A continuous and pulsatile flow circulation system for evaluation of cardiovascular devices

In a previous report we suggested that muscle fibers in distal myopathy with rimmed vacuoles (DMRV) were degraded by both lysosomal proteolysis (cathepsins) and Ca2+-dependent, nonlysosomal proteolysis (calpain). Given recent evidence of abnormal ubiquitin accumulation in rimmed vacuoles, we examined the role of the ATP-ubiquitin-dependent proteolytic pathway (proteasomes) in myofiber degradation in this myopathy. Immunohistochemically, proteasomes (26S) were located in the cytoplasm in normal human muscle, but the staining intensity was weak. Quantitative analysis showed more reactivity for proteasomes in DMRV muscles and, to a lesser extent, in muscles from muscular dystrophy, polymyositis, and amyotrophic lateral sclerosis patients. In DMRV, proteasomes often were located within or on the rim of rimmed vacuoles, and in the cytoplasm of atrophic fibers. Ubiquitin accumulation was marked within rimmed vacuoles and was seen less extensively in the cytoplasm of atrophic fibers. The latter proteins colocalized well. In other diseased muscles, proteasomes and ubiquitin showed a positive reaction in the atrophic or necrotic fibers. The results indicate increased proteasome and ubiquitin in these muscle fibers as well as in other diseased muscle fibers. We suggest that the ATP-ubiquitin-proteasome proteolytic pathway as well as the nonlysosomal calpain and the lysosomal proteolytic pathway may participate in the muscle fiber degradation in DMRV.     

Rimmed vacuoles with beta-amyloid and ubiquitinated filamentous deposits in the muscles of patients with long-standing denervation (postpoliomyelitis muscular atrophy): similarities with inclusion body myositis

In the chronically denervated muscles of patients with prior paralytic poliomyelitis, there are secondary myopathic features, including endomysial inflammation and rare vacuolated fibers. To assess the frequency and characteristics of the vacuoles and their similarities with those seen in inclusion body myositis (IBM), we examined 58 muscle biopsy specimens from patients with prior paralytic poliomyelitis for (1) the presence of rimmed vacuoles; (2) acid-phosphatase reactivity; (3) Congo-red-positive amyloid deposits; (4) electron microscopy, searching for tubulofilaments; and (5) immunoelectron microscopy, using antibodies against beta-amyloid and ubiquitin. We found vacuolated muscle fibers in 18 of 58 (31%) biopsies, with a mean frequency of 2.06 +/- 0.42 fibers per specimen. The vacuoles contained acid phosphatase-positive material in 6 of the 18 (33.30%) specimens and stained positive for Congo red in five (27.80%). By immunoelectron microscopy, the vacuoles contained 5.17 +/- 0.13 nm fibrils and 14.9 +/- 0.31 nm filaments that immunoreacted with antibodies to beta-amyloid and ubiquitin in a pattern identical to the one seen in IBM. We conclude that vacuolated muscle fibers containing filamentous inclusions positive for amyloid and ubiquitin are not unique to IBM and the other vacuolar myopathies but can also occur in a chronic neurogenic condition, such as postpoliomyelitis. The chronicity of the underlying disease, rather than the cause, may lead to vacuolar formation, amyloid deposition, and accumulation of ubiquitinated filaments.     

Transgenic mice over-expressing the C-99 fragment of betaPP with an alpha-secretase site mutation develop a myopathy similar to human inclusion body myositis

Inclusion body myositis (IBM) is the most common muscle disease in the elderly. Amyloid-beta protein (A beta) has been shown to accumulate abnormally in the vacuolated fibers and to localize to amyloid-like fibrils in muscles from IBM patients. We studied the skeletal muscles from a line of transgenic mice over-expressing the carboxyl-terminal 99 amino acids (C99) of the beta-amyloid precursor protein (betaPP) with a substitution of lysine-612 to valine (K612V), intended to abolish alpha-secretase recognition and to preserve the A beta domain of C99. The majority (87%) of the 24-month-old transgenic mice showed myopathic changes, and approximately one-third of them had degenerating fibers with sarcoplasmic vacuoles and thioflavin-S-positive deposits. Ultrastructurally, the inclusions were aggregates of short thin amyloid-like fibrils, 6 to 8 nm in diameter. These features are similar to those of human IBM. Immunocytochemistry using an antibody against A beta showed membranous staining in most muscle fibers of transgenic mice, as well as granular or vacuolar cytoplasmic staining in the atrophic fibers. Western blots showed a high level of accumulation of carboxyl-terminal fragments of betaPP in the muscles of the transgenic mice with the most severe IBM-like lesions. The expression of IBM-like lesions was age dependent. These transgenic mice provide a model for the study of IBM and for the peripheral expression of a key element in the pathogenesis of Alzheimer disease.     

Inclusion body myositis: abnormal protein accumulation does not trigger apoptosis

To examine whether apoptosis may contribute to muscle fiber loss in inclusion body myositis, we used the terminal deoxynucleotidyl transferase-mediated X-dUTP nick-end labeling (TUNEL) assay to compare the occurrence of DNA fragmentation in muscle samples from patients with inclusion body myositis and polymyositis. TUNEL-positive nuclei in nonnecrotic muscle fibers were rare even in the vicinity of amyloid-like material; significantly more frequent in polymyositis than inclusion body myositis; and several times less frequent than necrotic muscle fibers or mononuclear cell myocytotoxicity in both patient groups. Apoptosis is unlikely to play a significant role in the pathogenesis of inclusion body myositis.     

Ragged red fibers in normal aging and inflammatory myopathy

Ragged red fibers are an important marker for mitochondrial disease. To evaluate the hypothesis that mitochondrial dysfunction may play a role in the pathogenesis of aging and inclusion body myositis, we studied the frequency of ragged red fibers in muscle biopsy specimens from 15 young and 13 old normal adults, and from 27 patients with inclusion body myositis, polymyositis, or dermatomyositis. Serial transverse cryostat sections were stained with modified Gomori trichrome, modified succinic dehydrogenase, and cytochrome c oxidase. The frequency of ragged red fibers, determined by measuring the percent number of succinic dehydrogenase-positive ragged red fiber equivalents, was significantly higher in old compared to young normal subjects (0.33 vs. 0.02%, p < 0.0001). With the exception of a single polymyositis biopsy specimen showing a large number of ragged red fibers, the frequency of ragged red fibers in patients with polymyositis or dermatomyositis was similar to that of age-matched normal control subjects. The frequency of ragged red fibers was more than 1% in 7 of 8 patients with inclusion body myositis (maximum, 15%). The modified succinic dehydrogenase stain was more sensitive than the modified Gomori trichrome in detecting accumulation of mitochondria in muscle fibers. Cytochrome c oxidase activity was deficient in most ragged red fibers. We conclude that the number of ragged red fibers increases with normal aging and may reflect an age-related decline in muscle mitochondrial oxidative metabolism. The frequent occurrence of ragged red fibers in inclusion body myositis suggests that mitochondrial function may be impaired in this disease.     

Spinal pathology in spinal muscular atrophy in comparison with amyotrophic lateral sclerosis

We analyze neuronal cytopathology and secondary reactions in spinal-muscular atrophy (SMA) in comparison with amyotrophic lateral sclerosis (ALS). In a series of SMA and ALS cases, immunohistochemistry was performed on spinal cord sections for neuronal, astroglial and microglial antigens, ubiquitin and tau proteins. Swollen motoneurons staining for phosphorylated neurofilament proteins are seen in most SMA but few ALS cases. Ubiquitinated inclusions are found only in ALS. In SMA, glial bundles are prominent in anterior roots, to lesser extent in posterior roots. In ALS, glial bundles are seen only in some cases. While basic histopathologies are similar in both types of motor neurone diseases, neuronal cytoskeletal pathology is more prominent in SMA, possibly reflecting a more acute degenerative process. The presence of axon spheroids and glial bundles also in posterior horns/roots of both types of motor neurone disease suggests spread of degenerative pathology beyond the motor system.     

Coronary aneurysm in Behcet''s disease. Report of a case

Polymyositis, dermatomyositis, and inclusion body myositis, although immunopathologically distinct, share 3 dominant histological features: inflammation, fibrosis, and loss of muscle fibers. Progress in molecular immunology and immunogenetics has enhanced our understanding of these cellular processes. Based on the T-cell receptor gene rearrangement, the autoinvasive CD8+ T cells in polymyositis and inclusion body myositis, but not dermatomyositis, are specifically selected and clonally expanded in situ by heretofore unknown muscle-specific autoantigens. The messenger RNA of cytokines is variably expressed, except for a persistent up-regulation of interleukin 1beta in inclusion body myositis and transforming growth factor beta in dermatomyositis. In inclusion body myositis, the interleukin 1, secreted by the chronically activated endomysial inflammatory cells, may participate in the formation of amyloid because it up-regulates beta-amyloid precursor protein (beta-APP) gene expression and beta-APP promoter and colocalizes with beta-APP within the vacuolated muscle fibers. In dermatomyositis, transforming growth factor beta is overexpressed in the perimysial connective tissue but is down-regulated after successful immunotherapy and reduction of inflammation and fibrosis. The degenerating muscle fibers express several antiapoptotic molecules, such as Bcl-2, and resist apoptosis-mediated cell death. In myositis, several of the identified molecules and adhesion receptors play a role in the process of inflammation, fibrosis, and muscle fiber loss, and could be targets for the design of semispecific therapeutic interventions.     

Cytosol concentrations of CD44 isoforms in breast cancer tissue

Skeins or skein-like inclusions (SLIs) in motor neurons detected by ubiquitin immunohistochemistry are a characteristic finding of amyotrophic lateral sclerosis (ALS). Here we report ubiquitinated SLIs in the putamen and caudate nucleus from a case of ALS with dementia. A 48-year-old Japanese man developed apathy and amimia. Mental and neurological examinations revealed severe character change, muscle atrophy and fasciculation of the distal upper extremities and the tongue, and an exaggeration of the deep tendon reflex. He subsequently showed dysphagia and dysarthria. He died at the age of 51 years, after a total clinical course of about 2.5 years. By immunohistochemistry, ubiquitin-immunoreactive intraneuronal inclusions were observed in the spinal anterior horn cells, the frontal, temporal and entorhinal cortices, dentate fascia of the hippocampus and the amygdala. In addition, ubiquitinated inclusions were also seen in the putamen and caudate nucleus, which appeared as aggregates of thread-like structures similar to SLIs in the spinal anterior horn neurons. They were not seen on hematoxylin-eosin staining, and they also did not show any argentophilia nor did they react with other antibodies, including antibody against tau protein. To our knowledge, this is the first report of the presence of SLIs in non-motor neurons. Our results thus support the notion that ALS is a multisystem disease, and not simply a disease of the motor neurons.     

Lack of selectin-dependent adhesion in prostate cancer cells expressing sialyl Le(x)

In the muscle lesions of inclusion body myositis (IBM), two populations of T cells can morphologically be distinguished, T cells that invade muscle fibers and T cells that remain in interstitial areas. Using combined immunohistochemistry and RT-PCR, we analysed the TCR expressed by these distinct T cell populations. In three of eight IBM muscle specimens, the autoinvasive T cells were stained with one of the available mAbs: anti-Vbeta5.3 in patient 1, anti-Vbeta5.2 in patient 2, and anti-Vbeta3 in patient 3. The corresponding TCR Vbeta mRNAs were amplified by RT-PCR and the PCR products were cloned and sequenced. In all three specimens, the TCRs expressed by the autoinvasive T cells were clonally restricted. Furthermore, in patient 1 two different mAbs labelled two distinct populations of T cells: an autoaggressive population of CD8 + Vbeta5.3 + cells that invaded muscle fibers and a noninvasive interstitial population of CD8 - Vbeta5.1 + cells. TCR sequence analysis revealed that the noninvasive Vbeta5.1 + T cells were clonally diverse, whereas the autoinvasive Vbeta5.3 + T cells were clonally restricted.     

Inclusion body myositis

Inclusion body myositis has been recently recognized as a clinical entity although its exact definition remains uncertain. Initially considered to be an inflammatory dermatomyositis, inclusion body myositis can actually take on three specific forms: disseminated muscle atrophy and weakness, pseudopolymyositis, or pseudo-degenerative disease. Inclusion body myositis is different from non-inflammatory neuromuscular diseases with vacuoles. Abnormal deposits are seen within the muscle fiber may contain amyloid substance, beta-amyloid precursor, ubiquitin, antichymotrypsin, protein tau, apolipoprotein E and even prions. The signification of these deposits is unknown. Deletions in mitochondrial DNA have been demonstrated but do not appear to play a causal role. More and more hereditary forms are being recognized and certain may be related to an abnormality in chromosome 9.     

Are muscle fibers denervated in myotonic dystrophy?

An underlying neurogenic abnormality has recently been postulated in the muscular dystrophies. To test this hypothesis, we applied a widely accepted criterion of denervation-ie, and increase in extrajunctional acetyicholine (ACh) receptor sites--to muscles biopsy specimens from nine patients with myotonic dystrophy and three with amyotrophic lateral scierosis (ALS). The ACh receptor sites were determined by means of iodine 125-labeled alpha-bungarotoxin binding, measured by scintillation counting and autoradiography. None of the myotonic dystrophy muscles showed increased extrajunctiona ACh receptor sites, even in the smallest fibers. By contrast, muscle biopsy specimens from patients with ALS showed notably increased extrajunctional ACh receptor sites, especially in the small fibers. Our findings do not support the hypothesis of a neurogenic defect in myotonic dystrophy.     

Inclusion body myositis: clinical and pathological boundaries

Inclusion body myositis, polymyositis, and dermatomyositis are three distinct categories of inflammatory myopathy. Some authorities commented on the selective early weakness of the volar forearm muscles, quadriceps, and ankle dorsiflexors in inclusion body myositis. The most important feature distinguishing inclusion body myositis from the other two inflammatory myopathies is the lack of responsiveness to immunosuppressive treatment. Although most patients with inclusion body myositis have characteristic muscle biopsy findings, some cannot be distinguished histologically early from polymyositis. Predicting responsiveness to immunosuppressive medications, independent of muscle histology, would be valuable to clinicians. We retrospectively reviewed the pattern of weakness and other clinical features of 46 patients newly diagnosed with either inclusion body myositis, polymyositis, or dermatomyositis. Asymmetrical muscle weakness with prominent wrist flexor, finger flexor, and knee extensor involvement was specific for inclusion body myositis and unresponsive polymyositis. Male sex, lower creatine kinase levels, slower rate of progression, and peripheral neuropathy were also more common in inclusion body myositis and unresponsive polymyositis than in responsive polymyositis and dermatomyositis patients. Repeat muscle biopsy in 2 patients in the unresponsive polymyositis group demonstrated histological features of inclusion body myositis. We suspect that patients with clinical features of inclusion body myositis but lacking histological confirmation may nonetheless have inclusion body myositis. Our study supports the recently proposed criteria for definite and possible inclusion body myositis.     

Muscular ultrasound in idiopathic inflammatory myopathies of adults

To evaluate the value of myosonography in inflammatory myopathies ultrasound of skeletal muscles was performed in 70 patients, aged 21-82 years, suffering from histologically proven polymyositis (n = 30), dermatomyositis (n = 18), granulomatous myositis (n = 9), inclusion body myositis (n = 13), and in 102 control persons. The sensitivity of muscle ultrasound in detecting histopathologically proven disease (82.9%) was not significantly different from electromyography (92.4%) or serum creatine kinase activity (68.7%). The positive predictive value of ultrasound was 95.1%, the negative predictive value 89.2%, and the accuracy 91.3%. The different types of inflammatory myopathies presented with typical, but not specific ultrasound features. Polymyositis showed atrophy and increased echointensity predominantly of lower extremity muscles, whereas in dermatomyositis clear muscle atrophy was rare and echointensities were highest in forearm muscles. Echointensities were lower in dermatomyositis compared to poly- and granulomatous myositis. Granulomatous myositis was characterized by the highest echointensities and a tendency towards muscle hypertrophy. Severe muscle atrophy was the most impressive feature in the majority of patients with inclusion body myositis. Comparison of ultrasound and histopathological findings indicates that muscle lipomatosis has a much greater impact on muscular echointensity than does muscle fibrosis. Ultrasound of myositis improved clinical assessment of patients by supplying differential diagnostic clues based on precise muscle size measurements and identification of mesenchymal abnormalities, particularly muscle lipomatosis.     

Vitamin A levels at birth of high risk preterm infants

Inclusion body myositis is an increasingly recognised form of inflammatory myopathy with characteristic clinical and histopathological features which has seldom been reported in the United Kingdom. This paper presents the clinicopathological features of a series of patients diagnosed in Nottingham from 1986 to 1990. During this period, 1319 muscle biopsy samples were processed by this laboratory and rimmed vacuoles were seen in 17 patients. Eleven patients had definite or probable inclusion body myositis according to published criteria. The mean age of the group was 69.4 years with a male to female ratio of 8:3. Typical clinical features were a slowly progressive painless, proximal lower limb weakness, with muscle wasting and early loss of reflexes. The median duration of illness from first symptom to presentation was five years (range 2-18 years). Falls were a prominent symptom in six patients and distal weakness occurred in nine patients. Creatine kinase was increased in 10 patients but only one had a level > 1000 IU/l; the erythrocyte sedimentation rate was normal in five patients. Treatment with steroids or cytotoxic drugs, or both, did not prevent disease progression. It is confirmed that inclusion body myositis is a distinct cause of inflammatory myopathy which is probably underdiagnosed in the United Kingdom. Clinically, it should be suspected in older patients presenting with muscle weakness of insidious onset. Pathologically, a careful search should be made for rimmed vacuoles and inflammation; ultrastructurally, the presence of inclusions will confirm the diagnosis.     

Vacuolar changes in neuromuscular disorders: a morphometric study

BACKGROUND: Vacuoles in muscle represent a nonspecific alternation and are found in a variety of neuromuscular disorders. To understand their significance, a morphometric study of the vacuolar formation in muscle biopsies from 340 patients was reviewed. METHODS: Vacuolar changes in muscles were found in 24 out of 340 patients with muscle biopsies. The specimens were prepared for histopathological, histochemical and electron microscopic examinations. The location, size, shape, number and content of the vacuoles were recorded. The number of fibers containing vacuoles was also assessed. RESULTS: Observed after modified Gomori trichrome stain, there were rimmed and non-rimmed vacuoles. Rimmed vacuoles were found in limb-girdle myopathy with rimmed vacuoles (5), oculopharyngeal muscular dystrophy (1). inclusion body myositis (2) and neurogenic disorder (1). These vacuoles were usually cleft-like in shape in 5-16% of muscle fibers with a diameter of 3-20 microns. An elevation of acid phosphatase activities and the presence of cytoplasmic debris suggested an autophagic process. In 15 patients with non-rimmed vacuoles, round and oval shapes with variable sizes and numbers were noted. Four with acid maltase deficiency (AMD) had numerous vacuoles containing glycogen, while three with lipid storage disease contained lipid. Interestingly, in AMD the size of the vacuoles was usually more than 10 microns in diameter, but less than 5 microns in lipid storage disease. In other diseases including polymyositis (5), Duchenne muscular dystrophy (2) and hypokalemic periodic paralysis (1), the numbers of vacuoles were usually fewer than three in each fiber. CONCLUSIONS: Vacuolar changes were not specific, but morphometric analysis of the vacuoles may provide some clues in differential diagnosis. The vacuoles were usually numerous in glycogen and lipid storage diseases, while rimmed vacuoles may be found in limb-girdle myopathy with rimmed vacuoles, oculopharyngeal muscular dystrophy, and inclusion body myositis.     

Tau protein immunoreactivity in muscle fibers with rimmed vacuoles differs from that in regenerating muscle fibers

To determine whether tau protein found in muscle fibers with rimmed vacuoles and in regenerating fibers was phosphorylated, we examined eight muscle biopsy samples containing rimmed vacuoles (from five patients with distal myopathy with rimmed vacuole formation and three patients with inclusion body myositis) and three muscle biopsy samples from patients with Duchenne muscular dystrophy containing numerous regenerating fibers. Although both rimmed vacuolated and regenerating fibers had increased immunoreactivity against tubulin and tau protein, tau protein in the former was more highly phosphorylated than that in the latter. While very few microtubules in muscle fibers with rimmed vacuoles were recognizable by electron microscopy, regenerating fibers, especially immature ones, contained numerous microtubules. Since tau protein found in vacuolated fibers is hyperphosphorylated, it can be considered to have reduced ability to bind tubulin molecules. Thus, the tau protein cannot stabilize microtubules, resulting in their depolymerization even in the presence of tubulin molecules.     

Focal myositis of the floor of mouth: report of two cases and review of the literature

Focal myositis is an uncommon inflammatory myopathy of unknown cause affecting skeletal muscle. It may be mistaken on clinical evaluation for a malignant neoplasm. We describe two cases, both involving the mylohyoid muscle of the floor of the mouth. In each case excisional biopsy of a firm indurated mass revealed a focal lymphocytic and histiocytic infiltrate associated with degenerating and regenerating skeletal muscle fibers. No clinical or biochemical evidence of generalized muscle disease was seen at presentation or at 1-year and 7-year follow-up examination. The literature on focal myositis involving the head and neck region is reviewed.     

Amyloid-beta deposition in skeletal muscle of transgenic mice: possible model of inclusion body myopathy

Inclusion body myopathy is a progressive muscle disorder characterized by nuclear and cytoplasmic inclusions and vacuolation of muscle fibers. Affected muscle fibers contain deposits of congophilic amyloid, amyloid-beta immunoreactive filaments, and paired helical filaments, all of which are pathological hallmarks of Alzheimer's disease in brain. Accumulations of amyloid-beta and its precursor are thought to play important roles in the pathogenesis of both inclusion body myopathy and Alzheimer's disease. Overexpression of mutant forms of beta protein precursor in transgenic mice by neuron-specific promoters has been reported to cause amyloid deposits in the brain. Here we report that overexpression in transgenic mice of the signal plus 99-amino acid carboxyl-terminal sequences of beta protein precursor, under the control of a cytomegalovirus enhancer/beta-actin promoter, resulted in vacuolation and increasing accumulation of the 4-kd amyloid-beta and the carboxyl-terminus in skeletal muscle fibers during aging. These deposits in transgenic muscle only rarely showed Congo red birefringence. Thus, overexpression of part of beta protein precursor in transgenic mice led to development of some of the characteristic features of inclusion body myopathy. These mice may be a useful model of inclusion body myopathy, which shares a number of pathological markers with Alzheimer's disease.     

Omeprazole 20 or 40 mg daily for healing gastroduodenal ulcers in patients receiving non-steroidal anti-inflammatory drugs

Amyloid deposition in skeletal muscle is a well-recognized but rare occurrence. Sixteen such cases seen in a 17-year period (1979 to 1996) out of a total of 3,937 muscle biopsy specimens (0.004%) form this study group. Either Congo red or sulfated alcian blue stains were routinely performed in each biopsy to screen for amyloid. Patients in this study (eight men, eight women) ranged in age from 42 to 90 years (mean, 61 years) at initial presentation. The most common symptoms at presentation included weakness/fatigue (n = 10), autonomic symptoms (n = 8), and weight loss/decreased appetite (n = 7). Five patients had a concomitant malignancy (myeloma, n = 3; malignant carcinoid tumor, n = 1; melanoma, n = 1). Two patients had known hereditary forms of amyloidosis. Five patients had amyloid diagnosed on another organ biopsy (excluding peripheral nerve). Histologically, amyloid was deposited in the interstitium or perivascular region in 14 muscles and endomysial region in seven muscles. All cases were confirmed with Congo red staining (apple green birefringence) or by electron microscopic identification of fibrillary amyloid material. Scattered angular atrophic esterase-positive muscle myofibers indicative of acute denervation atrophy were seen in 14 muscles. Eight muscles showed small group atrophy, and seven showed myofiber type grouping. Scattered regenerating muscle fibers were seen in nine cases, degenerating myofibers in six, and foci of chronic endomysial and perivascular inflammation in two. Four muscles showed type II muscle fiber atrophy. A concomitant sural nerve biopsy specimen was evaluated in seven patients; all seven contained amyloid, confirmed either by Congo red staining or electron microscopic examination. In two nerves, there was a mild loss of myelinated axons; four had a moderate loss, and one, severe loss. Six of seven nerves showed predominantly axonopathic changes. In conclusion, (1) the prevalence rate of amyloid myopathy in muscle biopsy specimens was low (in this series, 0.004%); (2) only a minority of patients had multiple myeloma, and most presented with muscle weakness/fatigue or autonomic symptoms; (3) most of the muscles showed neurogenic features histologically; (4) all concomitant sural nerve biopsy specimens contained amyloid, and most showed a predominance of axonopathic changes.