Fast 2-dimension scanning and line-scanning of intracellular Ca2+ transients in cardiac myocytes / 中国应用生理学杂志

<p><b>AIM</b>Fast 2-dimension scanning and line-scanning of confocal imaging were employed for measurement of cardiac Ca2+ transients, and the advantages and disadvantages about these two scannings were discussed.</p><p><b>METHODS</b>Single adult SD rat cardiac myocytes were made freshly and loaded with fluo4-AM. Intracellular Ca2+ was imaging by the LSMS10 META system. The Ca2+ transients were evoked by electrical field stimulation from an electronic stimulator which was triggered to work synchronically with the confocal imaging system.</p><p><b>RESULTS</b>Fast 2-dimension scanning showed the global Ca2+ signal clearly, which would be more helpful especially in monitoring a cell of Ca2+ overload or in other pathological conditions. And the images could be packaged into a vivid animation, which showed the process of Ca2+ transients and cell contraction visually and virtually. Line-scanning showed the Ca2+ transients in good temporal and spacial resolutions along the long axis of the cell. And the dynamic shortening of the cell length could be used for indicating the contraction of the cell. Data from line-scanning would be helpful for drawing some more exact conclusions.</p><p><b>CONCLUSION</b>In general, fast 2-dimension scanning and line-scanning could work reciprocally to show a more perfect picture of the intracellular Ca2+ transients in cardiac myocytes.</p>

Spastin gene mutation in Chinese patients with hereditary spastic paraplegia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the mutation characteristics of spastin gene in Chinese patients with hereditary spastic paraplegia (HSP) and thus provide a basis for the gene diagnosis of HSP.</p><p><b>METHODS</b>Mutation of spastin gene was screened by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) combined with DNA direct sequencing in 31 unrelated affected HSP individuals in China, of whom 22 were from autosomal dominant families and 9 were sporadic HSP patients. Co-segregation analysis was carried out after the finding of abnormal SSCP bands.</p><p><b>RESULTS</b>Six cases were found to have abnormal SCP bands, and among them, two missense mutations (T1258A, A1293G in exon 8) and one deletion mutation (1667delACT or 1668delCTA or 1669delTAC in exon 14) were found and all of them were not reported previously. They were all co-segregated with the disease and were localized within the functional domain of spastin gene. Besides, T1258A was seen in two unrelated families.</p><p><b>CONCLUSION</b>The mutation rate (18.2%) in autosomal dominant HSP in Chinese patients is comparatively low. Point mutation is the major mutation type and exon 8 may be the mutation hot spot.</p>