唐古特白刺果实酚酸类化学成分及α-葡萄糖苷酶抑制活性研究

目的 对蒺藜科白刺属植物唐古特白刺Nitraria tangutorum果实中酚酸类成分及α-葡萄糖苷酶抑制活性进行研究。方法 采用硅胶柱色谱、MCI色谱及半制备高效液相色谱法等技术对其进行分离纯化,结合NMR和MS等波谱学数据鉴定单体化合物结构,对化合物的蔗糖酶和麦芽糖酶抑制活性进行筛选,并对活性较好的化合物进行蔗糖酶和麦芽糖酶分子对接分析。结果 从唐古特白刺果实中分离得到11个化合物,分别鉴定为6’-O-对香豆酰基-α-槐糖（1）、6’-O-对香豆酰基-β-吡喃葡萄糖基-(1-2)-α-甘露糖（2）、4-羟基苯甲酸（3）、香草酸（4）、原儿茶酸甲酯（5）、对香豆酸（6）、咖啡酸（7）、6-O-对香豆酰基-D-半乳糖（8）、反式-4-O-β-D-吡喃喃葡糖基阿魏酸（9）、cynarin(10)、芍药苷（11）。化合物7对蔗糖酶和麦芽糖酶的半数抑制浓度（median inhibition concentration,IC50）值分别为809.1和768.5μmol/L,化合物10的IC50值分别为473.3和114.3μmol/L;分子对接显示化合物7对蔗糖酶和麦芽糖酶结合自由能分别为...     

Acid maltase deficiency in non-identical adult twins

Summary Acid maltase deficiency is described in non-identical adult twins. The onset of the disease can be traced into late infancy; the clinical picture is one of severe muscular dystrophy; respiratory insuficiency was the cause of death in one case. The autopsy showed the central nervous system, heart and liver to be spared. Glycogen filled vacuoles are found in skin, mesenchymal cells, small nerves and skeletal muscles. The light microscopic study of 9 different muscles showed extremely variable involvement ranging from normal appearance to overt vacuolization. A 6–20% residual acid -glucosidase activity was found in visceral organs, cultured fibroblasts and in some skeletal muscles. No satisfactory explanation can be given why this generalized acid -glucosidase deficiency produces a selective involvement of skeletal muscles. If compared with infantile AMD (Pompe's disease) our cases have a much higher residual acid -glucosidase activity and show the presence of an antigenically detectable protein.From our study and from a similar report in the literature (de Barsy et al., 1975), it appears that a combined approach of light microscopy, electron microscopy and biochemical analysis (determination of acid -glucosidase) is necessary to make a diagnosis of AMD in adults.Dr. Th. de Barsy is a Research Fellow of the Fonds National de la Recherche Scientifique.     

Synthesis and In Situ Localization of Lysosomal α-Glucosidase in Muscle of an Unusual Variant of Glycogen Storage Disease Type II

The lysosomal α-glucosidase activity is reduced to 10% to 25% of the average control value in most late-onset cases of glycogen storage disease type II (GSDII). Some adult patients, however, have been identified with an exceptionally low (<5%) residual enzyme activity. We have investigated one such unusual variant. The rate of α-glucosidase synthesis appeared normal but the residual enzyme activity was only approximately 3% in cultured fibroblasts, cultured muscle cells, and muscle tissue of the patient. It appeared that fully matured enzyme molecules were more abundantly present in muscle tissue than in cultured cells. The acid phosphatase activity of affected muscle fibers was enhanced due to an increased number of lysosomes. Lysosomes were particularly abundant in vacuolated areas and they contained, as judged by immunoelectron microscopy, even more α-glucosidase molecules than usual. An excessive amount of enzyme molecules were also observed in the endoplasmic reticulum, the site of lysosomal enzyme synthesis, and the cisternae were dilated. These observations suggest that the lysosomal system is stimulated in response to intralysosomal glycogen storage and onset of cellular injury. We hypothesize that the onset of gross pathologic abnormalities is delayed in this particular case of adult GSDII by an increased synthesis of lysosomal α-glucosidase, and as a consequence, an increased residual activity in storage-prone muscle fibers.     

Enzyme therapy for Pompe disease: from science to industrial enterprise

Pompe disease or glycogen storage disease type II (OMIM 232300) is a metabolic myopathy with a broad clinical spectrum. Generalised muscle weakness combined with cardiomegaly presents within the first 3 months after birth, if the lysosomal α-glucosidase (AGLU) deficiency is complete. Residual enzyme activity prevents cardiac involvement and delays onset of muscle weakness. Enzyme therapy, by intravenous administration of acid AGLU, aims to supplement the missing enzyme activity. At the SHS symposium on Glycogen Storage Diseases Type I and II, in Fulda, two interim accounts were given of studies on the efficacy of enzyme therapy for Pompe disease; one with recombinant human acid AGLU produced in Chinese hamster ovary cells and the other with the same enzyme produced in the milk of transgenic rabbits.Conclusion: this review focuses on the latter study, discusses the scientific, technological and commercial aspects of the enterprise, and addresses the prospects and challenges of enzyme therapy for Pompe disease. Published online: 13 August 2002     

Ergebnisse klinischer,biochemischer, lichtmikroskopischer und ultrastruktureller Untersuchungen einer kindlichen Muskelglykogenose bei zwei Brüdern und deren schwester

Zusammenfassung Es wird über eine abortive muskuläre Form der Typ II-Glykogenose (Pompe) bei drei Geschwistern (zwei Buben und deren Schwester) berichtet.Die klinischen und routinehistologischen Befunde entsprechen dem Bild einer primär degenerativen Myopathie. Erst spezielle lichtmikroskopische (PAS-Reaktion), elektronenmikroskopische und biochemische Untersuchungen führten zur Sicherung der Diagnose.Im elektronenmikroskopischen Bild weisen die betroffenen Muskelzellen aller drei Geschwister große, autophage Vacuolen auf, die neben aggregierten Glykogengranula häufig myelinartige Abbauprodukte cytoplasmatischer Membranen enthalten. Daneben werden unspezifische Veränderungen an den übrigen Zellorganellen und den Myofibrillen beobachtet. Die biochemische Untersuchung einer Muskelbiopsie ergibt den Nachweis eines Mangels an -1,4-Glucosidase.

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Results of clinical, biochemical, Light-microscopical and ultrastructural studies of childhood glycogenosis in two brothers and their sister

Summary This report describes a mild muscular form of type II glycogenosis (Pompe) in 3 children (two boys and their sister).The clinical picture and results of routine histological tests were in keeping with the picture of a primary degenerative myopathy. It was not possible to confirm the diagnosis until special preparations were examined by light microscopy (PAS stain) and by electromicroscopical and biochemical techniques.Electron-microscopical examination of muscle cells from the affected areashowed large, autophagic vacuoles in all three sibs, which contained aggregated glycogen granules and myelin-like degradation products of cytoplasmic membranes. Nonspecific changes of the other cell organelles and the myofibrils were also observed. Biochemical examination of a muscle biopsy revealed an -1,4-glucosidase deficiency.

Wir danken Frau Prof. Dr. E. Freund-Mölbert (Lehrstuhl für Mikrobiologie, Biologie II der Universität Freiburg i. Br.) für ihre freundliche Unterstützung.     

Familial X-linked cardiomyopathy (Danon disease): diagnostic confirmation by mutation analysis of the LAMP2gene

A boy presented at age 2.5 years with mild left ventricular hypertrophy and mild myopathy. Hypertrophic cardiomyopathy progressed relentlessly, leading to death at age 16 years shortly before planned heart transplantation. During the course of the disease, his mother developed severe dilated cardiomyopathy and died of its complications at 46 years of age. The combination of myopathy and cardiomyopathy, the biochemical and electron microscopy findings in a muscle biopsy, and the pedigree suggested Danon disease (MIM 300257), an X-linked lysosomal storage disorder caused by deficiency of lysosome-associated membrane protein-2 (LAMP2). The diagnosis was confirmed by the identification of a novel mutation, G138A, in the LAMP2gene, leading to the premature stop codon W46X. Conclusion:Early diagnosis of Danon disease is important for genetic counselling and timely cardiac transplantation, the only effective therapeutic option.     

Human acid maltase-deficient myogenic cell transformation with origin-defective SV40: characterization of a cloned line

A clonal human skeletal muscle cell line showing acid maltase deficiency (AMD) was established through the transfection of origin-defective SV40 DNA. The low acid alpha-glucosidase activity and glycogenosomes in this clone corresponded to AMD. This clone, in spite of loading glycogenososmes, was competent not only as to proliferation without contact inhibition but also as to myogenic differentiation to some extent. Dexamethasone promoted the formation by the transformant of multinucleated myotubes, which expressed acetylcholine receptors. The existence of glycogenosomes did not seem to affect the proliferation or differentiation of myoblasts. The aberrant acid alpha-glucosidase expressed in the transformed myogenic clone was shown to be biochemically identical to that in AMD fibroblasts. This transformant should be of great value for investigating the pathogenesis of AMD because of the possibility of supplying semi-permanently a uniform myogenic cell line expressing AMD.     

Enzyme replacement therapy in adult‐onset glycogenosis II: Is quantitative muscle MRI helpful?

Although it has been shown that muscle magnetic resonance imaging (MRI) improves the phenotypic characterization of patients with neuromuscular disorders and allows accurate quantification of muscle and adipose tissue distribution, to date quantitative MRI has not been used to assess the therapeutic response in clinical trials of neuromuscular diseases. We discuss quantitative MRI findings after a 6‐month course of enzyme replacement therapy administered to nine patients with adult‐onset glycogenosis II. Muscle Nerve 40: 122–125, 2009     

Long-term management of acute respiratory failure in metabolic myopathy

Objective To describe how patients cope with the proposal of treatment with intermittent artificial ventilation after acute respiratory failure due to progressive respiratory muscle weakness.Design Case series, follow-up study.Setting Neurological intensive care unit (ICU).Patients 7 consecutive patients with metabolic myopathy treated for acute respiratory failure between 1983 and 1992.Interventions Intermittent positive pressure ventilation (IPPV) via tracheostomy.Measurements and results Symptoms of chronic hypoventilation preceded acute respiratory failure for months. With one exception, patients were mainly disabled from respiratory muscle weakness and sleep-related breathing disorders. IPPV was recommended to prevent recurrent respiratory failure. Two of three patients who accepted home IPPV returned to full-time jobs. One patient, who decided against IPPV, died from CO₂ narcosis several months after discharge. All patients adhered to the respiratory regimen once instituted.Conclusions Acute respiratory failure in chronic myopathy is heralded by daytime drowsiness. IPPV, or at least regular monitoring of waking and sleeping partial pressure of carbon dioxide, is highly recommended even if weaning is successful. IPPV improved quality of life. The treatment strategy at discharge from the ICU should be optimal, as patients are reluctant to modify regimens.     

A novel mutation of the GAA gene in a Finnish late‐onset pompe disease patient: Clinical phenotype and follow‐up with enzyme replacement therapy

Pompe disease is a rare, progressive disease leading to skeletal muscle weakness due to deficiency of the acid α‐glucosidase (GAA) enzyme. Herein we report the first diagnosed Finnish patient with a phenotype compatible with the late‐onset form of Pompe disease. Molecular genetic analysis of the GAA gene revealed a novel missense mutation, 1725C>A (Y575X), combined with a previously reported mutation, 1634C>T (P545L). Human recombinant α‐glucosidase enzyme (alglucosidase‐α) treatment was initiated for this patient at age 20 years. After 12 months she was no longer fully wheelchair‐bound, and muscle strength had improved. No disease progression was visible on muscle magnetic resonance imaging of the lower limbs, and the energy state of the muscle cells increased by 46% on phosphorus magnetic resonance spectroscopy. Overall, our findings suggest that enzyme replacement therapy is indicated, even in patients with late‐onset Pompe disease, to halt disease progression and improve the quality of daily life. Muscle Nerve, 2009