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Yun Yuan

Publications and source records attributed to Yun Yuan.

17 recordsLinked to original sources
PubMed2006

[Immunopathological changes of micro-vessels in dermatomyositis].

OBJECTIVE: To investigate the immunopathological changes of micro-vessels in dermatomyositis. METHODS: Twelve patients with dermatomyositis, 5 males and 7 females, aged 40.8 (6 - 72), underwent muscle biopsy of biceps muscle of arm (n = 11) or deltoid muscle (n = 1). The specimens underwent routine histological, enzyme histochemical, and immunohistochemical staining and microscopy. Ten biopsy specimens from patients with other diseases were used as controls. RESULTS: Perifascicular atrophy of muscular fibers and inflammatory infiltration in perimysium were seen in all patients with dermatomyositis. Non-specific esterase staining showed deep staining of capillaries and micro vascular endothelium among the muscular fibers. Immunohistochemistry showed remarkable reduction of capillaries positive in von Willebrand factor (vWF), thrombomodulin (TM), and endothelial cell nitric oxide synthase (eNOS) in the perifascicular region, and low expression of .eNOS and TM in the microvascular endothelium in the perimysium. CONCLUSION: The vascular lesions of dermatomyositis are located not only in capillaries, but also in other microvessels. Lower expression of TM and eNOS in vascular endothelium suggests the reduction of anticoagulation and vasodilation functions of vascular endothelium. Dermatomyositis is an inflammatory vascular endothelial disease.

Adolescent↗
PubMed2006

[Rheumatoid leptomeningitis: a case report and literature review].

To report the clinical, radiological and neuropathological findings of a patient with rheumatoid meningitis. The patient was a 71-year-old Chinese man with a two-year history of rheumatoid arthritis and no other significant medical history, who presented to our hospital recurrent weakness of his left extremities, dysarthria and a continuous bilateral hand tremor. Cerebrospinal fluid (CSF) and serum examinations were normal apart from a mildly raised serum perinuclear antineutrophil cytoplasmic autoantibody (p-ANCA). Brain magnetic resonance imaging (MRI) showed leptomeningeal enhancement in both frontal and parietal lobes, in addition to several old white matter infarcts. Meningeal biopsy showed numerous infiltrating macrophages and lymphocytes within the leptomeninges. The patient responded clinically and radiologically to corticosteroid and cyclophosphamide therapy. The patient subsequently developed herpes zoster over his left chest as a complication of his immunosuppressive treatment. His cyclophosphamide was ceased and intravenous immunoglobulin (IVIG) therapy was commenced, with good clinical response to both the herpes zoster and meningitis. According to the result of the biopsy, aseptic meningitis was considered the MRI results and the patient's clinical history were given, and a diagnosis of rheumatoid meningitis was made. The patient was p-ANCA positive. Although there was no evidence for cerebral vasculitis on biopsy, it remains a possibility that the patient's recurrent minor cerebral infarcts visible on MRI were vasculitic in nature.

Aged↗
PubMed2006

Clinical and laboratory survey of 65 Chinese patients with Leigh syndrome.

BACKGROUND: Leigh syndrome is an inherited neurodegenerative disease that emerges in infancy and childhood and presents with a clinically heterogeneous variety of neuromuscular and non-neuromuscular disorders. It can result from the inheritance of mutations in either nuclear or mitochondrial DNA. In the current study, we performed a retrospective study in 65 patients in order to investigate the clinical and genetic characteristics of Leigh syndrome in Chinese patients. METHODS: Sixty-five unrelated cases (35 men and 30 women) who were hospitalized in the past 12 years were reviewed. Diagnosis was based on both the clinical presentation and the characteristic neuropathologic findings of bilateral symmetric necrotizing lesions in the basal ganglia and brain stem as detected using cranial computed tomography (CT) scan or magnetic resonance imaging (MRI). The differential diagnosis of organic acidurias and fatty acid beta-oxidation defects were performed. Specific point mutations and deletions in mitochondrial DNA (T8993G, T8993C, T9176C, A8344G, A3243G) were screened by PCR-restriction analysis and Southern blot. The SURF1 gene was sequenced. Skeletal muscle biopsies were performed in 17 (26.2%) of the patients. The diagnosis was confirmed by autopsy in 6 (9.2%) patients. RESULTS: The patients had various forms of metabolic encephalomyopathy. Fifty-nine (90.8%) of the patients had the typical neuroradiological features of Leigh syndrome, including symmetrical necrotizing lesions scattered within the basal ganglia, thalamus and brain stem. Twenty (30.8%) patients were confirmed by genetic, biochemical analysis and autopsy. Specific point mutations in mitochondrial DNA were found in 5 cases (7.7%). Of these, the A8344G mutation was detected in 2 patients. The T8993G, T8993C, and A3243G point mutations were identified in 3 other patients, respectively. SURF1 mutations associated with cytochrome c oxidase deficiency were identified in 8 (12.3%) families by DNA sequencing. A G604C mutation was identified in 6 (9.2%) patients. The genotypes of 52 patients remained unknown. CONCLUSIONS: Leigh syndrome presents as a diverse array of clinical features and can result from specific mutations in nuclear or mitochondrial DNA. In this study, SURF1 mutations associated with cytochrome c oxidase deficiency were identified in 8 (12.3%) out of 65 patients with Leigh syndrome. It indicates that SURF1 mutations might be a common cause of Leigh syndrome in China. The etiology of Leigh syndrome in Chinese patients represents a persistent challenge to clinicians.

Adolescent↗
PubMed2006

[Two novel mutations in palmitoyl-protein thioesterase gene in two Chinese babies with infantile neuronal ceroid lipofuscinosis].

OBJECTIVE: To search for possible novel mutations in palmitoyl-protein thioesterase 1 (PPT1) gene in two Chinese babies with infantile neuronal ceroid lipofuscinosis (INCL). METHODS: Two probands with INCL, confirmed clinically and pathologically, were used for mutation search in PPT1 gene. Onset of the disease occurred before the age of 1 year and they mainly showed progressive mental and motor retardation. The 9 coding exons and their flanking intron sequences of palmitoyl-protein thioesterase 1 (PPT1) gene were amplified by using PCR and sequenced. The parents of proband 1 were also examined. RESULTS: One splicing mutation and two missense mutations were identified in the two probands: the proband 1 carrying a compound heterozygous mutation of a IVS1 + 1G-->A mutation in intron 1 and a c550G-->A mutation in exon 6 leading to the amino acid substitution of E184K. Additionally, the parents of the proband 1 also harbored one of the mutations of the patient, respectively. The proband 2 carrying a homozygous mutation of c272A-->C in exon 3, which resulted in the amino acid substitutions of Q91P. CONCLUSIONS: The IVS1 + 1G-->A mutation and Q91P mutation are novel mutations, which lead to INCL. The genetic abnormalities of PPT1 in Chinese patients may not be completely the same as those in the patients of other regions of the world.

Age of Onset↗
PubMed2005

[Diffuse muscular calcification with subcutaneous cysts].

OBJECTIVE: Diffuse muscular calcification was rare myopathological change due to abnormal metabolism of calcium, which was mainly found in dermatomyositis and myositis ossificans progressiva. Here we reported a case of diffuse muscular calcification that clinically mimicked myositis ossificans progressiva. The disease might be a new type of congenital calcium metabolic disease. METHODS: A 15-year-old girl developed subcutaneous cysts in the wrist and ankle when she was 1 year old. At the age of 9, she developed recurrent fever with myalgia, fatigue and diffuse muscular calcification. It was difficult for her to squat, run or walk. Protuberance presented in the subcutaneous tissue of her trunk. Some nodules ruptured with outflow of chalky material. ESR, ENA, RF, CRP, PTH, CK were in normal limits. EMG was unremarkable. X-ray confirmed diffuse calcification in the muscle and subcutaneous tissues. Biceps muscle biopsy was performed. RESULTS: Numerous inflammatory cells infiltrated around vessels in the perimyosium with perifascicular muscle fiber atrophy and degeneration. Many RRF and SDH positive fibers were also observed. EM showed tubular reticular inclusions in vascular endothelium. CONCLUSION: Diffuse muscular calcification indicated existence of systemic calcium metabolic abnormality. As the clinical symptoms and distribution pattern of calcification were different from dermatomyositis with subcutaneous calcification and myositis ossificans progressiva, our case might be a new type of disease. The microvascular changes might result in the lesion of muscle fibers.

Adolescent↗
PubMed2005

[Neurolymphomatosis, a case report].

Neurolymphomatosis (NL) is characterized by lymphomatous infiltration of the peripheral nervous system. We report a case of neurolymphomatosis (NL) which was confirmed by sural nerve biopsy. Sural nerve specimen from a 49-year-old female patient with weakness of limbs was examined with routine histochemical and immunohistochemistry staining, in which the first antibodies against CD3, CD20, CD45, CD45RO and CD68 were used. Numerous T-lymphoma cells invaded in the adipose tissue of epineurium of sural nerve. The nerve biopsy showed marked axonal degeneration of myelinated fibers. The clinical and histopathologic findings confirmed the diagnosis of neurolymphomatosis.

Female↗
PubMed2005

[Phenotype heterogeneity associated with mitochondrial DNA A3243G mutation].

OBJECTIVE: To discuss the clinical characteristics associated with mitochondrial DNA A3243G mutation. METHODS: Clinical manifestations as well as results of brain CT and/or MRI scanning, blood level of lactic acid and muscle biopsy results of 25 mitochondrial encephalomyopathies patients whose A3243G mutations were analyzed. RESULTS: Although all of the 25 patients carried mtDNA A3243G point mutation, their clinical manifestations varied greatly. Among them, there were 19 cases of mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS), 2 cases of encephalopathies which could not be classified into any specific type, 2 cases of floppy infants, one case of Kearns-Sayer syndrome (KSS) and one case of mitochondrial entero-myopathy. Most patients showed abnormal cranial radiological findings and ragged-red-fibers on muscle biopsies. Elevation of blood lactic acid was notably found in all of the 25 patients. CONCLUSIONS: Significant variations in clinical manifestation and brain images are the prominent features in patients with A3243G mutation. Mitochondrial diseases should be considered in patients with multiple organ involvement and elevated serum lactic acid mtDNA mutation examination is necessary for the diagnosis of mitochondrial diseases.

Adolescent↗
PubMed2005

Novel GLA gene mutations in two Chinese families with classic Fabry disease.

OBJECTIVE: To search mutations in GLA gene in two Chinese families with classic Fabry disease. METHODS: Two families with Fabry disease confirmed by pathological and clinical studies were reported here. In pedigree 1, 12 family members had paroxysmal pain on limb extremities. In pedigree 2, there were 8 patients and most of them had multi-organ involvement at the end stage of the disease. Two probands from the two families together with several of their family members were searched for mutations in GLA gene. After extraction of genomic DNA from peripheral leukocytes, all of the 7 exons and their flanking introns were amplified by PCR and directly sequenced. RESULTS: Both the proband 1 and proband 2 were identified to be hemizygotes of novel GLA missense mutations. G132T (TGG-->TGT) mutation in exon 1, resulting in the substitution of amino acid from tryptophan to cysteine (W44C), was detected in proband 1. G874C (GCT-->CCT) mutation in exon 6, resulting in the substitution of amino acid from alanine to praline (A292P), was detected in proband 2. Mothers of the 2 probands were heterozygotes carrying the same mutation as their sons. CONCLUSION: We report here 2 novel missense mutations in two Chinese families with classic Fabry disease. Different mutations in the same gene can result in phenotypes with significant deviation. Several female patients with the same clinical manifestations as male patients in the 2 families suggest that the X-linked dominant inheritance of the disease, possibly related to be the random X chromosome inactivation.

Adolescent↗
PubMed2004

[NOTCH3 gene mutations in four Chinese families with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy].

OBJECTIVES: To search for mutations in NOTCH3 gene in four Chinese families with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). METHODS: Four probands from four unrelated families with typical manifestations of CADASIL were studied. The 1 approximately 12 coding exons and their flanking intron sequences of NOTCH3 gene were amplified by PCR and sequenced. Some family members in the pedigree 2 and 4 were also examined for the NOTCH3 gene mutations. RESULTS: Four heterozygous missense mutations were identified in the four families: the proband 1 carrying a 268C-->T mutation in exon 3, the proband 2 a 322 C-->T mutation in exon 3, the proband 3 a 328 C-->T mutation inexon 3, and the proband 4 a 1819 C-->T mutation in exon 11, which resulted in the amino acid substitutions of R90C, C108R, R110C, and R607C respectively. Among them the C108R is a novel mutation not reported previously. Additionally, some members in the pedigree 2 and 4 also harbored the same mutations with the probands. CONCLUSION: Four heterozygous missense mutations in NOTCH3 gene have been found in four Chinese families with CADASIL. Different point mutations in NOTCH3 lead to similar phenotype of the disease. To search for mutations in NOTCH3 in related patients will help further understand and accurately diagnose the disease and perform prenatal diagnosis in CADASIL families.

Adult↗
PubMed2004

[Clinical features in 4 Chinese families with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)].

OBJECTIVE: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL) is an inherited cerebral arteriolar disease in adulthood, which is caused by NOTCH3 gene mutation. The main symptoms were migraine, cerebral stroke, later with mood disorders and dementia in Caucasian patients. Recently, the disease was also recognized in Asian patients, in whom the migraine is rarely reported. In order to give the clinical features of Chinese patients, we described the clinical symptoms in 4 CADASIL families. METHODS: CADASIL was diagnosed by the investigation of ultra-structure changes of arteriole in sural nerve and NOTCH3 gene mutation in the 4 index cases. Detailed clinical and routine laboratory examinations were performed in these 4 patients, including electrocardiography, nerve conduction velocity, serum glycogen, and serum homocysteine. Additionally, we also collected the clinical data of the other 83 family members through interviews and the available medical records. RESULTS: Of the 83 persons, 29 were classified as clinical suspected patients, who presented one or more of the disease-related neurological symptoms, such as cerebral ischemic events and the cognitive impairment. All of them showed no common risk factors for stroke, such as diabetic mellitus, hypertension, and heart disease. The clinical suspected patients distributed in every consecutive generations and involved both sexes, which was according to the autosomal dominant inherited pattern. The onset age of the disease ranged from 28 to 70-year-old and mainly between the 4th and the 5th decades. The main symptoms were recurrent episodic vertigo, with or without hemiplegia. At the same time or a little bit later, the cognitive impairment was developed in some patients. Compared with the typical presentations of the disease in European patients, none of our 29 patients showed migraine,one index case showed mild sensory disturbance in extremities. Elevated serum homocysteine level and abnormal of nerve conduction study in two index cases (3 and 4) were noticed. CONCLUSION: The onset age of the disease of our patients is similar to that of Caucasian patients. The main symptoms were stroke and dementia. Involvement of post circulation system was the main clinical feature for ischemic events in our patients. Dementia could be found in the early stage of disease. Migraine should not be regarded as a common clinical feature in our patients. The involvement of the peripheral nerves expanded the disease expression outside the central nervous system.

Adult↗
PubMed2003

[Mitochondrial DNA mutations in patients with chronic progressive external ophthalmoplegia and Kearns-Sayre syndrome].

OBJECTIVE: Kearns-Sayre syndrome (KSS) and chronic progressive external ophthalmoplegia (CPEO) belong to neurological diseases caused by a defect in the energy-producing system of mitochondria, and are known to be associated with a deletion in the mitochondrial genome. This study was aimed to understand with greater clearness the characteristics of mitochondrial DNA (mtDNA) mutations in 11 Chinese patients with CPEO (7 cases) or KSS (4 cases). METHODS: Densitometry of the bands on Southern blot, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequencing were performed to search large scale deletions and A3243G point mutation in patients' muscle mtDNA. RESULTS: Large deletions in mtDNA were detected in 2 CPEO and 3 KSS patients, the size of deletion ranged from 3.0 kb to 8.0 kb. Moreover, mtDNA A3243G point mutation was identified in 1 KSS patient. The proportion of mutant mtDNA was 37.6%-87.0%. Direct sequencing of the PCR products revealed 5 novel large deletions not reported by others. CONCLUSION: The findings in this study being consistent with the reports by others, large scale deletions of mtDNA are frequently found in Chinese patients with KSS and CPEO. mtDNA A3243G mutation may also exist in some patients with KSS and CPEO.

Adolescent↗
PubMed2003

[Clinical pathology and molecular genetics on familial amyloidotic polyneuropathy].

OBJECTIVE: To report the clinical, pathologic and molecular genetic features of a Chinese family with familial amyloidotic polyneuropathy (FAP) in Beijing area. METHODS: The proband was a 52-year-old woman with 7 years history of vomitting and diarrhea and weakness as well as anaesthesia. In her family there were 5 patients with initial presentation in three consecutive generations ranging in age from 21 to 45 years. Sensory neuropathy and systemic autonomic symptoms appeared in all the 5 patients, with muscle weakness in 2 cases in the later stage of disease. Gastrointestinal involvement appeared in the early stage of disease in all patients. Sural nerve biopsy was performed on the proband. The nerve specimens were applied for routine histological and ultrastructural investigation as well as immuno-histochemical staining with monoclonal antibodies against transthyretin (TTR) protein, immunoglobulin kappa- and lambda-chains. DNA analysis was performed on the proband and her son for TTR gene and apolopoprotein A1. RESULTS: Amyloid, identified as amorphous eosinophilic extracellular deposits on Congo red staining and recognized by its characteristic fibrillar ultrastructure with electron microscopy, was identified arround small vessel in the endoneurium. Axonal loss was recorded as severe (> 75%). Immunoglobulin kappa- and lambda-chains as well as TTR positive deposits were not demonstrated in the accumulated amyloid material. There was neither TTR nor apolopoprotein A1 coding gene mutation detected in the proband and her son. CONCLUSION: The pathological findings demonstrated existence of a FAP. However, the immuno-pathological and genetic results could not classified the type of this FAP family. Further genetic studies are required to identify it.

Adult↗
PubMed2002

Neuropathologic and clinical features in eight Chinese patients with Leigh disease.

We present the neuropathologic and clinical features of eight Chinese patients with Leigh disease. Five cases had onset before 1 year of age, the other three after 1 year of age. Cranial magnetic resonance imaging (MRI) demonstrated symmetric and bilateral long T1 and long T2 lesions mainly in the basal ganglia and brain stem. The putamen was most commonly and severely affected. Brain neuropathologic examinations showed multiple symmetric foci of degeneration and necrosis with capillary proliferation and dilation. In contrast to previous reports, these foci were mainly in the brain stem, not the basal ganglia. We examined mitochondrial DNA from three patients and found the T8993G mitochondrial DNA mutation in one of them. This patient inherited the mutation from his mother, who does not display any symptoms now. From this study, we found that the nuclei in the brain stem can be more frequently affected than those in the basal ganglia.

Age of Onset↗
PubMed2002

Detection of A3243G point mutation in mitochondrial DNA from 10 cases of MELAS.

OBJECTIVE: To search for A3243G point mutations in mitochondrial DNA (mtDNA) from 10 cases of mitochondrial encephalomyopathy, lactic acidosis and strokelike episodes (MELAS). METHODS: Using PCR-restriction analysis, we investigated A3243G point mutations in mtDNA of muscle and/or blood cells from 10 patients and their 8 maternal relatives. We also quantitated the A3243G mtDNA in samples harboring the mutation. RESULTS: A3243G point mutations were identified in all muscle and/or blood samples from 10 MELAS patients. The proportion of mutant mtDNA was 10.8%-47.8% in blood (7 cases), and 39.4%-67.7% in muscle (5 cases). This ratio was invariably higher in muscle than in blood from two patients whose blood and muscle samples were both available. Younger patients usually carried higher proportions of A3243G mutant mtDNA in blood. Eight maternal relatives from 6 families were also examined. Maternal transmission of the disease could be identified in one family. No A3243G point mutations were found in mothers' blood from 3 families and siblings' blood from 2 families. CONCLUSIONS: All 10 MELAS patients were found to have the mtDNA A3243G mutation in their muscle and/or blood. The A3243G mutation seems to be sporadic in 5 of the families examined, suggesting the mechanism of de novo mutation for the pathogenesis of their MELAS syndrome.

Adolescent↗