Abstract: The novel extracellular matrix structures called fractones are found in the lateral ventricle walls, the principal adult brain stem cell niche. By electron microscopy fractones were shown to contact neural stem and progenitor cells (NSPC), suggesting a role in neurogenesis. Here, we investigated spatial relationships between proliferating NSPC and fractones, identified basic components and the first function of fractones. Using BrdU for birth-dating cells in the adult mouse lateral ventricle wall, we found most mitotic cells next to fractones, although some cells emerged next to capillaries. Like capillary basement membranes, fractones were immunoreactive for laminin beta1 and gamma1, collagen IV, nidogen, and perlecan, but not laminin-alpha1, in the adult rat, mouse and human. Intriguingly, N-sulfate HSPG (heparan sulfate proteoglycan) immunoreactivity was restricted to fractone subpopulations and infrequent subependymal capillaries. Double immunolabel for BrdU and N-sulfate HSPG revealed preferential mitosis next to N-sulfate HSPG immunoreactive fractones. To determine whether N sulfate HSPG immunoreactivity within fractones reflects a potential for binding neurogenic growth factors, we identified biotinylated FGF-2 binding sites in situ on frozen sections, and in vivo after intracerebroventricular injection of biotinylated FGF-2 in the adult rat or mouse. Both binding assays revealed biotinylated FGF-2 on fractone subpopulations and on infrequent subependymal capillaries. The binding of biotinylated FGF-2 was specific and dependant upon HSPG as demonstrated in vitro and in vivo by inhibition with heparatinase, and by the concomitant disappearance of N-sulfate HSPG immunoreactivity. These results strongly suggest that fractones promote growth factor activity in the neural stem cell niche.

Abstract: Heparin-binding growth factors are crucial for the formation of human epidermis, but little is known about the role of heparan sulfate proteoglycans in this process. Here we investigated the role of the heparan sulfate proteoglycan, perlecan, in the formation of human epidermis, by utilizing in vitro engineered human skin. By disrupting perlecan expression either in the dermis or the epidermis, we found that epidermally derived perlecan is essential for epidermal formation. Perlecan-deficient keratinocytes formed a strikingly thin and poorly organized epidermis because of premature apoptosis and failure to complete their stratification program. Exogenous perlecan fully restored epidermal formation. Perlecan deposition in the basement membrane zone correlated with formation of multilayered epidermis. Perlecan deficiency, however, had no effect on the lining and deposition of major basement membrane components as was evident by a continuous linear staining of laminin and collagen IV. Similarly, perlecan deficiency did not affect the distribution of beta1 integrin. Addition of the perlecan ligand, fibroblast growth factor 7, protected perlecan-deficient keratinocytes from cell death and improved the thickness of the epidermis. Taken together, our results revealed novel roles for perlecan in epidermal formation. Perlecan regulates both the survival and terminal differentiation steps of keratinocytes. Our results suggested a model whereby perlecan regulates these processes via controlling the bioavailability of perlecan-binding soluble factors involved in epidermal morphogenesis.

Abstract: The laminin alpha4 chain is widely distributed in various mesodermal tissues, including the perineurium of peripheral nerves, dorsal root ganglion (DRG), skeletal muscle, and capillaries, and plays important roles in synaptic specialization at the neuromuscular junction and in microvascular formation. The C-terminal globular domain (G domain) of the laminin alpha4 chain was previously found to be critical for heparin binding and cell attachment activity. Here, we focused on neurite outgrowth activity of the laminin alpha4 chain G domain. We found that the recombinant alpha4 chain G domain protein (rec-alpha4G) promoted neurite outgrowth of rat pheochromocytoma PC12 cells. When 114 overlapping synthetic peptides that covered the entire G domain were tested for neurite outgrowth activity, nine peptides were active, but the 105 remaining peptides did not exhibit activity. Three of the nine active peptides, A4G6 (LAIKNDNLVYVY), A4G20 (DVISLYNFKHIY), and A4G107 (VIRDSNVVQLDV), strongly promoted neurite outgrowth of PC12 cells. A4G107 was found to form amyloid-like fibrils in Congo red, X-ray, and electron microscopy analyses. We also synthesized cyclic peptides to evaluate their conformational requirements. Cyclic peptide A4G82X (cyc-A4G82X;TLFLAHGRLVFX, where X is norleucine) significantly enhanced neurite outgrowth activity, but the rest of the cyclic peptides eliminated the activity. The A4G82 sequence is located on the loop region, suggesting that the activity of A4G82 is required for a loop conformation. These peptides also exhibited neurite outgrowth activity with dorsal root ganglion (DRG) explants and with DRG cells from E14.5 mouse embryos, indicating that they are active in both neuronal cell lines and native neuronal cells. Taken together, the data suggest that the peptides from the laminin alpha4 chain G domain promote neurite outgrowth activity via a specific conformation.

Abstract: Among the autophagic vacuolar myopathies (AVMs), a subgroup is characterized pathologically by unusual autophagic vacuoles with sarcolemmal features (AVSF) and includes Danon disease and X-linked myopathy with excessive autophagy. The diagnostic importance and detailed morphologic features of AVSF in different AVMs have not been well established, and the mechanism of AVSF formation is not known. To address these issues, we have performed detailed histologic studies of myopathies with AVSF and other AVMs. In Danon disease and related AVMs, at the light microscopic level, autophagic vacuoles appeared to be accumulations of lysosomes, which, by electron microscopy consisted of clusters of autophagic vacuoles, indicative of autolysosomes. Some autolysosomes were surrounded by membranes with sarcolemmal proteins, acetylcholinesterase activity, and basal lamina. In Danon disease, the number of fibers with AVSF increased linearly with age while the number with autolysosomal accumulations decreased slightly, suggesting that AVSF are produced secondarily in response to autolysosomes. Most of the AVSF form enclosed spaces, indicating that the vacuolar membranes may be formed in situ rather than through sarcolemmal indentation. This unique intracytoplasmic membrane structure was not found in other AVMs. In conclusion, AVSF with acetylcholinesterase activity are autolysosomes surrounded by secondarily generated intracytoplasmic sarcolemma-like structure and delineates a subgroup of AVMs.

Abstract:

Abstract: Laminin alpha2 is subunit of laminin-2 (alpha2beta1gamma1), which is a major component of the muscle basement membrane. Although the laminin alpha2 chain is expressed in the early stage of dental mesenchyme development and localized in the tooth germ basement membrane, its expression pattern in the late stage of tooth germ development and molecular roles are not clearly understood. We analyzed the role of laminin alpha2 in tooth development by using targeted mice with a disrupted lama2 gene. Laminin alpha2 is expressed in dental mesenchymal cells, especially in odontoblasts and during the maturation stage of ameloblasts, but not in the pre-secretory or secretory stages of ameloblasts. Lama2 mutant mice have thin dentin and a widely opened dentinal tube, as compared with wild-type and heterozygote mice, which is similar to the phenotype of dentinogenesis imperfecta. During dentin formation, the expression of dentin sialoprotein, a marker of odontoblast differentiation, was found to be decreased in odontoblasts from mutant mice. Furthermore, in primary cultures of dental mesenchymal cells, dentin matrix protein, and dentin sialophosphoprotein, mRNA expression was increased in laminin-2 coated dishes but not in those coated with other matrices, fibronectin, or type I collagen. Our results suggest that laminin alpha2 is essential for odontoblast differentiation and regulates the expression of dentin matrix proteins.

Abstract: The hypothesis that lipoprotein association with perlecan is atherogenic was tested by studying atherosclerosis in mice that had a heterozygous deletion of perlecan, the primary extracellular heparan sulfate proteoglycan in arteries. We first studied the expression of perlecan in mouse lesions and noted that this proteoglycan in aorta was found in the subendothelial matrix. Perlecan was also a major component of the lesional extracellular matrix. Mice with a heterozygous deletion had a reduction in arterial wall perlecan expression. Atherosclerosis in these mice was studied after crossing the defect into the apolipoprotein E (apoE) and LDL receptor knockout backgrounds. At 12 weeks, chow-fed apoE null mice with a heterozygous deletion had less atherosclerosis. However, at 24 weeks and in the LDL receptor heterozygous background, the presence of a perlecan knockout allele did not significantly alter lesion size. Thus, it appears that loss of perlecan leads to less atherosclerosis in early lesions. Although this might be attributable to a decrease in lipoprotein retention, it should be noted that perlecan might mediate multiple other processes that could, in sum, accelerate atherosclerosis.

Abstract: The collagen-tailed form of acetylcholinesterase (AChE) is concentrated at the vertebrate neuromuscular junction (NMJ), where it is responsible for rapidly terminating neurotransmission. This unique oligomeric form of AChE, consisting of three tetramers covalently attached to a collagen-like tail, is more highly expressed in innervated regions of skeletal muscle fibers, where it is externalized and attached to the synaptic basal lamina interposed between the nerve terminal and the receptor-rich postsynaptic membrane. Although it is clear that the enzyme is preferentially synthesized in regions of muscle contacted by the motoneuron, the molecular events underlying its localization to the NMJ are not known. Here we show that perlecan, a multifunctional heparan sulfate proteoglycan concentrated at the NMJ, is the unique acceptor molecule for collagen-tailed AChE at sites of nerve-muscle contact and is the principal mechanism for localizing AChE to the synaptic basal lamina.

Abstract: Perlecan, a large heparan sulfate proteoglycan, is a component of the basement membrane and other extracellular matrices and has been implicated in multiple biological functions. Mutations in the perlecan gene (HSPG2) cause two classes of skeletal disorders: the relatively mild Schwartz-Jampel syndrome (SJS) and severe neonatal lethal dyssegmental dysplasia, Silverman-Handmaker type (DDSH). SJS is an autosomal recessive skeletal dysplasia characterized by varying degrees of myotonia and chondrodysplasia, and patients with SJS survive. The molecular mechanism underlying the chondrodystrophic myotonia phenotype of SJS is unknown. In the present report, we identify five different mutations that resulted in various forms of perlecan in three unrelated patients with SJS. Heterozygous mutations in two patients with SJS either produced truncated perlecan that lacked domain V or significantly reduced levels of wild-type perlecan. The third patient had a homozygous 7-kb deletion that resulted in reduced amounts of nearly full-length perlecan. Unlike DDSH, the SJS mutations result in different forms of perlecan in reduced levels that are secreted to the extracellular matrix and are likely partially functional. These findings suggest that perlecan has an important role in neuromuscular function and cartilage formation, and they define the molecular basis involved in the difference in the phenotypic severity between DDSH and SJS.

Abstract: Perlecan, a large heparan sulfate proteoglycan (HSPG), is present in the basement membrane and other extracellular matrices. Its protein core is 400 kDa in size and consists of five distinct structural domains. A number of in vitro studies suggest multiple functions of perlecan in cell growth and differentiation and tissue organization. Recent studies with gene knockout mice and human diseases revealed critical in vivo roles of perlecan in cartilage development and neuromuscular junction activity.

Abstract: Dyssegmental dysplasia, Silverman-Handmaker type (DDSH), is a lethal autosomal recessive form of dwarfism with characteristic anisospondylic micromelia. The remarkable similarities in the radiographic, clinical, and chondroosseous morphology of DDSH patients to those of perlecan-null mice led to the identification of mutations in the perlecan gene (HSPG2) of DDSH. Perlecan, a large heparan sulfate proteoglycan, is expressed in various tissues and is a component of all basement membrane extracellular matrices. A chondrodysplasia phenotype caused by the loss of perlecan was unexpected, because cartilage does not have basement membranes. Insertion and splicing mutations in HSPG2 of DDSH were found that were predicted to create a premature termination codon. Immunostaining and biochemical analysis revealed that the mutant perlecan molecules were unstable and not secreted into the extracellular matrix. These results indicate that DDSH is caused by functional null mutations of HSPG2 and that perlecan is essential for cartilage development. Published 2002 Wiley-Liss, Inc.

Abstract: We report a right-handed 34-year-old woman with diffuse muscle atrophy. The patient was a full-term infant of uneventful delivery, however, motor milestones were delayed in that neck control was obtained at 10 months of the age and she started to walk unassisted at 2 years of the age. Mental development was normal. She was unable to run with her mates at her kindergarten and she required a handrail when she walk up the stairs. She could not close her mouth completely at the primary school. She was unable to use a straw as a middle school pupil. Recently, she noted difficulty in raising her head from the supine position, and has become unable to walk a long distance. She was admitted to our hospital in September 17, 1994 when she was 34-year-old. On admission, general physical examination revealed that she looked slender weighing 38 kg with 149.5 cm height. She showed a high arched palate, slight scoliosis, and pes equinus. Otherwise general physical examination was unremarkable. Upon neurologic examination, she was alert and well oriented. Cranial nerves were unremarkable except for bilateral facial atrophy and moderate weakness. Her voice was of nasal quality, and swallowing was slightly difficult. No atrophy was noted in the sternocleidomastoid muscle. She showed waddling gait and positive Gowers' sign. Diffuse muscle atrophy was noted and mild to moderate weakness was presented more in the proximal part in both upper and lower extremities, however, deltoid muscles retained normal power. No ataxia was noted. All the deep tendon reflexes were lost. Sensation was intact. Routine laboratory examination was unremarkable. Serum CK was 56 IU/l. Electromyography revealed myogenic changes in the deltoid, biceps, and quadriceps muscles. A diagnostic biopsy was performed in the left biceps brachii muscle. The patient was discussed in the neurologic CPC, and the chief discussant arrived at the conclusion that the patient had nemaline myopathy. Opinions were divided among nemaline myopathy, central core disease, and congenital fiber type disproportion. Histologic examination of the biopsied specimen revealed marked atrophy of type 1 muscle fibers; many central nuclei were seen in the type 1 fibers. Approximately 70% of the muscle fibers were type 1 fibers. No nemaline rods or central cores were noted. Histologic appearance was consistent with the diagnosis of congenital fiber type disproportion.

Abstract: We report a right-handed 22-year-old man with muscle atrophy. His prenatal course and the delivery were uneventful, but he walked unsupported at 15 months of the age for the first time. He was apparently well but he was in the slowest group in running in schools. He noted a difficulty in climbing up stairs at 19 years of the age, and he was admitted to our hospital for the work up when he was 22-year-old. His family history and past medical history were unremarkable. On admission, he was a slender and tall guy in no acute distress. General physical examination was unremarkable, but he had high-arched palate and high-arched feet. On neurologic examination, mental status and higher cerebral functions were normal. Cranial nerves appeared intact, however, he had a thin and long face without weakness. The sternocleidomastoid muscles appeared somewhat atrophic and were moderately weak. He was able to walk normally, however, he needed a handrail when he went up stairs. Thigh muscles and triceps surae muscles were atrophic and slightly weak (4/ 5). Muscle tone was hypotonic and no deep tendon reflexes were elicited except for jaw jerk. No ataxia or involuntary movements were seen; sensation was intact. Laboratory examination was unremarkable except for slight increase in serum CK to 145 IU/L. An ischemic forearm exercise test revealed slight elevation of lactate and pyruvate in that base line levels were 5.4 mg/dl and 0.52 mg/dl, respectively, which rose to 11.4 mg/dl and 0.85 mg/dl, respectively, 20 minutes after the initiation of the ischemic exercise. The base line serum ammonia was 102.5 micrograms/dl which decreased to 64.8 micrograms/dl at 20 minutes. A diagnostic biopsy was performed from the left quadriceps femoris muscle. The patient was discussed in a neurologic CPC, and the chief discussant arrived at the conclusion that the patient had nemaline myopathy. Opinions were divided between nemaline myopathy and debranching enzyme deficiency. The results of the ischemic exercise was not typical of glycogen storage disease, but elevations of lactate and pyruvate did not appear to be sufficient to be interpreted as normal. Histologic examination of the biopsied specimen revealed marked type I fiber predominance and abundant nemaline rods. Cytoplasmic bodies were also seen. Histologic characteristics were consistent with the diagnosis of nemaline myopathy. The possibility of concomitant presence of AMP deaminase deficiency was discussed, because serum ammonia did not elevate in the ischemic exercise test.

Abstract: We report a 54-year-old man with progressive proximal muscle atrophy and gynecomastia. The patient had an insidious onset of weakness in his lower extremities at age 14, in that he noted a difficulty in standing up from a chair. Soon after he noted some difficulty in climbing up stairs. At age 35, he noted weakness in his arms; his weakness slowly progressed in that he became unable to walk or stand alone before 40 years of age. He also noted gynecomastia at that age. He was admitted to our hospital for the work up on September 16, 1993, when he was 54-year-old. On admission, he was alert and oriented; his BP was 150/70 mmHg; he had bilateral gynecomastia, however, no other skeletal deformities were found. On neurologic examination, he was mentally sound without dementia, and his higher cerebral functions were normal. Cranial nerves also appeared intact without facial atrophy, dysarthria, or dysphagia; no atrophy was noted in the tongue. He had marked muscle atrophy in both upper and lower extremities more marked in the proximal portions; muscle strength was approximately in the range of 2/5 to 3/5 in the proximal parts, and 4/5 in the distal parts in both upper and lower extremities. No fasciculation was noted; muscle tone was flaccid; no ataxia was present. Deep reflexes were either lost or markedly diminished. No Babinski sign was noted. Sensation was intact. Laboratory examination revealed normal blood counts; serum CK was slightly increased to 131 IU/l; ECG showed complete right bundle branch block; EMG revealed no active units in the right biceps brachii, deltoid, quadriceps femoris, and triceps surae muscles; in other muscles tested, motor unit potentials of low amplitude and short duration were seen; in the right tibialis anterior muscle, however, motor unit potentials with an amplitude up to 6 m V were also seen. Nerve conduction velocities were normal. A diagnostic procedure was performed. He was discussed in the neurological CPC, and the chief discussant arrived at the conclusion that this patient had Becker type of progressive muscular dystrophy. In her differential diagnosis, the possibility of Kennedy-Alter-Sung syndrome was discussed because this patient had gynecomastia. However, the discussant excluded that possibility because of absence of both bulbar symptoms and typical neurogenic changes in his EMG. The diagnostic procedure was a muscle biopsy on the left tibialis anterior muscle. Histologic observation on HE stained specimens revealed marked inequality in the muscle fiber diameters, increase in endomysial nuclei, proliferation of connective tissue, and fiber splitting.(ABSTRACT TRUNCATED AT 400 WORDS)

Abstract: We report a 21-year-old man with distal dominant progressive muscle atrophy. The patient was apparently well until 17 years of age when he noted a decrease in exercise tolerance. One year later, he noted difficulty in arising his heels when the walked. He was admitted to our service for the work up in June 10, 1992. On admission, the patient was rather slender in the body build up; otherwise general physical examination was unremarkable. Upon neurologic examination, mental status and higher cerebral functions were normal. In the cranial nerves, the sternocleidomastoid muscles were atrophic bilaterally; other cranial nerves appeared intact. His gait was unstable and he showed steppage gait; walking on toes and heels were impossible. Distal dominant muscle atrophy was noted in both upper and lower extremities. Muscle strength in the deltoid, biceps brachii and triceps brachii was normal. In the lower extremities, both tibialis anterior and triceps surae muscles were weak (3/5). The iliopsoas and quadriceps femoris muscles were normal, however, the adductor muscles of the thigh showed marked weakness (2/5). Myotonia was absent. Deep reflexes were decreased; sensation was intact. Routine blood tests were unremarkable; CK was 96 IU/l, lactate 6.9 mg/dl, and pyruvate 0.61 mg/dl. After an ischemic forearm exercise test, blood lactate level rose to 22.5mg/dl (base line 11.2), and blood ammonia to 88.3 micrograms/dl (base line 71.2). EMG showed myogenic changes and myotonic discharges. A diagnostic biopsy was performed. The patient was discussed in a neurologic CPC, and the chief discussant arrived at the conclusion that the patient had type III glycogen storage disease. The differential diagnosis included rimmed vacuole type myopathy, Miyoshi type distal muscular dystrophy, Welander type muscular dystrophy, adult type acid-maltase deficiency, and lysosomal glycogen storage disease with normal acid maltase. However, characteristic clinical presentation of initial weakness in the triceps surae muscle associated with atrophy of the sternocleidomastoid muscle confirmed best of the clinical characteristics of type III glycogen storage disease; the only finding which did not fit with its diagnosis was elevation of the blood lactate level after the ischemic exercise test. The muscle biopsy specimen showed marked vacuole formation; approximately 20 to 30% of the vacuoles were rimmed vacuoles, however, the majority was not rimmed. PAS staining on an epon-embedded specimen revealed marked accumulation of PAS-positive materials in those vacuoles as well as in the interfascular space. The non-rimmed vacuoles were not positively stained in the acid-phosphatase staining, which exclude the diagnosis of acid maltase deficiency. No mitochondrial abnormalities were found.(ABSTRACT TRUNCATED AT 400 WORDS)

Abstract: To better define limb-girdle muscular dystrophy (LGMD), we examined 58 patients clinically and pathologically who fulfilled the criteria for LGMD and had normal dystrophin expression in their muscle biopsies. Only 27.6% of patients had evidence of inheritance. The onset of disease varied from 2 to 58 years of age, averaging 17.2 years. The disease progression also differed from patient to patient. In addition to evidence of muscle fiber necrosis and regeneration, in all muscle biopsies there were fibers with architectural changes of disorganized intermyofibrillar networks including moth-eaten (100%), lobulated (40%), whorled (17%) and targetoid (8%) fibers. The lobulated fibers which have never been reported in Duchenne muscular dystrophy (DMD) were seen in the advanced stages of LGMD, although the significance of such fibers remains unknown. On immunohistochemical examination, dystrophin-associated proteins (DAPs) and laminin were normally expressed along the surface membrane of muscle fibers, including the lobulated fibers.

Abstract: Abnormalities of dystrophin, a cytoskeletal protein of muscle and nerve, are generally considered specific for Duchenne and Becker muscular dystrophy. However, several patients have recently been identified with dystrophin deficiency who, before dystrophin testing, were considered to have Fukuyama congenital muscular dystrophy (FCMD) on the basis of clinical findings. Epidemiologic data suggest that only 1/3500 males with autosomal recessive FCMD should have abnormal dystrophin. To explain the observation of 3/23 FCMD males with abnormal dystrophin, we propose that dystrophin and the FCMD gene product interact and that the earlier onset and greater severity of these patients' phenotype (relative to Duchenne muscular dystrophy) are due to their being heterozygous for the FCMD mutation in addition to being hemizygous for Duchenne muscular dystrophy, a genotype that is predicted to occur in 1/175,000 Japanese males. This model may help explain the genetic basis for some of the clinical and pathological variability seen among patients with FCMD, and it has potential implications for understanding the inheritance of other autosomal recessive disorders in general. For example, sex ratios for rare autosomal recessive disorders caused by mutations in proteins that interact with X chromosome-linked gene products may display predictable deviation from 1:1.

Abstract: Of the 3,048 diagnostic muscle biopsies processed by the National Institute of Neuroscience, Tokyo, over 12 years, 41 cases carried the clinical diagnosis of limb-girdle muscular dystrophy. We have analyzed all 41 cases for dystrophin content in muscle by both immunofluorescence and immunoblot. We identified five male patients with an abnormal dystrophin pattern diagnostic of Becker muscular dystrophy, and two female patients with dystrophin patterns consistent with a manifesting carrier of Duchenne muscular dystrophy diagnosis. Thus, 17% of our limb-girdle patients showed a dystrophinopathy, indicating that they in fact had a disorder related to Duchenne/Becker muscular dystrophy. Misclassification of isolated male limb-girdle patients was 31% (4/13), while misclassification of isolated female limb-girdle patients was 13% (2/15). Using multiplex polymerase chain reaction analyses of small amounts of muscle biopsy DNA confirmed a dystrophin gene deletion in all five male Becker dystrophy patients identified. This study emphasizes the clinical overlap between limb-girdle muscular dystrophy and dystrophinopathies, and reinforces the necessity of dystrophin protein and gene studies for the accurate clinical diagnosis of isolated cases of muscular dystrophy.

Abstract: Using immunocytochemical methods, we examined the intensity and distribution of dystrophin and spectrin immunostaining of skeletal muscles from 51 congenital muscular dystrophy (CMD) patients including 36 Fukuyama congenital muscular dystrophy (FCMD) and 15 non-FCMD (other CMD). 17 age-matched spinal muscular atrophy (SMA) and 5 Duchenne muscular dystrophy (DMD) patient biopsies were studied as controls. All 15 non-FCMD and SMA patients showed normal localization of dystrophin at the surface membrane of each muscle fiber which was undetectable in DMD. In contrast, 34 of 36 FCMD patients exhibited an unusual immunostaining pattern with occasional (17-43%; mean = 28) negative or abnormally immunoreacted (partially deficient, fluffy or intense) fibers for dystrophin. Dystrophin was absent in 2 of 36 patients having a clinical diagnosis of FCMD, and intragenic deletion of the DMD gene was detected in one. Spectrin, a membrane cytoskeletal protein related to dystrophin, also showed an increased number of abnormally immunostained fibers in FCMD (25%), but not so high in age-matched DMD (9%) or SMA patient muscle (0%). Thus, our results suggested the presence of intrinsic factor(s) that produce abnormality of the plasma membrane of FCMD muscle.

Abstract: Duchenne muscular dystrophy (DMD) is a fatal X-linked recessive disorder of muscle in children. The DMD gene product, "dystrophin", is absent from DMD, while the allelic disease, Becker muscular dystrophy (BMD), exhibits dystrophin of abnormal size and/or quantity. But we are still uncertain about the scenario that internally deleted (or duplicated) dystrophin in BMD possesses its carboxy (C)-terminal region, and severely truncated dystrophin in DMD does not. Here we use a new monoclonal antibody directed against an peptide in the C-terminal end of the dystrophin molecule to show that the C-terminus is preserved in 30 BMD and 24 control skeletal muscles but not in 21 DMD specimens. This result, taken together with data on deletions of the dystrophin gene, emphasizes both the diagnostic and biological importance of the C-terminal domain which is required for proper function and stability of dystrophin, and substantiates the validity of the reading frame hypothesis for DMD versus BMD deletions on a biochemical level.

Abstract: We examined dystrophin, the protein product of the Duchenne muscular dystrophy gene, in muscle biopsy specimens from 4 male patients with quadriceps myopathy, all of whom showed a mild and slowly progressive myopathy confined to the quadriceps muscles. All 4 patients had clear abnormalities of dystrophin, and were diagnosed as having Becker muscular dystrophy by both immunofluorescence and immunoblot examinations; that is, dystrophin of an abnormal molecular mass was visualized in muscle cryosections as "patchy" or discontinuous immunostaining at the surface membrane of the muscle fibers. One patient had a brother who showed widespread myopathic changes consistent with typical Becker muscular dystrophy. We conclude that the syndrome called quadriceps myopathy includes a group of forme fruste Becker muscular dystrophy.

Abstract: A 23-year-old male patient with Becker muscular dystrophy (BMD) who showed schizophrenic symptoms was reported. He tumbled easily and was poor at running since age at 8 years. He had difficulty in climbing stairs and was idle away all day long since age at 21 years. Although his premorbid personality was not schizoid, he showed auditory hallucinations and delusions without any psychogenetic moment at the age of 23. At first, he seemed to be schizophrenic, but after the treatment with antipsychotics, he always had an insight into his disease and exhibited natural emotional communication. He showed no autism and character changes. According to the Wechsler Adult Intelligence Scale (WAIS), intellectual impairment was notified (total IQ58). Neurological examinations revealed weakness and atrophy of muscles in the proximal part of his lower extremities, and pseudohypertrophy of calves. In the serum enzyme, serum creatine kinase (CK) level was elevated (700 U/L). Abnormal Q waves appeared in the leads, II, III, aVF, V5, V6 on the electrocardiogram (ECG), and the finding of the echocardiography suggested dilated cardiomyopathy. The electroencephalogram (EEG) revealed the basic rhythm of 9-10 Hz with 0 activities of 6-7 Hz which were predominant in frontparietal and central leads. The electromyogram (EMG) revealed a myopathic pattern with low voltage and short duration. A muscle biopsy from right biceps brachii disclosed the abnormal immunofluorescent staining pattern of dystrophin which is consistent with BMD patient, i.e., "patchy," discontinuous and faint immunoreaction at surface membrane of the fiber. Both molecular weight (380 kd: n = 400) and amount (30%; n = 100) of dystrophin were reduced.(ABSTRACT TRUNCATED AT 250 WORDS)