Clinical features of long segmental myelopathy caused by nitrous oxide / 北京大学学报(医学版)

OBJECTIVE@#To analyze the clinical and imaging characteristics of the neurological damage caused by nitrous oxide (N2O).@*METHODS@#In the study, 10 patients in the Department of Neurology of China-Japan Friendship Hospital from October 2015 to February 2018 were retrospectively analyzed for the demographic data, the history of inhaled N2O, clinical features, blood examination, electrophysiological examination, spinal magnetic resonance imaging and therapeutic efficacy profiles.@*RESULTS@#The male-to-female ratio was 4:6 and it presented with an age-of-onset 17-26 years [the average age: (20.80±3.12) years]. The time from inhaled N2O to onset was 1 month to 1 year [the average time: (6.95±4.19) months]. Paralysis in all the patients and numbness in 9 patients were the main clinical features, while positive Lhermitte's sign in 3 patients, urinary and defecation disturbance in 4 patients were also found. Blood examination indicated anemia in 2 patients, giant cell anemia in 1 case and small cell hypochromic anemia in 1 case. 3 cases had been treated with vitamin B12 in an external hospital, and the other 7 cases had abnormal increase in homocysteine levels. Electrophysiological examinations showed sensory and motor nerve involvement in 9 patients, and motor nerve involvement in 1 patient. The severity of lower extremity lesion was significantly heavier than that of upper extremity. Spinal magnetic resonance imagings showed that long segmental lesions were present in the cervical spinal cord of all the patients, 3 cases with long segmental lesions of the thoracic cord and 2 cases with spinal cord swelling. In 6 cases, the horizontal axis had an "inverted V-type" T2 high signal, 1 case was classified as "crescent", and 3 cases were "eight-shaped". The symptoms in these 10 cases were alleviated in varying degrees after stopping the inhalation of nitrous oxide, actively supplementing high doses of vitamin B12 and doing early rehabilitation exercises.@*CONCLUSION@#Myelopathy with nitrous oxide presents as paralysis and numbness in limb extremities. In imaging, cervical spinal cord damage is common, accompanied by thoracic spinal cord damage. The horizontal axis is more common in the "inverted V-type". Treatment with high doses of vitamin B12 is effective.

Diagnosis of Muscular Dystrophy Using Western Blot with Micro-sample of Muscle / 中国医学科学院学报

<p><b>OBJECTIVE</b>To diagnose muscular dystrophy using Western blot (WB) by improving the method of the protein extraction.</p><p><b>METHOD</b>Firstly,we compared the effect of different sample buffer solutions and processing Methods on the extraction of muscle protein in rats,then selected the appropriate extracting method and the process of the muscular protein.</p><p><b>RESULTS</b>We put the selected sample buffer into the micro-sample,then mixed. The concentration of the extracting protein was much more,and the loss during the process was much less. We extracted enough protein in 62 cases. The protein bands were showed clearly by WB,and the abnormal protein bands were shown in some patients. Compared with the Results of immunohistochemical staining detected the severe abnormal expressions of Dys-R,Dys-C,and Dys-N in the specimens,we did not detect the corresponding target band in WB. We detected the target protein band of the specimens were abnormal position,light or normal staining in WB,while Dys were mildly expressed in immunohistochemical staining.</p><p><b>CONCLUSIONS</b>The improved protein extraction method can save the muscle tissue,and the protein bands can be used for diagnosing the muscular dystrophy. For clinically suspected patients with dystrophinopathy,if normal or mild deficiency is shown by immunohistochemistry,WB should be applied to detect the dystrophin protein band.</p>

A study on PARKIN gene in three pedigrees with autosomal recessive early-onset Parkinson's disease / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To detect the possible relationship between PARKIN gene and the Chinese pedigree with autosomal recessive early-onset Parkinson's disease(AREP).</p><p><b>METHODS</b>Clinical examination was carried out in 6 patients from 3 Chinese pedigrees with AREP and their 23 family members. PCR amplification of all exons of PARKIN gene was performed. The PCR products were analyzed by denaturing high-performance liquid chromatography(DHPLC) to screen for point mutation and polymorphism. And in the samples with abnormal DHPLC result, further sequencing was conducted to confirm the type of mutation and polymorphism.</p><p><b>RESULTS</b>All exons of PARKIN gene from the research subjects were successfully amplified. A heterozygous point mutation (Gly284Arg) in exon 7 was found in one pedigree. A polymorphism (Ser167Asn) in exon 4 was found in another pedigree. All the patients had the past history of exposure to environmental poison.</p><p><b>CONCLUSION</b>When acting together with risky environmental factors, the heterozygous mutation Gly284Arg in PARKIN gene may cause AREP. The polymorphism Ser167Asn in PARKIN gene increases the risk of developing Parkinson's disease and may cause AREP when acting together with hydrargyrism.</p>

Cytochrome C oxidase subunit 1 mutation result in mitochondrial encephaiomyopathy with lactic acidosis and stroke-like episodes / 中华神经科杂志

Objective To report a 33-year-old man with post-headache stroke-like episodes,with whom ischemic changes were found in basal ganglia and occipital-temporal lobe and muscle biopsy revealed abnormal mitochondrial structure and function without regular mutations detected in mtDNA.Methods Gene chip technique was used to detect the mutation of whole sequence of mtDNA,and direct sequencing technique was used to confirm the mutations.Results Three mutations were found.A new mutation in the mitochondrial cytochrome C oxidase subunit 1 (MTCO1),a T→C transition at nucleotide position 6253 resulted in conservative methionine transferring to threonine.His mother also held the mutation,which was not found in 98 control samples.So T6253C was considered the nosogenetic mutation.Conclusion This is the first time to report a mutation in MTCO1 responsible of MELAS.