Phenotypic Changes of Intermediate Filament Proteins during Degeneration and Regeneration of Rat Leg Muscles following Physical Injury / 대한정형외과학회잡지

PURPOSE: The aim of this experiment was to observe the phenotypic changes of intermediate filaments in skeletal muscle fibers during the degeneration and regeneration of the physical injury. MATERIALS AND METHODS: The gastrocnemius muscles of rats were physically damaged by needles and serial cryosections of the damaged muscles were prepared at 2, 4, 6, 9, 15, 21 and 35 days after injury. The cryosections were immunolabelled with desmin, vimentin and histochemically reacted with NADH-TR (nicotinamide adenine dinucleotide tetrazolium reductase). RESULTS: Myotubes, asvisualized by desmin and vimentin, appeared at 9 days after injury. The regenerative myofibers were similar to normal muscles 35 days after injury. Degeneration and regeneration occurred simultaneously and positive reactions for desmin disappeared earlier than those of vimentin. CONCLUSION: Both desmin and vimentin are strong staining tools for the evaluation of myopathy. The phenotypic patterns of intermediate filaments showed various degrees of regeneration in the early stages after physical injury.

Phenotypic Changes of Intermediate Filament Proteins during Degeneration and Regeneration of Rat Leg Muscles following Sciatic Nerve Injury / 대한정형외과연구학회지

PURPOSE: The intermediate filament proteins, desmin and vimentin, are specific components of the cytoskeleton of striated muscle fibers and of mononuclear cells of mesenchymal origin including myoblasts, respectively. Desmin has also been found in presumptive myoblasts of mammals. The aim of this experiment was attempted to observe the phenotypic changes of intermediate filaments in skeletal muscle fibers during early stages of sciatic nerve crushing injury. MATERIALS AND METHODS: The sciatic nerves of rats were surgically crushed by hemostat and serial cryosections of soleus and extensor digitorum longus(EDL) muscles were prepared at 2, 4, 6, 8, 10, 15, 20 and 27 days after nerve injury. Serial cryosections were immunolabelled with desmin, vimentin and laminin and were histochemically reacted with NADH-TR. RESULTS: 1) Firstly, desmin positive fibers were appeared in fast-twitch type C fibers of both muscles at 6 days after nerve crushing, but were not reacted for vimentin. 2) Co-expressions of desmin and vimentin were firstly detected in fast-twitch type A fibers of EDL muscles at 8 days after nerve injury. In soleus muscles, co-expressions of desmin and vimentin were firstly seen in slow-twitch type B fibers at 10 days after nerve injury. Many atrophic fibers, that contained several central nuclei like myotubes and co-expressed desmin and vimentin, were appeared in EDL muscles at 10 days after nerve injury. Although whole regions of fibers were regenerated in EDL muscles, only peripheral regions of fibers were regenerated in soleus muscles at 15 days after nerve injury. Many atrophic fibers, co-expressed of desmin and vimentin, were appeared in EDL muscles at 20 days after nerve injury. These whole fibers represented various degrees of regenerating stages. Most of mature fibers containing several central nuclei, only expressed vimentin slightly, were seen in soleus muscles at 20 days after nerve injury. Most fibers of both muscles were matured at 27 days after nerve injury, but some fibers in EDL muscles were still in processing of degeneration and regeneration. No expressions of desmin and vimentin indicated that muscle fibers were almostly matured in soleus muscles at 27 days after nerve injury. 3) Targetoid or target fibers which informed reinnervation, were appeared firstly in soleus muscles at 20 days and were seen in both muscles at 27 days after nerve injury. All targetoid and target fibers were type B fibers. CONCLUSION: Desmin was revealed in processes of degeneration and regeneration and vimentin was appealed in regeneration process. At the same time, positive immunoreactivity of desmin and vimentin showed specific differences in degree of degeneration and regeneration according to different muscles and muscle fibers.

Phenotypic Changes of Intermediate Filament Proteins during Degeneration and Regeneration of Rat Leg Muscles following Sciatic Nerve Injury / 대한정형외과연구학회지

PURPOSE: The intermediate filament proteins, desmin and vimentin, are specific components of the cytoskeleton of striated muscle fibers and of mononuclear cells of mesenchymal origin including myoblasts, respectively. Desmin has also been found in presumptive myoblasts of mammals. The aim of this experiment was attempted to observe the phenotypic changes of intermediate filaments in skeletal muscle fibers during early stages of sciatic nerve crushing injury. MATERIALS AND METHODS: The sciatic nerves of rats were surgically crushed by hemostat and serial cryosections of soleus and extensor digitorum longus(EDL) muscles were prepared at 2, 4, 6, 8, 10, 15, 20 and 27 days after nerve injury. Serial cryosections were immunolabelled with desmin, vimentin and laminin and were histochemically reacted with NADH-TR. RESULTS: 1) Firstly, desmin positive fibers were appeared in fast-twitch type C fibers of both muscles at 6 days after nerve crushing, but were not reacted for vimentin. 2) Co-expressions of desmin and vimentin were firstly detected in fast-twitch type A fibers of EDL muscles at 8 days after nerve injury. In soleus muscles, co-expressions of desmin and vimentin were firstly seen in slow-twitch type B fibers at 10 days after nerve injury. Many atrophic fibers, that contained several central nuclei like myotubes and co-expressed desmin and vimentin, were appeared in EDL muscles at 10 days after nerve injury. Although whole regions of fibers were regenerated in EDL muscles, only peripheral regions of fibers were regenerated in soleus muscles at 15 days after nerve injury. Many atrophic fibers, co-expressed of desmin and vimentin, were appeared in EDL muscles at 20 days after nerve injury. These whole fibers represented various degrees of regenerating stages. Most of mature fibers containing several central nuclei, only expressed vimentin slightly, were seen in soleus muscles at 20 days after nerve injury. Most fibers of both muscles were matured at 27 days after nerve injury, but some fibers in EDL muscles were still in processing of degeneration and regeneration. No expressions of desmin and vimentin indicated that muscle fibers were almostly matured in soleus muscles at 27 days after nerve injury. 3) Targetoid or target fibers which informed reinnervation, were appeared firstly in soleus muscles at 20 days and were seen in both muscles at 27 days after nerve injury. All targetoid and target fibers were type B fibers. CONCLUSION: Desmin was revealed in processes of degeneration and regeneration and vimentin was appealed in regeneration process. At the same time, positive immunoreactivity of desmin and vimentin showed specific differences in degree of degeneration and regeneration according to different muscles and muscle fibers.

Changes of the Fracture Fragments of Lesser Trochanter after Operative Treatment in the Unstable Femoral Intertrochanteric Fractures / 대한정형외과학회잡지

Unstable femoral intertrochanteric fractures are characterized by comminution of the posteromedial cortex, resulting in a fragment of variable size containing the lesser trochanter. Need for fixation of the fracture fragment of lesser trochanter remained controversial. We assessed the superior and medial migration of the fracture fragment of lesser trochanter, bone union, change of hip flexor power, limitation of motion and clinical results in a 29 unstable femoral intertrochanteric fractures which had been internally fixed with gamma interlocking nail (14 cases), compression hip screw (10 cases) and anatomical bent plate (5 cases). The fracture fragment of lesser trochanter was fixed with long trans-fixation screw in the cases of the anatomical bent plate. Superior migration of the fracture fragment of lesser trochanter is statistically different between Gamma interlocking nail and the other operations (P0.05). Although the stability could be provided by trans-fixation of the fracture fragment of lesser trochanter because the fragment acts as a buttress, clinical results was not influenced whether the fixation of the fracture fragment of lesser trochanter was done or not. We conclude that additional trans-fixation screw doesn t need if major fracture site was firmly fixed through any operation.

Radiologic Evaluation of Aseptic Loosening in Uncemented Total Hip Replacement Arthroplasty / 대한정형외과학회잡지

The aseptic loosening has emerged as one of the most common and serious long term complications, which requires the revision of total hip replacement arthroplasty. We studied the radiologic finding of the aseptic loosening in 79 patients of uncemented total hip replacement arthroplasty which had been performed in our hospital from March 1991 to December 1994. We evaluated the white reaction lines, osteolysis state, translation and migration in postoperative and last follow-up radiographies. The white reactive lines around the femoral stem and the acetabular cup were most frequent in zone IV and zone II. But it was not progressive and need more long term follow-up evaluations to confirm whether these lines are related to loosening or not. In assessment for stable state, the more stable at initial fixations, the better state of long term stability. Some patients have pain without loosening but all patients with loosening have pain. Press fit is the most important factor of the late stability. The osteolysis is not directly proportional to femoral loosening in this study, but it might be due to short follow up time.

Effect of Parathyroid Hormone on the intracellular pH Regulation of Osteoblast-like Cells / 대한정형외과학회잡지

Intracellular pH regulation of osteoblasts is of a great importance in the process of bone formation and resorption, and has been suggested to be mediated via intracellular Ca2+ and cAMP messenger systems. To elucidate the mechanism of modulation of intracellular pH by parathyroid hormone and PMA(Phorbo1-12-myristate-13-acetate), effects of these agonists on the individual transporter system, Na+-H+ antiporter and Cl−-HCO3-(−OH−) exchanger, were investigated. Intracellular pH and Ca2+ were measured by using the fluorescent dye BCECF and fura-2, respectively, in UMR-106 cell monolayer grown on glass coverslip. Addition of tumor promotor, PMA(luM) caused 0.14 unit pH rise of resting intracellular pH(pHi) and 38% increase of the initial rate of pHi recovery after cytosolic acid load. Perfusion of Cl−-free solution resulted in rapid cytosolic alkalinization of which the rate was increased 26% by preincubation of PMA. Ca2+ ionophore, ionomycin (1uM) decreased resting pHi by 0.17 unit, but had no effect on the initial rate of pHi recovery after cytosolic acid load. However, the addition of ionomycin augmented the initial rate of pHi increase after Cl−-depletion outside the cells by 34% over the control. Stimulation of cells with parathyroid hormone(10-8M) caused an initial acidification (0.27 unit) followed by cytosolic alkalinization, with inhibiting effect on the initial rate of pHi recovery after acid load (42%). But parathyroid hormone did not have any significant effect on the rate of pHi increase after Cl−-depletion. PMA caused a sustained increase of intracellular Ca2+, of which the peak depended on the concentration of Ca2+ in extracellular medium. Ionomycin caused a transient increase of Ca2+ but PTH had no significant increase of intracellular Ca2+ in the concentration range of 10-6M to 10-12M tested. 10-8M PTH increased cAMP levels by about 10-fold and 10-10M PTH did by 1.6-fold. PMA, which increased cytosolic Ca2+ concentration, also had an stimulatory effect on cAMP production in the concentration range of 10-5M to 10-6M by 2-fold. These findings suggest that in UMR-106 cells Ca2+ and cAMP can influence pHi by altering the activity of pHi regulatory transporter system, and parathyroid hormones modulate pHi by inhibiting Na+-H+ antiporter via intracellular increase of cAMP, which is probably accounts for the inhibitory effect of parathyroid hormone on the proliferation of osteoblasts.

Herniated Intervertebral Disc of Lumbar Spine in the Teenager / 대한정형외과학회잡지

The incidence of herniated lumbar disc under the age of 19 years is increasing due to increased sports activity of teenager and development of diagnostic methods. 33 cases of herniated lumbar disc of the teenager was analyzed at Department of Orthopaedic Surgery, Dong-A College of Medicine from March 1990 to May 1994. The results were obtained as follows: 1) Among 413 patients, 33 patients(7.9%) were teenagers and the sex ratio was 2.3:1 in male to female. 2) Average intervals between the onset of clinical symptoms and the admission were 13.2 months. 3) 20 cases(60.6%) had a definite trauma history, and among these cases, 14 cases(70.0%) were associated with sports activity. 4) The most common level of herniation was L4-5 in 29 cases(64.4%), straight leg raising test was positive in 32 cases(97.0%), sensory change in 13 cases(39.4%), motor weakness in 10 cases(30.3%). 5) Among positive MRI findings(32 cases), 17 cases(53.1%) were the protruded type. 6) Among 23 operative cases, 21 cases had excellent or good results.