies. The cristae appeared irregular in 12 patients (40%) Type 1 paracrystalline inclusions were detected in five samples (16.6%) and dense bodies in eight (26.6%). Fibers with ubiquitin-positive inclusions were detected by immunohistochemistry in 13 patients (43.3%). As shown by the electron microscope, these corresponded to granulofilamentous inclusions and polyglucosan bodies. The samples were submitted to genetical analysis because biochemical studies showed reduced activity of the respiratory chain enzymes. Normal mitochondrial deoxyribonucleic acids of unchanged length were detected. CONCLUSIONS: Apart from nonspecific myopathic changes such as those observed in rimmed vacuoles and rods, increased numbers of polyglucosan bodies were detected. This increase in polyglucosan bodies currently has not been described in patients with otherwise normal muscles.     

Fat cell invasion in long-term denervated skeletal muscle

There are several differences between red and white muscles submitted to different experimental conditions, especially following denervation: a) denervation atrophy is more pronounced in red than white muscles; b) the size of the fibers in the red muscles does not vary between different parts of the muscle before and after denervation, when compared to white muscles; c) the regional difference in the white muscles initially more pronounced after denervation than red muscle; d) red muscle fibers and fibers of the deep white muscle present degenerative changes such as disordered myofibrils and sarcolemmal folds after long-term denervation; e) myotube-like fibers with central nuclei occur in the red muscle more rapidly than white after denervation. Denervation of skeletal muscles causes, in addition to fibers atrophy, loss of fibers with subsequent regeneration, but the extent of fat cell percentage invasion is currently unknown. The present article describes a quantitative study on fat cell invasion percentage in red m. soleus and white m. extensor digitorum longus (EDL) rat muscles at 7 weeks for up to 32 weeks postdenervation. The results indicate that the percentage of fat cells increase after denervation and it is steeper than the age-related fat invasion in normal muscles. The fat percentage invasion is more pronounced in red compared with white muscle. All experimental groups present a statistically significant difference as regard fat cell percentage invasion.     

Microcirculatory hemodynamics of the rat cremaster muscle flap in reduced blood flow states

Recent studies revealed that muscle and musculocutaneous flaps have the lowest peripheral resistance and best flap survival. The critical values of flow rates responsible for this survival have not been established. The authors evaluated the effect of prolonged arterial flow reduction on flow hemodynamics and muscle flap survival, independent of neovascularization using the rat cremaster muscle island flap model for microcirculatory studies. Muscle flaps were implanted into a transparent Plexiglas chamber to allow prolonged observation of the microcirculation. Twenty-six male Sprague-Dawley rats were studied in three experimental groups. In group I (control; no occlusion), after flap isolation, the cremaster muscle was implanted into the tissue chamber and microcirculatory measurements were performed from day 0 to day 3. In group II, after flap isolation, flow in the main feeding artery (the iliac) was reduced with a silk suture loop between 47% and 62%. In group III, arterial flow was reduced between 63% and 80%. Vessel diameters, red blood cell velocities, number of perfused capillaries, and number of rolling, sticking, and transmigrating leukocytes were reduced daily for each rat. Immediately after flow reduction, mean arteriolar (A1) diameters were significantly smaller in group II (25%) and group III (29%) compared with the controls (p<0.05). This reduction was confirmed by a drop in red blood cell velocities of 37% and 58% in groups II and III respectively (p<0.05). At day 1, more than 60% of group III flaps had no arterial flow, whereas normal flow was observed in control flaps for as long as 3 days. In addition, the number of perfused capillaries dropped significantly (by 42%) in group II flaps after 3 days (p<0.05). The authors conclude that continuous arterial blood flow reduction exceeding 60% of the normal volume, independent of angiogenesis, is incompatible with flap viability in the rat cremaster muscle model.     

腰椎后路术后骶棘肌损伤的实验研究

目的 观察腰椎后人路手术时骶棘肌不同程度的外科创伤与其组织形态学之间的相关性。方法 将成年新西兰大白兔20只随机均匀地分为五组：A组(对照组)，B组(假手术组)，C组(低张力组)，D组(高张力短时间组)，E组(高张力长时间组)。每组分别于术中骶棘肌牵开前、术后即刻、术后2d、1周、2周、1月、2月取压力感应片下的深层骶棘肌肌肉，分别送石蜡、冰冻及透射电镜检查。结果 各后路手术实验组随骶棘肌剥离、牵拉和持续时间的逐渐加大而呈现逐渐加剧的病理改变，总的结果是呈现变性、坏死和修复反应的顺序演变。在损伤早期，主要呈现不同程度的横纹肌细胞间水肿、炎细胞浸润和核内移；严重者可出现腊样变性及液化性坏死，腊样变性肌细胞。从术后第1周起，肌组织的坏死越来越明显，并逐渐向修复反应过渡，可出现片状的小群状肌萎缩或肌纤维同型化；后期最主要的是纤维组织大量增生并替代大片萎缩的肌纤维。电镜的病理改变与光镜结果相一致，后期可见大量的胶原纤维和成纤维细胞增生，有大量脂滴聚集现象。结论 不同程度的骶棘肌剥离、牵拉能造成不同程度的骶棘肌损伤，其牵拉力和持续时间的大小与组织学结果相平行，电镜与光镜组织学结果是相一致的；多种损伤机制(压迫、缺血、代谢紊乱、失神经支配)参与了后路手术时对骶棘肌的损伤反应。     

阳萎患者阴茎海绵体平滑肌细胞超微结构的研究

阴茎海绵体平滑肌细胞超微结构的改变对阴茎勃起功能具有重要的意义。以阳萎患者与对照组对比研究的方法，观察了阳萎患者阴茎海绵体组织细胞超微结构改变。结果表明，阳萎阴茎海绵体平滑肌细胞超微结构有明显的病理改变，以线粒体退变、微丝减少或消失、内质网损害扩张、糖原缺乏等为主，也可见到微血管腔闭塞的现象，提示局部有微循环障碍的问题。引起这种病理损害的原因可能与局部组织缺血缺氧有关。认为海绵体组织的这种病理改变可能是引起阳萎的直接因素之一。     

What determines the symptoms associated with subclavian artery occlusive disease?

Symptoms associated with subclavian artery stenosis are related to reduced cerebral or arm blood flow. A large difference in blood pressure between the two arms is associated with symptoms of arm ischemia alone and is usually caused by an anatomic variant. The presence or absence of a radiologic steal alone did not seem to determine the type or presence of symptoms. The type of cerebral symptoms seems to be determined by the location of other extracranial vascular stenosis. In patients with hemispheric symptoms there was a higher incidence of anterior circulation insufficiency and a greater reduction in the overall cerebral blood flow. In patients with nonhemispheric symptoms a higher incidence of posterior circulation insufficiency occurred. There may be a small group with nonhemispheric symptoms and a subclavian artery stenosis in whom reversed vertebral artery blood flow is the sole determinant. Perhaps more accurate delineation of other extracranial vascular stenosis would help determine what stenosis in addition to the subclavian artery occlusive disease determines the presenting symptoms. Surgical repair of these lesions may lead to an improved cure rate in this group of patients.     

The effect of hypertonic saline resuscitation on responses to severe hemorrhagic shock by the skeletal muscle, intestinal, and renal microcirculation systems: seeing is believing

BACKGROUND: Decompensated hemorrhagic shock is often refractory to resuscitation, and we show here that it is associated with loss of vascular tone in skeletal muscle precapillary arterioles. We tested the hypothesis that microvascular derangements in the skeletal muscle, intestinal, and renal microcirculation systems would be reversed by initial hypertonic saline-dextran infusion. METHODS: Male Sprague-Dawley rats underwent precollicular brain stem transection without anesthesia for study. Parameters measured by in vivo videomicroscopy included cardiac output, mean arterial pressure, and microvascular responses in the skeletal muscle, ileum, and renal (i.e., the hydronephrotic kidney) microcirculation systems. Hemorrhaged was induced to a mean arterial pressure of 50 mmHg until decompensation occurred. The rats were then initially resuscitated with (1) 4 mL/kg 7.5% NaCl in 6% dextran 70, (2) 33 mL/kg .9% NaCl in 6% dextran 70, or (3) 33 mL/kg .9% NaCl. Twenty minutes later they received shed blood plus 33 mL/kg .9% NaCl to maintain mean arterial pressure at baseline levels. RESULTS: Decompensated hemorrhagic shock decreased cardiac output to between 24% and 35% of baseline values and profoundly decreased microvascular blood flow to between 10% and 19% of baseline. At the completion of resuscitation cardiac output increased to greater than baseline in all groups. Microvascular blood flow increased toward baseline transiently but then progressively deteriorated to between 36% and 69% of baseline in the 3 tissues. There was no significant difference between the three resuscitative fluids. CONCLUSIONS: Despite return of cardiac output to greater than baseline levels, muscle, intestinal, and renal microvascular blood flows remained significantly depressed. Hypertonic saline and/or dextran did not improve these deficits.     

Histochemical analysis of respiratory muscles of patients with esophageal cancer--with special reference to the preoperative nutritional state

Postoperative pulmonary complication and respiratory failure, frequently seen in undernourished patients such as those with esophageal cancer, were suspected to be due to respiratory muscle wasting caused by nutritional depletion. Based on this idea, the respiratory muscles obtained by biopsies during operation from diaphragm, external intercostal muscle, and rectus abdominis muscle were assessed histochemically in 32 patients. The specimens were stained for myosin ATPase to differentiate the types of muscle fibers, and then the size and distribution of the muscle fibers of each type were measured. In diaphragm muscle, cross-sectional areas of type 1 & 2 and the ratio of the area occupied by each fiber were usually the same; in external intercostal muscle, however, type 1 fibers were dominant and in rectus abdominis muscle, type 2 fibers were dominant. The cross-sectional area of each respiratory muscle fiber well correlated with certain anthropometrical indexes, and the nutritionally depleted cases, the muscle fibers were of a smaller size suggesting less respiratory muscle strength. The ratio of the area occupied by type 1 fibers in diaphragm muscle was linearly related to serum albumin, total cholesterol, and PNI (prognostic nutritional index). Type 2 fibers were dominant in malnourished patients, suggesting greater fatigue compared to well-nourished cases. Opposite findings were obtained in external intercostal muscle and rectus abdominis muscle, and the ratio of the area occupied by type 2 fibers was smaller in the undernourished cases, suggesting reduced maximum strength of these muscles.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of muscle flap coverage on bone blood flow following devascularization of a segment of tibia: an experimental investigation in the dog

Severe tibial fractures may be associated with soft tissue loss, devascularization of cortical bone, and significant morbidity. Local rotational muscle flap coverage is used to obtain coverage of acute open tibial fractures and to treat chronic osteomyelitis of the tibia. The purpose of this study was to determine (a) the longitudinal and cross-sectional regional blood flow characteristics of the canine tibia and (b) whether a muscle flap was superior to vascularized skin coverage in restoring blood flow to devascularized canine tibial cortex. A 2.5-cm segment of tibia between two standardized osteotomies was devascularized. The segment was replaced anatomically and stabilized with a plate. The animals were divided into two experimental groups: (a) skin coverage (n = 8), and (b) muscle flap coverage (n = 8). Thirty-one days postoperatively Ce141 microspheres were injected to measure bone blood flow. The tibial diaphysis was divided into proximal, middle (devascularized), and distal segments. The unoperated leg was used as a control. In the control tibiae, the middle segment was less vascular than either the proximal or distal segment and no difference between anterior and posterior cortical blood flow was observed. Blood flow to the devascularized segment of tibia was significantly greater when it was covered with a muscle flap (p less than 0.025). The most significant increase in bone blood flow in the muscle flap coverage group versus the skin coverage group occurred in the anterior cortex of the tibia (p less than 0.005). This may be clinically important since the soft tissues over the anterior tibia are commonly deficient following open fractures.(ABSTRACT TRUNCATED AT 250 WORDS)     

Closed versus open medullary nailing of femoral fractures. Blood flow and healing studied in rats.

In rats, bilateral closed femoral fractures were produced. On the left side, closed intramedullary nailing was done, and on the right side, the nail was inserted by an open procedure. The healing process of the fractures was evaluated at 4, 8, and 12 weeks, bone and muscle blood flows were also determined. Reaming had no acute impact on bone blood flow, while reaming and fracture halved total bone flow (P < 0.04), and reduced cortical diaphyseal flow to approximately one quarter (P < 0.01). No differences were found between the open and closed methods. At 4 weeks, the bending moment, rigidity, and fracture energy of the fractures treated by closed medullary nailing were greater than those treated by open nailing. The fracture energy was still greater at 8 weeks, while no differences were seen in bending moment and rigidity. At 12 weeks, however, there were no differences in the mechanical parameters. Bone blood flows in both the cortical diaphysis and callus area were increased at 4 and in the callus area at 8 weeks in bones treated by the open method. No differences were found at the end of the experiment. Muscle blood flow was not different in the two limbs, and was constant during the experimental period. We conclude that femoral fractures treated by closed nailing heal better in the initial phase compared with those that have been openly nailed. This difference cannot be explained by an impaired muscle or bone blood flow due to open surgery.     

Ultrastructural changes in human skeletal muscles following tendon and nerve injuries. I. Ultrastructural changes following tendon injuries]

During reconstructive procedures performed 4-16 weeks after the tendon lesion the specimens obtained from the injured muscle have been examined by the authors. It was found that after the tendon injury inactivity atrophy develops and a condition of equilibrium could be observed at this time. The most important changes in the fine structure were seen in the contractile elements: these were atrophied, homogenized, fragmentated and ragged independently from the functional unities. The number of the mitochondria was considerably decreased, the sarcoplasmic reticulum was increased, and the difference between the originally red and white muscular fibres was indistinct. The glycogen content of the musculature was decreased, or it disappeared completely. No pathologic changes have been observed in the sarcolemma, the cell nuclei and the motor nerve end-organs.     

Altered Skeletal Muscle Mitochondrial Proteome As the Basis of Disruption of Mitochondrial Function in Diabetic Mice

Insulin plays pivotal role in cellular fuel metabolism in skeletal muscle. Despite being the primary site of energy metabolism, the underlying mechanism on how insulin deficiency deranges skeletal muscle mitochondrial physiology remains to be fully understood. Here we report an important link between altered skeletal muscle proteome homeostasis and mitochondrial physiology during insulin deficiency. Deprivation of insulin in streptozotocin-induced diabetic mice decreased mitochondrial ATP production, reduced coupling and phosphorylation efficiency, and increased oxidant emission in skeletal muscle. Proteomic survey revealed that the mitochondrial derangements during insulin deficiency were related to increased mitochondrial protein degradation and decreased protein synthesis, resulting in reduced abundance of proteins involved in mitochondrial respiration and β-oxidation. However, a paradoxical upregulation of proteins involved in cellular uptake of fatty acids triggered an accumulation of incomplete fatty acid oxidation products in skeletal muscle. These data implicate a mismatch of β-oxidation and fatty acid uptake as a mechanism leading to increased oxidative stress in diabetes. This notion was supported by elevated oxidative stress in cultured myotubes exposed to palmitate in the presence of a β-oxidation inhibitor. Together, these results indicate that insulin deficiency alters the balance of proteins involved in fatty acid transport and oxidation in skeletal muscle, leading to impaired mitochondrial function and increased oxidative stress.     

Closed versus open medullary nailing of femoral fractures

In rats, bilateral closed femoral fractures were produced. On the left side, closed intramedullary nailing was done, and on the right side, the nail was inserted by an open procedure. The healing process of the fractures was evaluated at 4, 8, and 12 weeks, bone and muscle blood flows were also determined. Reaming had no acute impact on bone blood flow, while reaming and fracture halved total bone flow (P < 0.04), and reduced cortical diaphyseal flow to approximately one quarter (P < 0.01). No differences were found between the open and closed methods. At 4 weeks, the bending moment, rigidity, and fracture energy of the fractures treated by closed medullary nailing were greater than those treated by open nailing. The fracture energy was still greater at 8 weeks, while no differences were seen in bending moment and rigidity. At 12 weeks, however, there were no differences in the mechanical parameters. Bone blood flows in both the cortical diaphysis and callus area were increased at 4 and in the callus area at 8 weeks in bones treated by the open method. No differences were found at the end of the experiment. Muscle blood flow was not different in the two limbs, and was constant during the experimental period.

We conclude that femoral fractures treated by closed nailing heal better in the initial phase compared with those that have been openly nailed. This difference cannot be explained by an impaired muscle or bone blood flow due to open surgery.