Reference Intervals of Mitochondrial DNA Copy Number in Peripheral Blood for Chinese Minors and Adults / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Mitochondrial DNA (mtDNA) content measured by different techniques cannot be compared between studies, and age- and tissue-related control values are hardly available. In the present study, we aimed to establish the normal reference range of mtDNA copy number in the Chinese population.</p><p><b>METHODS</b>Two healthy cohorts of 200 Chinese minors (0.1-18.0 years) and 200 adults (18.0-88.0 years) were recruited. Then, they were further categorized into eight age groups. The absolute mtDNA copy number per cell was measured by a quantitative real-time polymerase chain reaction. We subsequently used this range to evaluate mtDNA content in four patients (0.5-4.0 years) with molecularly proven mitochondrial depletion syndromes (MDSs) and 83 cases of mitochondrial disease patients harboring the m.3243A>G mutation.</p><p><b>RESULTS</b>The reference range of mtDNA copy number in peripheral blood was 175-602 copies/cell (mean: 325 copies/cell) in minors and 164-500 copies/cell (mean: 287 copies/cell) in adults. There was a decreasing trend in mtDNA copy number in blood with increasing age, especially in 0-2-year-old and >50-year-old donors. The mean mtDNA copy number level among the mitochondrial disease patients with m.3243A>G mutation was significantly higher than that of healthy controls. The mtDNA content of POLG, DGUOK, TK2, and SUCLA2 genes in blood samples from MDS patients was reduced to 25%, 38%, 32%, and 24%, respectively.</p><p><b>CONCLUSIONS</b>We primarily establish the reference intervals of mtDNA copy number, which might contribute to the clinical diagnosis and monitoring of mitochondrial disease.</p>

Clinical and Molecular Characteristics in 100 Chinese Pediatric Patients with m.3243A>G Mutation in Mitochondrial DNA / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Mitochondrial diseases are a group of energy metabolic disorders with multisystem involvements. Variable clinical features present a major challenge in pediatric diagnoses. We summarized the clinical spectrum of m.3243A>G mutation in Chinese pediatric patients, to define the common clinical manifestations and study the correlation between heteroplasmic degree of the mutation and clinical severity of the disease.</p><p><b>METHODS</b>Clinical data of one-hundred pediatric patients with symptomatic mitochondrial disease harboring m.3243A>G mutation from 2007 to 2013 were retrospectively reviewed. Detection of m.3243A>G mutation ratio was performed by polymerase chain reaction (PCR)-restriction fragment length polymorphism. Correlation between m.3243A>G mutation ratio and age was evaluated. The differences in clinical symptom frequency of patients with low, middle, and high levels of mutation ratio were analyzed by Chi-square test.</p><p><b>RESULTS</b>Sixty-six patients (66%) had suffered a delayed diagnosis for an average of 2 years. The most frequent symptoms were seizures (76%), short stature (73%), elevated plasma lactate (70%), abnormal magnetic resonance imaging/computed tomography (MRI/CT) changes (68%), vomiting (55%), decreased vision (52%), headache (50%), and muscle weakness (48%). The mutation ratio was correlated negatively with onset age (r = -0.470, P < 0.001). Myopathy was more frequent in patients with a high level of mutation ratio. However, patients with a low or middle level of m.3243A>G mutation ratio were more likely to suffer hearing loss, decreased vision, and gastrointestinal disturbance than patients with a high level of mutation ratio.</p><p><b>CONCLUSIONS</b>Our study showed that half of Chinese pediatric patients with m.3243A>G mutation presented seizures, short stature, abnormal MRI/CT changes, elevated plasma lactate, vomiting, and headache. Pediatric patients with these recurrent symptoms should be considered for screening m.3243A>G mutation. Clinical manifestations and laboratory abnormalities should be carefully monitored in patients with this point mutation.</p>

Clinical, pathological and molecular biological characteristics of mitochondrial encephalomyopathy with lactic acidosis and stroke-like episode in children / 中华儿科杂志

<p><b>OBJECTIVE</b>To delineate the characteristics of the clinical manifestation, pathology of skeletal muscle and gene mutations of mitochondrial encephalomyopathy with lactic acidosis and stroke-like episode (MELAS) in children.</p><p><b>METHOD</b>The clinical manifestation, laboratorial data, brain images, muscle pathology and mitochondrial gene mutations were analyzed in 24 patients with MELAS who were diagnosed in Department of Pediatrics, Peking University First Hospital. Their prognosis was evaluated by following up.</p><p><b>RESULT</b>Symptoms of central nervous system such as stroke-like episodes, vomiting, convulsion and headache were present in all the 24 cases. Nine cases had the symptoms of myopathy. Twenty cases had developmental delay. Short stature, being thin and hairy was very common in these cases. Serum lactate level increased in all the cases, pyruvate increased in 17 cases. Elevated CSF lactate was found in 2 cases. Magnetic resonance imaging (MRI) was performed on 24 cases, out of them 23 were abnormal. The lesions mainly involved cerebral lobes. Occipital lobe was the most common site of lesions. Computed tomography (CT) was performed on 13 cases, low density lesions were present in 10 cases, basal ganglia calcifications in 5 cases. Muscle biopsy was performed on 8 cases, ragged-red fibers (RRF) were found in 4/8 cases, and abnormal accumulation of mitochondria were found in 3/8 cases. The mtDNA gene mutational analysis showed A3243G mutation in these patients. The mutation rates varied from 11.6% to 75.0%. The same mutation were found in 4/5 mothers who had the genetic tests, and the mutation rates of the mothers varied from 15.0% to 23.6%. The clinical information of 11 cases was available through recent following up. Three cases died, the others had some degrees of mental retardation.</p><p><b>CONCLUSION</b>Children with MELAS had various clinical manifestations. Central nervous system and skeletal muscle were usually involved. Short stature and hypertrichosis were common signs. The prognosis of this disease was disappointing. mtDNA A3243G was the most common mutation in MELAS. Fully understanding the characteristics of its clinical manifestation, laboratory tests, brain image, muscle pathology and molecular features can be helpful to the early diagnosis and treatment.</p>

Analysis on resistance testing and technological research of acupoints / 中国针灸

In order to summarize and analyze the progresses and problems of resistance testing and technology research on acupoints, investigate the related solutions, articles on resistance testing from 1990 to 2011 were collected, and advantages and shortcomings of different types of testing instruments were discussed in this article as well. Detection technology of acupoint impedance has under updating changes, which are often applied on locating acupoints and clinical diagnosis. The progresses of those technologies are mainly embodied in improvement of circuit model, which enable a longer testing duration, less media interference and so on. The previous studies often focus on resistance testing of the skin. Since dermal resistance does not equal to acupoint resistance, the designation of equivalent circuit does not embody the condition of cells, tissues and nerves at acupoints, and testing technology is often affected by factors such as polarization of electrodes, contact medium and anatomical characteristics of acupoints, the resistance of acupoints can not be taken as the effective framework of the diagnostic standard and judgement of therapeutic effect in clinic. Based on the key problems in resistance testing of acupoints, it is proposed by the article that the techniques and designation of circuit model should be reformed, and mathematical model should be established in the study to meet the requirement of the life system. Inductance of human body should be considered in resistance research of acupoints, and interference factors should be eliminate as far as possible in designation of equipments. Thus, the change law of acupoint resistance in the inner part of the body can be fully embodied by the designation of experiments.

Effects of 650 nm laser and moxibustion pretreatment on enteric nervous system and medullary visceral zone in rats with visceral traction pain / 中国针灸

<p><b>OBJECTIVE</b>To explore effects of 650 nm laser and moxibustion pretreatment on visceral traction pain (VTP) and its mechanism.</p><p><b>METHODS</b>Forty male SD rats were randomly devided into a sham operation group (group A), a VTP group (group B), a 650 nm laser pretreatment group (group C), a moxibustion pretreatment group (group D). Rats in group A and group B were not treated except sham operation or VTP model. In group C and D, the VTP models were produced immediate after 650 nm laser irradiation or moxibustion at "Zusanli" (ST 36), respectively. The changes of pain score and systolic pressure were investigated and the activity of AChE, the content of SP and leu-enkephaline (LEK), and the positive index of c-Fos protein and glial fibrillary acidic protein (GFAP) were detected by biochemistry, radio-immunity method and immunohistochemistry, respectively.</p><p><b>RESULTS</b>Compared with group A, the pain score, systolic pressure, the activity of AChE, the content of SP, and the positive index of c-Fos protein and GFAP of group B increased significantly (all P < 0.05); compared with group B, the pain score, AChE activity, the content of SP and the positive index of c-Fos protein and GFAP of both group C and group D decreased significantly (all P < 0.05); compared with group B, the content of LEK increased and systolic pressure decreased significantly in group C (both P < 0.05).</p><p><b>CONCLUSION</b>Both 650 nm laser and moxibustion pretreatment can inhibit VTP and the mechanism may be related to reducing the activity of AChE and the content of SP, and increasing the activity of LEK and decreasing the expression of c-Fos protein and GFAP.</p>

Molecular genetic analysis of mitochondrial DNA C1494T mutation in non-syndromic hearing loss of Chinese population / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To conduct a molecular epidemiological survey on the mitochondrial DNA C1494T mutation in non-syndromic hearing loss patients in Chinese population.</p><p><b>METHODS</b>Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) were used to screen the mitochondrial DNA 12S rRNA C1494T mutation in 20 patients with aminoglycoside antibiotic induced hearing loss, 136 sporadic non-syndromic hearing loss patients and 50 probands of pedigrees with non-syndromic hearing loss.</p><p><b>RESULTS</b>The C1494T mutation did not appear in all cases except for the positive control.</p><p><b>CONCLUSION</b>Incidence of mitochondrial DNA C1494T mutation is much lower than that of mitochondrial DNA A1555G mutation in non-syndromic hearing loss of Chinese population. Mitochondrial DNA C1494T mutation may be a rare variation in non-syndromic hearing loss and is not the main cause of aminoglycoside antibiotic induced-deafness.</p>

Five single nucleotide polymorphisms of casein kinase I gamma 2 gene in children with familial febrile convulsions / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the association between single nucleotide polymorphisms (SNPs) of casein kinase I gamma 2 (CSNK1G2) gene and children with familial febrile convulsions.</p><p><b>METHODS</b>The study samples were collected from unrelated Chinese Han population of Hebei province, including a cohort of 53 children with familial febrile convulsions(FC) and a control cohort of 101 individuals. Genotypes of SNPs rs2074882, rs740423, rs2277737, rs4806825, rs1059684 were typed by polymerase chain reaction-restriction fragment length polymorphism.</p><p><b>RESULTS</b>The frequencies of the five SNPs complied well with the Hardy-Weinberg equilibrium in FC group and normal group. The distribution of genotype and frequencies of alleles of the SNPs rs740423, rs2277737, rs1059684 in familial febrile convulsions group was significantly different from that in control group. No significant difference was observed in the distribution of genotypes and frequencies of alleles at SNP rs2074882 between two groups. Analysis on rs4806825 was not made owing to its less allele frequency.</p><p><b>CONCLUSION</b>These data indicate that SNPs rs740423, rs2277737, rs1059684 of CSNK1G2 gene may contribute to familial febrile convulsions in children.</p>