Augmentation Cystoplasty using Hydroxapatite/chitosan Composite Sheet Seeded with Autologous Muscle-derived Stem Cells / 대한비뇨기과학회지

PURPOSE: This study was designed to investigate the feasibility of a hydroxyapatite/chitosan (HAp/chitosan) composite, seeded with autologous muscle-derived stem cells, as a partial bladder substitute in rats. MATERIALS AND METHODS: Muscle-derived stem cells were isolated from the gastrocnemius muscle of 6 female Sprague-Dawley rats, using the preplate technique, and cultured on HAp/chitosan composite sheets. Sheets with 10mm diameters were implanted into the urinary bladder of rats following a hemicystectomy in an autologous fashion. Three rats were sacrificed 4 and 8 weeks postoperatively, and the morphological changes subsequently assessed by H&E and immunofluorescence staining using DAPI, myogenin and alpha-smooth muscle actin (SMA). RESULTS: All rats survived the scheduled duration. Adequate epithelialization was observed to be completed after postoperative week 4. Abundant muscle bundles, showing positive alpha-SMA staining, were observed after the 4th week. The bladder shape was well preserved after the 8th week. Ingrowing smooth muscles were observed on the periphery of the composite and muscular bundles, with positive myogenin immunostaining in the middle of the composite. CONCLUSIONS: A HAp/chitosan composite sheet, seeded with autologous muscle-derived stem cells, showed a degree of skeletal muscle differentiation 8 weeks after augmentation cystoplasty, in an autologous fashion. This new material seeded with muscle-derived stem cells may, in the future, prove to be a viable option as a partial bladder substitute.

Preliminary Study of Tissue Engineered Bladder Regeneration with Poly (epsilon-caprolactone) (PCL) Sheet Seeded with Autologous Muscle-derived Stem Cell / 대한비뇨기과학회지

PURPOSE: To investigate the feasibility of using a poly (epsilon-caprolactone) (PCL) sheet seeded with autologous muscle-derived stem cells as a bladder substitute. MATERIALS AND METHODS: Muscle-derived stem cells were isolated from the gastrocnemius muscle of 9 female Sprague-Dawley rats using a preplate technique, and cultured on a 5x5mm PCL sheet. The sheets were implanted into the mesentery of the rats in an autologous manner. Three rats were sacrificed 2, 4 and 8 weeks after implantation, and the morphological changes were assessed by H&E and immunofluorescence staining including DAPI, myosin heavy chain (MHC) and choline acetyl transferase (CAT). RESULTS: All the rats survived for the scheduled time. A mild inflammatory reaction was observed around the PCL sheet in the postoperative 2-week specimen but this receded with time. Muscle cells on the sheet were observed over the experimental period. The 8-week specimen showed a moderate amount of muscle cells on the sheet, and MHC and CAT immunofluorescence staining showed a positive reaction. The muscle layer was not well organized. Angiogenesis was quite noticable between the sheet and the muscle cells on the 8-week specimen. CONCLUSIONS: A PCL sheet seeded with autologous muscle-derived stem cells showed skeletal muscle differentiation on the sheets 8 weeks after mesenteric implantation in an autologous manner. This suggests the feasibility of using a PCL sheet seeded with autologous muscle-derived stem cell as a bladder substitute.

The Temperature Differences among the Three Urethral Portions (Distal, Middle & Proximal) and Bladder in Incontinent Women

PURPOSE: We tried to find out an adequate sol-gel transition temperature of female urethra for the injection of thermosensitive polymer in incontinent patients. We measured the temperatures of three portions of female urethra and bladder. MATERIALS AND METHODS: Total of 53 female incontinent patients participated, excluding those with any kind of infection which could lead to an elevation of body temperature. The basal body temperatures were checked at the axilla, tympanic membrane and mouth. Temperatures of the proximal(U1), middle(U2), distal(U3) urethra and bladder(B) were measured by a digital thermometer under a lithotomy position. We divided our patients into 3 groups which were patients in follicular phase(F), luteal phase(L) and menopause(M). The temperature difference between the 4 portions of the urethra(D1; between U1 and U2, D2; between U2 and U3, D3: between U3 and B), was also analyzed. Statistics was done by the ANOVA of repeated measures, one-way ANOVA and Pearson correlation coefficient. RESULTS: The mean age of the patients was 48.1+/-10.7 years. The mean temperature of B, U1, U2, and U3 groups were 37.1+/-0.25 degreesC, 37.0+/-0.25 degreesC, 36.9+/-0.24 degreesC, and 36.7+/-0.25 degreesC. The mean temperature difference of D1, D2, and D3 were 0.2471+/-0.089 degreesC, 0.079+/-0.066 degreesC and 0.066+/-0.058 degreesC. The Pearson correlation coefficient of D1, D2 and D3 were 0.938, 0.965 and 0.970. This showed there was a constant temperature increase from distal urethra to bladder step by step. The number of patients in F, L and M groups were 25(47.2%), 10(18.9%) and 18(33.9%). There was no significant urethral temperature difference at each point(U1, U2, U3 and B) among these three groups. CONCLUSION: There was a constant temperature increase from distal urethra to bladder step by step. This is a baseline study for female urethra for future clinical study. We suggest that our data can be used as deciding the sol-gel transition temperature for thermosensitive polymer injection into incontinent female urethra.

The Isolation and Characterization of Muscle Derived Stem Cells from Gastrocnemius Muscle of Rats Using the Modified Preplate Method / 대한비뇨기과학회지

PURPOSE: This study attempted to characterize the muscle derived stem cells isolated from the primary cultured skeletal muscle of the rat gastrocnemius muscle; in addition, we modified the preplate method and then compared this to the original preplate method. MATERIALS AND METHODS: The hind limbs (gastrocnemius muscles) were removed from a 3-6 week olds SD-rat and the bone was dissected away. The muscle mass was finely minced and chopped using razor blades. In an original preplate method, the cells were dissociated using a triple enzyme mixture (collagenase XI, dipase and trypsin) for 1 hour at 37degreesC. The muscle cell extract was preplated on culture flasks as described by Dr. Qu (Qu et al., 1998). The pp1-pp4 cells were referred to as the early plate (EP) cells, and the pp5-pp6 cells were referred to as the late plate (LP) cells. When we modified the preplate method, the pp1-pp2 cells were called the early plate (EP) cells and the pp3-pp4 cells were called to late plate (LP) cells. The phenotypical characteristics of EP and LP cells were compared by immunostaining and FACS. RESULTS: In the original preplate methods, the early plate (EP) cells were mixed with myogenic cells (mostly fibroblasts, 90% desmin + cells). Yet in the modified preplate method, the muscle derived stem cells were determined to be CD34 (+ or -), CD45- and desmin- cells by immunohistochemical staining and FACS. CONCLUSIONS: In original methods, the LP cells exhibited stem cell properties (CD34+, less than 30%), and they were not from a hematogeous origin (CD45-), but rather, they were from a myogenic origin (desmin+). Yet in the modified preplate method, we purified the LP cells much earlier than the original method. The LP cells displayed CD34+(more than 50%), and CD45-; thus, we isolated more primitive (desmin-) cells.

The Isolation and Characterization of Muscle Derived Stem Cells from Gastrocnemius Muscle of Rats Using the Modified Preplate Method / 대한비뇨기과학회지

PURPOSE: This study attempted to characterize the muscle derived stem cells isolated from the primary cultured skeletal muscle of the rat gastrocnemius muscle; in addition, we modified the preplate method and then compared this to the original preplate method. MATERIALS AND METHODS: The hind limbs (gastrocnemius muscles) were removed from a 3-6 week olds SD-rat and the bone was dissected away. The muscle mass was finely minced and chopped using razor blades. In an original preplate method, the cells were dissociated using a triple enzyme mixture (collagenase XI, dipase and trypsin) for 1 hour at 37degreesC. The muscle cell extract was preplated on culture flasks as described by Dr. Qu (Qu et al., 1998). The pp1-pp4 cells were referred to as the early plate (EP) cells, and the pp5-pp6 cells were referred to as the late plate (LP) cells. When we modified the preplate method, the pp1-pp2 cells were called the early plate (EP) cells and the pp3-pp4 cells were called to late plate (LP) cells. The phenotypical characteristics of EP and LP cells were compared by immunostaining and FACS. RESULTS: In the original preplate methods, the early plate (EP) cells were mixed with myogenic cells (mostly fibroblasts, 90% desmin + cells). Yet in the modified preplate method, the muscle derived stem cells were determined to be CD34 (+ or -), CD45- and desmin- cells by immunohistochemical staining and FACS. CONCLUSIONS: In original methods, the LP cells exhibited stem cell properties (CD34+, less than 30%), and they were not from a hematogeous origin (CD45-), but rather, they were from a myogenic origin (desmin+). Yet in the modified preplate method, we purified the LP cells much earlier than the original method. The LP cells displayed CD34+(more than 50%), and CD45-; thus, we isolated more primitive (desmin-) cells.

Evaluation of the Beam Quality of Intraoral X-ray Equipments using Intraoral Standard Films / 대한구강악안면방사선학회지

PURPOSE: This study was to evaluate the beam quality of intraoral X-ray equipments used at Yonsei University Dental Hospital(YUDH) using the half value layer(HVL) and the characteristic curve of intraoral standard X-ray film. MATERIALS AND METHODS: The study was done using the intraoral X-ray equipments used at each clinical department at YUDH. Aluminum filter was used to determine the HVL. Intraoral standard film was used to get the characteristic curve of each intraoral X-ray equipment. RESULTS: Most of the HVLs of intraoral X-ray equipments were higher than the least recommended thickness, but the REX 601 model used at the operative dentistry department and the X-707 model used at the pediatric dentistry department had HVLs lower than the recommended thickness. The slopes of the characteristic curves of films taken using the PANPAS 601 model and REX 601 model at operative dentistry department, the X-70S model of prosthodontic dentistry department, and the REX 601 model at the student clinic were relatively low. CONCLUSION: HVL and the characteristic curve of X-ray film can be used to evaluate the beam quality of intraoral X-ray equipment. In order to get the best X-ray films with the least radiation exposure to patients and best diagnostic information in clinical dentistry, X-ray equipment should be managed in the planned and organized fashion.