Study On The Muscle And Leukocyte By Histochemistry, Electron Microscopy And MRI Inspection In Lipid Storage Myopathy

Objective: 1 Our purpose was to investigate the ultrastructural characters of muscular cells in lipid storage myopathy and other muscular diseases with lipid droplets in muscle fibers, which render an objective evidence for further differential diagnosis. 2 Electron microscopy and histochemistry of leukocytes in LSM patients were also carried out to explore the significance of the detection of lipid droplets in leukocyte cytoplasmas of LSM. 3> In addition, muscular MRI investigations of LSM and polymyositis were undergone to evaluate MRI in diagnosis of LSM as well as differential diagnosis between LSM and polymyostis.Methods: K 14 cases of LSM and 11 cases of other muscular diseases with lipid droplets in muscle fibers were selected as research subjects. Ultrastructural characters were obtained through electron microscopy to see what were the differences between two kinds of such diseases. 2^ Peripheral blood of 8 patients with LSM and 5 normal controls were extracted to observe the lipid droplets storage in leukocytes through electron microscopy. The amounts of neutrophils with lipid droplets in cytoplasmas and lipid droplets were counted, the results of which were analyzed by SPSS 10.0 statistical software package. Blood of 3 patients with LSM and 3 controls was individually smeared and stained by oil red O to observe the storage of lipid droplets in leukocyte cytoplasmas. 3^ 8 patients with LSM, 4 patients with polymyositis andone normal control were selected to axes scan buttock and leg muscles, utilizing MRI sequences of TiWL T2WI and STIR. Finally, the image characters were distinguished.Results: 1 -, Under electron microscope, the muscular cells of LSM stored lots of lipid droplets whose volumes were comparatively large and diameters were about 0.1 ~5 u m. They were often lined string by string. While other muscular diseases had their own pathological characters with sprinkled lipid droplets whose amount was a few and whose volumes were small. 2> The average population of neutrophils with lipid droplets included in cytoplasmas was 43.25?17.47/50 cells and the positive rate of cells with lipid droplets out of all neutrophils was 42.0?.75%. These number was significance higher than those of controls ( average 8.40?.97/50 cells and 16.8?.93%, respectively )( P<0.01 ). The positive droplets were found in neutrophils of two cases of LSM among three ones whose peripheral blood was smeared and stained by oil red O. Otherwise, no lipid droplets were presented in those of normal cases taken as control. 3> The presentation of MRI image in LSM patients revealed that all of the abnormal muscles had high signals in sequences of TiWI and T2WI. These muscles mostly located near the tendon. The high signal of STIR sequence was restrained. But the front ones remained comparatively sound. Back muscular groups and inside ones accounted for the majority of the damaged muscles. So the injure was selective. The MRI image of polymyositis was featured as the signal of inflammatory edema. Sometimes the mixture of two kinds of signals was presented. While the signal of damaged muscles in STIR sequence was not restrained or only partly restrained.Conclusions: 1 -, The pathological character of LSM muscle is that lots of lipid droplet are stored. Although muscular cells of other musculardiseases may contain lipid droplets in cytoplasmas, there are different volume, amount, arrangement and distribution of lipid droplets between them. So the character may provide objective evidence for further differential diagnosis of LSM and other muscular diseases. 2 The amounts of lipid droplets in leukocytes of LSM cases increased, so electron microscopy together with oil red O staining can provide viableindex for early selection, follow-up of LSM cases and judgement of curative effect. 3 The MRI scan of muscle appears characteristic image presentation. This may be applied into not only diagnosis of LSM judgement of curative effect, assessment of prognosis, but also accurate location for EMG investigation and mu...