PubMed Health⌕ Search

Biomedical subjects

Masamitsu Kuwahara

Publications and source records attributed to Masamitsu Kuwahara.

At least 19 recordsLinked to original sources
PubMed2006

Perforating pilomatricoma on the upper eyelid.

We report a rare case of perforating pilomatricoma. A 50 x 40-mm oval nodule, with a whitish scale on its tip, developed on the left upper eyelid of a 43-year-old Japanese woman. There was no history of injury to the left upper eyelid. Histologic examination revealed typical microscopic features of pilomatricoma. In addition, however, an interesting phenomenon was observed: a portion of the tumor mass had extruded from the upper dermis to the skin surface through a perforating epidermal channel in the middle of the tumor. These findings are consistent with the diagnosis of perforating pilomatricoma.

Adult↗
PubMed2005

Mortality and recurrence rate after pressure ulcer operation for elderly long-term bedridden patients.

We operated on 16 sacral pressure ulcers in elderly and long-term residential patients who were immobile as a result of cerebral vascular disease. The mean age of patients was 76 years. Eight ulcers were treated with local fascial flaps and 8 by simple closure. The follow-up period was from 1 to 4 years. Recurrence and mortality rates were examined retrospectively. In the 16 patients, recurrence occurred in 37.5%, and 43.8% died without recurrence. The recurrence rate was 37.5% for local fascial flaps and 37.5% for simple closure. Overall mortality was 68.8% in the follow-up period. Because postoperative death was common, we should not only focus on reducing local pressure but also pay attention to any underlying disease. Because of this high mortality rate, the least invasive procedure possible should be used. Because the recurrence rate of simple closure was the same as for local fascial flaps, simple closure should be considered as a reconstructive method.

Age Factors↗
PubMed2004

Expression of N-cadherin and alphaN-catenin in the degeneration/regeneration process of rat skeletal muscle after nerve injury.

The authors investigated the expression of N-cadherin and alphaN-catenin (which is strongly related to N-cadherin function) in the denervation/reinnervation process using a rat sciatic nerve and gastrocnemius model. In a rat model, the right sciatic nerve was exposed at the mid-thigh region, and the nerve was transected with small scissors. Then, the nerve was sutured using 10-0 monofilament perineurial nylon sutures. At various periods up to 24 weeks after the operation, the gastrocnemius muscle of the treated hindlimbs was removed. Four rats were used at each time point in both groups. N-cadherin and alphaN-catenin expressions were detected by Western blot analysis and immunofluorescent staining with anti N-cadherin and alphaN-catenin antibodies. The level of N-cadherin was already elevated in the first postoperative week, and the level in the second postoperative week was almost the same as in the first. The level decreased gradually after the fourth postoperative week and, in the ninth postoperative week, returned to almost the same as the control level. The level of alphaN-catenin was almost the same as the control (1.0) within the second postoperative week. After the fourth postoperative week, the level elevated gradually, with a peak in the sixth postoperative week. The level then decreased and returned almost to that of the control after the twelfth postoperative week. Immunofluorescent staining was observed along the muscular membrane in all specimens of both proteins, and the time course of the degree of immunofluorescent staining was similar to the results of Western blot analysis. These results suggest that N-cadherin and alphaN-catenin expressions are elevated in the degeneration/regeneration processes of the muscle after nerve injury, but that the kinetics between the two proteins differ.

Animals↗
PubMed2004

Adult umbilical hernia with vertical dislocation.

We present a case of adult umbilical hernia with vertical dislocation along the abdominal wall. The hernial sac arose from the internal ring and connected to the umbilicus 20 mm below the internal ring. The postoperative course was uneventful. Two years and four months after the operation there was no evidence of recurrent hernia even when abdominal pressure was increased, and the umbilicus looked acceptable. An umbilical hernia is usually within the umbilicus. The hernial sac arose from the internal ring so should be called an umbilical hernia not an epigastric hernia. It is unusual that the umbilical hernia dislocates vertically along the abdominal wall, while the umbilicus stays depressed. This atypical form of umbilical hernia has not been described previously as far as we know.

Aged↗
PubMed2004

Expression of N-cadherin by skeletal muscle in the degeneration and the degeneration/regeneration processes after nerve injury.

We investigated the expression of N-cadherin by skeletal muscle during the degeneration and degeneration/regeneration processes using the rat sciatic nerve and gastrocnemius muscle model. The right sciatic nerve was exposed in the mid-thigh region, and the nerve was transsected with small scissors. After then, nerve was sutured (sutured group), or both edges of the resected nerve were turned and sutured to the muscle of each side (unsutured group). At various periods up to 24 weeks after the operation the middle portion of the gastrocnemius muscle of the treated hindlimbs was removed. Expression of N-cadherin was detected by western blot analysis and immunofluorescent staining with an anti N-cadherin antibody. In the both groups, the degree of expression had already increased by the end of the first postoperative week, but there were no significant differences between the first and second postoperative weeks between the two groups. However, the values recorded at the fourth, sixth, ninth, and twelfth postoperative weeks were significantly higher in the unsutured group than in the sutured group. Immunofluorescent staining was present around the muscular membrane in all specimens including the control. These results indicated that there was a difference in the kinetics of expression of N-cadherin in skeletal muscle between the degeneration and degeneration/regeneration processes of the muscle after injury to the nerve. It was also clear that N-cadherin has a role at the surface of the muscle cell in skeletal muscle, not in the satellite and inflammatory cells, in both groups.

Animals↗
PubMed2004

Successful free osteocutaneous scapular flap transfer for mandibular reconstruction in a 93-year-old patient.

With the extension of the average life span and the development of surgical technique, anesthesia, and pre- and postoperative management, operations for elderly patients have become more widely accepted. In the field of plastic surgery, free-flap transfers using microvascular techniques have become a common surgical procedure in reconstruction of the head and neck region after surgical removal of a cancer. There have been several reports of free-flap transfer in patients older than 90 years, but the authors know of no reports of free osteocutaneous flap transfer for mandibular reconstruction, which is a very invasive free-flap surgery, for such patients. The mandible plays a significant role in various kinds of dynamic functions, such as mastication, deglutition, and articulation. Disorder of these functions causes a deterioration in the patient's quality of life. The authors have performed a mandibular reconstruction using an osteocutaneous scapular free flap after resection of a gingival cancer invading the mandibular bone in a 93-year-old Japanese woman. In our case, an osteocutaneous scapular free flap, which permits the patient rapid rehabilitation of the lower leg, is thought to be a good choice because it allows the patient to get out of bed as quickly as possible in the postoperative period to minimize additional complications.

Aged↗
PubMed2004

Dermatofibrosarcoma protuberans arising from a burn scar of the axilla.

It is well-known that the development of a malignant tumor in a chronic burn scar is one of the long-term complications of a severe burn. Most of these tumors are squamous cell carcinomas, and sarcomas are much rarely seen in chronic burn scars. In the previous literature, 24 cases of burn scar sarcomas were reported. The authors report the second case of dermatofibrosarcoma protuberans arising in a chronic, severe burn scar. A 68-year-old woman with a reddish tumor in the right axilla was referred to the authors' hospital. The patient had sustained severe burns in the right axilla, upper arm, and trunk at the age of 6 years. A biopsy specimen revealed dermatofibrosarcoma protuberans. There was no evidence of distant metastasis. The tumor was excised widely to include the surrounding burn scar. Two years after the operation, there was no evidence of tumor recurrence. As surgeons, we should recognize the possibility of the occurrence of various malignant tumors including sarcomas on burn scars.

Aged↗
PubMed2003

An evaluation of functional improvement following surgical corrections of severe burn scar contracture in the axilla.

This report present an evaluation 13 consecutive cases of severe burn scar contracture of the axilla and investigates the factors that influence functional improvement. The operation was performed at various times during the period from 3 months to 63 years after the initial burn wound healed. The active range of shoulder abduction before the operation in these patients was restricted to 30-90 degrees. The scar contractures in the axilla were released in all cases and the defects of the axillary region were covered with musculocutaneous flaps or fasciocutaneous flaps. Following operation rehabilitation was performed with the range of shoulder abduction had reached a plateau. The relations between the improved range of shoulder abduction, time to reach a stable range of abduction, patient age and duration of illness in each patient are discussed. Patient with long post-injury periods required a longer time to reach a stable range of abduction. Furthermore, the patients with an extremely long period before operation had difficulties such as nerve injury or stiff joint which restricted improvement. In conclusion, adequate surgical treatment in early period after occurrence of contracture is desirable for burn scar contracture of the axilla.

Adolescent↗
PubMed2003

Expression of alpha, beta, and gamma catenins in vascularized and nonvascularized nerve grafts during the regeneration process.

The authors investigated the expression of three kinds of catenins (alpha, beta, gamma) in vascularized and non-vascularized nerve grafts, using the rat sciatic nerve model. The vascularized nerve, 15 mm in length, was elevated with its nutrient vessels in the left hindlimb of rats. In the right hindlimb, a 15-mm segment of the sciatic nerve was elevated (resected) without the nutrient vessels as a non-vascularized nerve. Both nerves were sutured to the original site. At various periods up to 14 weeks after operation, the entire graft was removed. Expression of three catenins was detected by Western blot analysis and histochemical staining, using the antibody to each catenin. The level of beta catenin increased during nerve regeneration in both the vascularized and non-vascularized grafts, while the level of alpha and gamma catenins did not increase in both grafts. There was no difference in the level of the three catenins between the two methods of nerve grafting. Histochemical findings showed that at the 4th and 14th postoperative weeks, alpha and gamma catenins were stained diffusely in both grafts, while beta catenin was stained around the regenerating axons in both grafts. The degree of beta catenin was greater in the 4th postoperative week than in the 14th postoperative week, but no obvious difference in the degree of staining of the three catenins between two grafts was found. These results suggest that beta catenin may play a different role from alpha and gamma catenins in nerve regeneration, and that the expression of these catenins is not influenced by vascularization of the nerve graft.

Animals↗
PubMed2003

Distortion and movement of the expander during skin expansion.

Distortion and movement of tissue expanders can cause expansion of the wrong area, such as the naevus or the scar that is to be resected. In 71 rectangular expanders, we examined the incidence of distortion (over 15 degrees) and movement (over 3 cm). We divided the expanders into three anatomical site groups: scalp, body, and extremities, and compared the complication rate between two study groups (distortion or movement, or not). In total, the incidence of distortion was 15/71 (21%) and that of movement 5/71 (7%). Distortion occurred mainly in the extremities (11/33,33%). The implanted expanders tended to move more often in the body part (3/15, 20%). In the extremities, the bigger the angle between the axis of the implanted expander and that of the extremity, the bigger the angle of distortion. Although the incidence of complications between the two groups was not significant, except for alteration in design of the flap, we recommend that these points should be considered when preoperative plans are being made for appropriate patients.

Adolescent↗
PubMed2003

Influence of periosteum on donor healing after harvesting hard palate mucosa.

The authors report the influence of periosteum on healing of palatal defect based on more than 10 years of experience of harvesting hard palate mucosa. Between June of 1991 and May of 2001, the authors harvested 80 hard palate mucosae as graft material for skin and mucosa defects. All grafts were harvested from the center of the hard palate. Patients ranged in age from 10 to 82 years old. Of 80 mucosae, 54 were harvested with periosteum, and periosteum was not retained in the defect bed. The other 26 mucosae were harvested without periosteum, which was therefore retained in the defect bed. The healing time increased depending on the defect size in both groups of patients retaining and not retaining periosteum. There was a significant relationship between the defect size and healing time in both groups (Spearman's rank correlation test, p < 0.0001 in both groups). In the two groups, there was no significant relationship between patient age and healing time in the patients with defect smaller than 1.99 cm or larger than 2.00 cm2. There were no significant differences in the rate of patients with pain and bleeding between the groups retaining and not retaining periosteum. In the group not retaining the periosteum, all 54 patients showed a flat or atrophic smooth surface at more than 6 months after epithelization and had no discomfort. However, 17 patients showed flat or atrophic smooth surface in the group retaining the periosteum and the remaining 9 patients showed hypertrophy at more than 6 months after epithelization, with accompanying discomfort. The rate of the patients with hypertrophy in the group of patients retaining periosteum was significantly high as compared with that in the group of patients not retaining periosteum (p = 0.000013, Fisher's exact test). In 26 patients retaining periosteum, the age of the patients with hypertrophic surface was significantly younger than that of the patients with flat or atrophic surface (p = 0.0010, Welch's -test), and the defect size in the patient with hypertrophic surface was significantly smaller than that of the patients with flat or atrophic surface (p = 0.0028, Welch's t-test). In conclusion, our study demonstrated that the existence of periosteum in the palate donor bed does not contribute to reduced healing time or reduced pain. Rather, retaining the periosteum caused hypertrophy of the donor site, leading to discomfort, especially in young patients with a comparatively small defect.

Adolescent↗
PubMed2003

Auricular composite graft for skin defect of the philtrum dimple.

Our method of performing an auricular composite graft for a skin defect of the philtrum dimple in a patient whose lip is not damaged and has retained its original softness and elasticity is presented. After resecting the lesion, an auricular composite graft is harvested from the conchal region. The size of the graft is almost the same as the size of the resected lesion, although the cartilage is harvested in an elliptical shape, and its size is approximately 60% in area of the overriding skin of the graft. The graft is harvested from the site, which has a similar curvature to the defect. The cartilage is sutured tightly to the graft bed at a minimum of four points with 6-0 absorbable suture. The transversal axis of the harvested cartilage is sutured as vertically as possible so as to fit the direction of the wrinkle line of the upper lip. The skin is sutured to the defect margin using 5-0 nylon suture. The graft donor site is closed primarily. This method has been used for the closure of six comparatively large skin defects after resecting a skin lesion (pigmented nevus in three cases and hypertrophic scar in three cases) in the philtrum dimple in six patients. In all cases, the upper lip was not damaged and retained its original softness and elasticity. The "take" of the graft was complete in all patients, and the donor site healed without any problem. In all cases, postoperative shrinkage of the graft was not significant during the follow-up period, and the graft had a smooth surface. In addition, no patients suffered from a feeling of discomfort in moving the mouth, and an acceptable shape of the philtrum dimple was achieved in all cases. There were no deformational changes in the graft donor site. In conclusion, our method is valid in the patient whose lip is not damaged and has retained its original softness and elasticity and in whom a full-thickness skin graft is selected as the covering method for a skin defect of the philtrum dimple.

Adolescent↗
PubMed2002

Rare case of a rudimentary medial metatarsal non-ossified structure.

A 9-year-old boy presented with a rudimentary medical metatarsal non-ossified structure. We considered his condition to be classified as hypoplastic medial member type in the metatarsal type of medial ray polydactyly. When it was considered as polydactyly, it had the longest delay of ossification among reported cases.

Child↗